Sulfonated syndiotactic polystyrene aerogels: properties and applications

Abstract

This paper evaluates the properties of aerogels obtained from sulfonated syndiotactic polystyrene (ssPS) and polyaniline-coated ssPS and elaborates two applications of such aerogel materials. The syndiotactic polystyrene (sPS) chains were sulfonated in chloroform solutions and ssPS gels at several levels of sulfonation were synthesized. The ssPS gels with high surface area were used as templates to adsorb, protonate, and polymerize aniline. The aerogels recovered after supercritical drying were characterized by scanning electron microscopy, wide angle X-ray diffraction (WAXD), nitrogen adsorption–desorption isotherms, and differential scanning calorimetry. The data revealed that enough crystalline domains remained in ssPS to offer mechanical integrity to the gel network, although the pore surface area reduced significantly at high sulfonation levels. The sulfonic acid groups in ssPS aerogel promoted fast moisture absorption. A large fraction of mesopores appeared in polyaniline-coated ssPS aerogels. The polyaniline-coated ssPS aerogel layer rendered an insulating macroporous membrane electrically conductive.