Synthesis of polymer–silica hybrid polyHIPEs by double in situ polymerization of concentrated water in oil emulsion

Abstract

Highly porous monoliths from polymerized high internal phase emulsions (polyHIPEs) are proposed for a number of applications including liquid absorbents, biocatalysis, tissue engineering, bioseparation etc. To overcome some limitations of fully organic polyHIPEs hybrid organic–inorganic templated porous polymers are particular attractive. Here we present a straightforward protocol towards hybrid polyHIPEs by combining fast photo polymerization of the organic HIPE with in-situ polycondensation of tetraethylorthosilicate (TEOS). While under acidic conditions TEOS polymerization leads to a more bicontinous structure, true double-layered morphologies were obtained under basic conditions as evident from SEM imaging, mercury intrusion porosimetry and nitrogen physisorption measurements. Moreover, chemical amine functionalization of the silica network surface of the hybrid polyHIPEs was demonstrated using a silane coupling agent and subsequent visualization by reaction with fluorescein isothiocyanate (FITC).