Texture Modifications of Silica-Alumina Gels by Microwave Drying

The porous texture of silica-alumina hydrogel can be taylored by controlling the operating parameters of the preparation process. As the drying drastically modifies the texture it is important to minimize pore volume and radius decreases. Owing to a low drying temperature microwave heating coupled with convective drying could be a way to preserve the hydrogel texture. Its effects have been studied and it appears that the characteristics of the air flow are the main parameters of this drying mode which does not present decisive advantages as compared with other drying modes.