A Unified Model for Non-Fickian Diffusion and Anomalous Swelling of Glassy Polymer Gels

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Lyu, Peihan, Ding, Zhaoyu, Doi, Masao, Man, Xingkun
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909209656819712
author Lyu, Peihan
Ding, Zhaoyu
Doi, Masao
Man, Xingkun
author_facet Lyu, Peihan
Ding, Zhaoyu
Doi, Masao
Man, Xingkun
contents A sheet of glassy polymers placed in a solvent shows swelling behaviors quite different from that of soft polymers (rubbers and gels). (1) Non-Fickian diffusion (called case II diffusion): As solvent permeates into the sample, a sharp front is created between the swollen part and the glassy part, and it moves toward the center at constant speed. (2) Nonmonotonous swelling: The thickness of the sample first increases and then decreases toward the equilibrium value. Here we propose a theory to explain such anomalous behavior by extending the previous theory for swelling of soft gels. We regard the material as a continuum mixture of a glassy polymer network and solvent. We assume that the polymer network is a viscoelastic gel of glassy polymers, and its relaxation time depends strongly on solvent concentration. We show that this theory explains the above two characteristics of glassy polymers in a simple and unified framework. The theory predicts how the permeation speed of the solvent and the characteristic times of the swelling process depend on material parameters and experimental conditions, which can be checked experimentally.
format Preprint
id arxiv_https___arxiv_org_abs_2402_03844
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A Unified Model for Non-Fickian Diffusion and Anomalous Swelling of Glassy Polymer Gels
Lyu, Peihan
Ding, Zhaoyu
Doi, Masao
Man, Xingkun
Soft Condensed Matter
A sheet of glassy polymers placed in a solvent shows swelling behaviors quite different from that of soft polymers (rubbers and gels). (1) Non-Fickian diffusion (called case II diffusion): As solvent permeates into the sample, a sharp front is created between the swollen part and the glassy part, and it moves toward the center at constant speed. (2) Nonmonotonous swelling: The thickness of the sample first increases and then decreases toward the equilibrium value. Here we propose a theory to explain such anomalous behavior by extending the previous theory for swelling of soft gels. We regard the material as a continuum mixture of a glassy polymer network and solvent. We assume that the polymer network is a viscoelastic gel of glassy polymers, and its relaxation time depends strongly on solvent concentration. We show that this theory explains the above two characteristics of glassy polymers in a simple and unified framework. The theory predicts how the permeation speed of the solvent and the characteristic times of the swelling process depend on material parameters and experimental conditions, which can be checked experimentally.
title A Unified Model for Non-Fickian Diffusion and Anomalous Swelling of Glassy Polymer Gels
topic Soft Condensed Matter
url https://arxiv.org/abs/2402.03844