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1. A Route to Complex Materials Consisting of Multiple Crystalline Phases Ir‐Ru‐IrxRu1‐xO2 as Multifunctional Electrocatalysts

Author

Sarra Knani, Perla Hajjar, Marie‐Agnès Lacour, Arie van derLee, Erwan Oliviero, Eddy Petit, Valerie Flaud, Julien Cambedouzou, Sophie Tingry, Teko W. Napporn, David Cornu, and Yaovi Holade

Subjects
electrocatalysis, hydrogen evolution reaction, iridium, oxides, oxygen evolution reaction, ruthenium, Physics, QC1-999, Technology
Abstract

Abstract The synthesis of catalytic materials containing active sites of various oxidation states (metal, oxide, etc.) for the dual use in reduction and oxidation reactions remains challenging because most of the reported methods for the metallic state are often incompatible with those for the oxide state. A new methodology is reported for the synthesis of a library of bimetallic metal‐oxide materials containing three crystalline phases Ir‐Ru‐IrxRu1‐xO2 by combining the calcination under air and the polymerization of aniline in the presence of IrCl3 and RuCl3 precursors. Morphology, structure, and surface oxidation state studies (XRD, SEM/EDX, S/TEM, XPS) confirm the hypothesis that IrCl3 evolves to Ir while RuCl3 evolves to RuO2 during the calcination under air. An Ir:Ru atomic ratio of 50:50 can be converted into a heterogeneous nanostructure composed of Ir, Ru, and IrxRu1‐xO2 to date, with remarkable catalytic activity for both hydrogen evolution reaction (HER) with a small overpotential of 40 mV and oxygen evolution reaction (OER) with a small overpotential of 290 mV at the metric current density of 10 mA cm−2 in 0.5 m H2SO4. The results can serve as a platform for the development of efficient multifunctional materials for practical use in both catalytic oxidation and reduction reactions.

Published
2024
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2. Recent Advances in Electrospun Fibers for Biological Applications

Author

Bénédicte Fromager, Emilie Marhuenda, Benjamin Louis, Norbert Bakalara, Julien Cambedouzou, and David Cornu

Subjects
electrospinning, single needle, multi-needle, nanofibers, parameters, scaffold, Chemical technology, TP1-1185, Biochemistry, QD415-436
Abstract

Electrospinning is a simple and versatile method to generate nanofibers. Remarkable progress has been made in the development of the electrospinning process. The production of nanofibers is affected by many parameters, which influence the final material properties. Electrospun fibers have a wide range of applications, such as energy storage devices and biomedical scaffolds. Among polymers chosen for biological scaffolds, such as PLA or collagen, polyacrylonitrile (PAN) has received increasing interest in recent years due to its excellent characteristics, such as spinnability, biocompatibility, and commercial viability, opening the way to new applications in the biotechnological field. This paper provides an overview of the electrospinning process of a large range of polymers of interest for biomedical applications, including PLA and PEO. It covers the main parameters and operation modes that affect nanofiber fabrication. Their biological applications are reviewed. A focus is placed on PAN fiber formation, functionalization, and application as scaffolds to allow cell growth. Overall, nanofiber scaffolds appear to be powerful tools in medical applications that need controlled cell culture.

Published
2023
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3. Encapsulation of Active Substances in Natural Polymer Coatings

Author

Emma Akpo, Camille Colin, Aurélie Perrin, Julien Cambedouzou, and David Cornu

Subjects
biopolymers, protection, ionic gelation, hydrogels, formulation, Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Engineering (General). Civil engineering (General), TA1-2040, Microscopy, QH201-278.5, Descriptive and experimental mechanics, QC120-168.85
Abstract

Already used in the food, pharmaceutical, cosmetic, and agrochemical industries, encapsulation is a strategy used to protect active ingredients from external degradation factors and to control their release kinetics. Various encapsulation techniques have been studied, both to optimise the level of protection with respect to the nature of the aggressor and to favour a release mechanism between diffusion of the active compounds and degradation of the barrier material. Biopolymers are of particular interest as wall materials because of their biocompatibility, biodegradability, and non-toxicity. By forming a stable hydrogel around the drug, they provide a ‘smart’ barrier whose behaviour can change in response to environmental conditions. After a comprehensive description of the concept of encapsulation and the main technologies used to achieve encapsulation, including micro- and nano-gels, the mechanisms of controlled release of active compounds are presented. A panorama of natural polymers as wall materials is then presented, highlighting the main results associated with each polymer and attempting to identify the most cost-effective and suitable methods in terms of the encapsulated drug.

Published
2024
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4. Encapsulation in Alginates Hydrogels and Controlled Release: An Overview

Author

Camille Colin, Emma Akpo, Aurélie Perrin, David Cornu, and Julien Cambedouzou

Subjects
hydrogels, alginates, encapsulation, controlled release, Organic chemistry, QD241-441
Abstract

This review aims to gather the current state of the art on the encapsulation methods using alginate as the main polymeric material in order to produce hydrogels ranging from the microscopic to macroscopic sizes. The use of alginates as an encapsulation material is of growing interest, as it is fully bio-based, bio-compatible and bio-degradable. The field of application of alginate encapsulation is also extremely broad, and there is no doubt it will become even broader in the near future considering the societal demand for sustainable materials in technological applications. In this review, alginate’s main properties and gelification mechanisms, as well as some factors influencing this mechanism, such as the nature of the reticulation cations, are first investigated. Then, the capacity of alginate gels to release matter in a controlled way, from small molecules to micrometric compounds, is reported and discussed. The existing techniques used to produce alginates beads, from the laboratory scale to the industrial one, are further described, with a consideration of the pros and cons with each techniques. Finally, two examples of applications of alginate materials are highlighted as representative case studies.

Published
2024
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5. Mesoporous SiC-Based Photocatalytic Membranes and Coatings for Water Treatment

Author

Karla Begonia Cervantes-Diaz, Martin Drobek, Anne Julbe, André Ayral, and Julien Cambedouzou

Subjects
silicon carbide, mesoporous membrane, photocatalysis, membrane reactor, Chemical technology, TP1-1185, Chemical engineering, TP155-156
Abstract

Photocatalytically active silicon carbide (SiC)-based mesoporous layers (pore sizes between 5 and 30 nm) were synthesized from preceramic polymers (polymer-derived ceramic route) on the surface and inside the pores of conventional macroporous α-alumina supports. The hybrid membrane system obtained, coupling the separation and photocatalytical properties of SiC thin films, was characterized by different static and dynamic techniques, including gas and liquid permeation measurements. The photocatalytic activity was evaluated by considering the degradation efficiency of a model organic pollutant (methylene blue, MB) under UV light irradiation in both diffusion and permeation modes using SiC-coated macroporous supports. Specific degradation rates of 1.58 × 10−8 mol s−1 m−2 and 7.5 × 10−9 mol s−1 m−2 were obtained in diffusion and permeation modes, respectively. The performance of the new SiC/α-Al2O3 materials compares favorably to conventional TiO2-based photocatalytic membranes, taking advantage of the attractive physicochemical properties of SiC. The developed synthesis strategy yielded original photocatalytic SiC/α-Al2O3 composites with the possibility to couple the ultrafiltration SiC membrane top-layer with the SiC-functionalized (photocatalytic) macroporous support. Such SiC-based materials and their rational associations on porous supports offer promising potential for the development of efficient photocatalytic membrane reactors and contactors for the continuous treatment of polluted waters.

Published
2023
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6. Glioma stem cells invasive phenotype at optimal stiffness is driven by MGAT5 dependent mechanosensing

Author

Emilie Marhuenda, Christine Fabre, Cunjie Zhang, Martà Martin-Fernandez, Thomas Iskratsch, Ali Saleh, Luc Bauchet, Julien Cambedouzou, Jean-Philippe Hugnot, Hugues Duffau, James W. Dennis, David Cornu, and Norbert Bakalara

Subjects
Mechanotransduction, 3D-nanofibre scaffold, Biomaterial, Stiffness, Glycosylation, Mgat5, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

Abstract Background Glioblastomas stem-like cells (GSCs) by invading the brain parenchyma, remains after resection and radiotherapy and the tumoral microenvironment become stiffer. GSC invasion is reported as stiffness sensitive and associated with altered N-glycosylation pattern. Glycocalyx thickness modulates integrins mechanosensing, but details remain elusive and glycosylation enzymes involved are unknown. Here, we studied the association between matrix stiffness modulation, GSC migration and MGAT5 induced N-glycosylation in fibrillar 3D context. Method To mimic the extracellular matrix fibrillar microenvironments, we designed 3D-ex-polyacrylonitrile nanofibers scaffolds (NFS) with adjustable stiffnesses by loading multiwall carbon nanotubes (MWCNT). GSCs neurosphere were plated on NFSs, allowing GSCs migration and MGAT5 was deleted using CRISPR-Cas9. Results We found that migration of GSCs was maximum at 166 kPa. Migration rate was correlated with cell shape, expression and maturation of focal adhesion (FA), Epithelial to Mesenchymal Transition (EMT) proteins and (β1,6) branched N-glycan binding, galectin-3. Mutation of MGAT5 in GSC inhibited N-glycans (β1–6) branching, suppressed the stiffness dependence of migration on 166 kPa NFS as well as the associated FA and EMT protein expression. Conclusion MGAT5 catalysing multibranched N-glycans is a critical regulators of stiffness induced invasion and GSCs mechanotransduction, underpinning MGAT5 as a serious target to treat cancer.

Published
2021
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7. SiC Foams for the Photocatalytic Degradation of Methylene Blue under Visible Light Irradiation

Author

Karla Begonia Cervantes-Diaz, Martin Drobek, Anne Julbe, and Julien Cambedouzou

Subjects
silicon carbide, preceramic polymers, SiC ceramic foam, photocatalysis, Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Engineering (General). Civil engineering (General), TA1-2040, Microscopy, QH201-278.5, Descriptive and experimental mechanics, QC120-168.85
Abstract

SiC foams were synthesized by impregnating preceramic polymer into polyurethane foam templates, resulting in a photo-catalytically active material for the degradation of methylene blue. The crystalline structure, electronic properties, and photocatalytic performance of the SiC foams were characterized using a series of experimental techniques, including X-ray diffraction, electron microscopy, energy dispersive X-ray spectroscopy, N2 physisorption measurements, UV-visible spectroscopy, and methylene blue photodegradation tests. The original polyurethane template’s microporous structure was maintained during the formation of the SiC foam, while additional mesopores were introduced by the porogen moieties added to the preceramic polymers. The prepared SiC-based photocatalyst showed attractive photocatalytic activity under visible light irradiation. This structured and reactive material offers good potential for application as a catalytic contactor or membrane reactor for the semi-continuous treatment of contaminated waste waters in ambient conditions.

Published
2023
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8. Current Trends in Pickering Emulsions: Particle Morphology and Applications

Author

Danae Gonzalez Ortiz, Celine Pochat-Bohatier, Julien Cambedouzou, Mikhael Bechelany, and Philippe Miele

Subjects
Pickering emulsions, Particle morphology, Two-dimensional nanoparticles, Photocatalysis, Water filtration, Engineering (General). Civil engineering (General), TA1-2040
Abstract

In recent years, Pickering emulsions and their applications have attracted a great deal of attention due to their special features, which include easy preparation and enhanced stability. In contrast to classical emulsions, in Pickering emulsions, solid microparticles or nanoparticles that localize at the interface between liquids are used as stabilizers, instead of surfactants, to enhance the droplet lifetime. Furthermore, Pickering emulsions show higher stability, lower toxicity, and stimuli-responsiveness, compared with emulsions that are stabilized by surfactants. Therefore, they can be considered attractive components for various uses, such as photocatalysis and the preparation of new materials. Moreover, the nanoparticle morphology strongly influences Pickering emulsion stability as well as the potential utilization of such emulsions. Here, we review recent findings concerning Pickering emulsions, with a particular focus on how the nanoparticles morphology (i.e., cube, ellipsoid, nanosheet, sphere, cylinder, rod, peanut) influences the type and stability of such emulsions, and their current applications in different fields such as antibacterial activity, protein recognition, catalysis, photocatalysis, and water purification.

Published
2020
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9. Probing Oxygen-to-Hydrogen Peroxide Electro-Conversion at Electrocatalysts Derived from Polyaniline

Author

Yaovi Holade, Sarra Knani, Marie-Agnès Lacour, Julien Cambedouzou, Sophie Tingry, Teko W. Napporn, and David Cornu

Subjects
conducting polymer, polyaniline, electrocatalysis, hydrogen peroxide, oxygen reduction reaction, electrosynthesis, Organic chemistry, QD241-441
Abstract

Hydrogen peroxide (H2O2) is a key chemical for many industrial applications, yet it is primarily produced by the energy-intensive anthraquinone process. As part of the Power-to-X scenario of electrosynthesis, the controlled oxygen reduction reaction (ORR) can enable the decentralized and renewable production of H2O2. We have previously demonstrated that self-supported electrocatalytic materials derived from polyaniline by chemical oxidative polymerization have shown promising activity for the reduction of H2O to H2 in alkaline media. Herein, we interrogate whether such materials could also catalyze the electro-conversion of O2-to-H2O2 in an alkaline medium by means of a selective two-electron pathway of ORR. To probe such a hypothesis, nine sets of polyaniline-based materials were synthesized by controlling the polymerization of aniline in the presence or not of nickel (+II) and cobalt (+II), which was followed by thermal treatment under air and inert gas. The selectivity and faradaic efficiency were evaluated by complementary electroanalytical methods of rotating ring-disk electrode (RRDE) and electrolysis combined with spectrophotometry. It was found that the presence of cobalt species inhibits the performance. The selectivity towards H2O2 was 65–80% for polyaniline and nickel-modified polyaniline. The production rate was 974 ± 83, 1057 ± 64 and 1042 ± 74 µmolH2O2 h−1 for calcined polyaniline, calcined nickel-modified polyaniline and Vulcan XC 72R (state-of-the-art electrocatalyst), respectively, which corresponds to 487 ± 42, 529 ± 32 and 521 ± 37 mol kg−1cat h−1 (122 ± 10, 132 ± 8 and 130 ± 9 mol kg−1cat cm−2) for faradaic efficiencies of 58–78%.

Published
2022
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10. Nanostructured Carbon-Nitrogen-Sulfur-Nickel Networks Derived From Polyaniline as Bifunctional Catalysts for Water Splitting

Author

Razik Djara, Yaovi Holade, Abdelhafid Merzouki, Marie-Agnès Lacour, Nathalie Masquelez, Valerie Flaud, Didier Cot, Bertrand Rebiere, Arie van der Lee, Julien Cambedouzou, Patrice Huguet, Sophie Tingry, and David Cornu

Subjects
polyaniline, hydrogen evolution reaction, oxygen evolution reaction, water splitting, electrocatalysis, noble metal-free, Chemistry, QD1-999
Abstract

The development of reliable production routes for sustainable hydrogen (H2), which is an essential feedstock for industrial processes and energy carrier for fuel cells, is needed. It appears to be an unavoidable alternative to significantly reduce the dependence on conventional energy sources based on fossil fuels without increasing the atmospheric CO2 levels. Among the different power-to-X scenarios to access high purity H2, the electrochemical approach based on electrolysis looks to be a promising sustainable solution at both the small and large industrial scales. However, the practical realization of this important opportunity faces several challenges, including the efficient design of cost-effective catalytic materials to be used as a cathode with improved intrinsic and durable activity. In this contribution, we report the design and development of efficient nanostructured catalysts for the electrocatalytic hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in aqueous media, whereby noble metal-free elements are embedded in a matrix of a conducting polymer, polyaniline (PANI). To increase the electrical conductivity and further the electrocatalytic ability toward HER of the chemically polymerized PANI in the presence of nickel (II) salt (nitrate), the PANI-based materials have first been stabilized at a mild temperature of 250–350°C in air and then carbonized at 800–1,000°C under nitrogen gas to convert the chemical species into nitrogen, sulfur, nickel, and carbon nanostructured networks (CNNs). Different physicochemical (TGA-DSC, Raman spectroscopy, XRD, SEM, EDX, ICP, CHNS, BET, and XPS) and electrochemical (voltammetry and electrochemical impedance spectrometry) methods have been integrated to characterize the as-synthesized CNNs materials and interrogate the relationship of material-to-performance. It has been found that those synthesis conditions allow for the substantial increase of the electrocatalytic performance toward HER and OER in alkaline media in terms of the onset potential and charge transfer resistance and overpotential at the specific activity of 10 milliamps per square centimeter, thus ranking the present materials among the most efficient noble metal-free catalysts and making them possible candidates for integration in practical low-energy consumption alkaline electrolyzers.

Published
2020
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11. Insights on the Electrocatalytic Seawater Splitting at Heterogeneous Nickel-Cobalt Based Electrocatalysts Engineered from Oxidative Aniline Polymerization and Calcination

Author

Perla Hajjar, Marie-Agnès Lacour, Nathalie Masquelez, Julien Cambedouzou, Sophie Tingry, David Cornu, and Yaovi Holade

Subjects
polyaniline, electrocatalysis, hydrogen evolution reaction, oxygen evolution reaction, seawater splitting, Organic chemistry, QD241-441
Abstract

Given the limited access to freshwater compared to seawater, a growing interest surrounds the direct seawater electrolysis to produce hydrogen. However, we currently lack efficient electrocatalysts to selectively perform the oxygen evolution reaction (OER) over the oxidation of the chloride ions that are the main components of seawater. In this contribution, we report an engineering strategy to synthesize heterogeneous electrocatalysts by the simultaneous formation of separate chalcogenides of nickel (NiSx, x = 0, 2/3, 8/9, and 4/3) and cobalt (CoSx, x = 0 and 8/9) onto a carbon-nitrogen-sulfur nanostructured network. Specifically, the oxidative aniline polymerization in the presence of metallic cations was combined with the calcination to regulate the separate formation of various self-supported phases in order to target the multifunctional applicability as both hydrogen evolution reaction (HER) and OER in a simulated alkaline seawater. The OER’s metric current densities of 10 and 100 mA cm−2 were achieved at the bimetallic for only 1.60 and 1.63 VRHE, respectively. This high-performance was maintained in the electrolysis with a starting voltage of 1.6 V and satisfactory stability at 100 mA over 17 h. Our findings validate a high selectivity for OER of ~100%, which outperforms the previously reported data of 87–95%.

Published
2021
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12. Iridium and Ruthenium Modified Polyaniline Polymer Leads to Nanostructured Electrocatalysts with High Performance Regarding Water Splitting

Author

Razik Djara, Marie-Agnès Lacour, Abdelhafid Merzouki, Julien Cambedouzou, David Cornu, Sophie Tingry, and Yaovi Holade

Subjects
conducting polymer, polyaniline, electrocatalysis, hydrogen evolution reaction, oxygen evolution reaction, water splitting, Organic chemistry, QD241-441
Abstract

The breakthrough in water electrolysis technology for the sustainable production of H2, considered as a future fuel, is currently hampered by the development of tough electrocatalytic materials. We report a new strategy of fabricating conducting polymer-derived nanostructured materials to accelerate the electrocatalytic hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and water splitting. Extended physical (XRD, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX)) and electrochemical (cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS)) methods were merged to precisely characterize the as-synthesized iridium and ruthenium modified polyaniline (PANI) materials and interrogate their efficiency. The presence of Ir(+III) cations during polymerization leads to the formation of Ir metal nanoparticles, while Ru(+III) induces the formation of RuO2 oxide nanoparticles by thermal treatment; they are therefore methods for the on-demand production of oxide or metal nanostructured electrocatalysts. The findings from using 0.5 M H2SO4 highlight an ultrafast electrochemical kinetic of the material PANI-Ir for HER (36 − 0 = 36 mV overpotential to reach 10 mA cm−2 at 21 mV dec−1), and of PANI-Ru for OER (1.47 − 1.23 = 240 mV overpotential to reach 10 mA cm−2 at 47 mV dec−1), resulting in an efficient water splitting exactly at its thermoneutral cell voltage of 1.45 V, and satisfactory durability (96 h).

Published
2021
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13. On the Operational Aspects of Measuring Nanoparticle Sizes

Author

Jean-Marie Teulon, Christian Godon, Louis Chantalat, Christine Moriscot, Julien Cambedouzou, Michael Odorico, Johann Ravaux, Renaud Podor, Adèle Gerdil, Aurélie Habert, Nathalie Herlin-Boime, Shu-wen W. Chen, and Jean-Luc Pellequer

Subjects
nanoparticles, nanotoxicology, metrology, AFM, TEM, SEM, wet-STEM, SAXS, DLS, Chemistry, QD1-999
Abstract

Nanoparticles are defined as elementary particles with a size between 1 and 100 nm for at least 50% (in number). They can be made from natural materials, or manufactured. Due to their small sizes, novel toxicological issues are raised and thus determining the accurate size of these nanoparticles is a major challenge. In this study, we performed an intercomparison experiment with the goal to measure sizes of several nanoparticles, in a first step, calibrated beads and monodispersed SiO2 Ludox®, and, in a second step, nanoparticles (NPs) of toxicological interest, such as Silver NM-300 K and PVP-coated Ag NPs, Titanium dioxide A12, P25(Degussa), and E171(A), using commonly available laboratory techniques such as transmission electron microscopy, scanning electron microscopy, small-angle X-ray scattering, dynamic light scattering, wet scanning transmission electron microscopy (and its dry state, STEM) and atomic force microscopy. With monomodal distributed NPs (polystyrene beads and SiO2 Ludox®), all tested techniques provide a global size value amplitude within 25% from each other, whereas on multimodal distributed NPs (Ag and TiO2) the inter-technique variation in size values reaches 300%. Our results highlight several pitfalls of NP size measurements such as operational aspects, which are unexpected consequences in the choice of experimental protocols. It reinforces the idea that averaging the NP size from different biophysical techniques (and experimental protocols) is more robust than focusing on repetitions of a single technique. Besides, when characterizing a heterogeneous NP in size, a size distribution is more informative than a simple average value. This work emphasizes the need for nanotoxicologists (and regulatory agencies) to test a large panel of different techniques before making a choice for the most appropriate technique(s)/protocol(s) to characterize a peculiar NP.

Published
2018
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14. Exfoliation of Hexagonal Boron Nitride (h-BN) in Liquide Phase by Ion Intercalation

Author

Danae Gonzalez Ortiz, Celine Pochat-Bohatier, Julien Cambedouzou, Mikhael Bechelany, and Philippe Miele

Subjects
liquid exfoliation, boron nitride nanosheets, ion intercalation, gelatin, Chemistry, QD1-999
Abstract

A green approach to prepare exfoliated hexagonal boron nitride nanosheets (h-BNNS) from commercially pristine h-BN involving a two-step procedure was investigated. The first step involves the dispersion of pristine h-BN within an aqueous solution containing gelatin and potassium or zinc chloride using a sonication method. The second involves the removal of larger exfoliated h-BNNS through a centrifugation procedure. The exfoliation was caused not only by the sonication effect but also by intercalation of K+ and Zn2+ ions. Transmission electronic microscopy, X-ray diffraction and Raman spectroscopy techniques show that the obtained h-BNNS generally display a thickness of about a few (2–3) layers with an exfoliation efficiency as high as 16.3 ± 0.4%.

Published
2018
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15. Effect of low content sintering aids addition on β-SiC sintered by spark plasma sintering

Author

Florimond Delobel, Julien Cambedouzou, Florence Moitrier, Sébastien Lemonnier, Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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), Institut franco-allemand de recherches de Saint-Louis (ISL), DGA-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), Institut Européen des membranes (IEM), 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), and French German Res Inst St Louis

Subjects
Silicon carbideSpark plasma sinteringSintering aids, Materials Chemistry, Ceramics and Composites, [CHIM]Chemical Sciences
Abstract

International audience; The influence of low content of sintering aids addition on the properties of beta-SiC sintered by spark plasma sintering was studied based on X-ray diffraction and SEM observations. Three dopants, respectively Al2O3, Al2O3- Y2O3 and Al2O3-AlN were chosen, and the investigation was undertaken in the [0.5-5 wt%] content range. The analyses revealed the possibility to increase the density of sintered pellets close to 100% of theoretical density (T. D.), even with the addition of very low sintering aids contents, as low as 0.5 wt%, for each dopant. The combination with high sintering pressure allowed keeping a fine microstructure and a pristine cubic crystalline structure while avoiding the formation of secondary phases.

Published
2022

16. Glioma stem cells invasive phenotype at optimal stiffness is driven by MGAT5 dependent mechanosensing

Author

David Cornu, Julien Cambedouzou, Luc Bauchet, Jean-Philippe Hugnot, Ali Saleh, Hugues Duffau, Christine Fabre, James W. Dennis, Norbert Bakalara, Marta Martin-Fernandez, Cunjie Zhang, Thomas Iskratsch, Emilie Marhuenda, Retiveau, Nolwenn, Institut des Neurosciences de Montpellier (INM), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Queen Mary University of London (QMUL), Institut Européen des membranes (IEM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Hôpital Saint Eloi (CHRU Montpellier), Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Mount Sinai Hospital [Toronto, Canada] (MSH), University of Toronto, Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and SATT AxLRMENRT fellowship (CBS2 Doctoral School)INSERM/INCA project PC201216 (Gliomatrack)

Subjects
0301 basic medicine, Cancer Research, Glycosylation, Mechanotransduction, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, Stiffness, Extracellular matrix, 0302 clinical medicine, Cell Movement, MESH: Cell Movement, Migration, RC254-282, biology, Brain Neoplasms, Chemistry, Mgat5, MESH: Glioblastoma, EMT, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, Cell biology, Phenotype, Oncology, MESH: N-Acetylglucosaminyltransferases, MESH: Brain Neoplasms, Neoplastic Stem Cells, Galectin, Stem cell, endocrine system, animal structures, Integrin, [SDV.CAN]Life Sciences [q-bio]/Cancer, Context (language use), [SDV.BC]Life Sciences [q-bio]/Cellular Biology, N-Acetylglucosaminyltransferases, MESH: Phenotype, Focal adhesion, 03 medical and health sciences, [SDV.CAN] Life Sciences [q-bio]/Cancer, Neurosphere, [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, Humans, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Epithelial–mesenchymal transition, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, 3D-nanofibre scaffold, MESH: Humans, Research, [SDV.NEU.NB] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, MESH: Neoplastic Stem Cells, Biomaterial, 030104 developmental biology, biology.protein, Glioblastoma, 030217 neurology & neurosurgery
Abstract

Background Glioblastomas stem-like cells (GSCs) by invading the brain parenchyma, remains after resection and radiotherapy and the tumoral microenvironment become stiffer. GSC invasion is reported as stiffness sensitive and associated with altered N-glycosylation pattern. Glycocalyx thickness modulates integrins mechanosensing, but details remain elusive and glycosylation enzymes involved are unknown. Here, we studied the association between matrix stiffness modulation, GSC migration and MGAT5 induced N-glycosylation in fibrillar 3D context. Method To mimic the extracellular matrix fibrillar microenvironments, we designed 3D-ex-polyacrylonitrile nanofibers scaffolds (NFS) with adjustable stiffnesses by loading multiwall carbon nanotubes (MWCNT). GSCs neurosphere were plated on NFSs, allowing GSCs migration and MGAT5 was deleted using CRISPR-Cas9. Results We found that migration of GSCs was maximum at 166 kPa. Migration rate was correlated with cell shape, expression and maturation of focal adhesion (FA), Epithelial to Mesenchymal Transition (EMT) proteins and (β1,6) branched N-glycan binding, galectin-3. Mutation of MGAT5 in GSC inhibited N-glycans (β1–6) branching, suppressed the stiffness dependence of migration on 166 kPa NFS as well as the associated FA and EMT protein expression. Conclusion MGAT5 catalysing multibranched N-glycans is a critical regulators of stiffness induced invasion and GSCs mechanotransduction, underpinning MGAT5 as a serious target to treat cancer.

Published
2021

17. Effects of density on the mechanical properties of spark plasma sintered β-SiC

Author

Raffaele D’Elia, Julien Cambedouzou, Florimond Delobel, Sébastien Lemonnier, Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Toughness, Materials science, Process Chemistry and Technology, Sintering, Young's modulus, 02 engineering and technology, Plasma, 021001 nanoscience & nanotechnology, 01 natural sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, symbols.namesake, Indentation, 0103 physical sciences, Spark (mathematics), Materials Chemistry, Ceramics and Composites, symbols, Knoop hardness test, [CHIM]Chemical Sciences, Composite material, 0210 nano-technology, Porosity
Abstract

The influence of density on the hardness value of β-SiC samples was studied based on Knoop and Vickers indentation tests. Hardness measurements were performed on additive-free spark plasma sintered SiC samples in the [80%–95%] density range and on highly dense samples (>99%) sintered with very low content of sintering aids. Results revealed that the density has a strong influence on the hardness value, which increases of about 7 GPa between samples presenting densities of 80% and 95% and even reaches 21 GPa under 2 kg with Knoop indenter for the densest samples sintered with very low content of sintering aids. These results allowed us to give a comprehensive model-supported analysis of the mechanical properties of spark plasma sintered β-SiC with controlled porosity that currently does not exist in the literature. The calculation of Young modulus and toughness further resulted in encouraging properties for our samples with regards to mechanical and ballistic performances.

Published
2020

18. Current Trends in Pickering Emulsions: Particle Morphology and Applications

Author

Philippe Miele, Julien Cambedouzou, Celine Pochat-Bohatier, Danae Gonzalez Ortiz, Mikhael Bechelany, Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Environmental Engineering, Materials science, Morphology (linguistics), General Computer Science, Materials Science (miscellaneous), General Chemical Engineering, Energy Engineering and Power Technology, New materials, Nanoparticle, Nanotechnology, Pickering emulsions, Water filtration, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Protein recognition, Photocatalysis, Nanosheet, General Engineering, Two-dimensional nanoparticles, 021001 nanoscience & nanotechnology, Pickering emulsion, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, lcsh:TA1-2040, Particle, Particle morphology, lcsh:Engineering (General). Civil engineering (General), 0210 nano-technology
Abstract

International audience; In recent years, Pickering emulsions and their applications have attracted a great deal of attention due to their special features, which include easy preparation and enhanced stability. In contrast to classical emulsions, in Pickering emulsions, solid microparticles or nanoparticles that localize at the interface between liquids are used as stabilizers, instead of surfactants, to enhance the droplet lifetime. Furthermore, Pickering emulsions show higher stability, lower toxicity, and stimuli-responsiveness, compared with emulsions that are stabilized by surfactants. Therefore, they can be considered attractive components for various uses, such as photocatalysis and the preparation of new materials. Moreover, the nanoparticle morphology strongly influences Pickering emulsion stability as well as the potential utilization of such emulsions. Here, we review recent findings concerning Pickering emulsions, with a particular focus on how the nanoparticles morphology (i.e., cube, ellipsoid, nanosheet, sphere, cylinder, rod, peanut) influences the type and stability of such emulsions, and their current applications in different fields such as antibacterial activity, protein recognition, catalysis, photocatalysis, and water purification.

Published
2020

19. Insights on the Electrocatalytic Seawater Splitting at Heterogeneous Nickel-Cobalt Based Electrocatalysts Engineered from Oxidative Aniline Polymerization and Calcination

Author

David Cornu, Yaovi Holade, Perla Hajjar, Nathalie Masquelez, Julien Cambedouzou, Sophie Tingry, and Marie-Agnès Lacour

Subjects
Materials science, Pharmaceutical Science, chemistry.chemical_element, Organic chemistry, Electrocatalyst, Article, polyaniline, Analytical Chemistry, law.invention, QD241-441, law, Drug Discovery, electrocatalysis, Calcination, Physical and Theoretical Chemistry, Electrolysis, seawater splitting, Oxygen evolution, hydrogen evolution reaction, Nickel, chemistry, Polymerization, Chemical engineering, Chemistry (miscellaneous), oxygen evolution reaction, Molecular Medicine, Seawater, Cobalt
Abstract

Given the limited access to freshwater compared to seawater, a growing interest surrounds the direct seawater electrolysis to produce hydrogen. However, we currently lack efficient electrocatalysts to selectively perform the oxygen evolution reaction (OER) over the oxidation of the chloride ions that are the main components of seawater. In this contribution, we report an engineering strategy to synthesize heterogeneous electrocatalysts by the simultaneous formation of separate chalcogenides of nickel (NiSx, x = 0, 2/3, 8/9, and 4/3) and cobalt (CoSx, x = 0 and 8/9) onto a carbon-nitrogen-sulfur nanostructured network. Specifically, the oxidative aniline polymerization in the presence of metallic cations was combined with the calcination to regulate the separate formation of various self-supported phases in order to target the multifunctional applicability as both hydrogen evolution reaction (HER) and OER in a simulated alkaline seawater. The OER’s metric current densities of 10 and 100 mA cm−2 were achieved at the bimetallic for only 1.60 and 1.63 VRHE, respectively. This high-performance was maintained in the electrolysis with a starting voltage of 1.6 V and satisfactory stability at 100 mA over 17 h. Our findings validate a high selectivity for OER of ~100%, which outperforms the previously reported data of 87–95%.

Published
2021

21. Influence of sintering temperature and pressure on the 3C-6H transition of silicon carbide

Author

Sébastien Lemonnier, Florimond Delobel, Julien Cambedouzou, and Elodie Barraud

Subjects
010302 applied physics, Phase transition, Materials science, Sintering, Spark plasma sintering, 02 engineering and technology, Atmospheric temperature range, 021001 nanoscience & nanotechnology, 01 natural sciences, Crystallinity, chemistry.chemical_compound, Chemical engineering, chemistry, Phase (matter), visual_art, 0103 physical sciences, Materials Chemistry, Ceramics and Composites, Silicon carbide, visual_art.visual_art_medium, Ceramic, 0210 nano-technology
Abstract

The influence of Spark Plasma Sintering pressure and temperature on the evolution of the phase composition of two sources of β-SiC ceramic were studied based on X-ray diffraction and Raman scattering measurements. A commercial powder and a powder derived from a preceramic polymer precursor were chosen, and the investigation was undertaken in the [1850-2200 °C] temperature range and in the [17–127 MPa] pressure range. Analyses revealed that the 3C-6H phase transition depends on sintering pressure, which is shown to stabilize the cubic phase. The stability domains of the cubic phase as a function of sintering P and T were determined for both powdery precursors and revealed that the cubic phase stability is also linked to the nature of powdery precursor and in particular to its crystallinity state. The improvement of cubic phase stability at higher temperature by applying pressure allows sintering β-SiC ceramic with high density.

Published
2019

22. Iridium and Ruthenium Modified Polyaniline Polymer Leads to Nanostructured Electrocatalysts with High Performance Regarding Water Splitting

Author

Julien Cambedouzou, Sophie Tingry, Marie-Agnès Lacour, Abdelhafid Merzouki, David Cornu, Razik Djara, Yaovi Holade, Université Ferhat-Abbas Sétif 1 [Sétif] (UFAS1), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Institut Européen des membranes (IEM), and Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)

Subjects
Materials science, Polymers and Plastics, 02 engineering and technology, Overpotential, 010402 general chemistry, Electrocatalyst, 01 natural sciences, water splitting, Article, polyaniline, lcsh:QD241-441, chemistry.chemical_compound, lcsh:Organic chemistry, Polyaniline, [CHIM]Chemical Sciences, electrocatalysis, conducting polymer, Electrolysis of water, Oxygen evolution, General Chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, hydrogen evolution reaction, chemistry, Chemical engineering, oxygen evolution reaction, Linear sweep voltammetry, Water splitting, Cyclic voltammetry, 0210 nano-technology
Abstract

The breakthrough in water electrolysis technology for the sustainable production of H2, considered as a future fuel, is currently hampered by the development of tough electrocatalytic materials. We report a new strategy of fabricating conducting polymer-derived nanostructured materials to accelerate the electrocatalytic hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and water splitting. Extended physical (XRD, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX)) and electrochemical (cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS)) methods were merged to precisely characterize the as-synthesized iridium and ruthenium modified polyaniline (PANI) materials and interrogate their efficiency. The presence of Ir(+III) cations during polymerization leads to the formation of Ir metal nanoparticles, while Ru(+III) induces the formation of RuO2 oxide nanoparticles by thermal treatment, they are therefore methods for the on-demand production of oxide or metal nanostructured electrocatalysts. The findings from using 0.5 M H2SO4 highlight an ultrafast electrochemical kinetic of the material PANI-Ir for HER (36 &minus, 0 = 36 mV overpotential to reach 10 mA cm&minus, 2 at 21 mV dec&minus, 1), and of PANI-Ru for OER (1.47 &minus, 1.23 = 240 mV overpotential to reach 10 mA cm&minus, 2 at 47 mV dec&minus, 1), resulting in an efficient water splitting exactly at its thermoneutral cell voltage of 1.45 V, and satisfactory durability (96 h).

Published
2021

23. Fe-Modified Pd as an Effective Multifunctional Electrocatalyst for Catalytic Oxygen Reduction and Glycerol Oxidation Reactions in Alkaline Media

Author

David Cornu, Nazym Tuleushova, Julien Cambedouzou, Mikhael Bechelany, Andrea Cassani, Qing Wang, Valerie Bonniol, Sophie Tingry, Hazar Guesmi, Yaovi Holade, Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)

Subjects
Materials science, Inorganic chemistry, Energy Engineering and Power Technology, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrocatalyst, 7. Clean energy, 01 natural sciences, Redox, Oxygen reduction, 0104 chemical sciences, Catalysis, chemistry.chemical_compound, chemistry, Materials Chemistry, Electrochemistry, Glycerol, Chemical Engineering (miscellaneous), Electrical and Electronic Engineering, 0210 nano-technology, [CHIM.OTHE]Chemical Sciences/Other
Abstract

International audience; The development of high-performance catalytic nanomaterials is important to implement sustainable and electrochemical energy devices of alkaline fuel cells, metal–air batteries, and electrolyzers in the envisaged energy-transition scenarios. Synthesizing effective nanocatalysts as both anode materials for oxidation of glycerol (byproduct of the biodiesel industry) and cathode materials for the oxygen reduction reaction (ORR) is still a bottleneck. Herein, we report palladium-based nanomaterials whose physicochemical and electrochemical properties are tuned by the judicious choice of the support (rGO, Vulcan XC72R), the addition of a coelement (Fe), and the structure (alloy/core–shell). The bimetallic-based electrode shows a drastically enhanced electrocatalytic performance with a beneficial shifting of the onset potential, production of high currents, and good durability for both the ORR (kinetic current density jk = 2 mA cmPd–2 or 1 A mgPd–1) and glycerol oxidation (jp = 2.3 mA cmPd–2 or 1.11 A mgPd–1 at the peak), higher than those of commercial catalysts and existing literature values. The present results also provide new fundamental insights about the accurate measurement of the kinetic metrics of the ORR by employing a rotating-disk (-ring) electrode setup in alkaline electrolytes with metallic catalysts. Indeed, the anodic scanning of the electrode from a low potential to a higher one results in an ultrafast electrochemical kinetics with a positive shift of the half-wave potential of ΔE1/2,anodic/cathodic = 60 mV from the cathodic direction to the anodic one. The kinetic current density dramatically increases, jk,anodic = 19.0×, 6.9×, 3.4×, and 2.4× jk,cathodic at 950, 900, 870, and 850 mVRHE, respectively. The advantage of the synthesis methodology relies on the nonuse of organic molecules as capping agents and surfactants in order to produce bare (ligand-free) bimetallic PdFe electrocatalysts with a clean catalytic surface in a facile and straightforward way.

Published
2021

24. Glioma stem cells invasive phenotype at optimal stiffness is driven by MGAT5 dependent mechanosensing

Author

Ali Saleh, Luc Bauchet, Norbert Bakalara, Marta Martin-Fernandez, David Cornu, Thomas Iskratsch, Hugues Duffau, Christine Fabre, Emilie Marhuenda, Julien Cambedouzou, Jean-Philippe Hugnot, James W. Dennis, and Cunjie Zhang

Subjects
animal structures, Glycosylation, biology, Integrin, Cell migration, Transmembrane protein, Cell biology, Focal adhesion, chemistry.chemical_compound, chemistry, biology.protein, Epithelial–mesenchymal transition, Stem cell, Mechanotransduction
Abstract

Glioblastomas stem-like cells (GSCs) by invading the brain parenchyma escape resection and radiotherapy. GSC invasion is associated with altered N-glycosylation pattern of integrins and other transmembrane proteins resulting in changed mechanosensing but details are elusive. Because the tumour microenvironment has an increased stiffness we studied the interaction between matrix stiffness, N-glycosylation and GSC migration. To mimic the fibrillar microenvironments, we designed 3D-ex-polyacrylonitrile nanofibers scaffolds (NFS) with adjustable stiffnesses by loading multiwall carbon nanotubes (MWCNT). We found that migration of GSCs was maximum at 166 kPa. Migration rate was correlated with cell shape, expression of focal adhesion (FA), Epithelial to Mesenchymal Transition (EMT) proteins and (β1,6) branched N-glycan binding, galectin-3. Mutation of MGAT5 in GSC inhibited N-glycans (β1–6) branching, suppressed the stiffness dependence of FA and EMT protein expression as well as migration on 166kPa NFS; underpinning the role of multibranched N-glycans as a critical regulator of mechanotransduction by GSC.Significance StatementDuring pathological processes in which cell migration is involved, cells undergo important functional changes in protein glycosylation and are responsive to environmental mechanical modifications. We addressed the question of the glycosylation role in mechanotransduction regulation of glioma stem cells. We created a bio-inspired 3D nanofiber scaffold (NFS) loaded with multiwall carbon nanotubes to obtain NFS of adjustable stiffness in physiological and pathological ranges. We highlighted and described a mechanism of fine mechanotransduction leading to a nonlinear migration response regarding to 3D microenvironment stiffness values. We show the importance to develop mechano-pharmacology as new therapeutic target by demonstrating the relationship existing between environmental stiffness and multibranched N-glycans catalysed by the MGAT5 enzyme to optimize directed migration.

Published
2020

25. Bromide-Regulated Anisotropic Growth of Desert-Rose-Like Nanostructured Gold onto Carbon Fiber Electrodes as Freestanding Electrocatalysts

Author

David Cornu, Julien Cambedouzou, Yaovi Holade, Shelley D. Minteer, Sophie Tingry, Paul Morandi, Nazym Tuleushova, Institut Européen des membranes (IEM), and Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)

Subjects
Materials science, Energy Engineering and Power Technology, Nanoparticle, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, 7. Clean energy, law.invention, Catalysis, chemistry.chemical_compound, law, Bromide, glycerol oxidation, Materials Chemistry, Electrochemistry, Chemical Engineering (miscellaneous), Electrical and Electronic Engineering, gas-diffusion electrodes, Electrolysis, anisotropic growth, Oxygen evolution, [CHIM.MATE]Chemical Sciences/Material chemistry, gold, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Anode, Chemical engineering, chemistry, Alcohol oxidation, Electrode, 0210 nano-technology, catalyst
Abstract

Three-dimensional (3D) gas-diffusion electrodes (GDEs) as support for catalytic nanoparticles are important to the electrolysis and fuel cell fields to facilitate reactant transport and distribution and reach higher current densities. Hence, the assembly of nanostructured catalytic particles directly onto GDEs during the synthesis could be a powerful one-step strategy to target high performance and long-term durability thanks to the induced strong nanoparticle–support interaction. We report herein the use of bromide anions to shape the anisotropic growth of nanostructured desert-rose-like gold particles directly onto the GDE, as a freestanding GDE–Au catalyst for straightforward use in electrolysis without an additional step. We showed that the bromide ions determine the anisotropy of the particles, resulting in the growth of gold into nanoplates enclosed by (111) facets. The formation of hierarchical nanostructured three-dimensional (3D) Au at the GDE surface was explained by the nanoparticle-mediated aggregation mechanism and the preferential adsorption of Br– on the (111) facet, leaving behind dominant planar structured nuclei, which then self-assemble. Electrocatalytic tests toward the glycerol electro-oxidation demonstrated that the as-synthesized freestanding surfactant- and binder-free GDE–Au material (100 μgAu cm–2) delivered a high specific peak current density of jp = 33 mA cmAu–2, which is three and seven times higher than the tested commercial Au/C nanocatalyst at loadings of 76 and 152 μgAu cm–2, respectively. This study provides future directions for the synthesis and application of nanostructured catalysts for alcohol oxidation as an alternative to anodic oxygen evolution, which consumes the majority of the electricity input during the electrolysis.

Published
2020

26. Self‐Supported Electrocatalysts Derived from Nickel‐Cobalt Modified Polyaniline Polymer for H2‐Evolution and O2‐Evolution Reactions

Author

Sophie Tingry, Nathalie Masquelez, Julien Cambedouzou, David Cornu, Razik Djara, Yaovi Holade, Marie-Agnès Lacour, Abdelhafid Merzouki, Institut Européen des membranes (IEM), and Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)

Subjects
Materials science, chemistry.chemical_element, 010402 general chemistry, Electrocatalyst, 7. Clean energy, 01 natural sciences, water splitting, Catalysis, polyaniline, law.invention, Inorganic Chemistry, Ammonia production, chemistry.chemical_compound, nickel, law, Polyaniline, electrocatalysis, [CHIM]Chemical Sciences, Calcination, Physical and Theoretical Chemistry, noble metal-free, 010405 organic chemistry, Organic Chemistry, Oxygen evolution, nitrogen doping, 0104 chemical sciences, hydrogen evolution reaction, chemistry, Chemical engineering, oxygen evolution reaction, Water splitting, Cobalt
Abstract

International audience; The water splitting aims to produce H2 for fuel cells and a number of industrial processes such as the ammonia synthesis and the metals refining. There is actually a major limitation about the development of cost-effective and efficient electrocatalysts to lower the cell voltage that must be overcome to perform sequentially the overall reaction that is 2H2O → 2H2 + O2. In the present study, we combined Ni and Co as the promising alternative catalytic metals to Pt-group metals as well as N and S as the doping elements to fabricate self-supported electrocatalysts for hydrogen evolution (HER) and oxygen evolution (OER) in alkaline media. To these ends, the polymerization of the aniline into polyaniline (PANI) in the presence of Ni(II) and Co(II) followed by calcination in air resulted in the formation of heterogeneous catalytic materials self-supported onto a matrix made of C, N, S, Ni and Co. Enhanced activity and durability were recorded for the hybrid and bimetallic PANI-NiCo composite.

Published
2020

27. Enhanced electrocatalytic activity and selectivity of glycerol oxidation triggered by nanoalloyed silver–gold nanocages directly grown on gas diffusion electrodes

Author

David Cornu, Rihab Boukil, Didier Cot, Sophie Tingry, Julien Cambedouzou, Yaovi Holade, Bertrand Rebiere, Nazym Tuleushova, Valerie Bonniol, Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Laboratoire de Physique des Solides (LPS), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Materials science, Gas diffusion electrode, Renewable Energy, Sustainability and the Environment, Electrochemical kinetics, Oxygen evolution, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrosynthesis, Electrocatalyst, 01 natural sciences, 7. Clean energy, Nanomaterial-based catalyst, 0104 chemical sciences, Catalysis, Nanocages, Chemical engineering, [CHIM]Chemical Sciences, General Materials Science, 0210 nano-technology
Abstract

There is currently great interest for the development of electrochemical reactors to be implemented for the emerging world-class reactions of hydrogen evolution (HER), CO2 reduction (CO2RR) and N2 reduction (N2RR) in order to electro-synthesize high value-added chemicals. However, precisely how this could be achieved in a cheap and sustainable way remains a puzzle for scientists since the electrochemical kinetics of the oxygen evolution reaction (OER) is the major limitation. Increasing interest surrounds the development of low energy consumption electrolyzers capable of oxidizing selectively biomass-based organics instead of water for a dual production of chemicals (paired electrosynthesis). Also, the state-of-the-art electrocatalyst is in the form of nanoparticles either dispersed on carbon supports or in liquids in the presence of stabilizers to prevent the nanoparticles' aggregation, detachment and performance loss. In this report, free-standing surfactant- and binder-free silver–gold nanoporous and nanoalloyed catalysts are successfully synthesized via a simple and effective approach directly on a gas diffusion electrode (GDE@AgAu). Physicochemical and electrocatalytic analyses show that the obtained activity and selectivity of metallic nanocatalysts towards the glycerol electrooxidation reaction in alkaline media depend on their morphology and composition. Specifically, an onset potential of Eonset = 0.3 V vs. RHE and a record peak current density of jpeak = 18 A mgAu−1 (290 mA cm−2) at GDE@AgAu in comparison with those of the tested commercial Au/C catalyst (Eonset = 0.7 V vs. RHE and jpeak = 2.8 A mgAu−1 or 44 mA cm−2) were obtained. Also, an unprecedented selectivity in glycerol electrooxidation towards two products of high interest, formate (66%) and glycolate (32%), has been obtained. GDE@AgAu is thus a potential substitute as an anode material for commercial Au and Pt-based catalysts for efficient alcohol electroreforming with low energy consumption and cogeneration of H2, CO2 or N2 electrolyzers. The present method that combines direct growth, galvanic replacement and nanostructuration provides a smart route for creating new designs for catalyst nanofabrication in order to target high electrocatalytic performance.

Published
2020

28. Targeted removal of aluminium and copper in Li-ion battery waste solutions by selective precipitation as valuable porous materials

Author

Michaël Carboni, Marine Cognet, Daniel Meyer, Julien Cambedouzou, Srinivasan Madhavi, School of Materials Science and Engineering, Energy Research Institute @ NTU (ERI@N), Systèmes HYbrides pour la Séparation (LHyS), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Nanayang Technological University (NTU), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Nanayang Technological University

Subjects
Battery (electricity), Chemistry::Organic chemistry [Science], Materials science, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Bipyridine, chemistry.chemical_compound, Aluminium, General Materials Science, Recycling, Porosity, Dissolution, ComputingMilieux_MISCELLANEOUS, Precipitation (chemistry), Mechanical Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Copper, 0104 chemical sciences, chemistry, Chemical engineering, Mechanics of Materials, Lithium-Ion Battery, Chemical stability, Materials::Energy materials [Engineering], 0210 nano-technology
Abstract

End-of life Li-ion batteries can be a source of valuable materials to rebuild new batteries or for other applications. In this way, we propose to precipitate metals from a dissolution solution of Li-ions batteries (LiBs) as hybrid organic–inorganic materials (metal–organic frameworks, MOFs), well known in many fields due to their specific properties (high porosity, large surface area and sometimes thermal and chemical stability). From raw LiBs containing Al, Cu, Mn, Ni, or Co mainly, a selective precipitation of different metals as MOFs has been possible. The use of a carboxylate ligand allowed complete precipitation of Al from the solution, whereas using a bipyridine ligand changes the selectivity to precipitate Cu as MOFs. This work shows that formation of different MOFs in a multi-metallic solution can be obtained depending on the precipitating agent. Ministry of National Development (MND) National Environmental Agency (NEA) Submitted/Accepted version Authors are grateful to Joseph Lautru and Xavier Le Goff for their help to characterize materials and to grant award from NEA (National Environmental agency, Singapore) and Ministry of National development (MND, Singapore) titled “Singapore –CEA Alliance for Research in Circular Economy (SCARCE, award number USS-IF-2018-4)”, which is a joint lab set up between Nanyang Technological University (NTU, Singapore) and the French Alternative Energies and Atomic Energy Commission (CEA, France).”

Published
2020

29. An original recycling method for Li-ion batteries through large scale production of Metal Organic Frameworks

Author

Julien Cambedouzou, Michaël Carboni, Marine Cognet, Julie Condomines, Srinivasan Madhavi, Daniel Meyer, Systèmes HYbrides pour la Séparation (LHyS), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Nanayang Technological University (NTU), Nanayang Technological University, School of Materials Science and Engineering, Energy Research Institute @ NTU (ERI@N), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Chemistry::Organic chemistry [Science], Thermogravimetric analysis, Environmental Engineering, Materials science, Health, Toxicology and Mutagenesis, 0211 other engineering and technologies, chemistry.chemical_element, 02 engineering and technology, 010501 environmental sciences, 7. Clean energy, 01 natural sciences, Lithium-ion battery, Adsorption, Environmental Chemistry, [CHIM]Chemical Sciences, Recycling, Waste Management and Disposal, Dissolution, 0105 earth and related environmental sciences, 021110 strategic, defence & security studies, Precipitation (chemistry), [CHIM.MATE]Chemical Sciences/Material chemistry, Pollution, Nickel, chemistry, Chemical engineering, [SDE]Environmental Sciences, Metal-organic framework, Materials::Energy materials [Engineering], Cobalt, Lithium-ion Battery
Abstract

A concept is proposed for the recycling of Li-ion batteries with an open-loop method that allows to reduce the volume of wastes and simultaneously to produce valuable materials in large amounts (Metal-Organic Frameworks, MOFs). After dissolution of Nickel, Manganese, Cobalt (NMC) batteries in acidic solution (HCl, HNO3 or H2SO4/H2O2), addition of organic moieties and a heat treatment, different MOFs are obtained. Solutions after precipitation are analyzed by inductively coupled plasma and materials are characterized by powder X-Ray diffraction, N2 adsorption, thermogravimetric analysis and Scanning electron microscope. With the use of Benzene-Tri-Carboxylic Acid as ligand, it has been possible to form selectively a MOF, based on Al metallic nodes, called MIL-96 in the literature, and known for its interesting properties in gas storage applications. The supernatant is then used again to precipitate other metals as MOFs after addition of a second batch of ligands. These two other MOFs are based on Cu (known as HKUST-1 in the literature) or Ni-Mn (with a new crystalline structure) depending of conditions. This method shows promising results at the lab scale (15 g of wastes can be converted in 10 g of MOFs), and opens interesting perspectives for the scaled-up production of MOFs. Ministry of National Development (MND) National Environmental Agency (NEA) Submitted/Accepted version This research was funded by NEA (National Environmental agency, Singapore) and Ministry of National development (MND, Singapore) titled “Singapore –CEA Alliance for Research in Circular Economy (SCARCE, award number USS-IF-2018-4)”, which is a joint lab set up between Nanyang Technological University (NTU, Singapore) and the French Alternative Energies and Atomic Energy Commission (CEA, France).

Published
2020

30. Influence of composition of nuclear waste glasses on vapor phase hydration

Author

Julien Cambedouzou, Sathya Narayanasamy, Martiane Cabié, Corentin Le Guillou, Nicole Godon, Frédéric Angeli, Stéphane Gin, Abdesselam Abdelouas, Patrick Jollivet, Laboratoire d'Etudes du Comportement à Long Terme des matériaux de conditionnement (LCLT), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Spectropôle - Aix Marseille Université (AMU SPEC), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut Européen des membranes (IEM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Unité Matériaux et Transformations - UMR 8207 (UMET), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Lille, CNRS, INRA, ENSCL, Laboratoire d'Etudes du Comportement à Long Terme des matériaux de conditionnement [LCLT], Institut Européen des membranes [IEM], Unité Matériaux et Transformations - UMR 8207 [UMET], Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Institut de Chimie du CNRS (INC)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut National de la Recherche Agronomique (INRA)

Subjects
Nuclear and High Energy Physics, Materials science, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 02 engineering and technology, 01 natural sciences, 010305 fluids & plasmas, 0103 physical sciences, General Materials Science, Fourier transform infrared spectroscopy, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Borosilicate glass, Small-angle X-ray scattering, Precipitation (chemistry), Radioactive waste, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Nuclear Energy and Engineering, Chemical engineering, 13. Climate action, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Composition (visual arts), 0210 nano-technology, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Layer (electronics), Water vapor
Abstract

International audience; For the first time, the influence of glass composition on the vapor hydration kinetics of the French AVM nuclear waste glass simulants was investigated. Three complex borosilicate glasses (>20 oxides) along with three simplified Na/(Ca, Na)/(Mg, Na)-alumino-borosilicate glasses with four or five oxides were altered at 50 °C in water vapor (95% RH) for up to 557 days. The solid characterization of the altered samples (by SEM, TEM, XRD, ToF-SIMS, SAXS) revealed that the rate-controlling vapor hydration mechanism is composition dependent. The vapor hydration rate of the more durable glasses, whose molar ratio of Al2O3/(CaO or MgO) is ≥ 1, seems to be limited by network-hydrolysis, whereas the overall glass alteration rate of the less durable glasses, whose Al2O3/MgO ratio is

Published
2019

31. Ion extraction applications of bilayer-structured hybrid silicas

Author

Romain Besnard, Robert Winkler, Stéphane Pellet-Rostaing, Guilhem Arrachart, Julien Cambedouzou, Tri ionique par les Systèmes Moléculaires auto-assemblés (LTSM), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Nanomatériaux pour l'Energie et le Recyclage (LNER), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Thermogravimetric analysis, Materials science, Small-angle X-ray scattering, Bilayer, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Adsorption, Chemical engineering, Amphiphile, Materials Chemistry, [CHIM]Chemical Sciences, General Materials Science, Lamellar structure, Fourier transform infrared spectroscopy, 0210 nano-technology, Hybrid material, ComputingMilieux_MISCELLANEOUS
Abstract

The self-assembly behaviour of amino-undecyl-triethoxysilane, which can be considered as an amphiphilic organosilane, has been used for the preparation of nanostructured materials. Due to the possibilities offered by this approach, lamellar hybrid materials bearing amine groups can be achieved. In this study, the reactive amino groups at the surface of the hybrid silica were modified for introducing ligands. For this purpose, various glycolamic acid groups have been introduced at the interface between two bilayers on the hybrid material obtained after condensation of silylated amines. The availability of the amino groups and the efficiency of the chemical immobilization of amic acid ligands onto the materials were followed by FTIR, NMR and TGA analysis, and the structural modifications induced by grafting were evaluated by SAXS experiments. The resulting materials exhibit a large number of amic acid groups. The adsorption capacities for rare earth elements were also investigated.

Published
2018

32. Development of novel h-BNNS/PVA porous membranes via Pickering emulsion templating

Author

Julien Cambedouzou, Celine Pochat-Bohatier, Danae Gonzalez-Ortiz, Mikhael Bechelany, Sana Gassara, Philippe Miele, Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, CROSS-LINKING, Biocompatibility, Microfiltration, INTERNAL PHASE EMULSIONS, Context (language use), 02 engineering and technology, 010402 general chemistry, CARBON NANOTUBES, 01 natural sciences, 7. Clean energy, Polyvinyl alcohol, ULTRAFILTRATION MEMBRANES, chemistry.chemical_compound, WATER, [CHIM]Chemical Sciences, Environmental Chemistry, chemistry.chemical_classification, HEXAGONAL BORON-NITRIDE, Polymer, 021001 nanoscience & nanotechnology, Pollution, Pickering emulsion, ANTIFOULING PROPERTIES, 0104 chemical sciences, POLYAMIDE COMPOSITE MEMBRANES, POLY VINYL ALCOHOL, Membrane, chemistry, Chemical engineering, 13. Climate action, Emulsion, GRAPHENE OXIDE, 0210 nano-technology
Abstract

International audience; Polymer-based membranes play an important role in water filtration, in particular in the removal of particles, microorganisms and organic pollutants. Developing a reliable fabrication method for membranes presenting both high flux and good selectivity remains challenging. Polyvinyl alcohol (PVA) is a well-known polymer with promising perspectives due to its specific properties such as nontoxicity, biocompatibility and biodegradability which is of great interest within the context of developing green technologies. Herein, a new strategy using mainly water as a solvent to produce porous membranes based on PVA has been developed using emulsion templating involving hexagonal boron nitride nanosheets (h-BNNS) as a stabilizer. The membranes displaying a pore size around 1 m show a water permeability over 2000 L m(-2) h(-1) bar(-1) and a rejection efficiency of approximate to 100%. Moreover, the membranes did not show a significant reduction of their performances after particle filtration. The results indicated that the h-BNNS/PVA porous membranes fabricated via Pickering emulsion templating are good candidates to be used as microfiltration membranes.

Published
2018

33. Inverse Pickering Emulsion Stabilized by Exfoliated Hexagonal-Boron Nitride (h-BN)

Author

Celine Pochat-Bohatier, Philippe Miele, Julien Cambedouzou, Mikhael Bechelany, Danae Gonzalez Ortiz, Sebastien Balme, Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Etude de la Matière en Mode Environnemental (L2ME), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), ANR-10-LABX-0005,CheMISyst,CHEmistry of Molecular and Interfacial Systems(2010), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, inverse emulsions, Inverse, Hexagonal boron nitride, Pickering emulsions, 02 engineering and technology, Surfaces and Interfaces, 2D materials, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Pickering emulsion, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Chemical engineering, Rheology, Emulsion, Polymer chemistry, Electrochemistry, General Materials Science, hexagonal boron nitride, 0210 nano-technology, Droplet size, Spectroscopy
Abstract

International audience; The formation of inverse Pickering emulsions using exfoliated hexagonal boron nitride (h-BN) as an effective particulate stabilizer without using any surfactants is reported for the first time. The stability and the type of h-BN Pickering emulsions formulated with different BN concentrations and by varying oil/water (o/w) ratios are studied and discussed. First the emulsion structure is analyzed microscopically through optical and epifluorescence microscopy and macroscopically by the study of the rheological behavior. The average droplet size decreases with h-BN concentration whereas the emulsions achieve good stability at 2 wt % BN concentrations and for a 1:1 o/w ratio. In all formulations, the emulsions are of water-in-oil (w/o) type due mainly to the hydrophobicity of h-BN.

Published
2017

34. Evolution of Silica Walls of Nanopores Filled with Water and Ions

Author

Julien Cambedouzou, Stephanie Szenknect, Markus Baum, M. Brossel, Diane Rébiscoul, Nanomatériaux pour l'Energie et le Recyclage (LNER), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Physikalisches Institut [Köln], Universität zu Köln, Interfaces de Matériaux en Evolution (LIME), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Universität zu Köln = University of Cologne

Subjects
nanoporous silica, confined media, Earth and Planetary Sciences(all), dissolution, Mineralogy, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Ion, Dissolution, Aqueous solution, Nanoporous, Small-angle X-ray scattering, water diffusion, SAXS, [CHIM.MATE]Chemical Sciences/Material chemistry, General Medicine, Microporous material, Mesoporous silica, 021001 nanoscience & nanotechnology, 6. Clean water, 0104 chemical sciences, Nanopore, Chemical engineering, Environmental science, aqueous solution, 0210 nano-technology
Abstract

International audience; The prediction of the evolution of nanoporous materials is of great interest in various fields particularly geology, environmental sciences, and nuclear waste management. Such prediction requires the use of modeling which is generally not adapted to confined media of few nanometers. In the present study, we have characterized the evolution of hexagonal mesoporous silica having 5 nm pore size (SBA15 type) at 50°C in water and in 0.2 M XCl 2 aqueous solutions, where X are different ions (X = Mg 2+ , Ca 2+ , Fe 2+ , Ba 2+), by in-situ Small Angle X-ray Scattering. The results allowed determination of the dissolution rates of the confining media, i.e. the silica, and water diffusion through the microporous silica wall as a function of the aqueous solution composition.

Published
2017

35. Soft templated mesoporous SiC from polycarbosilane grafted onto triblock copolymers

Author

Julien Cambedouzou, B. Gouze, Thibaud Nardin, Olivier Diat, Etude de la Matière en Mode Environnemental (L2ME), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Ions aux Interfaces Actives (L2IA), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
chemistry.chemical_classification, Materials science, Mechanical Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Polymer, Liquid medium, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Mechanics of Materials, Specific surface area, Silicon carbide, Copolymer, General Materials Science, Polystyrene, Composite material, 0210 nano-technology, Porosity, Mesoporous material, ComputingMilieux_MISCELLANEOUS
Abstract

Mesoporous silicon carbide (SiC) presenting very large specific surface area was elaborated following an original soft-templating approach based on polymeric precursors. The polystyrene units of a poly(styrene-block-butadiene-block-styrene) triblock copolymer are used as a templating agent, while a polycarbosilane preceramic polymer is employed as SiC precursor. Thanks to the self-organization of polycarbosilane around PS blocks in liquid medium, and to the subsequent elimination of the copolymer during the polycarbosilane conversion into SiC, a mesoporous SiC can be formed. High specific surface areas of more than 400 m 2 g −1 are measured on the final SiC, opening the doors to the viable production of SiC of controlled porosity.

Published
2016

36. Pickering emulsions stabilized with two-dimensional (2D) materials: A comparative study

Author

Danae Gonzalez Ortiz, Celine Pochat-Bohatier, Philippe Miele, Mikhael Bechelany, Julien Cambedouzou, Institut Européen des membranes (IEM), and Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)

Subjects
Materials science, Graphene, Oxide, Hexagonal boron nitride, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Microstructure, 01 natural sciences, Pickering emulsion, 0104 chemical sciences, law.invention, chemistry.chemical_compound, Colloid and Surface Chemistry, chemistry, Chemical engineering, Rheology, law, Emulsion, [CHIM]Chemical Sciences, 0210 nano-technology, Droplet size, ComputingMilieux_MISCELLANEOUS
Abstract

In this paper, we study the preparation of Pickering emulsions using two-dimensional (2D) materials: graphene oxide (GO) and hexagonal boron nitride nanosheets (h-BNNS). The type of the obtained emulsions, the droplet size and the rheological behavior were investigated for both GO and h-BNNS based emulsions. The results show that two types of emulsion, direct oil-in-water (O/W) and indirect water-in-oil (W/O) may be produced due to the different hydrophilic properties of the 2D materials. Besides, similar microstructures and droplet sizes are obtained, as well as analogue rheological behaviors. Thus, depending on the potential application, it is possible to tune the emulsion type, W/O or O/W, by choosing the 2D material possessing the most interesting properties for the sought application.

Published
2019

37. On the Operational Aspects of Measuring Nanoparticle Sizes

Author

Jean-Luc Pellequer, Christian Godon, Aurélie Habert, Louis Chantalat, Shu-wen W. Chen, Julien Cambedouzou, Johann Ravaux, Adèle Gerdil, Renaud Podor, Michael Odorico, Jean-Marie Teulon, Nathalie Herlin-Boime, Christine Moriscot, Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-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)-Centre National de la Recherche Scientifique (CNRS), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Signalisation de l'Adaptation des Végétaux à l'Environnement (SAVE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Nanomatériaux pour l'Energie et le Recyclage (LNER), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Etude de la Matière en Mode Environnemental (L2ME), Laboratoire Edifices Nanométriques (LEDNA), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Vinay, Laboratoire des Intéractions et Reconnaissances Moléculaires (LIRM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Project: AFM4NanoMed&Bio, Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-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), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Plant Environmental Physiology and Stress Signaling (PEPSS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Scanning electron microscope, General Chemical Engineering, DLS, Nanoparticle, Nanotechnology, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, Article, lcsh:Chemistry, chemistry.chemical_compound, Dynamic light scattering, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Scanning transmission electron microscopy, General Materials Science, wet-STEM, 0105 earth and related environmental sciences, Small-angle X-ray scattering, Scattering, SAXS, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, metrology, lcsh:QD1-999, chemistry, Transmission electron microscopy, [SDV.TOX]Life Sciences [q-bio]/Toxicology, SEM, TEM, nanoparticles, Polystyrene, nanotoxicology, AFM, 0210 nano-technology
Abstract

International audience; Nanoparticles are defined as elementary particles with a size between 1 and 100 nm for at least 50% (in number). They can be made from natural materials, or manufactured. Due to their small sizes, novel toxicological issues are raised and thus determining the accurate size of these nanoparticles is a major challenge. In this study, we performed an intercomparison experiment with the goal to measure sizes of several nanoparticles, in a first step, calibrated beads and monodispersed SiO$_2$ Ludox®, and, in a second step, nanoparticles (NPs) of toxicological interest, such as Silver NM-300 K and PVP-coated Ag NPs, Titanium dioxide A12, P25(Degussa), and E171(A), using commonly available laboratory techniques such as transmission electron microscopy, scanning electron microscopy, small-angle X-ray scattering, dynamic light scattering, wet scanning transmission electron microscopy (and its dry state, STEM) and atomic force microscopy. With monomodal distributed NPs (polystyrene beads and SiO$_2$ Ludox®), all tested techniques provide a global size value amplitude within 25% from each other, whereas on multimodal distributed NPs (Ag and TiO$_2$) the inter-technique variation in size values reaches 300%. Our results highlight several pitfalls of NP size measurements such as operational aspects, which are unexpected consequences in the choice of experimental protocols. It reinforces the idea that averaging the NP size from different biophysical techniques (and experimental protocols) is more robust than focusing on repetitions of a single technique. Besides, when characterizing a heterogeneous NP in size, a size distribution is more informative than a simple average value. This work emphasizes the need for nanotoxicologists (and regulatory agencies) to test a large panel of different techniques before making a choice for the most appropriate technique(s)/protocol(s) to characterize a peculiar NP.

Published
2019

38. Highly crystalline silicon carbide of controlled mesoporosity

Author

Julien Cambedouzou, Olivier Diat, B. Gouze, Thibaud Nardin, K.B. Cervantes-Diaz, Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Amorphous solid, Carbide, Crystallinity, chemistry.chemical_compound, Chemical engineering, chemistry, Specific surface area, Silicon carbide, [CHIM]Chemical Sciences, General Materials Science, Crystalline silicon, 0210 nano-technology, Mesoporous material, Porosity
Abstract

The control of porosity in silicon carbide (SiC) at the mesoporous scale is a major concern for a range of separation applications. It was recently reported that mesoporous amorphous SiC could be synthesized by templating polycarbosilane precursors around polymeric templates, and after pyrolysis at 1000 °C under inert atmosphere. In this publication, we report the synthesis of highly crystalline mesoporous β-SiC based on the same approach, but involving much higher temperature pyrolyses (up to 1900 °C). The structure evolution with regards to the pyrolysis temperature is carefully studied by means of various analytical tools. Finally, the influence of different synthesis parameters on the control of the mesoporous structure is also discussed. It is shown for the first time that pure mesoporous β-SiC with 10 nm pore diameter and a specific surface area larger than 50 m2/g can be obtained with a very high degree of crystallinity.

Published
2020

39. Exfoliation of Hexagonal Boron Nitride (h-BN) in Liquide Phase by Ion Intercalation

Author

Julien Cambedouzou, Mikhael Bechelany, Celine Pochat-Bohatier, Philippe Miele, Danae Gonzalez Ortiz, Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, General Chemical Engineering, Sonication, Intercalation (chemistry), chemistry.chemical_element, 02 engineering and technology, Zinc, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 7. Clean energy, 01 natural sciences, Article, lcsh:Chemistry, gelatin, symbols.namesake, boron nitride nanosheets, Phase (matter), General Materials Science, liquid exfoliation, Aqueous solution, ion intercalation, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Exfoliation joint, 0104 chemical sciences, chemistry, Chemical engineering, lcsh:QD1-999, symbols, 0210 nano-technology, Raman spectroscopy, Dispersion (chemistry)
Abstract

A green approach to prepare exfoliated hexagonal boron nitride nanosheets (h-BNNS) from commercially pristine h-BN involving a two-step procedure was investigated. The first step involves the dispersion of pristine h-BN within an aqueous solution containing gelatin and potassium or zinc chloride using a sonication method. The second involves the removal of larger exfoliated h-BNNS through a centrifugation procedure. The exfoliation was caused not only by the sonication effect but also by intercalation of K+ and Zn2+ ions. Transmission electronic microscopy, X-ray diffraction and Raman spectroscopy techniques show that the obtained h-BNNS generally display a thickness of about a few (2&ndash, 3) layers with an exfoliation efficiency as high as 16.3 &plusmn, 0.4%.

Published
2018
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40. Tuning the morphology of functionalized silica using amphiphilic organosilanes

Author

Romain Besnard, Julien Cambedouzou, Guilhem Arrachart, Stéphane Pellet-Rostaing, Tri ionique par les Systèmes Moléculaires auto-assemblés (LTSM), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Etude de la Matière en Mode Environnemental (L2ME), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Dispersity, Nanoparticle, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Biomaterials, chemistry.chemical_compound, Amphiphile, Homogeneity (physics), nanostructures, Materials Chemistry, Organic chemistry, sol-gel, Ammonium, Tetrahydrofuran, chemistry.chemical_classification, morphologies, General Chemistry, Organosilane, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, chemistry, Chemical engineering, Solubilization, Ceramics and Composites, Counterion, 0210 nano-technology
Abstract

International audience; The co-condensation of tetraethoxysilane and an amphiphilic organosilane precursor containing an ammonium part is investigated in presence of different counter-ions. We highlight the morphological versatility offered by such “one pot” synthesis, resulting of the combinatory effects of the addition of tetraethoxysilane and of the nature of the counter-ion involved in the sol-gel process. Indeed, the interactions at the interface governed by the ammonium species affect the shape of the aggregates, making of the counter-ion a critical morphological parameter. The morphology of the particles is also closely linked to the homogeneity of the system. Thereby, using the immiscibility of the tetraethoxysilane/water mixture, we showed that it is possible to get macroporous, blackberry-like or cerasome materials. Oppositely, the use of tetrahydrofuran able to solubilize all the systems leads to monodisperse nanoparticles whose size can be modulated as a function of the involved counter ion.

Published
2017

41. Copper hexacyanoferrate functionalized singlewalled carbon nanotubes for selective cesium extraction

Author

Julien Cambedouzou, Mohamed Ali Zaïbi, Meherzi Oueslati, Jérémy Causse, Jean-Louis Bantignies, H. Draouil, Laurent Alvarez, Valérie Flaud, Unité de nanomatériaux et photonique [Tunis], Faculté des Sciences Mathématiques, Physiques et Naturelles de Tunis (FST), Université de Tunis El Manar (UTM)-Université de Tunis El Manar (UTM), Université de Tunis, Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Nanomatériaux pour l'Energie et le Recyclage (LNER), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Etude de la Matière en Mode Environnemental (L2ME), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Thermogravimetric analysis, Chemistry, Inorganic chemistry, chemistry.chemical_element, Nanoparticle, Sorption, 02 engineering and technology, General Chemistry, Carbon nanotube, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Copper, Catalysis, 0104 chemical sciences, law.invention, [CHIM.GENI]Chemical Sciences/Chemical engineering, X-ray photoelectron spectroscopy, law, Caesium, Desorption, Materials Chemistry, 0210 nano-technology
Abstract

Single-walled carbon nanotubes (SWCNTs) are functionalized with copper hexacyanoferrate (CuHCF) nanoparticles and therefore constitutes promising solid substrates for the sorption of Cs+ ions from liquid effluents. The high mechanical resistance and large electrical conductivity of SWCNTs are associated to the ability of CuHCF nanoparticles to selectively complex Cs+ ions in order to achieve membrane-like buckypapers presenting high loading capacity of cesium. The materials are thoroughly characterized using electron microscopy, Raman scattering, X-ray photoelectron spectroscopy and thermogravimetric analyses. Cs sorption isotherms are plotted after liquid phase ionic chromatography of the Cs solutions before and after exposure to the materials. It is found that the total sorption capacity of the material reaches 230 mg.g-1, and that one third of the sorbed Cs (80 mg.g-1) is selectively complexed in the CuHCF nanoparticles grafted on SWCNTs. These high values open interesting perspectives in the integration of such materials in electrically driven devices for the controlled sorption and desorption of these ions.

Published
2017

42. How hexagonal mesoporous silica evolves in water on short and long term: Role of pore size and silica wall porosity

Author

Julien Cambedouzou, Diane Rébiscoul, Sandra Parrès-Maynadié, B. Gouze, Laboratoire d'Etudes du Comportement à Long Terme des matériaux de conditionnement (LCLT), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Etude de la Matière en Mode Environnemental (L2ME), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
In situ, Materials science, Small-angle X-ray scattering, Scattering, Mineralogy, chemistry.chemical_element, 02 engineering and technology, General Chemistry, Mesoporous silica, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Nitrogen, 0104 chemical sciences, Chemical engineering, chemistry, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Mechanics of Materials, General Materials Science, 0210 nano-technology, Saturation (chemistry), Porosity, Dissolution, ComputingMilieux_MISCELLANEOUS
Abstract

In this study, we have determined the evolution of the morphology and the structure of mesoporous silica MCM41 and SBA15 in saturation condition during short and long term alteration by water at 60 °C. These materials were characterized using in situ/ex situ Small Angle X-ray Scattering (SAXS), and ex-situ by nitrogen adsorption–desorption and 29Si Nuclear Magnetic Resonance (NMR). The results have shown that MCM41 lost its hexagonal order of pores. This phenomenon has been attributed to a change of the pore shape probably due to the dissolution of silica wall and to the recondensation of hydrolysed silica on the pore surface leading also to a partial pore clogging at high alteration progress. In the case of SBA15, as soon as the porous silica is in contact with water, an altered silica layer is formed at the pore surface and dissolved at a rate of 120 nm year−1 leading to a pore size increase. When an equilibrium between dissolution and recondensation of the silica is reached, the silica dissolution rate strongly decreases (7 nm year−1) and the altered layer growth follows a diffusive process with a diffusion coefficient of D = 1.4 × 10−24 m2 s−1. The differences of evolution between the two silica are explained by their different pore diameter and the presence of microporosity in the case of SBA15.

Published
2014

44. Enhanced Ionic Transport Mechanism by Gramicidin A Confined Inside Nanopores Tuned by Atomic Layer Deposition

Author

Julien Cambedouzou, Mathilde Le Poitevin, Philippe Déjardin, Fabien Picaud, Mikhael Bechelany, Thierry Thami, Philippe Miele, Adib Abou Chaaya, Jean-Marc Janot, Simon Cabello-Aguilar, Emmanuel Balanzat, Sebastian Kraszewski, Sebastien Balme, Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Centre de recherches internationales (CERI), Sciences Po (Sciences Po)-Centre National de la Recherche Scientifique (CNRS), Nanomédecine, imagerie, thérapeutique - UFC (EA 4662) (NIT / NANOMEDECINE), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Laboratoire des colloïdes, verres et nanomatériaux (LCVN), Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Solides (LPS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), 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), Centre de recherches internationales (Sciences Po, CNRS) (CERI), Nanomédecine, imagerie, thérapeutique - UFC (UR 4662) (NIT / NANOMEDECINE), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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), Institut Européen des membranes ( IEM ), Centre National de la Recherche Scientifique ( CNRS ) -Ecole Nationale Supérieure de Chimie de Montpellier ( ENSCM ) -Université Montpellier 2 - Sciences et Techniques ( UM2 ) -Université de Montpellier ( UM ), Centre d'études et de recherches internationales ( CERI ), Sciences Po-Centre National de la Recherche Scientifique ( CNRS ), Nanomédecine, imagerie, thérapeutique - UFC ( NIT / NANOMEDECINE ), Université Bourgogne Franche-Comté ( UBFC ) -Université de Franche-Comté ( UFC ), Laboratoire des colloïdes, verres et nanomatériaux ( LCVN ), Université Montpellier 2 - Sciences et Techniques ( UM2 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique des Solides ( LPS ), Université Paris-Sud - Paris 11 ( UP11 ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de recherche sur les Ions, les MAtériaux et la Photonique ( CIMAP - UMR 6252 ), Université de Caen Normandie ( UNICAEN ), Normandie Université ( NU ) -Normandie Université ( NU ) -Ecole Nationale Supérieure d'Ingénieurs de Caen ( ENSICAEN ), Normandie Université ( NU ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire des Multimatériaux et Interfaces ( LMI ), Université Claude Bernard Lyon 1 ( UCBL ), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS )

Subjects
Materials science, Fabrication, [ PHYS.COND.CM-MS ] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Ionic bonding, Nanotechnology, 02 engineering and technology, Surface finish, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Nanopore, Atomic layer deposition, General Energy, Membrane, Chemical engineering, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Gramicidin A, Physical and Theoretical Chemistry, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Ion transporter
Abstract

The confinement and the understanding of ion transport through ionic channels when they are confined inside solid-state nanopores smaller than 10 nm remains a challenge. Here we report on the fabrication of biomimetic nanopores with high length (5 μm)/diameter (smaller than 10 nm) ratio obtained using both a track-etched technique and atomic layer deposition on flexible membranes. These membranes present uniform hydrophobic nanopores with a low roughness inside the pores. Gramicidin A is then confined inside nanopores (diameter 10.6, 5.7, and ∼2 nm) leading to the NaCl ionic transport mechanism through a hybrid nanopore similar to the biological ones especially for small diameter (5.7 and ∼2 nm).

Published
2013

45. Unravelling low lying phonons and vibrations of carbon nanostructures: The contribution of inelastic and quasi-elastic neutron scattering

Author

Julien Cambedouzou, Stéphane Rols, Pascale Launois, V. A. Davydov, Jacques Ollivier, Colin Bousige, Helmut Schober, V. N. Agafonov, J.L. Sauvajol, Institut Laue-Langevin (ILL), ILL, Laboratoire de Physique des Solides (LPS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), 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 (UT)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Fullerene, Phonon, Intercalation (chemistry), General Physics and Astronomy, Nanotechnology, Carbon nanotube, Dispersion Curve, Neutron scattering, 01 natural sciences, Molecular physics, Inelastic neutron scattering, 010305 fluids & plasmas, law.invention, Condensed Matter::Materials Science, chemistry.chemical_compound, law, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Molecule, General Materials Science, Physical and Theoretical Chemistry, 010306 general physics, ComputingMilieux_MISCELLANEOUS, chemistry, Cubane, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Carbon Nanotubes
Abstract

We illustrate the contribution of inelastic neutron scattering to the understanding of the vibrations and lattice excitations of fullerenes and carbon nanotubes, through some significant experimental results. Particular emphasis is placed on the study of intra and inter-molecular modes of fullerene C60, as well as on the order/disorder transition characteristic of these molecules. In addition, a significant part of this article is dedicated to various intercalation compounds of fullerenes and carbon nanotubes, such as the co-crystal “fullerene-cubane” consisting of an arrangement of molecules of spherical and cubic shapes, or the compound called “peapods”, in which fullerene C60 are inserted inside carbon nanotubes.

Published
2012

46. Tuning the Nanostructure of Highly Functionalized Silica Using Amphiphilic Organosilanes: Curvature Agent Effects

Author

Romain Besnard, Guilhem Arrachart, Julien Cambedouzou, Stéphane Pellet-Rostaing, Tri ionique par les Systèmes Moléculaires auto-assemblés (LTSM), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Etude de la Matière en Mode Environnemental (L2ME), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nanostructure, Nanotechnology, 02 engineering and technology, 010402 general chemistry, Curvature, 01 natural sciences, Micelle, Cerasomes, Dynamic light scattering, nanofibers, Amphiphile, Scanning transmission electron microscopy, Electrochemistry, Moiety, Molecule, General Materials Science, blackberry-like particles, Spectroscopy, Chemistry, Surfaces and Interfaces, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, highly functionalized silica, 0104 chemical sciences, Chemical engineering, 0210 nano-technology, bilayers
Abstract

International audience; The self-assembly of amino-undecyl-triethoxysilane (AUT) as micelles in water is considered. The behavior of acid/AUT systems is governed by a complete proton transfer from the acid to the amine, leading to the formation of an ammonium headgroup. This moiety is responsible for the bending of the interface between the organic core of the micelles and the surrounding water. By playing with the size of the acid used as curvature agent, the amphiphilic behavior of the organosilane molecule may be adjusted. We follow the aggregation as the curvature agent size increases. This approach constitutes an efficient and original method in order to tune the nanostructure of highly functionalized silica at the early stage of the elaboration. Small-angle X-ray scattering, wet scanning transmission electron microscopy, dynamic light scattering, and complementary characterization techniques indicate that hybrid organic–inorganic planar objects and vesicles are obtained for smaller curvature agents. Increasing the size of the curvature agent results in a transition of the aggregation geometry from vesicles to cylindrical direct micelles, finally leading to nanofibers organized in a 2D hexagonal network resembling a “reverse MCM-41 structure”. A geometrical molecular self-assembly model is finally proposed, considering the dimensions of the surfactant tail and those of the head groups

Published
2016

47. Quantitative small-angle scattering on mesoporous silica powders: from morphological features to specific surface estimation

Author

Julien Cambedouzou and Olivier Diat

Subjects
Materials science, Adsorption, Basis (linear algebra), Scattering, Experimental data, Nanotechnology, Function (mathematics), Small-angle scattering, Mesoporous silica, Mesoporous material, Biological system, General Biochemistry, Genetics and Molecular Biology
Abstract

A comprehensive method allowing experimentalists to perform a quantitative analysis of small-angle scattering patterns of powdered mesoporous materials of hexagonal symmetry is presented in this paper. Thanks to the rigorous processing of experimental data, and to a straightforward model for the small-angle scattering data simulation, the direct comparison of experimental and calculated patterns is made without any artificial background correction oradhocfunction. This allows the specific surface of mesopores to be estimated without resorting to other methods such as adsorption methods. This approach and its precision are discussed on the basis of the analysis of two real samples.

Published
2012

48. Monte Carlo Studies of C60- and C70-Peapods

Author

Gerhard Gompper, Bart Verberck, Julien Cambedouzou, Pascale Launois, and Gerrit Vliegenthart

Subjects
Physics, Fullerene, Organic Chemistry, Monte Carlo method, Radius, Carbon nanotube, Molecular physics, Atomic and Molecular Physics, and Optics, law.invention, Chemistry, Condensed Matter::Materials Science, law, Physics::Atomic and Molecular Clusters, Dynamic Monte Carlo method, Harmonic, Molecule, General Materials Science, Statistical physics, Physical and Theoretical Chemistry, Engineering sciences. Technology, Monte Carlo molecular modeling
Abstract

We present results of Monte Carlo simulations of chains of C-60 and chains of C-70 molecules encapsulated in a single-walled carbon nanotube (SWCNT). We observe the changes in the configuration of the fullerene molecules when varying tube radius and temperature. In particular, the evolution of the pair correlation functions reveal a transition from linear harmonic chain behavior to a hard-sphere liquid upon heating, demonstrating the possibility of tuning properties of C-60- and C-70@SWCNT peapods with radius and temperature.

Published
2012

50. A Monte Carlo study of C70 molecular motion in C70@SWCNT peapods

Author

Gerrit Vliegenthart, Julien Cambedouzou, Bart Verberck, Pascale Launois, and Gerhard Gompper

Subjects
Chemistry, Physics, Monte Carlo method, chemistry.chemical_element, General Chemistry, Carbon nanotube, Molecular physics, law.invention, Chain (algebraic topology), law, Computational chemistry, Physics::Atomic and Molecular Clusters, Molecular motion, Harmonic, Molecule, General Materials Science, Tube (fluid conveyance), Carbon
Abstract

We present Monte Carlo simulations of chains of C70 molecules encapsulated in a single-walled carbon nanotube (SWCNT). For various tube radii R (6.5 Å less-than-or-equals, slant R less-than-or-equals, slant 7.5 Å), we analyze rotational and translational motion of the C70 molecules, as a function of temperature. Apart from reproducing the experimentally well-established lying and standing molecular orientations for small and large tube radii, respectively, we observe, depending on the tube diameter, a variety of molecular motions, orientational flipping of lying molecules, and the migration of molecules resulting in a continual rearrangement of the C70 molecules in clusters of varying lengths. With increasing temperature, the evolution of the pair correlation functions reveals a transition from linear harmonic chain behavior to a hard-sphere liquid, making C70@SWCNT peapods tunable physical realizations of two well-known one-dimensional model systems.

Published
2011

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