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Your search keyword '"Soumaya Ben Jabrallah"' showing total 3 results
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3 results on '"Soumaya Ben Jabrallah"'

1. Direct experimental evidences of the density variation of ultrathin polymer films with thickness

Author

Nicolas Delorme, Soumaya Ben Jabrallah, Joanna Giermanska, Jean-Paul Chapel, Guillaume Vignaud, Centre de Recherche Paul Pascal (CRPP), Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche Dupuy de Lôme (IRDL), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Centre National de la Recherche Scientifique (CNRS), Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR-18-CE06-0016,SISAL,Auto-Assemblage de bicouches de copolymères amphiphiles induit par une surface(2018), Teulet, Nadine, and APPEL À PROJETS GÉNÉRIQUE 2018 - Auto-Assemblage de bicouches de copolymères amphiphiles induit par une surface - - SISAL2018 - ANR-18-CE06-0016 - AAPG2018 - VALID

Subjects
chemistry.chemical_classification, [CHIM.POLY] Chemical Sciences/Polymers, Materials science, Polymers and Plastics, Organic Chemistry, 02 engineering and technology, Quartz crystal microbalance, Polymer, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Thermal expansion, 0104 chemical sciences, Condensed Matter::Soft Condensed Matter, chemistry.chemical_compound, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Volume (thermodynamics), Materials Chemistry, Polystyrene, Composite material, Thin film, 0210 nano-technology, Glass transition, Dissolution
Abstract

International audience; Beyond the peculiar glass transition temperature (Tg) studied extensively for over two decades, we have investigated in this work the variation of the mass density of polymer thin films, a key property barely put forward in the literature. We were able to directly measure the mass density of polystyrene (PS) and poly (methyl methacrylate) (PMMA) thin films as a function of their thickness from accurate Quartz Crystal Microbalance (QCM) dissolution experiments. Depending on the chemical nature of the polymers, the results showed an unambiguous variation of the mass density when the film thickness was reduced: an increase for PS and a decrease for PMMA films. In the last part, we measured the coefficient of thermal expansion (CTE) of both polymers to rationalize the apparent inconsistency of an increase/decrease in the mass density with the commonly observed depression/rise of the Tg of PS/PMMA films. Surprisingly, the coefficient of thermal expansion and the mass density showed a similar variation with thickness, pointing out a clear correlation between the glass transition temperature, the coefficient of thermal expansion and the free volume of the polymer.

Published
2021
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2. X-ray Standing Waves and Molecular Dynamics Studies of Ion Surface Interactions in Water at a Charged Silica Interface

Author

Kunyu Wang, Soumaya ben Jabrallah, Philippe Fontaine, Luc Girard, Bertrand Siboulet, Jean Daillant, Florent Malloggi, Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS), 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-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-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), Ions aux Interfaces Actives (L2IA), 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), Modélisation Mésoscopique et Chimie Théorique (LMCT), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), HPC resources of [TGCC/CINES/IDRIS] under the allocation 2019-A0070910963 made by GENCI, European Project: 316866,EC:FP7:PEOPLE,FP7-PEOPLE-2012-ITN,SOMATAI(2012), 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), and 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)

Subjects
Chemical substance, Materials science, Molar concentration, X-ray standing waves, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Ion, Standing wave, Molecular dynamics, General Energy, Adsorption, 13. Climate action, Chemical physics, Physical and Theoretical Chemistry, 0210 nano-technology, Science, technology and society
Abstract

International audience; The adsorption of monovalent ions in millimo-lar concentrations at the silica-solution interface has been investigated using x-ray standing waves, a method which combines element sensitivity and sub-nanometer depth resolution. Results were analyzed using a model free analysis and a Gouy-Chapman-Stern model giving access to interfacial concentration proles. We nd the concentration of Potassium cations in the Stern layer to be slighly higher than that of Cesium cations. They also come closer to the interface, in agreement with our molecular dynamics simulations which suggest that our experimental results can be explained by the higher ability of smaller cations to share their hydration shell with the surface. Extension of the method to dierent systems can provide the necessary experimental basis to benchmark ion-surface potentials, a necessary step to predict interfacial behavior of ions which is of high relevance to several areas of science and technology .

Published
2019
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3. Swelling of Poly(n-butyl methacrylate) Films Exposed to Supercritical Carbon Dioxide: A Comparative Study with Polystyrene

Author

Ikbal Ahmed, J. K. Bal, Alain Gibaud, Yves Grohens, Mohamed Souheib Chebil, Guillaume Vignaud, Soumaya Ben-Jabrallah, Thomas Beuvier, Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ingénierie des Matériaux de Bretagne (LIMATB), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), and Université de Brest (UBO)-Université de Brest (UBO)

Subjects
02 engineering and technology, 010402 general chemistry, Methacrylate, 01 natural sciences, chemistry.chemical_compound, Polymer chemistry, Electrochemistry, medicine, General Materials Science, Spectroscopy, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, [PHYS]Physics [physics], Supercritical carbon dioxide, Chemistry, Relaxation (NMR), Surfaces and Interfaces, Polymer, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Reflectivity, Poly n-butyl methacrylate, 0104 chemical sciences, Chemical engineering, Polystyrene, Swelling, medicine.symptom, 0210 nano-technology
Abstract

We report here the swelling and relaxation properties of confined poly(n-butyl methacrylate) (PBMA) films having thicknesses of less than 70 nm under supercritical carbon dioxide (scCO2) using the X-ray reflectivity technique. Swellability is found to be dominant in thinner films compared to thicker ones as a consequence of the confinement-induced densification of the former. Swellability is proportionately increased with the density of the film. PBMA films exhibit a more significant swelling than do PS films, and their differences become more prominent with the increase in film thickness. A comparison between the results obtained for polystyrene (PS) and PBMA ultrathin films reveals that the swellability is dependent upon the specific intermolecular interaction between CO2 and the chemical groups available in the polymers. Owing to strong Lewis acid-base interactions with scCO2 and the lower glass-transition temperature (bulk Tg ≈ 29 °C), PBMA films exhibit a greater amount of swelling than do PS films (bulk Tg ≈ 100 °C). Though they reach to the different swollen state upon exposition, identical relaxation behavior as a function of aging time is evidenced. This unprecedented behavior can be ascribed to the strong bonding between trapped CO2 and PBMA that probably impedes the release of CO2 molecules from the swollen PBMA films manifested in suppressed relaxation.

Published
2016
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