Functionalization of aerogels by the use of pre-constructed monomers: the case of trifluoroacetylated (3-aminopropyl) triethoxysilane

Abstract

A novel strategy for aerogels' functionalization, based on the preliminary modification of monomers before gelation, is proposed. The strategy is illustrated by the synthesis of trifluoroacetylated (3-aminopropyl) triethoxysilane (APTES)-based aerogels. An aerogel sample prepared by cogelation of APTES with tetraethoxysilane (TEOS), followed by trifluoroacetylation of free aminogroups, had a BET-surface area of 100–180 m² g⁻¹, while the samples prepared by cogelation of a preliminary trifluoroacetylated monomer with TEOS had a 2–5 times larger specific surface area. Trifluoroacetylated aerogels' properties showed strong dependence on the supercritical drying media.