Influence of gelation temperature and catalysts on the mesoporous structure of resorcinol-formaldehyde aerogels

Resorcinol-formaldehyde (RF) hydrogels were synthesized by sol-gel polycond ensation of resorcinol with formaldehyde using a few kinds of catalysts at a gelation temperature of 238 or 332 K. RF aerogels were prepared by superc ritical drying with carbon dioxide. The aerogels were characterized by nitr ogen adsorption. The experimental results suggest that the gelation tempera ture does not greatly influence the porous properties and that sodium hydro xide and sodium hydrogencarbonate can be used as catalysts in the preparati on of the aerogels. (C) 2000 Academic Press.