Preparation of Al2O3 bulk aerogels by non-supercritical fluid drying technology

Al2O3 bulk aerogels were prepared by using Al(H2O)(9)(NO3)(3) as a precursor and 1, 2-epoxy propane as a gelation agent. Methane amide was used as drying control chemical additives(DCCA) to improve the gel texture and the structure evolution. Wet gels were aged by a successively solvent exchanging of alcohol, tetraethylorthosilicate (TEOS)/alcohol and alcohol at a certain temperature. The aged gels were dried at the non-supercritical fluid drying condition to obtain bulk alumina aerogels. Those aerogels had high surface areas and porosity. The mechanism about drying Al2O3 wet gels at an ambient pressure was also discussed.