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arXiv · 2310.14680

How Tuning Interfaces Impacts the Dynamics and Structure of Polymer Nanocomposites Simultaneously

Anne-Caroline Genix·Vera Bocharova·Bobby Carroll·Philippe Dieudonné-George·Edouard Chauveau·Alexei Sokolov·Julian Oberdisse
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Abstract

Fundamental understanding of macroscopic properties of polymer nanocomposites (PNCs) remains difficult due to the complex interplay of microscopic dynamics and structure, namely interfacial layer relaxations and three-dimensional nanoparticle arrangements. The effect of surface modification by alkyl methoxysilanes at different grafting densities has been studied in PNCs made of poly(2-vinylpyridine) and spherical 20 nm silica nanoparticles (NPs). The segmental dynamics has been probed by broadband dielectric spectroscopy, and the filler structure by small-angle X-ray scattering and reverse Monte Carlo simulations. By combining the particle configurations with the interfacial layer properties, it is shown how surface modification tunes the attractive polymer-particle interactions: bare NPs slow down the polymer interfacial layer dynamics over a thickness of ca. 5 nm, while grafting screens these interactions. Our analysis of interparticle spacing and segmental dynamics provides unprecedented insight into the effect of surface modification on the main characteristics of PNCs: particle interactions and polymer interfacial layers.

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Anne-Caroline Genix, Vera Bocharova, Bobby Carroll, Philippe Dieudonné-George, Edouard Chauveau, Alexei Sokolov, Julian Oberdisse. 2023-10-23. How Tuning Interfaces Impacts the Dynamics and Structure of Polymer Nanocomposites Simultaneously. https://doi.org/10.1021/acsami.2c18083

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