The effect of dynamically heterogeneous interphases on the particle dynamics of polymer nanocomposites. Issue 15 (29th March 2023)

• Record Type: Journal Article
• Authors: Wu, Di; Narayanan, Suresh; Li, Ruhao; Feng, Yi; Akcora, Pinar
• Is Part Of: Soft matter. Volume 19:Issue 15(2023)
• Page Start: 2764
• Page End: 2770
• Publication Date: 2023-03-29
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/d2sm01617f
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : The entanglements of dynamically asymmetric polymer layers influence relaxations of nanoparticles in polymer nanocomposites. Abstract : The entanglements of dynamically asymmetric polymer layers influence relaxations of nanoparticles in polymer nanocomposites. In this work, the dynamics of polymer-adsorbed and polymer-grafted nanoparticles in a poly(methyl acrylate) matrix polymer was investigated using X-ray photon correlation spectroscopy (XPCS) to understand the role of chain rigidity and chemical heterogeneities in particle dynamics. Locations of dynamic heterogeneities close to nanoparticles and away from particle surfaces were examined with the comparison of adsorbed and grafted nanoparticles. Our results show that the chemical heterogeneities around dispersed nanoparticles transitioned the particle dynamics from Brownian diffusion into hyperdiffusion, and moreover, the high rigidity of chains in the chemically heterogeneous interfacial layers slowed down the particle dynamics. The hyperdiffusion measured both in grafted particles and adsorbed particles was attributed to the dense interfacial mixing of dynamically heterogeneous chains.