Hierarchically porous polyHIPEs fabricated via ex-situ swelling strategy towards supports for noble-metal Ag nanoparticles

This work demonstrates an ex-situ swelling strategy for fabrication of the robust hierarchically porous polyHIPE. Specially, a cationic polyHIPE was prepared by copolymerization of 2-(methacryloyloxy) ethyltrimethylammonium chloride, styrene and divinylbenzene within a water-in-oil (w/o) high internal phase emulsion (HIPE). The hierarchically porous polyHIPE was achieved via simply swelling the polyHIPE in decane at 70 °C, and subsequent removal of the solvent at room temperature . There were large amounts of small pores found on the void wall surface. Compared with the hierarchically porous polyHIPE fabricated with decane as porogen (in-situ swelling, conventional route), the ex-situ swelling strategy endowed the materials semblable complex pore morphology but much less damage to its compression performance. The young's modulus of the hierarchically porous polyHIPE herein was 37% higher than that obtained by a conventional way. Afterwards, the hierarchically porous polyHIPE was utilized as a carrier for AgNPs (AgNPs@polyHIPE). The AgNPs@polyHIPEs exhibited eminent catalytic activity and recyclability for the reduction of the rhodamine B. Thereby, a facile approach for preparation of high strength and hierarchically porous polyHIPE was presented, and the resulted polyHIPE can be an ideal support for noble metal nanoparticle catalysts.