Surface mobility gradient and emergent facilitation in glassy films

Confining glassy polymers into films can substantially modify their local and film-averaged properties. We present a lattice model of film geometry with void-mediated facilitation behaviors but free from any elasticity effect. We analyze the spatially varying viscosity to delineate the transport pro...

Full description

Saved in:
Bibliographic Details
Published in:Soft matter 2024-06, Vol.2 (22), p.4389-4394
Main Authors: Zhai, Qiang, Gao, Xin-Yuan, Lee, Chun-Shing, Ong, Chin-Yuan, Yan, Ke, Deng, Hai-Yao, Yang, Sen, Lam, Chi-Hang
Format: Article
Language:English
Subjects:
Free surfaces
Mobility
Polymers
Transport properties
Viscous flow
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Confining glassy polymers into films can substantially modify their local and film-averaged properties. We present a lattice model of film geometry with void-mediated facilitation behaviors but free from any elasticity effect. We analyze the spatially varying viscosity to delineate the transport properties of glassy films. The film mobility measurements reported by Yang et al. , Science , 2010, 328 , 1676 are successfully reproduced. The flow exhibits a crossover from a simple viscous flow to a surface-dominated regime as the temperature decreases. The propagation of a highly mobile front induced by the free surface is visualized in real space. Our approach provides a microscopic treatment of the observed glassy phenomena. A distinguishable-particle lattice model of film geometry is proposed and a crossover from bulk-viscosity dominated flow to surface dominated flow is demonstrated.
ISSN:1744-683X
1744-6848
1744-6848
DOI:10.1039/d4sm00221k