ISSN:
1435-1536
Keywords:
Key words Charged polymeric membranes
;
macroscopic inhomo-geneities
;
activity coefficients
;
coion exclusion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract We consider a simple model to evaluate mean activity coefficients in charged polymeric membranes with an inhomogeneous distribution of the fixed charge concentration on the macroscopic spatial scale, and apply the results obtained to the coion exclusion characteristic of the Donnan equilibrium. Model calcula-tions with two fixed charge distributions of experimental interest (the asymmetric and the skin-core distributions) show that the inhomogeneity effects can be important when M28.8n the external salt solution concentration is lower than the membrane-fixed charge concen-tration, especially if spatial regions of low charge concentration exist within the membrane. The results obtained appear to be in qualitative agreement with previous experiments.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003960050124
Permalink