Abstract
The volume swelling behaviors of poly(vinyl amine) (PVAm) gels were predicted on the basis of the Donnan theory with the ionic strength of KCl solutions at three different pH (acidic, basic, neutral solution). At neutral (pH 7) and basic (pH 11) conditions, maximum volume swellings were observed in the intermediate concentration of KCl due to the difference in the ionic swelling pressure with the salt concentration. On the contrary, at acidic (pH 3) condition, maximum volume swelling was not found. This was attributed to the full dissociation of the amino groups of PVAm gels even at very low concentration of KCl. In the comparison of the experimental results with the theoretical ones, the experimental results agreed fairly well with the simple Donnan theory, verifying a possible application of the Donnan theory to the prediction of the cation-typed gels.
ACKNOWLEDGEMENTS
This work was supported by Korean Science and Engineering Foundation (96-0300-12-01-3). J. W. Kim wishes to acknowledge the scholarship of the Korea Research Foundation made in the program year of 1998.