Nanofibrous, hierarchically porous poly(ether sulfone) xerogels templated from gel emulsions for removing organic vapors and particulate matters

Abstract

Emulsion-templated method is an emerging technology for the fabrication of porous polymers, but the conventionally chemical crosslinking still restricts the popularization. Based on the physical gelation, emulsion-templated porous polymers (polyHIPEs) can be possible to break the bottleneck. This work reports gel emulsions and corresponding xerogels solidified by solvent-induced crystallization of the poly(ether sulfone) for removing organic vapors and particulate matters. Gel emulsions showed wide adaptability in the dispersed phase fraction (from 5% to 80%) and high stability over 5 months without change in appearance. Emulsion-templated xerogels were obtained from gel emulsions by atmospheric drying, which represents a facile method for the preparation of emulsion-templated porous polymers. The resulting xerogels exhibited controllable external shapes, low shrinkages, emulsion-templated voids, nanofibrous structures, hierarchically interconnecting pores, robust mechanical properties and the reshape ability, which are much more advantageous than conventional polyHIPEs. The xerogels exhibited high adsorption capacities to the organic solvent vapors from air (1.21 mL g−1 for toluene and 1.45 mL g−1 for chloroform), high reusability (without deterioration after five adsorption-desorption cycles) and enhanced adsorption rate imposed by emulsion-templated structures. Moreover, the xerogels captured a mass of particulate matters from air with high durability. The wide adaptability, facile preparation, unique morphology and high capacity and stability to capture solvent vapors and particulate matters enable the current xerogels to be excellent candidates for cleaning air.