Descriptor: "[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]" / Publisher: royal society of chemistry (rsc) - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]"' showing total 56 results

Start Over Descriptor "[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]" Publisher royal society of chemistry (rsc)

56 results on '"[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]"'

1. Cu segregation in Au–Cu nanoparticles exposed to hydrogen atmospheric pressure: how is fcc symmetry maintained?

Author: Q. Wang, A. Nassereddine, D. Loffreda, C. Ricolleau, D. Alloyeau, C. Louis, L. Delannoy, J. Nelayah, H. Guesmi, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), Laboratoire Matériaux et Phénomènes Quantiques (MPQ (UMR_7162)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Chimie - UMR5182 (LC), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Réactivité de Surface (LRS), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and ANR-17-CE07-0031,TOTEM,Microscopie Électronique en Transmission Operando et Résolue en Temps pour la Catalyse Hétérogène(2017)
Subjects: [PHYS]Physics [physics], [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, [CHIM]Chemical Sciences, [CHIM.CATA]Chemical Sciences/Catalysis, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Physical and Theoretical Chemistry
Abstract: International audience; In a recent work [A. Nassereddine et al., Small 2021, 17, 2104571] we reported the atomic-scale structure and dynamics of sub-4 nm sized Au nanoparticles (NPs) supported on titania in H2 at atmospheric pressure obtained by using aberration-corrected environmental transmission electron microscopy (ETEM), density functional theory (DFT) optimizations and ab initio molecular dynamic (AIMD) simulations. Our results showed unstable Au NPs losing their face-centred cubic (fcc) symmetry (from fcc to non-fcc symmetries) and revealed the drastic effect of hydrogen adsorption. In this work, we use the same approach to study the dynamics of equiatomic Au–Cu NPs in the same range of size and the results show an enhanced structural stability upon alloying by Cu. In spite of the morphology evolution from facetted to rounded shapes, the observed Au–Cu NPs are found to keep their fcc symmetry under atmospheric hydrogen pressure. AIMD simulation evidences a Cu segregation process from the sub-surface toward the upper surface layer, and a reversed segregation of Au atoms from the surface towards the sub-surface sites. The analysis of the chemical ordering in the core shows a tendency to a local chemical ordering where Au–Cu hetero-atomic bindings are favoured. The segregating Cu seems to play a major role in reducing the fluxionality of Au–Cu NPs in H2 and thus, maintaining their fcc symmetry.
Published: 2023

2. Interplay between interdiffusion and shape transformations in nanoalloys evolving from core–shell to intermixed structures

Author: Diana Nelli, Christine Mottet, Riccardo Ferrando, Università degli studi di Genova = University of Genoa (UniGe), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Physical and Theoretical Chemistry
Abstract: International audience; Nanoalloys are often grown or synthesized in non-equilibrium configurations whose further evolution towards equilibrium can take place through complex pathways. In this work, we consider bimetallic systems with tendency towards intermixing, namely AgAu, PtPd and AuCu. We analyze their evolution starting from non-equilibrium initial configurations, such as phase-separated core@shell ones, by means of molecular dynamics (MD) simulations. These systems present some differences, since AuCu bulk alloys make ordered phases at low temperature whereas AgAu and PtPd remain in solid solution. Moreover, Cu, Au and Ag have similar cohesive energies whereas Pt is much more cohesive than Pd. We consider both truncated octahedral and icosahedral initial shapes in the size range between 2 and 3 nm. For each AB system, we consider both A@B and B@A core@shell starting configurations. The evolution is characterized by monitoring the time-dependent degree of intermixing and the evolution of the shape. The simulations are performed up to temperatures close to the melting range. The approach to thermodynamic equilibrium is monitored by MD simulations and compared with the equilibrium chemical configurations obtained by Monte Carlo simulations.
Published: 2023

3. Optical excitation processes: general discussion

Author: Martin Appleby, Kyle Barlow, Martina Basini, Lara Benfatto, Yorrick Boeije, Andrew Burnett, Lin X. Chen, Eric Collet, Hermann A. Dürr, Graham Fleming, Aswathy V. Girija, Mohammed Th. Hassan, Hamoon Hedayat, Shinichiro Iwai, J. Olof Johansson, Steven L. Johnson, Kota Katsumi, Pyosang Kim, James K. McCusker, Ryan Phelps, Jan Michael Rost, Erica Sutcliffe, Julian Wagner, Julia Weinstein, Serhane Zerdane, Univ Roma La Sapienza, Dept Phys, CNR ISC, I-00185 Rome, Italy, Chemical Sciences and Engineering Division [Argonne], Argonne National Laboratory [Lemont] (ANL), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa, Institute of Cardiovascular Regeneration [Frankfurt, Germany] (Centre for Molecular Medicine), Goethe-University Frankfurt am Main, German Center for Cardiovascular Research (DZHK), and Berlin Institute of Health (BIH)
Subjects: [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Physical and Theoretical Chemistry
Abstract: International audience
Published: 2022

4. Fast and versatile thermo-osmotic flows with a pinch of salt

Author: Cecilia Herrero, Michael De San Féliciano, Samy Merabia, Laurent Joly, Modélisation de la matière condensée et des interfaces (MMCI), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)
Subjects: [PHYS]Physics [physics], Fluid Dynamics (physics.flu-dyn), FOS: Physical sciences, Physics - Fluid Dynamics, 02 engineering and technology, Condensed Matter - Soft Condensed Matter, 021001 nanoscience & nanotechnology, 01 natural sciences, 0103 physical sciences, Soft Condensed Matter (cond-mat.soft), General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: Thermo-osmotic flows - flows generated in micro and nanofluidic systems by thermal gradients - could provide an alternative approach to harvest waste heat. However, such use would require massive thermo-osmotic flows, which are up to now only predicted for special and expensive materials. There is thus an urgent need to design affordable nanofluidic systems displaying large thermo-osmotic coefficients. In this paper we propose a general model for thermo-osmosis of aqueous electrolytes in charged nanofluidic channels, taking into account hydrodynamic slip, together with the different solvent and solute contributions to the thermo-osmotic response. We apply this model to a wide range of systems, by studying the effect of wetting, salt type and concentration, and surface charge. We show that intense thermo-osmotic flows can be generated using slipping charged surfaces. We also predict for intermediate wettings a transition from a thermophobic to a thermophilic behavior depending on the surface charge and salt concentration. Overall, this theoretical framework opens an avenue for controlling and manipulating thermally induced flows with common charged surfaces and a pinch of salt., 7 pages, 3 figures
Published: 2022

5. Thermal conductivity of benzothieno-benzothiophene derivatives at the nanoscale

Author: Claudio Melis, Vincent Lemaur, Alexandre Vercouter, Rémy Jouclas, Guillaume Schweicher, Yves Geerts, Stéphane Lenfant, Aleandro Antidormi, David Guerin, Magatte N. Gueye, Jérôme Cornil, Dominique Vuillaume, National Fund for Scientific Research (Belgium), Fonds de la Recherche Scientifique (Fédération Wallonie-Bruxelles), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), University of Mons [Belgium] (UMONS), Université libre de Bruxelles (ULB), Centrale de Micro Nano Fabrication - IEMN (CMNF - IEMN), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Nanostructures, nanoComponents & Molecules - IEMN (NCM - IEMN), Catalan Institute of Nanoscience and Nanotechnology (ICN2), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Barcelona Institute of Science and Technology (BIST), International Solvay Institutes for Physics and Chemistry [Brussels], Vrije Universiteit Brussel (VUB)-Université libre de Bruxelles (ULB), Dipartimento di Fisica, Universita di Cagliari (Dipartimento di Fisica, Universita di Cagliari), Universita degli Studi di Cagliari [Cagliari], PCMP PCP, Renatech Network, ANR-16-CE05-0029,Harvesters,Récuperer l'energie thermique de l'environnement à l'aide d'un générateur thermoélectrique polymère pour alimenter un capteur autonome(2016), Université catholique de Lille (UCL)-Université catholique de Lille (UCL), Université catholique de Lille (UCL)-Université catholique de Lille (UCL)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Université libre de Bruxelles (ULB)-Vrije Universiteit Brussel (VUB), and Università degli Studi di Cagliari = University of Cagliari (UniCa)
Subjects: Scanning thermal microscopy, Yield (engineering), Materials science, Thermal resistance, Analytical chemistry, FOS: Physical sciences, 02 engineering and technology, organic thermoelectricity, 010402 general chemistry, 01 natural sciences, [SPI]Engineering Sciences [physics], chemistry.chemical_compound, Molecular dynamics, Thermal conductivity, Thermal conductance, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Benzothiophene derivatives, Chimie, General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Anisotropy, Nanoscopic scale, [PHYS]Physics [physics], thermal conducHvity, Condensed Matter - Mesoscale and Nanoscale Physics, organic semiconductor, Physique, Approach to equilibrium, Benzothiophene, Crystalline directions, 021001 nanoscience & nanotechnology, scanning thermal microscopy (SThM), Thickness dependence, 0104 chemical sciences, Anisotropy factor, Molecular dynamics calculation, chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], approach to equilibrium molecular dynamics (AEMD), 0210 nano-technology
Abstract: We study by scanning thermal microscopy the nanoscale thermal conductance of films (40-400 nm thick) of [1]benzothieno[3,2-b][1]benzothiophene (BTBT) and 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT-C8). We demonstrate that the out-of-plane thermal conductivity is significant along the interlayer direction, larger for BTBT (0.63 ± 0.12 W m-1 K-1) compared to C8-BTBT-C8 (0.25 ± 0.13 W m-1 K-1). These results are supported by molecular dynamics calculations (approach to equilibrium molecular dynamics method) performed on the corresponding molecular crystals. The calculations point to significant thermal conductivity (3D-like) values along the 3 crystalline directions, with anisotropy factors between the crystalline directions below 1.8 for BTBT and below 2.8 for C8-BTBT-C8, in deep contrast with the charge transport properties featuring a two-dimensional character for these materials. In agreement with the experiments, the calculations yield larger values in BTBT compared to C8-BTBT-C8 (0.6-1.3 W m-1 K-1versus 0.3-0.7 W m-1 K-1, respectively). The weak thickness dependence of the nanoscale thermal resistance is in agreement with a simple analytical model. This journal is, M. G., D. G., S. L. and D. V. thank the ANR for financial support (ANR-16-CE05-0029). Y. G. is thankful to the Belgian National Fund for Scientific Research (FNRS) for financial support through research projects BTBT (# 2.4565.11), Phasetrans (# T.0058.14), Pi-Fast (# T.0072.18), 2D to 3D (# 30489208), and DIFFRA (# U.G001.19). Financial supports from the French Community of Belgian (ARC # 20061) is also acknowledged. G. S. acknowledges postdoctoral fellowship support from the FNRS. The work in the Laboratory for Chemistry of Novel Materials was supported by the Consortium des Équipements de Calcul Intensif (CÉCI), funded by the Fonds de la Recherche Scientifique de Belgique (F.R.S.-FNRS) under grant # 2.5020.11. J.C. and A.V. are FNRS research fellows.
Published: 2021

6. Biomechanics as driver of aggregation of tethers in adherent membranes

Author: Ana-Sunčana Smith, Kheya Sengupta, Franck Thibaudau, Mohammad Arif Kamal, Bernd Henning Stumpf, Long Li, Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and ANR-18-CE92-0033,microCJ,Rôle du micro-environnement mécanique dans la formation précoce des jonctions cadhérines(2018)
Subjects: Lipid Bilayers, Biophysics, 02 engineering and technology, Cell membrane, 03 medical and health sciences, chemistry.chemical_compound, medicine, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Cell adhesion, Lipid bilayer, Unilamellar Liposomes, 030304 developmental biology, [PHYS]Physics [physics], 0303 health sciences, Membranes, Physics, Vesicle, General Chemistry, Adhesion, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Biomechanical Phenomena, medicine.anatomical_structure, Membrane, chemistry, 0210 nano-technology, Linker, DNA
Abstract: Cell adhesion is an important cellular process and is mediated by adhesion proteins residing on the cell membrane. Sometimes, two types of linker proteins are involved in adhesion, and they can segregate to form domains through a poorly understood size-exclusion process. We present an experimental and theoretical study of adhesion via linkers of two different sizes, realised in a mimetic model-system, based on giant unilamellar vesicles interacting with supported lipid bilayers. Here, adhesion is mediated by DNA linkers with two different lengths, but with the same binding enthalpy. We study the organisation of these linkers into domains as a function of relative fraction of long and short DNA constructs. Experimentally, we find that, irrespective of the composition, the adhesion domains are uniform with coexisting DNA bridge types, despite their relative difference in length of 9 nm. However, simulations suggest formation of nanodomains of the minority fraction at short length scales, which is below the optical resolution of the microscope. The nano-aggregation is more significant for long bridges, which are also more stable.
Published: 2021

7. Time dependent reduced density matrix functional theory at strong correlation: insights from a two-site Anderson impurity model

Author: Stefano Di Sabatino, Pina Romaniello, Claudio Verdozzi, Systèmes de Fermions Finis - Agrégats (LPT), Laboratoire de Physique Théorique (LPT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Groupe Méthodes et outils de la chimie quantique (LCPQ) (GMO), Laboratoire de Chimie et Physique Quantiques Laboratoire (LCPQ), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche « Matière et interactions » (FeRMI), European Theoretical Spectroscopy Facility (ETSF), new, ANR-18-CE30-0025,PhemSpec,Spectres de photoémission de Quantum Monte Carlo et de la théorie des perturbations à plusieurs corps: le meilleur des deux mondes(2018), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie et Physique Quantiques (LCPQ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: Density matrix, Physics, Work (thermodynamics), Trace (linear algebra), 010304 chemical physics, Time evolution, General Physics and Astronomy, 01 natural sciences, Adiabatic theorem, symbols.namesake, 0103 physical sciences, symbols, Statistical physics, Hilbert transform, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Physical and Theoretical Chemistry, 010306 general physics, Adiabatic process, Anderson impurity model, ComputingMilieux_MISCELLANEOUS
Abstract: The one-body density matrix has recently attracted considerable attention as a promising key quantity for the description of systems out of equilibrium. Its time evolution is given in terms of the two-body density matrix, and thus the central challenge is to find approximations to the latter. An extra layer of difficulty is added when dealing with strong electron correlations. In this work, we explore precisely this regime by looking at the two-site Anderson impurity model as a case study. To address the system's dynamics, we use an adiabatic approximation based on the exact ground-state two-body density matrix. We find that this adiabatic extension does not reproduce the exact results even for a slow switch-on of the external perturbation, and we trace back this behavior to the lack of an accurate imaginary part of the adiabatic approximation to the two-body density matrix. The attempt to restore an approximate imaginary part through a Hilbert transform of the real part works well only for very short times, but quickly deteriorates for longer times, with the one-body density matrix being pushed out of its N-representability domain. Our results thus pose an important constraint on practical prescriptions to perform the time evolution of the one-body density matrix.
Published: 2021

8. Relaxation moduli of glass-forming systems: temperature effects and fluctuations

Author: J. P. Wittmer, L. Klochko, Alexander N. Semenov, Jörg Baschnagel, Institut Charles Sadron (ICS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Semenov, Alexander, and Wittmer, Joachim
Subjects: Materials science, Monte Carlo method, Thermodynamics, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, [PHYS.COND.CM-SCM] Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], Moduli, Stress (mechanics), Molecular dynamics, Superposition principle, 0103 physical sciences, Relaxation (physics), [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, Adiabatic process, Glass transition, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], [PHYS.COND] Physics [physics]/Condensed Matter [cond-mat]
Abstract: International audience; Equilibrium and dynamical properties of a two-dimensional polydisperse colloidal model system are characterized by means of molecular dynamics (MD) and Monte Carlo (MC) simulations. We employed several methods to prepare quasi-equilibrated systems: in particular, by slow cooling and tempering with MD (method SC-MD), and by tempering with MC dynamics involving swaps of particle diameters (methods Sw-MD, Sw-MC). It is revealed that the Sw-methods are much more efficient for equilibration below the glass transition temperature Tg leading to denser and more rigid systems which show much slower self-diffusion and shear-stress relaxation than their counterparts prepared with the SC-MD method. The shear-stress relaxation modulus G(t) is obtained based on the classical stress-fluctuation relation. We demonstrate that the α-relaxation time τα obtained using a time-temperature superposition of G(t) shows a super-Arrhenius behavior with the VFT temperature T0 well below Tg. We also derive novel rigorous fluctuation relations providing isothermic and adiabatic compression relaxation moduli in the whole time range (including the short-time inertial regime) based on correlation data for thermostatted systems. It is also shown that: (i) the assumption of Gaussian statistics for stress fluctuations leads to accurate predictions of the variances of the fluctuation moduli for both shear (μF) and compression (ηF) at T ≳ Tg. (ii) The long-time (quasi-static) isothermic and adiabatic moduli increase on cooling faster than the affine compression modulus ηA, and this leads to a monotonic temperature dependence of ηF which is qualitatively different from μF(T) showing a maximum near Tg..
Published: 2021

9. How heat controls fracture: the thermodynamics of creeping and avalanching cracks

Author: Loïc Vanel, Alain Cochard, Renaud Toussaint, Knut Jørgen Måløy, Lamine Hattali, Tom Vincent-Dospital, Eirik Grude Flekkøy, Daniel Bonamy, Stéphane Santucci, Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Physics [Oslo], Faculty of Mathematics and Natural Sciences [Oslo], University of Oslo (UiO)-University of Oslo (UiO), Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Lavrentyev Institute of Hydrodynamics (LIH), SBRAS, Liquides et interfaces (L&I), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes (SPHYNX), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Fluides, automatique, systèmes thermiques (FAST), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut national des sciences de l'Univers (INSU - CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), University of Oslo (UiO), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Kelvin, FOS: Physical sciences, Thermodynamics, statistical physics, 02 engineering and technology, Condensed Matter - Soft Condensed Matter, 01 natural sciences, Extreme temperature, Physics - Geophysics, thermal weakening, 0103 physical sciences, Material failure theory, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, Rupture dynamics, Fracture mechanics, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Geophysics (physics.geo-ph), Creep, Pressure sensitive, Soft Condensed Matter (cond-mat.soft), Sublimation (phase transition), Adhesive, 0210 nano-technology
Abstract: While of paramount importance in material science, the dynamics of cracks still lacks a complete physical explanation. The transition from their slow creep behavior to a fast propagation regime is a notable key, as it leads to full material failure if the size of a fast avalanche reaches that of the system. We here show that a simple thermodynamics approach can actually account for such complex crack dynamics, and in particular for the non-monotonic force-velocity curves commonly observed in mechanical tests on various materials. We consider a thermally activated failure process that is coupled with the production and the diffusion of heat at the fracture tip. In this framework, the rise in temperature only affects the sub-critical crack dynamics and not the mechanical properties of the material. We show that this description can quantitatively reproduce the rupture of two different polymeric materials (namely, the mode I opening of polymethylmethacrylate (PMMA) plates, and the peeling of pressure sensitive adhesive (PSA) tapes), from the very slow to the very fast fracturing regimes, over seven to nine decades of crack propagation velocities. In particular, the fastest regime is obtained with an increase of temperature of thousands of kelvins, on the molecular scale around the crack tip. Although surprising, such an extreme temperature is actually consistent with different experimental observations that accompany the fast propagation of cracks, namely, fractoluminescence (i.e., the emission of visible light during rupture) and a complex morphology of post-mortem fracture surfaces, which could be due to the sublimation of bubbles., Comment: 19 pages, 18 figures, including 4 appendices. Soft Matter, 2020
Published: 2020

10. Liquid crystal ordering of nucleic acids

Author: Yves Lansac, Prabal K. Maiti, Suman Saurabh, Supriyo Naskar, Yun Hee Jang, GREMAN (matériaux, microélectronique, acoustique et nanotechnologies) (GREMAN - UMR 7347), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours-Centre National de la Recherche Scientifique (CNRS), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Stacking, 02 engineering and technology, Molecular Dynamics Simulation, 010402 general chemistry, 01 natural sciences, Molecular dynamics, Liquid crystal, Nucleic Acids, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Potential of mean force, Anisotropy, ComputingMilieux_MISCELLANEOUS, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Aspect ratio (image), Liquid Crystals, 0104 chemical sciences, Chemical physics, Volume fraction, Nucleic Acid Conformation, Thermodynamics, Umbrella sampling, 0210 nano-technology
Abstract: Several analytical calculations and computer simulations propose that cylindrical monodispersive rods having an aspect ratio (ratio of length to diameter) greater than 4 can exhibit liquid crystal (LC) ordering. But, recent experiments demonstrated the signature of LC ordering in systems of 4- to 20-base pair (bp) long nucleic acids (NAs) that do not satisfy the shape anisotropy criterion. Mechanisms of end-to-end adhesion and stacking have been proposed to explain this phenomenon. In this study, using all-atom molecular dynamics (MD) simulation, we explicitly verify the end-to-end stacking of double-stranded RNA (dsRNA) and demonstrate the LC ordering at the microscopic level. Using umbrella sampling (US) calculation, we quantify the potential of mean force (PMF) between two dsRNAs for various reaction coordinates (RCs) and compare our results with previously reported PMFs for double-stranded DNA (dsDNA). The PMF profiles demonstrate the anisotropic nature of inter-NA interaction. We find that, like dsDNA, dsRNA also prefers to stack on top of each other while repelling sideways, leading to the formation of supra-molecular-columns that undergo LC ordering at high NA volume fraction (φ). We also demonstrate and quantify the nematic ordering of the RNAs using several hundred nanosecond-long MD simulations that remain almost invariant for different initial configurations and under different external physiological conditions.
Published: 2020

11. Stable and high yield growth of GaP and In0.2Ga0.8As nanowire arrays using In as a catalyst

Author: Andrea Scaccabarozzi, Andrea Cattoni, Frank Glas, Fabrice Oehler, Jean-Christophe Harmand, Gilles Patriarche, Stéphane Collin, Laurent Travers, Centre de Nanosciences et de Nanotechnologies (C2N), and Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, Materials science, Yield (engineering), Silicon, business.industry, Nanowire, chemistry.chemical_element, 02 engineering and technology, Crystal structure, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, Contact angle, chemistry, law, 0103 physical sciences, Optoelectronics, General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Crystallization, 0210 nano-technology, business, Indium, Molecular beam epitaxy
Abstract: International audience; We report the first investigation of indium (In) as the vapor-liquid-solid catalyst of GaP and GaAs nanowires by molecular beam epitaxy. A strong asymmetry in the Ga distribution between the liquid and solid phases allows one to obtain pure GaP and In 0.2 Ga 0.8 As nanowires while the liquid catalyst remains nearly pure In. This uncommon In catalyst presents several advantages. First, the nanowire morphology can be tuned by changing the In flux alone, independently of the Ga and group V fluxes. Second, the nanowire crystal structure always remains cubic during steady state growth and catalyst crystallization, despite the low contact angle of the liquid droplet measured after growth (95 •). Third, the vertical yield of In-catalyzed GaP and (InGa)As nanowires arrays on patterned silicon substrates increases dramatically. Combining straight sidewalls, controllable morphologies and a high vertical yield, In-catalysts provide an alternative to the standard Au or Ga alloys for the bottom-up growth of large scale homogeneous arrays of (InGa)As or GaP nanowires. We note that the SET and NT curves nearly coincide over all 78 the explored composition range. This typical of NW growth and 79 was already observed by Glas on [Ga]-(AlGa)As NWs 34. It relates 80 to the low concentration of group V in the liquid catalyst, as com-81 puted using SET (see Supplementary Information †) or deduced 82 from other experiments 36. 83 From both NT and SET, we find that the Ga distribution is 84 strongly asymmetric. This particular Ga distribution is not unique 85 to our system and similar curves were calculated for ternary 86 [Au]-(InGa)As NWs using NT 25. These fast changes in the solid 87 (x) at near constant liquid composition (y) are often hindering 88 the fabrication of NW with uniform composition. Yet, away from 89 these abrupt changes, the solid composition varies slowly over 90 large ranges of liquid composition. Most relevant to the present 91 work, Ga contents (x) in solid In 1−x Ga x P and In 1−x Ga x As reach 92 near unity while the Ga fractions (y) in the liquid remain below 93 a few atomic percents. Hence the VLS growth of nearly pure GaP 94 and GaAs NWs from nearly pure In catalyst seems achievable. 95 3 Steady state growth 96 In light of the above calculations, we have proceeded to grow 97 [In]-(InGa)P and [In]-(InGa)As NWs on patterned Si(111) sub-98 strates using MBE (see experimental). Both In and Ga atoms are 99 supplied continuously to sustain the NW growth so that In evap-100 oration is compensated and the catalyst composition remains In-101 rich. Compared to [Ga]-GaAs or [Ga]-GaP NWs, typically grown 102 at 600 • C 15,36 , the substrate temperature is reduced to 520 • C to 103 limit the evaporation of In adatoms. Identical Si(111) wafers with 104 hexagonal arrays (300 nm pitch) of 50 nm diameter holes in a 105 14 nm thick silica mask are used to grow selectively the GaAs and 106 GaP NWs. The details of the growth and patterning procedures 107 can be found in the experimental section.
Published: 2020

12. A tunable filter for high molecular weight DNA selection and linked-read sequencing

Author: Adrien Castinel, Frederic Ginot, Aurélien Bancaud, Audrey Gibert, Olivier Bouchez, Géraud Bouwmans, Juan-Luis Fuentes Rojas, Cécile Donnadieu, Audrey Boutonnet, Laurent Bigot, Nicolas Milon, Karen Baudelle, Équipe Micro-Nanofluidique pour les sciences de la vie et de l’environnement (LAAS-MILE), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Génome et Transcriptome - Plateforme Génomique ( GeT-PlaGe), Plateforme Génome & Transcriptome (GET), Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Picometrics Technologies, ANR-16-CE18-0028,MicroLAS,µ-Laboratoire d'Analyse et de Séparation des chromosomes : développement d'un outil pour le typage rapide des bactéries, levures et cellules de mammifères(2016), ANR-16-ASTR-0020,BIOPULSE,Dispositif de détection biologique ultrasensible de pathogènes prélevés par air pulsé.(2016), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J), Institut National de la Recherche Agronomique (INRA), Laboratoire de Génétique Cellulaire (LGC), Ecole Nationale Vétérinaire de Toulouse (ENVT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Recherche Agronomique (INRA), Photonique (Photonique), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), and Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: Computer science, Sequencing data, Biomedical Engineering, Bioengineering, 02 engineering and technology, Third generation sequencing, Computational biology, Biochemistry, [SPI.MAT]Engineering Sciences [physics]/Materials, 03 medical and health sciences, Cucumis melo, Particle Size, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Throughput (business), ComputingMilieux_MISCELLANEOUS, Selection (genetic algorithm), 030304 developmental biology, 0303 health sciences, DNA, Sequence Analysis, DNA, General Chemistry, 021001 nanoscience & nanotechnology, Molecular Weight, genomic DNA, Filter (video), [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, 0210 nano-technology, Block size, High molecular weight dna
Abstract: International audience; In third generation sequencing, the production of quality data requires the selection of molecules longer than ∼20 kbp, but the size selection threshold of most purification technologies is smaller than this target. Here, we describe a technology operated in a capillary with a tunable selection threshold in the range of 3 to 40 kbp controlled by an electric field. We demonstrate that the selection cut-off is sharp, the purification yield is high, and the purification throughput is scalable. We also provide an analytical model that the actuation settings of the filter. The selection of high molecular weight genomic DNA from the melon Cucumis melo L., a diploid organism of ∼0.45 Gbp, is then reported. Linked-read sequencing data show that the N50 phase block size, which scores the correct representation of two chromosomes, is enhanced by a factor of 2 after size selection, establishing the relevance and versatility of our technology.
Published: 2020

13. The Laplace approach in microrheology

Author: Dongjie Chen, Xiaoguang Peng, Gregory B. McKenna, Qi Li, Laboratoire d'Energétique, d'Electronique et Procédés (LE2P), Université de La Réunion (UR), and Texas Tech University [Lubbock] (TTU)
Subjects: Microrheology, Work (thermodynamics), 02 engineering and technology, 01 natural sciences, Displacement (vector), Viscoelasticity, [SPI.MAT]Engineering Sciences [physics]/Materials, 010305 fluids & plasmas, Moduli, [SPI]Engineering Sciences [physics], symbols.namesake, 0103 physical sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], Physics, Laplace transform, Mathematical analysis, Inverse Laplace transform, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Condensed Matter::Soft Condensed Matter, Fourier transform, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], symbols, 0210 nano-technology, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: When coupled with the generalized Stokes-Einstein (GSE) equation, it is often reported that micro-rheology probes the dynamic properties differently than do macroscopic rheological measurements, especially in relatively condensed systems. In the present work, we empirically examine the GSE in its widely used form: following an analytical continuation, the Fourier transformed particle mean-square displacement (MSD) is used to determine the dynamic moduli [G'(ω) and G''(ω)] and we compare the results with those obtained by direct inverse Laplace transform calculation of the relevant viscoelastic functions (either relaxation modulus or creep compliance) from the MSD. The results show that the inverse Laplace approaches can differ from the Fourier approach and give better agreement with macroscopic rheological measurements when this is the case. Some instances of agreement between the Fourier approach and the direct Laplace transform approaches are also shown. It is recommended that micro-rheology MSD data be interpreted using one of the direct Laplace transform based approaches.
Published: 2020

14. Cancer treatment by magneto-mechanical effect of particles, a review

Author: François Berger, Cécile Naud, Yanxia Hou, Robert Morel, Caroline Thébault, Bernard Dieny, Hélène Joisten, Marie Carrière, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Chimie Interface Biologie pour l’Environnement, la Santé et la Toxicologie (CIBEST ), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Département Interfaces pour l'énergie, la Santé et l'Environnement (DIESE), Chimie pour la Reconnaissance et l’Etude d’Assemblages Biologiques (CREAB ), Groupe d'imagerie neurofonctionnelle (GIN), Institut des Maladies Neurodégénératives [Bordeaux] (IMN), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Joisten, Hélène
Subjects: Materials science, Field (physics), [CHIM.THER] Chemical Sciences/Medicinal Chemistry, Quantitative Biology::Tissues and Organs, Physics::Medical Physics, [SDV.CAN]Life Sciences [q-bio]/Cancer, Bioengineering, Nanotechnology, [CHIM.THER]Chemical Sciences/Medicinal Chemistry, 02 engineering and technology, Treatment parameters, Quantitative Biology::Cell Behavior, 03 medical and health sciences, [SDV.CAN] Life Sciences [q-bio]/Cancer, General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Magneto, 030304 developmental biology, [SDV.IB] Life Sciences [q-bio]/Bioengineering, 0303 health sciences, Range (particle radiation), General Engineering, General Chemistry, 021001 nanoscience & nanotechnology, Mechanical force, Atomic and Molecular Physics, and Optics, 3. Good health, Cancer treatment, Magnetic field, Magnetic nanoparticles, [SDV.IB]Life Sciences [q-bio]/Bioengineering, 0210 nano-technology, human activities, [PHYS.COND] Physics [physics]/Condensed Matter [cond-mat]
Abstract: International audience; Cancer treatment by magneto-mechanical effect of particles (TMMEP) is a growing field of research. The principle of this technique is to apply a mechanical force on cancer cells in order to destroy them thanks to magnetic particles vibrations. For this purpose, magnetic particles are injected in the tumor or exposed to cancer cells and a low-frequency alternating magnetic field is applied. This therapeutic approach is quite new and a wide range of treatment parameters are explored to date, as described in the literature. This review explains the principle of the technique, summarizes the parameters used by the different groups and reports the main in vitro and in vivo results.
Published: 2020

15. Atomic-scale phonon scatterers in thermoelectric colusites with a tetrahedral framework structure

Author: Hikaru Saito, Toshiro Takabatake, Hidetaka Kasai, Katsuaki Hashikuni, Koichiro Suekuni, Yuta Shimizu, Eiji Nishibori, Kosuke Watanabe, Daichi Yoshimoto, Raju Chetty, Michihiro Ohta, Yohan Bouyrie, Michitaka Ohtaki, Emmanuel Guilmeau, Kyushu University, Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University, Fukuoka (DMS), Université de Tsukuba = University of Tsukuba, National Institute of Advanced Industrial Science and Technology (AIST), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Hiroshima University, Kyushu University [Fukuoka], École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)
Subjects: Materials science, Condensed matter physics, Renewable Energy, Sustainability and the Environment, Phonon, 02 engineering and technology, General Chemistry, Crystal structure, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Thermoelectric materials, 01 natural sciences, 7. Clean energy, 0104 chemical sciences, Thermal conductivity, Electrical resistivity and conductivity, Seebeck coefficient, Thermoelectric effect, [CHIM.CRIS]Chemical Sciences/Cristallography, General Materials Science, Sublimation (phase transition), [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology
Abstract: International audience; Copper-based chalcogenides with tetrahedral framework structures have been attracting increasing attention as environmentally friendly thermoelectric materials. A representative group of such thermoelectric chalcogenides is the Cu26A2M6S32 (A = V, Nb, Ta; M = Ge, Sn) family of colusites, which exhibit low electrical resistivity, a large Seebeck coefficient, and low thermal conductivity; these properties are necessary for efficient thermal-to-electronic energy conversion. Here, we show the impact of crystal structure on the lattice thermal conductivity of colusite with A = Nb, M = Sn. The crystal structure can be modified by controlling the cationic compositions and the deficiency in the sulfur content as Cu26−xNb2Sn6+xS32−δ. The Cu/Sn ratio is found to be the key parameter for exsolution into distinct phases with ordered and disordered arrangements of cations. For the ordered-structure phase, sulfur sublimation induces atomic-scale defects/disordered states including interstitial defects, anti-site defects, and site splitting, which function as strong phonon scatterers, and the lowest lattice thermal conductivity of ∼0.5 W K−1 m−1 is achieved for the modified ordered structure. This finding provides a simple approach to modifying the crystal structure of thermoelectric chalcogenides via the loss of anions to reduce their lattice thermal conductivity.
Published: 2019

16. Precursors of fluidisation in the creep response of a soft glass

Author: Kirsten Martens, Raffaela Cabriolu, Pinaki Chaudhuri, Jürgen Horbach, Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU), Heinrich Heine Universität Düsseldorf = Heinrich Heine University [Düsseldorf], Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), and Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: [PHYS]Physics [physics], Boundary effects, Materials science, FOS: Physical sciences, 02 engineering and technology, General Chemistry, Mechanics, Computational Physics (physics.comp-ph), Condensed Matter - Soft Condensed Matter, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Amorphous solid, Creep, Shear stress, Soft Condensed Matter (cond-mat.soft), Periodic boundary conditions, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], Physics - Computational Physics, ComputingMilieux_MISCELLANEOUS
Abstract: Using extensive numerical simulations, we study the fluidisation process of dense amorphous materials subjected to an external shear stress, using a three-dimensional colloidal glass model. In order to disentangle possible boundary effects from finite size effects in the process of fluidisation, we implement a novel geometry-constrained protocol with periodic boundary conditions. We show that this protocol is well controlled and that the longtime fluidisation dynamics is, to a great extent, independent of the details of the protocol parameters. Our protocol, therefore, provides an ideal tool to investigate the bulk dynamics prior to yielding and to study finite size effects regarding the fluidisation process. Our study reveals the existence of precursors to fluidisation observed as a peak in the strain-rate fluctuations, that allows for a robust definition of a fluidisation time. Although the exponents in the power-law creep dynamics seem not to depend significantly on the system size, we reveal strong finite size effects for the onset of fluidisation.
Published: 2019

17. Evolution of inter-layer coupling in artificially stacked bilayer MoS2

Author: Goutham Nayak, Laëtitia Marty, Nedjma Bendiab, Johann Coraux, Aveek Bid, Jaydeep Kumar Basu, Suman Sarkar, Vincent Bouchiat, Julien Renard, H. L. Pradeepa, Indian Institute of Science, Systèmes hybrides de basse dimensionnalité (HYBRID), Institut Néel (NEEL), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Photoluminescence, Materials science, Coupling strength, Inter layer, Bilayer, General Engineering, Bioengineering, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Molecular physics, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Coupling (electronics), symbols.namesake, symbols, General Materials Science, Emission spectrum, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Raman spectroscopy, Intensity (heat transfer)
Abstract: International audience; In this paper, we show experimentally that for van der Waals heterostructures (vdWh) of atomically-thin materials, the hybridization of bands of adjacent layers is possible only for ultra-clean interfaces. This we achieve through a detailed experimental study of the effect of interfacial separation and adsorbate content on the photoluminescence emission and Raman spectra of ultra-thin vdWh. For vdWh with atomically-clean interfaces, we find the emergence of novel vibrational Raman-active modes whose optical signatures differ significantly from that of the constituent layers. Additionally, we find for such systems a significant modification of the photoluminescence emission spectra with the appearance of peaks whose strength and intensity directly correlate with the inter-layer coupling strength. Our ability to control the intensity of the photoluminescence emission led to the observation of detailed optical features like indirect-band peaks. Our study establishes that it is possible to engineer atomically-thin van der Waals heterostructures with desired optical properties by controlling the inter-layer spacing, and consequently the inter-layer coupling between the constituent layers.
Published: 2019

18. Force transmission and the order parameter of shear thickening

Author: Romain Mari, Ryohei Seto, Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS), and Osaka University [Osaka]
Subjects: Dilatant, Rolling resistance, FOS: Physical sciences, 02 engineering and technology, Condensed Matter - Soft Condensed Matter, 010402 general chemistry, 01 natural sciences, Physics::Fluid Dynamics, Stress (mechanics), Rheology, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], ComputingMilieux_MISCELLANEOUS, Physics, Order (ring theory), General Chemistry, Mechanics, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Condensed Matter::Soft Condensed Matter, Distribution (mathematics), Transmission (telecommunications), Soft Condensed Matter (cond-mat.soft), SPHERES, 0210 nano-technology, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: The origin of the abrupt shear thickening observed in some dense suspensions has been recently argued to be a transition from frictionless (lubricated) to frictional interactions between immersed particles. The Wyart-Cates rheological model, built on this scenario, introduced the concept of fraction of frictional contacts $f$ as the relevant order parameter for the shear thickening transition. Central to the model is the "equation-of-state" relating $f$ to the applied stress $\sigma$, which is directly linked to the distribution of the normal components of non-hydrodynamics interparticle forces. Here, we develop a model for this force distribution, based on the so-called $q$-model that we borrow from granular physics. This model explains the known $f(\sigma)$ in the simple case of sphere contacts displaying only sliding friction, but also predicts strong deviation from this "usual" form when stronger kinds of constraints are applied on relative motion. We verify these predictions in the case of contacts with rolling friction, in particular a broadening of the stress range over which shear thickening occurs. We finally discuss how a similar approach can be followed to predict $f(\sigma)$ in systems with other variations from the canonical system of monodisperse spheres with sliding friction, in particular the case of large bidispersity., Comment: 11 pages, 10 figures
Published: 2019

19. Toward an operational methodology to identify industrial-scaled nanomaterial powders with the volume specific surface area criterion

Author: Philip L. Llewellyn, Olivier Witschger, Vanessa Fierro, Sébastien Bau, Claire Dazon, Laboratoire de Métrologie des Aérosols, Département Métrologie des Polluants (MP), Institut national de recherche et de sécurité (Vandoeuvre lès Nancy) (INRS ( Vandoeuvre lès Nancy))-Institut national de recherche et de sécurité (Vandoeuvre lès Nancy) (INRS ( Vandoeuvre lès Nancy)), Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Matériaux divisés, interfaces, réactivité, électrochimie (MADIREL), Aix Marseille Université (AMU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, business.industry, General Engineering, Nanoparticle, Bioengineering, 02 engineering and technology, General Chemistry, Nitrogen adsorption, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Nanomaterials, Volume (thermodynamics), Gas pycnometer, Specific surface area, Nano, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Materials Science, Particle size, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Process engineering, business
Abstract: International audience; Nanoparticulate powders are increasingly found in the workplace. Inhalation exposure to airborne nanoparticles (NPs) is possible throughout the life-cycle of the powders. As the toxicity of NPs has never been demonstrated, it remains essential to evaluate the risks associated with NPs in order to propose preventative measures. The first step of a risk assessment strategy consists in the identification of the ‘nano’ nature of a material, which suffers from a lack of an operational methodology. Here, we present a simplified and operational strategy relying on the volume specific surface area (VSSA) for nanomaterial identification, based on the recommendation stemming from the European Commission and previous work on this topic from the European Project Nanodefine. The proposed strategy was tested on a set of 15 representative industrial powders (TiO2, SiO2, CuO, and ZnO), covering a wide range of properties, and previous published data. The VSSA classification was validated via a comparison with the particle size obtained by transmission electron microscopy (TEM). It was evidenced that the VSSA is in accordance with particle size for nanomaterial powder classification. The proposed methodology involves relatively accessible methods such as thermogravimetric analysis, nitrogen adsorption and helium pycnometry and limits the detection of false negatives. Moreover, it does not imply systematic confirmation of the results with the reference particle size criterion. Our results suggest that the VSSA is a promising parameter to be used for risk assessment and should be further investigated on powder mixings to confirm its relevancy to define nanomaterial powders.
Published: 2019

20. Fine structure of excitons and electron–hole exchange energy in polymorphic CsPbBr3single nanocrystals

Author: Christophe Testelin, Léon Marcel Andriambariarijaona, Violette Steinmetz, Nicolas Goubet, Laurent Legrand, Alberto Bramati, Emmanuel Lhuillier, Maria Chamarro, Thierry Barisien, F. Bernardot, Julien Ramade, Photonique et cohérence de spin (INSP-E12), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Physico-chimie et dynamique des surfaces (INSP-E6), Laboratoire Kastler Brossel (LKB (Jussieu)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ANR-11-IDEX-0004,SUPER,Sorbonne Universités à Paris pour l'Enseignement et la Recherche(2011), European Project: 756225,blackQD, Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)
Subjects: Materials science, Photoluminescence, Absorption spectroscopy, Exciton, Exchange interaction, 02 engineering and technology, Electron hole, 010402 general chemistry, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, Molecular physics, 0104 chemical sciences, Crystal, Condensed Matter::Materials Science, Tetragonal crystal system, General Materials Science, Orthorhombic crystal system, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology
Abstract: International audience; All inorganic CsPbX3 (X = Cl, Br, I) nanocrystals (NCs) belong to the novel class of confined metal–halide perovskites which are currently arousing enthusiasm and stimulating huge activity across several fields of optoelectronics due to outstanding properties. A deep knowledge of the band-edge excitonic properties of these materials is thus crucial to further optimize their performances. Here, high-resolution photoluminescence (PL) spectroscopy of single bromide-based NCs reveals the exciton fine structure in the form of sharp peaks that are linearly polarized and grouped in doublets or triplets, which directly mirror the adopted crystalline structure, tetragonal (D4h symmetry) or orthorhombic (D2h symmetry). Intelligible equations are found that show how the fundamental parameters (spin–orbit coupling, ΔSO, crystal field term, T, and electron–hole exchange energy, J) rule the energy spacings in doublets and triplets. From experimental data, fine estimations of each parameter are obtained. The analysis of the absorption spectra of an ensemble of NCs with a “quasi-bulk” behavior leads to ΔSO = 1.20 ± 0.06 eV and T = −0.34 ± 0.05 eV in CsPbBr3. The study of individual luminescence responses of NCs having sizes comparable to the exciton Bohr diameter, 7 nm, allows us to estimate the value of J to be around ≈3 meV in both tetragonal and orthorhombic phases. This value is already enhanced by confinement.
Published: 2018

21. Spin-glass-like aging in colloidal and granular glasses

Author: Francesco Zamponi, Beatriz Seoane, Laboratoire de Physique Théorique de l'ENS (LPTENS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Phase transition, Spin glass, Materials science, Crossover, FOS: Physical sciences, Condensed Matter - Soft Condensed Matter, Condensed Matter::Disordered Systems and Neural Networks, 01 natural sciences, 010305 fluids & plasmas, Colloid, Phase (matter), 0103 physical sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, ComputingMilieux_MISCELLANEOUS, Condensed Matter - Statistical Mechanics, [PHYS]Physics [physics], Statistical Mechanics (cond-mat.stat-mech), Condensed matter physics, Disordered Systems and Neural Networks (cond-mat.dis-nn), General Chemistry, Hard spheres, Condensed Matter - Disordered Systems and Neural Networks, Renormalization group, Condensed Matter Physics, Condensed Matter::Soft Condensed Matter, Mean field theory, Soft Condensed Matter (cond-mat.soft)
Abstract: Motivated by the mean field prediction of a Gardner phase transition between a "normal glass" and a "marginally stable glass", we investigate the off-equilibrium dynamics of three-dimensional polydisperse hard spheres, used as a model for colloidal or granular glasses. Deep inside the glass phase, we find that a sharp crossover pressure $P_{\rm G}$ separates two distinct dynamical regimes. For pressure $P < P_{\rm G}$, the glass behaves as a normal solid, displaying fast dynamics that quickly equilibrates within the glass free energy basin. For $P>P_{\rm G}$, instead, the dynamics becomes strongly anomalous, displaying very large equilibration time scales, aging, and a constantly increasing dynamical susceptibility. The crossover at $P_{\rm G}$ is strongly reminiscent of the one observed in three-dimensional spin-glasses in an external field, suggesting that the two systems could be in the same universality class, consistently with theoretical expectations., 13 pages, 12 figures (two figures added and one extra Appendix section)
Published: 2018

22. Effect of organic and inorganic ions on the lower critical solution transition and aggregation of PNIPAM

Author: Jordi Faraudo, Delfi Bastos-González, Carlos Drummond, Leonor Pérez-Fuentes, Biocolloid and Fluid Physics Group, University of Granada [Granada], Institut de Ciència de Materials de Barcelona (ICMAB), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Centre de Recherche Paul Pascal (CRPP), and Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Kosmotropic, Hofmeister series, Chemistry, Ionic bonding, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, General Chemistry, Inorganic ions, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Lower critical solution temperature, 0104 chemical sciences, Dynamic light scattering, Chemical engineering, 13. Climate action, Phase (matter), Molecule, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology
Abstract: International audience; We have studied the effect of different ions belonging to the extended Hofmeister series on the thermosensitive polymer poly(N-isopropylacrylamide) (PNIPAM), by combining Differential Scanning Calorimetry (DSC) and Dynamic Light Scattering (DLS). The variations in the lower critical solution temperature (TLCS) and enthalpy change during PNIPAM phase separation evidence the importance of considering both hydration and hydrophobicity to explain the interaction of ions with interfaces. The results obtained in the presence of inorganic ions can be explained by the tendency of water molecules to preferentially hydrate the PNIPAM chains or the ions, depending on the kosmotropic (highly hydrated) or chaotropic (poorly hydrated) character of the ions. On the contrary, tetraphenyl organic ions (Ph4B− and Ph4As+) interact with the hydrophobic moieties of PNIPAM chains, inducing a significant reduction of the TLCS. DLS results show that the aggregation state of PNIPAM above the TLCS is also strongly influenced by the presence of ions. While macroscopic phase separation (formation of a polymer-rich phase insoluble in water) was apparent in the presence of inorganic ions, we observed the formation of submicron PNIPAM aggregates at temperatures above the TLCS in the presence of the hydrophobic ions. Kinetically arrested monodisperse PNIPAM nanoparticles were formed in the presence of the Ph4B− anion, while a rather polydisperse distribution of particle sizes was observed in the presence of Ph4As+. These results show that ionic specificity influences both the static (thermodynamic) and dynamic (kinetically controlled aggregation) states of PNIPAM in an aqueous environment.
Published: 2018

23. Linear defects forming the ground state of polar free standing smectic-C* films

Author: V. K. Dolganov, E. I. Kats, P. V. Dolganov, P. Cluzeau, Institute of Solid State Physics Russian Academy of Sciences, L.D. Landau Institute for Theoretical Physics of RAS, Russian Academy of Sciences [Moscow] (RAS), Centre de Recherche Paul Pascal (CRPP), and Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Condensed matter physics, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Rotation, 01 natural sciences, Chirality (electromagnetism), Orientation (vector space), Transformation (function), Liquid crystal, 0103 physical sciences, Polar, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Elasticity (economics), 010306 general physics, 0210 nano-technology, Ground state, ComputingMilieux_MISCELLANEOUS
Abstract: In this paper we report on observations of unusual linear defects forming spontaneously in polar free-standing smectic-C* films near the temperatures of thinning transitions. At high temperature a periodic structure of defects becomes the ground state of the system. We found that the defects are characterized by continuous rotation of the molecular orientation with a change of the sense of the rotation across the defects. We develop a simple theoretical model that describes the observed behavior. The structure of the defects is governed by the competition between two-dimensional quadratic and linear orientational elasticity. The proposed model explains the origin of the linear defects, the periodic structure and their transformation with temperature and chirality of the liquid crystal.
Published: 2018

24. Sub-molecular spectroscopy and temporary molecular charging of Ni-phthalocyanine on graphene with STM

Author: Eric Duverger, Gérald Dujardin, Philippe Sonnet, Andrew J. Mayne, Mali Zhao, Faisal Almarzouqi, Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Institut de Science des Matériaux de Mulhouse (IS2M), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Strasbourg (UNISTRA)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Laboratoire de Photophysique Moléculaire (PPM), Matériaux et nanosciences d'Alsace, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)
Subjects: Materials science, General Physics and Astronomy, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, 7. Clean energy, [SPI.MAT]Engineering Sciences [physics]/Materials, law.invention, chemistry.chemical_compound, law, Molecule, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Physical and Theoretical Chemistry, Spectroscopy, ComputingMilieux_MISCELLANEOUS, Quantum tunnelling, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Graphene, Resolution (electron density), 021001 nanoscience & nanotechnology, Resonance (chemistry), 0104 chemical sciences, chemistry, Chemical physics, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Phthalocyanine, Density functional theory, 0210 nano-technology
Abstract: In this study, the self-assembled molecular network and electronic properties of Ni-phthalocyanine (NiPc) molecules on monolayer graphene (MLG)/6H-SiC(0001) were studied by room temperature Scanning Tunnelling Microscopy (STM) and Density Functional Theory (DFT) calculations. In this study, a very weak electronic coupling between the graphene and the NiPc molecules is found. This is due to the very small charge transfer of only 0.035e- per molecule. The weak molecule-graphene interaction has two observable consequences: sub-molecular resolution was obtained in the STM spectroscopy at room-temperature with the molecules adsorbed directly on the graphene, and the occupied and unoccupied molecular resonance peaks were observed to shift their position in energy as a function of the tip-surface distance. This is due to the temporary local charging (either positive or negative) that is achieved by decreasing the surface voltage under the STM tip. This may have important consequences for future studies of the opto-electronic properties of such hybrid graphene-molecule systems.
Published: 2018

25. Atomic-scale understanding of high thermal stability of the Mo/CoFeB/MgO spin injector for spin-injection in remanence

Author: Abdelhak Djeffal, Xavier Devaux, Xavier Marie, Yuan Lu, Stéphane Mangin, Jean-Marie George, Philippe Barate, Zhanguo Wang, Xiufeng Han, Henri Jaffrès, Pierre Renucci, Shiheng Liang, Bo Xu, Bingshan Tao, Frougier Julien, Michel Hehn, Institut Jean Lamour (IJL), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Unité mixte de physique CNRS/Thalès (UMP CNRS/THALES), THALES-Centre National de la Recherche Scientifique (CNRS), University of Science and Technology of China [Hefei] (USTC), Institut National des Sciences Appliquées (INSA), University of Chinese Academy of Sciences [Beijing] (UCAS), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), THALES [France]-Centre National de la Recherche Scientifique (CNRS), IMPACT N4S, Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)
Subjects: 010302 applied physics, Materials science, Annealing (metallurgy), Analytical chemistry, 02 engineering and technology, Electroluminescence, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, Magnetic field, Remanence, law, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Materials Science, Thermal stability, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology, Spectroscopy, ComputingMilieux_MISCELLANEOUS, Quantum tunnelling, Light-emitting diode
Abstract: International audience; Remanent spin injection into a spin light emitting diode (spin-LED) at zero magnetic field is a prerequisite for future application of spin optoelectronics. Here, we demonstrate the remanent spin injection into GaAs based LEDs with a thermally stable Mo/CoFeB/MgO spin injector. A systematic study of magnetic properties, polarization-resolved electroluminescence (EL) and atomic-scale interfacial structures has been performed in comparison with the Ta/CoFeB/MgO spin injector. The perpendicular magnetic an-isotropy (PMA) of the Mo/CoFeB/MgO injector shows more advanced thermal stability than that of the Ta/CoFeB/MgO injector and robust PMA can be maintained up to 400 °C annealing. The remanent circular polarization (P C) of EL from the Mo capped spin-LED reaches a maximum value of 10% after 300 °C annealing, and even remains at 4% after 400 °C annealing. In contrast, the Ta capped spin-LED almost completely loses the remanent P C under 400 °C annealing. Combined advanced electron microscopy and spectroscopy studies reveal that a large amount of Ta diffuses into the MgO tunneling barrier through the CoFeB layer after 400 °C annealing. However, the diffusion of Mo into CoFeB is limited and never reaches the MgO barrier. These findings afford a comprehensive perspective to use the highly thermally stable Mo/CoFeB/MgO spin injector for efficient electrical spin injection in remanence.
Published: 2018

26. Strengthening and drying rate of a drying emulsion layer

Author: Vincent Gaudefroy, Xavier Chateau, Mathilde Coquil, Emmanuel Keita, Stéphane Rodts, Julie Goyon, Philippe Coussot, Marie Goavec, Laboratoire Navier (navier umr 8205), École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Rhéophysique, École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Laboratoire des matériaux et structures du génie civil (LMSGC), and Laboratoire Central des Ponts et Chaussées (LCPC)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, 02 engineering and technology, General Chemistry, Penetration (firestop), 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Free surface, Oil droplet, Emulsion, Mechanical strength, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Composite material, 0210 nano-technology, Water content, Elastic modulus, Shrinkage
Abstract: International audience; From direct observations and MRI measurements we demonstrate that during the drying of a direct (oil in water) emulsion the whole system essentially concentrates homogeneously, which leads to shrinkage, without air penetration. The structure and mechanical strength (i.e. the elastic modulus) of this concentrated bulk are not significantly different from those of an emulsion directly prepared at this higher concentration. Despite this phenomenon, the drying rate continuously and rapidly decreases as the water content decreases, in contrast with the drying of a simple granular packing. This results from a concentration gradient which develops towards the free surface of the sample where the oil droplets finally coalesce, ultimately forming an oil layer covering the sample through which the water molecules have to diffuse before evaporating. Moreover, as during the process, the liquid is transported towards the free surface where it evaporates, surfactants accumulate and tend to form a thin solid layer below the oil layer, which tends to further reduce the drying rate.
Published: 2018

27. CO oxidation activity of Pt, Zn and ZnPt nanocatalysts: a comparative study by in situ near-ambient pressure X-ray photoelectron spectroscopy

Author: François Rochet, Rabah Benbalagh, Fabrice Bournel, Ahmed Naitabdi, Giorgia Olivieri, Anthony Boucly, Robert Fagiewicz, Jean-Jacques Gallet, Fausto Sirotti, Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), and Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Oxide, Nanoparticle, chemistry.chemical_element, 02 engineering and technology, Atmospheric temperature range, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Nanomaterial-based catalyst, 0104 chemical sciences, Chemical state, chemistry.chemical_compound, X-ray photoelectron spectroscopy, Catalytic oxidation, Chemical engineering, chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Platinum, ComputingMilieux_MISCELLANEOUS
Abstract: The investigation of nanocatalysts under ambient pressure by X-ray photoelectron spectroscopy gives access to a wealth of information on their chemical state under reaction conditions. Considering the paradigmatic CO oxidation reaction, a strong synergistic effect on CO catalytic oxidation was recently observed on a partly dewetted ZnO(0001)/Pt(111) single crystal surface. In order to bridge the material gap, we have examined whether this inverse metal/oxide catalytic effect could be transposed on supported ZnPt nanocatalysts deposited on rutile TiO2(110). Synchrotron radiation near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) operated at 1 mbar of O2 : CO mixture (4 : 1) was used at a temperature range between room temperature and 450 K. To tackle the complexity of the problem, we have also studied the catalytic activity of nanoparticles (NPs) of the same size, consisting of pure Pt and Zn nanoparticles (NPs), for which, moreover, NAP-XPS studies are a novelty. The comparative approach shows that the CO oxidation process is markedly different for the pure Pt and pure Zn NPs. For pure Pt NPs, CO poisoned the metallic surfaces at low temperature at the onset of CO2 evolution. In contrast, the pure Zn NPs first oxidize into ZnO, and trap carbonates at low temperature. Then they start to release CO2 in the gas phase, at a critical temperature, while continuously producing it. The pure Zn NPs are also immune to support encapsulation. The bimetallic nanoparticle borrows some of its characteristics from its two parent metals. In fact, the ZnPt NP, although produced by the sequential deposition of platinum and zinc, is platinum-terminated below the temperature onset of CO oxidation and poisoned by CO. Above the CO oxidation onset, the nanoparticle becomes Zn-rich with a ZnO shell. Pure Pt and ZnPt NPs present a very similar activity towards CO oxidation, in contrast with what is reported in a single crystal study. The present study demonstrates the effectiveness of NAP-XPS in the study of complex catalytic processes at work on nanocatalysts under near-ambient pressures, and highlights once more the difficulty of transposing single crystal surface observations to the case of nanoobjects.
Published: 2018

28. How does the motion of the surrounding molecules depend on the shape of a folding molecular motor?

Author: Victor Teboul, Nicolae Hurduc, Simona Ciobotarescu, 'Gheorghe Asachi' Technical University of Iasi (TUIASI), Laboratoire de Photonique d'Angers (LPHIA), and Université d'Angers (UA)
Subjects: Physics, Work (thermodynamics), Photoisomerization, FOS: Physical sciences, General Physics and Astronomy, 02 engineering and technology, Condensed Matter - Soft Condensed Matter, Chromophore, 021001 nanoscience & nanotechnology, 01 natural sciences, Folding (chemistry), chemistry.chemical_compound, Azobenzene, chemistry, Chemical physics, 0103 physical sciences, Molecular motor, Soft Condensed Matter (cond-mat.soft), Molecule, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Physics::Chemical Physics, Physical and Theoretical Chemistry, 010306 general physics, 0210 nano-technology, Isomerization
Abstract: Azobenzene based molecules have the property of isomerizing when illuminated. In relation with that photoisomerization property, azobenzene containing materials are the subject of unexplained massive mass transport. In this work we use an idealised rectangular chromophore model to study the dependence of the isomerization induced transport on the chromophore dimensions. Our results show the presence of a motor arm length threshold for induced transport, which corresponds to the host molecule size. Above the threshold, the diffusive motions increase proportionally to the chromophore length. Intriguingly, we find only a very small chromophore width dependence of the induced diffusive motions. Our very simplified motor reproduces relatively well the behavior observed using the real DR1 motor molecule, suggesting that the complex closing procedure and the detailed shape of the motor are not necessary to induce the molecular motions., 8 pages
Published: 2016

29. Micro-heterogeneity versus clustering in binary mixtures of ethanol with water or alkanes

Author: Larisa Zoranić, Aurélien Perera, Franjo Sokolić, Martina Požar, Bernarda Lovrinčević, Tomislav Primorac, University of Split, Laboratoire de Physique Théorique de la Matière Condensée (LPTMC), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: binary mixtures, microheterogeneity, cluster analysis, molecular dynamics, Alkane, chemistry.chemical_classification, Aggregate (data warehouse), General Physics and Astronomy, Inverse, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Correlation function (statistical mechanics), chemistry, Chemical physics, Cluster (physics), Organic chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Physical and Theoretical Chemistry, 0210 nano-technology, Cluster analysis, Structure factor, Mixing (physics)
Abstract: International audience; Ethanol is a hydrogen bonding liquid. When mixed in small concentrations with water or alkanes, it forms aggregate structures reminiscent of, respectively, the direct and inverse micellar aggregates found in emulsions, albeit at much smaller sizes. At higher concentrations, micro-heterogeneous mixing with segregated domains is found. We examine how different statistical methods, namely correlation function analysis, structure factor analysis and cluster distribution analysis, can describe efficiently these morphological changes in these mixtures. In particular, we explain how the neat alcohol pre-peak of the structure factor evolves into the domain pre-peak under mixing conditions, and how this evolution differs whether the co-solvent is water or alkane. This study clearly establishes the heuristic superiority of the correlation function/structure factor analysis to study the micro-heterogeneity, since cluster distribution analysis is insensitive to domain segregation. Correlation functions detect the domains, with a clear structure factor pre-peak signature, while the cluster techniques detect the cluster hierarchy within domains. The main conclusion is that, in micro-segregated mixtures, the domain structure is a more fundamental statistical entity than the underlying cluster structures. These findings could help better understand comparatively the radiation scattering experiments, which are sensitive to domains, versus the spectroscopy-NMR experiments, which are sensitive to clusters.
Published: 2016

30. Long-range antiferromagnetic order in malonate-based compounds Na2M(H2C3O4)2·2H2O (M = Mn, Fe, Co, Ni)

Author: Guillaume Radtke, Yannick Klein, Gwenaëlle Rousse, Hania Ahouari, Chimie du solide et de l'énergie (CSE), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Réseau sur le stockage électrochimique de l'énergie (RS2E), Université de Nantes (UN)-Aix Marseille Université (AMU)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Collège de France (CdF (institution))-Université de Picardie Jules Verne (UPJV)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Advanced Lithium Energy Storage Systems - ALISTORE-ERI (ALISTORE-ERI), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire réactivité et chimie des solides - UMR CNRS 7314 (LRCS), Université de Picardie Jules Verne (UPJV)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU), Université de Picardie Jules Verne (UPJV)-Institut de Chimie du CNRS (INC)-Aix Marseille Université (AMU)-Université de Pau et des Pays de l'Adour (UPPA)-Université de Nantes (UN)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Collège de France (CdF (institution))-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), and Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: Magnetic structure, Magnetic moment, Chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 3. Good health, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, Crystallography, Malonate, Ferromagnetism, Transition metal, Antiferromagnetism, Condensed Matter::Strongly Correlated Electrons, Density functional theory, Carboxylate, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology
Abstract: International audience; The recently discovered metal-malonate compounds of formulae Na 2 M(H 2 C 3 O 4) 2 ·2H 2 O with M = Mn, Fe, Co, Ni are investigated for their magnetic properties. While the Cu-based material is a weak ferromagnet, all other members present antiferromagnetic interactions. Neutron powder diffraction experiments reveal the establishment of a long range magnetic order at low temperature in the Pbca Shubnikov magnetic group. The magnetic structures are characterized by antiferromagnetic layers perpendicular to [001]. These layers are stacked antiparallel (M = Fe) or parallel (M = Mn, Ni) in the (a, c) plane. Magnetic moments are collinear to b for the former and to c for the latter. The M = Co malonate exhibits a non-collinear magnetic structure intermediate between the two latter, with components along b and c. Density functional theory calculations indicate that the dominant magnetic interaction, J 1 , occurs along a malonate group via a carboxylate and links two transition metals within the same layer, while other interactions (inter-or intra-layer) are much weaker, so that these compounds present the dominant characteristics of 2D-antiferromagnets.
Published: 2016

31. Chemical engineering of donor–acceptor liquid crystalline dyads and triads for the controlled nanostructuration of organic semiconductors

Author: Lydia Sosa-Vargas, David Kreher, Benoît Heinrich, Emmanuelle Lacaze, Fabrice Mathevet, Yiming Xiao, Bertrand Donnio, Xiaolu Su, André Jean Attias, Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Physico-chimie et dynamique des surfaces (INSP-E6), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Key Laboratory of Digital Agricultural Early-warning Technology Ministry of Agriculture, Groupe de Physique des Solides (GPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Triphenylene, Nanotechnology, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Molecule, [CHIM.COOR]Chemical Sciences/Coordination chemistry, General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], HOMO/LUMO, ComputingMilieux_MISCELLANEOUS, Alkyl, chemistry.chemical_classification, [CHIM.ORGA]Chemical Sciences/Organic chemistry, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Acceptor, 0104 chemical sciences, Organic semiconductor, Crystallography, chemistry, Cyclic voltammetry, 0210 nano-technology, Perylene
Abstract: International audience; Multi-segregated columnar structures provide a geometrically ideal scheme for ambipolar organic semiconductors, but are not easy to design. A set of novel materials with dyad and triad architectures based on 2 different discotic cores is reported and the conditions of emergence of such complex structures are investigated. The designed molecules associate together electron-donor triphenylene cores (D) and perylene or naphthalene diimides as acceptor moieties (A), both entities being linked via alkyl chain spacers. The evaluation in solution of their HOMO/LUMO energy levels by cyclic voltammetry demonstrates the preservation of the individual features of the D and A units. Their thermal and self-organization behaviors were studied by polarized-light optical microscopy, differential scanning calorimetry, temperature-dependent small-angle X-ray scattering and dilatometry, which permitted detailed investigation of the self-organization behaviour. These D–A compounds turned out to spontaneously self-organize into columnar mesophases at room temperature, with the D and A moieties segregated into either alternated stacks within mixed columns or in distinct columns, the latter providing an ideal configuration for 1D hole and electron transport pathways. In view of potential applications of the triad/dyad template, thin films of these self-organized materials were also probed by atomic force microscopy and grazing incidence X-ray scattering.
Published: 2016

32. New routes for improving adhesion at the metal/α-Al2O3(0001) interface

Author: Jacek Goniakowski, Alexey Koltsov, Rémi Lazzari, Jacques Jupille, Didier Loison, Rémi Cavallotti, Ha-Linh Thi Le, ArcelorMittal Maizières Research SA, ArcelorMittal, Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Oxydes en basses dimensions (INSP-E9), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Inorganic chemistry, Ab initio, Oxide, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, Zinc, Adhesion, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Metal, chemistry.chemical_compound, Adsorption, Transition metal, chemistry, Chemical engineering, visual_art, visual_art.visual_art_medium, Surface charge, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Physical and Theoretical Chemistry, 0210 nano-technology
Abstract: International audience; With the advent of new steel grades, the galvanic protection by zinc coating faces a new paradigm. Indeed, enrichment in strengthening elements prone to oxidation such as Al, Mn, and Si, leads to the formation of oxide films that are poorly wet by zinc. We study herein routes for improvement of adhesion at the model Zn/α-Al 2 O 3 interface by metallic additions. As a first step, with help of ab initio results on adsorption characteristics of transition metal adatoms at α-alumina surfaces, we establish and rationalize clear trends in the behavior of both metal-alumina interaction strength and in the relative thermodynamic stability of configurations with weakly and strongly bound metal adatoms. The reasons of enhanced binding strength of transition metals, such as Cr, maintained regardless the precise alumina termination and surface charge state are pointed out. On these grounds, possible improvements of adhesion in realistic conditions are discussed. It is predicted that an enrichment in transition metals, such as Cr, may produce strongly adhesive interfaces that lead to cohesive cleavage.
Published: 2016

33. Microscopy investigations of the microstructural change and thermal response of cobalt-based nanoparticles confined inside a carbon nanotube medium

Author: Walid Baaziz, Vasiliki Papaefthimiou, Simona Moldovan, Ovidiu Ersen, Cuong Pham-Huu, Dominique Begin, Ileana Florea, Sylvie Begin-Colin, Spyridon Zafeiratos, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Matériaux, Surfaces et Procédés pour la Catalyse (LMSPC), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)
Subjects: inorganic chemicals, Materials science, Annealing (metallurgy), Aucun, Oxide, Nanoparticle, Sintering, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, Carbon nanotube, 010402 general chemistry, 7. Clean energy, 01 natural sciences, law.invention, chemistry.chemical_compound, law, [CHIM]Chemical Sciences, General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], Renewable Energy, Sustainability and the Environment, Thermal decomposition, technology, industry, and agriculture, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, 021001 nanoscience & nanotechnology, Microstructure, 0104 chemical sciences, chemistry, Chemical engineering, 0210 nano-technology, Cobalt
Abstract: Faceted cobalt-cobalt oxide based nanoparticles (NPs) with high density and narrow size distribution (50 +/- 5 nm) were selectively cast inside the channels of multi-walled carbon nanotubes (CNTs) through the controlled thermal decomposition of cobalt stearate in the presence of oleic acid as surfactant. The total loading of the NPs is ca. 60 wt% due to the confinement effect of CNTs, which play the role of “nanoreactors” for the cobalt complex filling and its further decomposition. The cast Co-based NPs consist of a Co-CoO core-shell structure with a relatively high contribution of the metallic phase, thanks to the confinement effect which prevents excessive oxidation. The Co-CoO NPs were transformed into highly porous cobalt aggregates constituted by small cobalt clusters (5 nm) after reduction with a high effective surface area. These cobalt clusters display an extremely high resistance towards oxidation, thanks to the confined medium. The evolution of the Co-based NP microstructure of the as-synthesized and the reduced composites, as a function of temperature, was evaluated by in situ heating the systems inside the TEM. On the as-synthesized sample with a mixture of Co and CoO the heating process leads to a rapid shape modification and coalescence of the NPs at a temperature of 400 degrees C along with the formation of a cobalt carbide interface. In contrast, the reduced sample displays a much higher sintering resistance upon annealing under the same conditions as cobalt NPs with a mean diameter of 10 nm, still present at an annealing temperature up to 800 degrees C. The work reported here underlines the benefit of the confinement effect to improve the oxidative and sintering resistance of cast metal NPs and also in the synthesis of a new porous structure containing small metal NPs which could be of great interest for catalytic and magnetic applications.
Published: 2015

34. Monitoring reactive microencapsulation dynamics using microfluidics

Author: Ingmar Polenz, Jean-Christophe Baret, Quentin Brosseau, Max Planck Institute for Dynamics and Self-Organization (MPIDS), Max-Planck-Gesellschaft, Centre de recherches Paul Pascal (CRPP), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.PHYS.PHYS-FLU-DYN]Physics [physics]/Physics [physics]/Fluid Dynamics [physics.flu-dyn], In situ, Polydimethylsiloxane, Kinetics, Microfluidics, Aqueous two-phase system, Nanotechnology, General Chemistry, Condensed Matter Physics, Physics::Fluid Dynamics, Chemistry, chemistry.chemical_compound, Monomer, Microfluidic, chemistry, Chemical engineering, Pulmonary surfactant, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Microencapsulation, Polyurea
Abstract: Monitoring encapsulation kinetics: a microfluidic tool is introduced that enables for the precise determination of microencapsulation dynamics by measuring droplet deformations., We use microfluidic polydimethylsiloxane (PDMS) devices to measure the kinetics of reactive encapsulations occurring at the interface of emulsion droplets. The formation of the polymeric shell is inferred from the droplet deformability measured in a series of expansion–constriction chambers along the microfluidic chip. With this tool we quantify the kinetic processes governing the encapsulation at the very early stage of shell formation with a time resolution of the order of the millisecond for overall reactions occurring in less than 0.5 s. We perform a comparison of monomer reactivities used for the encapsulation. We study the formation of polyurea microcapsules (PUMCs); the shell formation proceeds at the water–oil interface by an immediate reaction of amines dissolved in the aqueous phase and isocyanates dissolved in the oil phase. We observe that both monomers contribute differently to the encapsulation kinetics. The kinetics of the shell formation process at the oil-in-water (O/W) experiments significantly differs from the water-in-oil (W/O) systems; the component dissolved in the continuous phase has the largest impact on the kinetics. In addition, we quantified the retarding effect on the encapsulation kinetics by the interface stabilizing agent (surfactant). Our approach is valuable for quantifying in situ reactive encapsulation processes and provides guidelines to generate microcapsules with soft interfaces of tailored and controllable interfacial properties.
Published: 2015

35. Evaporation-induced self-assembling of few-layer graphene into a fractal-like conductive macro-network with a reduction of percolation threshold

Author: Izabela Janowska, Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Chemical Physics (physics.chem-ph), Condensed Matter - Materials Science, Materials science, Graphene, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, General Physics and Astronomy, Percolation threshold, Nanotechnology, [CHIM.MATE]Chemical Sciences/Material chemistry, Nonlinear Sciences - Adaptation and Self-Organizing Systems, law.invention, Few layer graphene, Fractal, law, Physics - Chemical Physics, Nano, Self assembling, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Physical and Theoretical Chemistry, Macro, Adaptation and Self-Organizing Systems (nlin.AO), Electrical conductor
Abstract: The transcription of nanoproperties to other dimensions in an efficient and simple way by the appropriate design of devices is a challenge, and conductive nanocarbon systems are considered here. The evaporation-induced self-assembling method is proposed to form branched, fractal-like "2D" conductive macrostructures from (nano) micro few-layer graphene flakes. The self-assembled conductive graphene networks reveal a reduction of percolation threshold compared to a random arrangement (a lower matter concentration is required to make a given substrate conductive and at a lower coverage), and become a promising matrix for conductive (transparent) films. The method is easy, cost-efficient and can potentially be applied on unlimited surfaces.
Published: 2015

36. Light mediated emergence of surface patterns in azopolymers at low temperatures

Author: Habib Tajalli, Victor Teboul, Peyman Tajalli, Regis Barille, Sonia Zielińska, Sohrab Ahmadi-Kandjani, Ewelina Ortyl, Propriétés Optiques des Matériaux et Applications (POMA), Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA), University of Tabriz [Tabriz], Laboratoire de Photonique d'Angers (LPHIA), Université d'Angers (UA), MOLTECH-Anjou, Université d'Angers (UA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Faculty of Chemistry Wroclaw, and University of Wrocław [Poland] (UWr)
Subjects: Chemical Physics (physics.chem-ph), Surface (mathematics), Condensed Matter - Materials Science, Materials science, Doping, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Pattern formation, General Chemistry, Condensed Matter Physics, 3. Good health, chemistry.chemical_compound, Viscosity, Azobenzene, chemistry, Chemical physics, Physics - Chemical Physics, [CHIM]Chemical Sciences, [PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], Irradiation, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Diffusion (business), [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], ComputingMilieux_MISCELLANEOUS, Beam (structure)
Abstract: Polymer thin films doped with azobenzene molecules do have the ability to organize themselves in spontaneous surface relief gratings (SRG) under irradiation with a single polarized beam. To shed some light in this still unexplained phenomenon, we use a new method that permits us to access experimentally the very first steps of the pattern formation process. Decreasing the temperature, we slow down the formation and organization of patterns, due to the large increase of the viscosity and relaxation time of the azopolymer. As a result decreasing the temperature allows us to access and study much shorter time scales,in the physical mechanisms underlying the pattern formation, than previously reported. We find that the patterns organize themselves in sub-structures which size increase with the temperature, following the diffusion coefficient evolution of the material. That result suggests that the pattern formation and organization is mainly governed by diffusive processes, in agreement with some theories of the SRG formation. Decreasing further the temperature we observe the emergence of small voids located at the junction of the sub-structures., Comment: 6 figures, 13 pages
Published: 2015

37. Adsorption of microgels at an oil–water interface: correlation between packing and 2D elasticity

Author: Pascal Massé, Walter Richtering, Bogdan Catargi, Véronique Schmitt, Lucio Isa, Valérie Ravaine, Florent Pinaud, Karen Geisel, Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institute of Physical Chemistry, Chimie et Biologie des Membranes et des Nanoobjets (CBMN), Université de Bordeaux (UB)-École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratory for Interfaces, Soft Matter and Assembly [ETH Zürich], Department of Materials [ETH Zürich] (D-MATL), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Centre de recherches Paul Pascal (CRPP), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Langmuir, Microgels, Materials science, Linear polymer, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Oil-Water interface, Elasticity, 0104 chemical sciences, Drop method, Adsorption, Chemical engineering, Surface elasticity, Polymer chemistry, Oil water, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Elasticity (economics), 0210 nano-technology, Flow properties
Abstract: International audience; The aim of this paper is to determine how microgels adsorb at a model oil–water interface and how they adapt their conformation to compression, which gives rise to surface elasticity depending on the microgel packing. The structure of the ﬁlm is determined by the Langmuir ﬁlms approach (forced compression) and compared to spontaneous adsorption using the pendant drop method. The behaviour of microgels diﬀers signiﬁcantly from that of non-deformable particles but resembles that of linear polymers or proteins. We also correlate the properties of microgels spontaneously adsorbed at model interfaces to their forced adsorption during emulsiﬁcation. Finally we propose a route to easily control a posteriori the microgel packing at the surface of droplets and the ﬂow properties of emulsions stabilised by the microgels.
Published: 2014

38. Design and optical investigations of a spironaphthoxazine/polyoxometalate/spiropyran triad

Author: Ali Saad, Olivier Oms, Guangjin Zhang, Pierre Mialane, Houda El Bekkachi, Anne Dolbecq, Philippe Deniard, Stéphane Jobic, Rémi Dessapt, Bineta Keita, Damien Garrot, Kamel Boukheddaden, Jérôme Marrot, Khadija Hakouk, Rongji Liu, Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes cedex 3, France, Groupe d'Etude de la Matière Condensée (GEMAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), and Key Laboratory of Green Process Engineering, Institute of Process Engineering, Chinese Academy of Sciences
Subjects: Spiropyran, Materials science, genetic structures, 010405 organic chemistry, education, Cationic polymerization, General Chemistry, 010402 general chemistry, Photochemistry, 01 natural sciences, eye diseases, 0104 chemical sciences, Crystallography, chemistry.chemical_compound, Photochromism, chemistry, Electrochromism, Polyoxometalate, Materials Chemistry, Molecule, Moiety, sense organs, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], health care economics and organizations, Derivative (chemistry)
Abstract: The assembly of two distinct organic photochromic groups and polyoxometalate (POM) within a single molecule has been realized. In the hetero-functionalized Anderson polyanion MnMo6O18(SP)(SN), one spiropyran and one spironaphthoxazine cap the two faces of a planar {MnIIIMo6VIO18} fragment. A related symmetrical POM where the {MnIIIMo6VIO18} inorganic moiety is connected to two spironaphthoxazines has also been obtained, and isolated as an organoammonium (MnMo6O18(SN)2) or a cationic spiropyran ((SP)3MnMo6O18(SN)2) salt. The structures of MnMo6O18(SN)2 and MnMo6O18(SP)(SN) have been solved by single-crystal X-ray diffraction analysis. In solution, both compounds exhibit electrochromic properties with multiple redox coloured states. The solid-state photochromism of all the compounds has also been extensively studied at room temperature. Contrary to the organic spironaphtoxazine derivative SNTris which is very poorly photochromic, the pale yellow colour of MnMo6O18(SN)2 shifts to deep blue with high coloration contrast which underlines the positive effect of the grafting onto the inorganic platform. In addition, MnMo6O18(SN)2 also shows good cyclability and exhibits a fast bleaching process. Finally, the temperature dependence of the solid-state photochromic properties of MnMo6O18(SN)2 is also reported and compared to that of the related MnMo6O18(SP)2. The photo-coloration process which is attenuated at low temperatures in both cases is clearly more affected for MnMo6O18(SN)2. Moreover, the thermal fading process becomes significant at 340 K for MnMo6O18(SP)2 and 260 K for MnMo6O18(SN)2 underlining strong different optical behaviours between both materials.
Published: 2014

39. Design principles for superamphiphobic surfaces

Author: Doris Vollmer, Periklis Papadopoulos, Martin Brinkmann, Matteo Ciccotti, Hans-Jürgen Butt, Ciro Semprebon, Max Planck Institute for Polymer Research, Max-Planck-Gesellschaft, Max Planck Institute for Dynamics and Self-Organization (MPIDS), Sciences et Ingénierie de la Matière Molle (SIMM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: CONTACT-ANGLE, Materials science, Capillary action, FLOW, EFFECTIVE SLIP, OIL-REPELLENT SURFACES, SUPERHYDROPHOBIC SURFACES, 02 engineering and technology, Slip (materials science), 010402 general chemistry, 01 natural sciences, DRAG, Physics::Fluid Dynamics, Contact angle, Optics, SURFACTANTS, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Composite material, COLLOIDAL PARTICLES, Nanoscopic scale, WATER-REPELLENT, [PHYS]Physics [physics], Normal force, business.industry, General Chemistry, OMNIPHOBIC SURFACES, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Condensed Matter::Soft Condensed Matter, Drag, SPHERES, Wetting, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 0210 nano-technology, business, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract: International audience; To predict the properties of superamphiphobic layers we analyzed the wetting of a square and a hexagonal array of vertical pillars composed of spheres (radius R) partially sintered together. Apparent contact angles above 150 degrees are obtained by pinning of a non-polar liquid surface at the underside of the top sphere resulting in a Fakir or Cassie state. Analytical equations are derived for the impalement pressure in the limiting case A(0) >> R-2, where A(0) is the area of the regular unit cell containing a single pillar. The case of close pillars is investigated numerically. By balancing forces at the rim of a drop, we calculate the apparent receding contact angle. To describe drag reduction of a flowing liquid we calculate the apparent slip length. When considering pressure-induced flow through cylindrical capillaries of radius r(c), significant drag reduction occurs only for thin capillaries. The mechanical stability with respect to normal forces and shear is analyzed. Nanoscopic silica glass pillars would be able to sustain the normal and shear stresses caused by capillary and drag forces. For a high impalement pressure and good mechanical stability A(0) should be small and R (respectively the neck diameter) should be large, whereas a large A(0) and a small R imply low contact angle hysteresis and high slip length.
Published: 2013

40. The dissipative rheology of bubble monolayers

Author: Séverine Costa, Sylvie Cohen-Addad, Reinhard Höhler, Anniina Salonen, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Matériaux Divisés et des Interfaces (LPMDI), Université Paris-Est Marne-la-Vallée (UPEM), European Space Agency [MAP AO 99-108], French Space Agency [103954], and Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)
Subjects: Materials science, Rheometer, Bubble, General Chemistry, Mechanics, Condensed Matter Physics, Plateau (mathematics), Physics::Fluid Dynamics, Condensed Matter::Soft Condensed Matter, Classical mechanics, Rheology, Monolayer, Dissipative system, Shear stress, Soap film, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]
Abstract: International audience; We confine a monodisperse bubble monolayer between the two parallel plates of a rheometer. One plate is fixed and the other undergoes an oscillatory tangential motion, so that the bubbles are sheared. We measure the shear stress as a function of the imposed strain amplitude and frequency. The interfacial shear and dilational moduli of the foaming solutions are studied in independent experiments. Like a 3D foam, the bubble monolayer consists of soap films connected via Plateau borders, but its structure is much simpler, enabling us to study and model the quantitative link between interfacial rheology and the macroscopic mechanical response.
Published: 2013

41. The coupling between foam viscoelasticity and interfacial rheology

Author: Séverine Costa, Sylvie Cohen-Addad, Reinhard Höhler, Institut des Nanosciences de Paris (INSP), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire de Physique des Matériaux Divisés et des Interfaces (LPMDI), Université Paris-Est Marne-la-Vallée (UPEM), European Space Agency [MAP AO 99-108], French Space Agency (agreement CNES/CNRS) [103954], and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Bubble, Loss factor, Modulus, General Chemistry, Condensed Matter Physics, Scale factor, Viscoelasticity, Condensed Matter::Soft Condensed Matter, Physics::Fluid Dynamics, Shear modulus, Viscosity, Rheology, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Composite material
Abstract: International audience; We study the impact of interfacial rheology on the linear viscoelastic relaxations of disordered 3D foams. Their complex shear modulus G(star) = G' + iG `' is measured as a function of frequency, bubble size, liquid viscosity and surface dilatational modulus. We show that for foams with very rigid interfaces the variations of G(star) with frequency f between 1 and 100 Hz deviate from the behavior G(star) similar to root if previously predicted as a generic consequence of topological disorder and observed for foams with mobile or moderately rigid interfaces. Our experiments demonstrate that the relaxations slow down as the bubble size or the foaming liquid viscosity increases. We show under which conditions, depending on the interfacial rigidity, the loss factor G `'/G' can be collapsed on master curves by applying a scale factor to the frequency. The dependence of this scale factor on the bubble size and viscosity constitutes a robust criterion helping to identify the dominant dissipation mechanism.
Published: 2013

42. Step-by-step on-surface synthesis: from manganese phthalocyanines to their polymeric form

Author: Mathieu Koudia, Mathieu Abel, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], In situ, Materials science, Annealing (metallurgy), Metals and Alloys, chemistry.chemical_element, General Chemistry, Manganese, Catalysis, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Crystallography, chemistry, Microscopy, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Materials Chemistry, Ceramics and Composites, Molecule, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], ComputingMilieux_MISCELLANEOUS, Quantum tunnelling
Abstract: On-surface synthesis of tetracyanobenzene molecules with Mn atoms is presented. From metal-organic coordination networks at room temperature, Mn-phthalocyanines and finally small domains of polymeric Mn-phthalocyanines are formed upon annealing on the Ag(111) surface. Step-by-step on-surface reaction is studied in situ by scanning tunnelling microscopy under ultra-high vacuum.
Published: 2014

43. A molecular photovoltaic system based on Dawson type polyoxometalate and porphyrin formed by layer-by-layer self assembly

Author: Michel Goldmann, Iftikhar Ahmed, Laurent Ruhlmann, Rana Farha, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), CNRS, Universite Paris-Sud (Paris), Universite de Strasbourg, University of Engineering & Technology, Lahore, H.E.C. (Higher Education Commission) of Pakistan, Universite Paris Descartes (Paris), and Universite Pierre et Marie Curie (Paris)
Subjects: Photocurrent, Chemistry, Photovoltaic system, Metals and Alloys, General Chemistry, Photochemistry, Electrostatics, Porphyrin, Catalysis, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, Layer by layer self assembly, Polyoxometalate, Materials Chemistry, Ceramics and Composites, Transient (oscillation), [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]
Abstract: International audience; Films based on electrostatic interactions between tetracationic porphyrin and Dawson type polyoxometalate are formed by the so called layer-by-layer method. Their photovoltaic performances are investigated by photocurrent transient measurements which showed significant photocurrent response.
Published: 2013

44. A magnetic nanogel based on O-carboxymethylchitosan for antitumor drug delivery: synthesis, characterization and in vitro drug release

Author: Piotr Dłużewski, Valdir Cechinel Filho, Fátima de Campos Buzzi, Carla Albetina Demarchi, Aline Debrassi, Clóvis Antonio Rodrigues, Pavlo Demchenko, Rogério Corrêa, Anna Ślawska-Waniewska, Jean-Marc Greneche, N. Nedelko, Institut des Molécules et Matériaux du Mans (IMMM), and Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nanogels, Maghemite, Antineoplastic Agents, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Polyethylene Glycols, Chitosan, Magnetics, Spectroscopy, Mossbauer, chemistry.chemical_compound, Polymer chemistry, Animals, Polyethyleneimine, Epichlorohydrin, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Particle Size, Magnetite Nanoparticles, ComputingMilieux_MISCELLANEOUS, Magnetite, [PHYS]Physics [physics], Drug Carriers, Calorimetry, Differential Scanning, Chemistry, Serum Albumin, Bovine, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Drug Liberation, Chemical engineering, Thermogravimetry, Drug delivery, engineering, Magnetic nanoparticles, Cattle, Adsorption, Particle size, 0210 nano-technology, Nanogel
Abstract: This paper studied the synthesis, characterization and use of the magnetic chitosan nanogel for carrying meleimidic compounds. The hydrogel polymer was prepared using O-carboxymethylchitosan, which was crosslinked with epichlorohydrin for subsequent incorporation of iron oxide magnetic nanoparticles. The characterization revealed that the magnetic material comprises about 10% of the hydrogel. This material is comprised of magnetite and maghemite and exhibits ferro-ferrimagnetic behavior. The average particle size is 4.2 nm. There was high incorporation efficiency of maleimides in the magnetic nanogel. The release was of sustained character and there was a greater release when an external magnetic field was applied. The mathematical model that best explained the process of drug release by the magnetic hydrogel was that of Peppas-Sahlin. The magnetic nanogel proved to be an excellent candidate for use in drug-delivery systems.
Published: 2014

45. Spectroscopic determination of crystal field splittings in lanthanide double deckers

Author: Liviu Ungur, Raphael Marx, Liviu F. Chibotaru, Milan Orlita, Fabrizio Moro, Wolfgang Frey, J. Taylor, Michael Waters, Shang-Da Jiang, María Dörfel, J. van Slageren, Orlita, Milan, Marx, R, Moro, F, Dörfel, M, Ungur, L, Waters, M, Jiang, S, Orlita, M, Taylor, J, Frey, W, Chibotaru, L, Van Slageren, J, Dipartimento di Geoscienze [Padova], Universita degli Studi di Padova, Institute for nanoscale physics and chemistry, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), California Polytechnic State University [San Luis Obispo] (CAL POLY), Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI-G), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Université Joseph Fourier - Grenoble 1 (UJF)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Lanthanide, Field (physics), Chemistry, Chemistry (all), Analytical chemistry, chemistry.chemical_element, General Chemistry, Electronic structure, Molecular physics, Inelastic neutron scattering, [PHYS] Physics [physics], 3. Good health, Crystal, Far infrared, Crystal field theory, [CHIM] Chemical Sciences, [CHIM]Chemical Sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Holmium, ComputingMilieux_MISCELLANEOUS, [PHYS.COND] Physics [physics]/Condensed Matter [cond-mat]
Abstract: We have investigated the crystal field splitting in the archetypal lanthanide-based single-ion magnets and related complexes (NBu4)+[LnPc2]-·2dmf (Ln = Dy, Ho, Er; dmf = N,N-dimethylformamide) by means of far infrared and inelastic neutron scattering spectroscopies. In each case, we have found several features corresponding to direct crystal field transitions within the ground multiplet. The observation of three independent peaks in the holmium derivative enabled us to derive crystal field splitting parameters. In addition, we have carried out CASSCF calculations. We show that exploiting the interplay of CASSCF calculation (for the composition of the states) and advanced spectroscopic measurements (for accurate determination of the energies) is a very powerful approach to gain insight into the electronic structure of lanthanide-based single-molecule magnets. © the Partner Organisations 2014
Published: 2014

46. Calcite formation by hydrothermal carbonation of portlandite: complementary insights from experiment and simulation

Author: A. Clement, Bertrand Fritz, German Montes-Hernandez, Claudine Noguera, Laboratoire d'Hydrologie et de Géochimie de Strasbourg (LHyGeS), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Ecole et Observatoire des Sciences de la Terre (EOST), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre (ISTerre), Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Ecole et Observatoire des Sciences de la Terre (EOST), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)
Subjects: Calcite, Aqueous solution, Mineral, Chemistry, Carbonation, Nucleation, Mineralogy, 02 engineering and technology, General Chemistry, engineering.material, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Portlandite, Hydrothermal circulation, 0104 chemical sciences, chemistry.chemical_compound, Chemical engineering, engineering, General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Dissolution
Abstract: International audience; The present study complements experimental results of calcite nanoparticle formation by hydrothermal carbonation of calcium hydroxide by a simulation strategy, in which both the chemical evolution of the aqueous solution and the solid phases - dissolution of portlandite and nucleation and growth of secondary calcite particles - are considered. The simulation is performed with the help of the NANOKIN code. It includes a full treatment of speciation processes in the aqueous solution, a rate equation for the dissolution of primary minerals, and a full account of nucleation and growth processes during the formation of new particles. This strategy has allowed us to decipher the various steps in the mineral transformation and solution evolution. The comparison between experiment and simulation puts strong constraints on simulation parameters, while modeling can give information on in situ conditions, currently not often available experimentally.
Published: 2013

47. Equilibrium shapes of supported silver clusters

Author: Nicoleta Crivat, Dominique Demaille, Jacques Jupille, Slavica Stankic, Jacek Goniakowski, Robinson Cortes-Huerto, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and French project [ANR-11-BS10-006 MIGRANI]
Subjects: Crystallography, Truncated octahedron, Morphology (linguistics), Materials science, Transmission electron microscopy, General Materials Science, Adhesion, Crystallite, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Anisotropy, Epitaxy, Silver nanoparticle
Abstract: International audience; The morphology of silver nanoparticles supported on MgO smoke crystallites was studied by combining Transmission Electron Microscopy (TEM) and atomistic simulations of clusters of realistic size. Advantage was taken of the occurrence of well-defined complex MgO surfaces, including stepped surfaces and contact lines between stacked crystallites, to analyze Ag clusters of various orientations. Silver clusters were seen to adopt systematically the shape of a truncated octahedron irrespective of the support morphology. The (100) Ag//(100) MgO epitaxy was evidenced and (100), (111) and (110) facets were identified. The agreement between observed shapes and simulated profiles demonstrated that the formers were close to equilibrium which allowed the use of Wulff-Kaishew construction to determine the anisotropy ratios gamma 100/gamma 111 (1.03 +/- 0.03) and gamma 110/gamma 111 (1.08 +/- 0.03) and the Ag(100)/MgO(100) adhesion energy (0.58 +/- 0.10 J m(-2)) for clusters large enough to escape stress effects.
Published: 2013

48. Structural and optical properties of self-catalytic GaAs:Mn nanowires grown by molecular beam epitaxy on silicon substrates

Author: J. F. Morhange, Abdulmenaf Altıntaş, Aloyzas Siusys, Takeshi Kasama, Wojciech Zaleszczyk, Hongqi Xu, Tomasz Wojciechowski, Wojciech Szuszkiewicz, Katarzyna Gas, Janusz Sadowski, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Swedish Research Council (VR), EU within the European Social Fund through the Human Capital Programme, ERC, EU within the European Regional Development Fund through grant Innovative Economy [POIG.01.01.02-00-008/08], European Commission Network SemiSpinNet [PITN-GA-2008-215368], European Regional Development Fund through the Innovative Economy grant [POIG.01.01.02-00-108/09], VR, National Basic Research Program of the Ministry of Science and Technology of China [2012CB932703, 2012CB932700], and [N N202 128639]
Subjects: Materials science, Photoluminescence, Silicon, Exciton, Nanowire, FOS: Physical sciences, chemistry.chemical_element, Cathodoluminescence, 02 engineering and technology, 01 natural sciences, 0103 physical sciences, General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010302 applied physics, Condensed Matter - Materials Science, business.industry, Doping, Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, 3. Good health, chemistry, Transmission electron microscopy, Optoelectronics, 0210 nano-technology, business, Molecular beam epitaxy
Abstract: Mn-doped GaAs nanowires were grown in the self-catalytic growth mode on oxidized Si(100) surface by molecular beam epitaxy and characterized by scanning and transmission electron microscopy, Raman scattering, photoluminescence, cathodoluminescence, and electron transport measurements. The transmission electron microscopy studies evidenced the substantial accumulation of Mn inside the catalyzing Ga droplets at the top of the nanowires. Optical and transport measurements revealed that the limit of Mn content for self-catalysed growth of GaAs nanowires corresponds to the doping level, i.e., is much lower than the Mn/Ga flux ratio (about 3%) used during the MBE growth. The resistivity measurements of individual nanowires confirmed that they are conductive, in accordance with the photoluminescence measurements which showed the presence of Mn2+ acceptors located at Ga sites of the GaAs host lattice of the nanowires. An anomalous temperature dependence of the photoluminescence related to excitons was demonstrated for Mn-doped GaAs nanowires., 19 pages, 11 figures
Published: 2013

49. Pattern formation by dewetting and evaporating sedimenting suspensions

Author: Daniel Bonn, Mehdi Habibi, Abdoulaye Fall, Peder Moller, Salima Rafaï, Laboratoire de Physique Statistique de l'ENS (LPS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Département Electronique et Physique (TSP - EPH), Institut Mines-Télécom [Paris] (IMT)-Télécom SudParis (TSP), Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Soft Matter (WZI, IoP, FNWI), Université Paris Diderot - Paris 7 (UPD7)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Département Electronique et Physique (EPH), and Fall, Abdoulaye
Subjects: Length scale, Materials science, Evaporation, Pattern formation, 01 natural sciences, [PHYS] Physics [physics], 010305 fluids & plasmas, Viscosity, Optics, 0103 physical sciences, Life Science, Dewetting, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Thin film, 010306 general physics, ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], business.industry, Contact line, General Chemistry, Condensed Matter Physics, [PHYS.COND.CM-SCM] Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], Chemical physics, Particle, business, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], [PHYS.COND] Physics [physics]/Condensed Matter [cond-mat]
Abstract: Pattern formation from drying droplets containing sedimenting particles and dewetting of thin films of such suspensions was studied. The dewetting causes the formation of finger-like patterns near the contact line which leave behind a deposit of branches. We find that the strikingly low speed of dewetting is due to the high particle concentration in the contact line region, leading to a strongly enhanced viscosity. For pattern formation from drying droplets (containing particles), evaporation also causes dewetting. In both cases, we find a similar relationship between the size of the patterns and the dewetting speed. The coefficient of this relationship gives us the effective viscosity at the contact line. We present a simple model that accounts for this, and that shows that the size of the particles is the relevant length scale in both problems.
Published: 2012

50. Influence of polymorphism on charge transport properties in isomers of fluorenone-based liquid crystalline semiconductors

Author: André Jean Attias, Jean Louis Fave, Frédéric Lincker, Patrice Rannou, Benoît Heinrich, Fabrice Mathevet, Bertrand Donnio, Renaud Demadrille, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Structures et propriétés d'architectures moléculaire (SPRAM - UMR 5819), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR, CNRS, CEA, Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Nanosciences et Cryogénie (INAC), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Materials science, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Catalysis, chemistry.chemical_compound, Materials Chemistry, Organic chemistry, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Fluorenes, Molecular Structure, business.industry, Liquid crystalline, Isotropy, Metals and Alloys, Mesophase, Stereoisomerism, General Chemistry, 021001 nanoscience & nanotechnology, Liquid Crystals, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Organic semiconductor, Crystallography, Semiconductor, Semiconductors, Fluorenone, chemistry, Polymorphism (materials science), Ceramics and Composites, Charge carrier, 0210 nano-technology, business
Abstract: International audience; We measured the charge carrier mobilities for two isomers of fluorenone-based liquid crystalline organic semiconductors from their isotropic down to crystalline states through one or two mesophases. Improved charge transport properties of melt-processed crystalline films were obtained for the isomer exhibiting a highly ordered mesophase below its disordered smectic phase.
Published: 2012

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