How Tuning Interfaces Impacts the Dynamics and Structure of Polymer Nanocomposites Simultaneously.
Anne-Caroline GenixVera BocharovaBobby CarrollPhilippe Dieudonné-GeorgeEdouard ChauveauAlexei P SokolovJulian OberdissePublished in: ACS applied materials & interfaces (2023)
Fundamental understanding of the 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 (NP) 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 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 spacings and segmental dynamics provides unprecedented insights into the effect of surface modification on the main characteristics of PNCs: particle interactions and polymer interfacial layers.
Keyphrases
- ionic liquid
- monte carlo
- molecular dynamics simulations
- high resolution
- photodynamic therapy
- electron transfer
- high throughput
- gene expression
- magnetic resonance imaging
- computed tomography
- optical coherence tomography
- gold nanoparticles
- reduced graphene oxide
- genome wide
- molecular dynamics
- dna methylation
- solar cells
- iron oxide