| Abstract: | A copolymer membrane composed of 4-vinylpyridine-styrene-divinylbenezene was reacted with long chain alkyl bromides (octyl bromide, dodecyl bromide, and hexadecyl bromide) in order to introduce hydrophobic groups into the anion exchange membrane by the quaternization reaction. The resulting membranes show a marked increased in fixed ion concentration as a result of lowered water content. Although the electrical resistance of the membranes increased slightly, the apparent diffusion coefficient of hydrochloric acid through the membranes decreased markedly. Complete quaternization of the membranes by methyl iodide after reaction with the long-chain alkyl bromides caused an increase in the water content and in the apparent diffusion coefficient of the acid and a decrease in the current efficiency in electrodialysis of the acid. This is explained by the high water content of the anion exchange membranes quaternized by methyl iodide. |
