Synthesis of mechanically reinforced silica aerogels via surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization

Mechanically reinforced polymer-silica aerogels have been successfully prepared by using surface-initiated reversible addition-fragmentation chain transfer polymerization. With this approach, well-defined polystyrene (PSt) and poly(butyl acrylate) (PBA) with Low polydispersities grew on the silica surface and improved the mechanical strength in relation to native aerogels. Moreover, it allowed establishing a structure-property relationship between the grafted polymer molecular weight and physical properties of the hybrid aerogels, thereby enabling the preparation of composites with tailored properties. The aerogel composites here obtained exhibited a Low density of 0.13-0.17 g cm(-3), high thermal insulation performance of 0.03-0.04 W m(-1) K-1 and a high specific surface area of 350-780 m(2) g(-1), with approximately one order of magnitude improvement in the compression strength over the non-reinforced aerogels.