Résumé
In this talk, some straightforward ways to obtain information from small-angle scattering on the structure of complex systems, in particular nanocomposites, will be given [1]. Polymer nanocomposites are mixtures of nanoparticles and polymer chains, where the particles – called filler – are usually added to enhance mechanical properties, like e.g. in car tires. Performances depend to a great extent on the structure of the filler, i.e. their 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.We will present 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]. The study led to the identification of a unique structure-determining parameter [3]. The generalization of the above-mentioned approach – the correlation hole analysis – will furthermore be illustrated by structural studies by small angle scattering of well-defined model systems, showing the influence of chain mass [4] or surface grafting of small molecules [5]. Finally, if the chairman is nice, a quick outlook on why contrast-matching with SANS in nanocomposites often fails will be proposed [6].[1] 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.[2] G. P. Baeza, A. C. Genix, C. Degrandcourt, L. Petitjean, J. Gummel, M. Couty and J. Oberdisse, Macromolecules, 2013, 46, 317-329.[3] G. P. Baeza, A.-C. Genix, C. Degrandcourt, J. Gummel, A. Mujtaba, K. Saalwächter, T. Thurn-Albrecht, M. Couty, and J. Oberdisse, ACS MacroLetters, 2014, 3 (5), 448–452[4] A. Banc, A. C. Genix, M. Chirat, C. Dupas, S. Caillol, M. Sztucki and J. Oberdisse, Macromolecules, 2014, 47, 3219–3230.[5] C. Schmitt Pauly, A.-C. Genix, J. G. Alauzun, M. Sztucki, P. H. Mutin and J. Oberdisse, Polymer, in press.[6] A. Banc, A.-C. Genix, C. Dupas, M. Sztucki, R. Schweins, M.-S. Appavou, J. Oberdisse, Macromolecules 2015, 48, 6596−6605.