Hole-Filling Theory of Anomalous Diffusion in Glassy Polymers. Effects of Microvoids

Abstract

Non-Fickian diffusion is often observed at low concentrations and without any obvious irreversible changes. This contradicts some of the predictions of the existing theories, which in general work quite well. For these cases, it is suggested that the filling of microvoids give rise to such effects. the effective diffusivity and a memory-dependent source/sink term are obtained for describing the overall transport in heterogeneous media under local volume averaging. Some comparisons with experiments are shown. This mechanism is confined to low concentrations and supplements the existing theories which are effective at higher concentrations.

Department(s)

Chemical and Biochemical Engineering

Keywords and Phrases

Anomalous Diffusion; Diffusion in Solids; Hole Filling Theory; Mass Transfer; Mathematical Models; Memory Dependent Source/Sink Term; Microvoids; Non Fickian Diffusion; Polymeric Glass; Structure (Composition)

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1993 Wiley-Blackwell, All rights reserved.

Publication Date

01 May 1993

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