Proton conducting polymer gel electrolytes with NO2 substituted carboxylic acids

Proton conducting polymer gel electrolytes based on different nitro substituted aromatic carboxylic acids have been studied. The conductivity of solution and gel electrolytes containing these acids has been found to depend upon the dissociation/acidity constant value of the acid and varies as sigma (ortho-) > sigma (meta-). The addition of polymethylmethacrylate (PMMA) modifies the conductivity of these gel electrolytes which depends upon the dissociation constant and concentration of the acid present. The rate of change of conductivity of gel electrolytes with gelling polymer (PMMA) has been found to be different in the low and high PMMA regions which has been explained to be due to different mechanisms being responsible for the modification of conductivity in the low and high PMMA regions. (C) 2003 Elsevier Science Ltd. All rights reserved.