Nanofibrous, porous monoliths formed from gelating high internal phase emulsions using syndiotactic polystyrene

Abstract

Gelating high internal phase emulsions (HIPEs) is critical for the preparation of emulsion-templated porous polymers, and the gelation is conventionally realized through chemical crosslinking of monomers or through physical interaction of a HIPE stabilizer. Here, we present a new method to gelate HIPEs and to fabricate emulsion-templated porous monoliths by incorporating a gelating polymer, syndiotactic polystyrene (sPS), into the continuous phase of an HIPE, without using any chemical crosslinker or any gelating stabilizer. The emulsion-templated sPSs exhibited controllable shapes, nanofibers (with average diameters of around 24 nm) on void walls, emulsion-templated macropores, and windows in two different scales (interconnecting pores from emulsion-templating and interconnecting pores among nanofibers), robust mechanical property (without failure even at a high compressive strain of 70%) and large surface areas (up to 325 m2 g−1), facilitating rapid absorption of airborne volatile organic compounds. After absorption, the porous sPSs could be easily regenerated under vacuum. Therefore, the porous monoliths can be excellent candidates for removal of airborne volatile organic compounds.