Structure de chaines et particules dans les nanocomposites polymères

Polymer nanocomposites are materials made of nanoparticles incorporated in a polymer matrix, where the filler particles are usually added to enhance mechanical properties, e.g. of car tire materials [1]. Material performance depends to a great extent on the structure of the filler, i.e. its dispersion state in the polymer matrix, as well as on the physical characteristics (mass, crosslinking, grafting, etc.) and the resulting conformation of the polymer chains. In this talk, we will first discuss how structural information can be extracted from small-angle neutron scattering [2], in particular using deuteration and zero average contrast. We will then present some recent results on chain structure in model nanocomposites [3], with special emphasis on difficulties encountered with contrast-matching in nanocomposites. As an outlook, the audience is invited to participate in a dream of a world where large quantities of deuterated polymer of any kind are available. [1] G. P. Baeza, A. C. Genix, C. Degrandcourt, L. Petitjean, J. Gummel, M. Couty and J. Oberdisse, Macromolecules 2013, 46, 317-329.[2] A.-C. Genix and J. Oberdisse, Structure and dynamics of polymer nanocomposites studied by X-ray and neutron scattering techniques. Current Opinion in Colloid & Interface Science 2015, 20, 293-303.[3] A. Banc, A.-C. Genix, C. Dupas, M. Sztucki, R. Schweins, M.-S. Appavou, J. Oberdisse, Macromolecules 2015, 48, 6596−6605, ILL Highlight.

Polymer nanocomposites are mixtures of nanoparticles and polymer chains, where the filler particles are usually added to enhance mechanical properties, e.g. of car tire materials. Performance depends to a great extent on the structure of the filler, i.e. its dispersion state in the polymer matrix, which itself depends on mixing protocols, but also on the thermodynamics of the system. The latter can be tuned by performing either chemical surface modifications of the nanoparticles, or by playing with the mass and/or grafting properties of the polymer chains. In this talk, some straightforward ways to obtain information from small-angle scattering on the structure of nanocomposites will be presented [1]. In particular, we will review recent results on nanocomposites close to industrial applications, including what is probably one of the first quantitative analyses of such disordered structures by a combination of SAXS, TEM and numerical simulations [2]. This analysis will then be applied to the impact of small molecules on such structures [3]. Concerning chain structure, a quick outlook on why contrast-matching with SANS in nanocomposites often fails will be proposed [4]. REFERENCES1.A.-C. Genix and J. Oberdisse, Structure and dynamics of polymer nanocomposites studied by X-ray and neutron scattering techniques. Current Opinion in Colloid & Interface Science 2015, 20, 293-303 (2015).2. G. P. Baeza, A. C. Genix, C. Degrandcourt, L. Petitjean, J. Gummel, M. Couty and J. Oberdisse, Multiscale Filler Structure in Simplified Industrial Nanocomposite Silica/SBR Systems Studied by SAXS and TEM, Macromolecules, 46, 317-329 (2013).3. D. Musino, A.-C. Genix, C. Fayolle, A. Papon, L. Guy, N. Meissner, P. Weda, T. Bizien, T. Chaussée, J. Oberdisse, Synergistic effect of small molecules on large-scale structure of simplified industrial nanocomposites, submitted.4. A. Banc, A.-C. Genix, C. Dupas, M. Sztucki, R. Schweins, M.-S. Appavou, J. Oberdisse, Origin of small-angle scattering from contrast-matched nanoparticles: A study of chain and filler structure in polymer nanocomposites, Macromolecules, 48, 6596−6605 (2015).