Templating Silica Aerogel with Polystyrene to Improve Their Mechanical Properties

Abstract

The sol-gel methods applied in the synthesis of aerogels lead to the formation of a disordered silica network. The resulting aerogel has poor structural definition that leads to poor mechanical properties. The work presented details our efforts to create a new hierarchical mesoporous silica aerogel. These meso-porous aerogels were formed utilizing a templating technique using polystyrene beads with varying diameters, 50 nm to 2 μm, dispersed during sol-gel polymerization. The resulting gel was super-critically dried creating a silica aerogel templated with polystyrene beads. The polystyrene beads were then thermal oxidized creating meso-porous silica aerogel monolith. The surface area, pore volume, pore diameter, and mechanical properties of the templated aerogels were determined. Interestingly the mechanical properties of the meso-porous aerogel were significantly improved. These improvements appear to be directly related to the polystyrene bead diameter and loading.