Abstract
Hydrophobic silica aerogels were prepared from methyltrimetoxysilane (MTMS) by the two-step sol-gel method using oxalic acid and ammonium hydroxide as catalysts, and characterized. The specific surface area, porosity and pore size distribution depended on the preparation conditions such as concentrations of MTMS and catalysts. The microstructure was observed by TEM. The grain size also depended on the MTMS concentration. The aerogel with the largest surface area and porosity was obtained using methanol (MeOH) solutions of high concentration MTMS, MTMS:MeOH=1:14 in mol. Effects of MTMS concentration and acid concentration on the microstructure of the aerogel have been discussed.
