Accueil >
Production scientifique
(139) Production(s) de GENIX A.-C.
|
|
Probing nanocomposites structure via Broadband Dielectric Spectroscopy 
Auteur(s): Baeza G., Genix A.-C., Couty Marc, Alegria Angel, Oberdisse J.
Conference: SoftComp/ESMI annual meeting (Heraklion, GR, 2014-05-26)
|
|
|
|
Studying Twin Samples Provides Evidence for a Unique Structure-Determining Parameter in Simplifed Industrial Nanocomposites
Auteur(s): Baeza G., Genix A.-C. , Degrandcourt Christophe, Gummel Jérémie, Mujtaba Ana, Saalwächter Kay, Thurn-Albrecht Thomas, Couty Marc, Oberdisse J.
(Article) Publié:
Acs Macro Letters, vol. 3 p.448-452 (2014)
|
|
|
|
Tuning Structure and Rheology of Silica-Latex Nanocomposites with the Molecular Weight of Matrix Chains: A Coupled SAXS-TEM-Simulation Approach
Auteur(s): Banc A., Genix A.-C., Chirat M., Dupas C., Caillol Sylvain, Sztucki Michael, Oberdisse J.
(Article) Publié:
Macromolecules, vol. 47 p.3219-3230 (2014)
Texte intégral en Openaccess : 
Ref HAL: hal-00993789_v1
Ref Arxiv: 1405.5411
DOI: 10.1021/ma500465n
WoS: 000336020900052
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
34 Citations
Résumé: The structure of silica-latex nanocomposites of three matrix chain masses (20, 50, and 160 kg/mol of poly(ethyl methacrylate)) are studied using a SAXS/TEM approach, coupled via Monte Carlo simulations of scattering of fully polydisperse silica nanoparticle aggregates. At low silica concentrations (1 vol. %), the impact of the matrix chain mass on the structure is quantified in terms of the aggregation number distribution function, highest mass leading to individual dispersion, whereas the lower masses favor the formation of small aggregates. Both simulations for SAXS and TEM give compatible aggregate compacities around 10 vol. %, indicating that the construction algorithm for aggregates is realistic. Our results on structure are rationalized in terms of the critical collision time between nanoparticles due to diffusion in viscous matrices. At higher concentrations, aggregates overlap and form a percolated network, with a smaller and lighter mesh in the presence of high mass polymers. The linear rheology is investigated with oscillatory shear experiments. It shows a feature related to the silica structure at low frequencies, the amplitude of which can be described by two power laws separated by the percolation threshold of aggregates.
|
 |
Structure and properties of highly-filled simplified industrial nanocomposites
Auteur(s): Baeza G., Genix A.-C., Couty Marc, Oberdisse J.
(Séminaires)
TU Munich (Munich, DE), 2014-01-13 |
|
Structure et Dynamique dans les Poly(n-alkyl methacrylate)s
Auteur(s): Genix A.-C.
(Séminaires)
Michelin (Clermond-Ferrand, FR), 2013-12-17 |
|
|
|
Evidence for a unique structure-determining parameter in simplified industrial SBR / Silica nanocomposites
Auteur(s): Baeza G., Genix A.-C., Degrandcourt Christophe, Couty Marc, Oberdisse J.
(Affiches/Poster)
Workshop Michelin / ESPCI (PARIS, FR), 2013-12-09
Résumé: Silica-filled styrene-butadiene nanocomposites with polymer molecules grafted on industrial silica have been formulated for various silica volume fractions (≈ 10% and 20%v), chain masses (40 – 280 kg.mol-1), and fractions of graftable chains (0 – 100%). The silica structure was analyzed using electron microscopy and small-angle x-ray scattering. The nominal density of grafted molecules per unit silica surface ρD3, which depends on all three aforementioned parameters, covered a domain from 0 to about 0.1 nm-2. By comparing the filler structures at fixed grafting density (so-called ‘twins’), a surprising match of the microstructures was evidenced. A quantitative tool expressing the similarity of structures in reciprocal space is proposed. By comparing it to typical structural evolutions of this nanocomposite system, the match is unambiguously proven. Dynamical mechanical analysis was used to compare the mechanical properties of the twins. The viscoelastic plateau modulus is determined by ρD3 at high volume fractions, and found to be close for twins. This highlights the possibility to set the structure and the modulus by ρD3, and then tune the terminal relaxation time of nanocomposites via the chain length at constant grafting density.
|
