Anomalous Diffusion of Vapors Through Solid Polymers. Part II: Anomalous Sorption

Abstract

Sorption of vapors in polymer membranes in the vicinity of and below the glass transition temperatures do not follow the Fickian (classical) diffusion. the reasons have been attributed to the molecular relaxation which affects both diffusivities and solubilities. a time- and memory-dependent diffusion coefficient has been evaluated in Part I, in a form which is analogous to the treatment in the rheology of such materials. Together with a time-dependent solubility, the conservation equation for the sorption process has been solved. Two special cases are considered, where the relaxation times are short and where they are long. the results explain the anomalous behavior observed in the experiments.

Department(s)

Chemical and Biochemical Engineering

Keywords and Phrases

Diffusion - Thermodynamics; Mass Transfer; Membranes; Polymers; Solutions; Vapors

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1983 Wiley-Blackwell, All rights reserved.

Publication Date

01 Sep 1983

Link to Full Text

Share

 
COinS