Polymer-assisted shapeable synthesis of porous frameworks consisting of silica nanoparticles with mechanical property tuning

Abstract

We report the shapeable synthesis of porous silica frameworks using polyacrylamide (PAAm) gel as an organic template and hydrolyzed silicon alkoxide as a silica source. Macroscopically shaped porous frameworks—such as plates, tablets and sheets—comprised of 20- to 40-nm diameter silica particles are obtained via PAAm–silica precursor gels. The mechanical properties (i.e., hardness and Young’s modulus) of the silica frameworks depend on the packing density and are controlled by changing the silica content in PAAm gels. Shapeable synthesis of porous silica frameworks was achieved in an aqueous system using polyacrylamide (PAAm) gel as an organic template and hydrolyzed silicon alkoxide as a silica source. Macroscopically shaped frameworks comprised of 10- to 50-nm diameter silica particles are obtained via PAAm–silica precursor gels. The mechanical properties of the silica frameworks depending on the packing density are controlled by changing the silica content in PAAm gels.