RF-aerogels catalysed by ammonium carbonate

The application of ammonium carbonate (AC) as catalyst for the preparation of RF-aerogels leads to organic aerogels without metallic impurities in contrast to conventional catalysts like sodium carbonate. To synthesize the AC catalyzed RF aerogels we varied the catalyst and formaldehyde concentration in wide ranges. The nanostructure varies accordingly over an order of magnitude. The particle sizes in the dry aerogel network, determined by scanning electron microscopy, are in the range of 0.15-4 mu m. The aerogel densities are in the range of 370-420 kg m(-3). The specific surface measured by nitrogen adsorption (BET) varies from 0.5 to 13 m(2) g(-1) which equals a specific surface area from 0.7 to 20 mu m(-1). Thermogravimetry is employed to study the drying process, annealing reactions and decomposition of the aerogel into a carbon aerogel.