Control of the structural properties of mesoporous polymers synthesized using porous silica materials as templates

Abstract

In the present work, the fabrication of high-surface area mesoporous polymers is investigated. A nanocasting technique based on mesoporous silica materials as sacrificial templates is employed to prepare these materials. In the first step, the porosity of the silica is filled with a monomer (divynilbenzene), which is polymerized in situ. Subsequently, the silica framework is selectively removed by an etching agent (NaOH), which allows a porous polymer to be retrieved. The structural characteristics (i.e. morphology and particle size) of the template are retained by the polymeric materials, which exhibit high BET surface areas and a large porosity made up of mesopores. What is more, by selecting the appropriate template, it is possible to fabricate porous polymers with a large variety of structural properties, i.e. particle shape, particle size and pore size. The technique used for polymerization also allows the textural properties to be controlled. Thus, when the polymerization is carried out under vacuum conditions, the synthesized porous polymers exhibit very high BET surface areas (up to 1010 m 2 g −1) and large pore volumes (up to 1.7 cm 3 g −1). Such polymeric materials are highly hydrophobic and they can be easily dispersed in organic media (hydrophobic) where they form stable dispersions.