Diffusion of Electrolyte in Shrunken Polyacrylamide Gel

Abstract

The diffusion coefficients of potassium chloride (KCl) in shrunken polyacrylamide gels were measured as a function of volume fraction of polymer in the gel, φ. The gel samples were first produced under a given condition and then shrunk in methanol-water mixtures to change the volume fractions in the gels. The partition coefficients of both KCl and methanol in the gel were also determined. As a result, the ratio of diffusion coefficient in gel to that in solution, which is an index exhibiting the degree of reduction in the diffusion rate for the shrunken gel, is found to well correlate with φ_s/(1 – φ).