ABSTRACT
This chapter covers all the important developments of silica-based membranes from the first to the third generation. It addresses some important developments in the preparation methods related to interlayer-free and rapid thermal processing silica-based membranes. The first generation of silica membranes was accompanied by fundamental studies on porous substrates and interlayer, silica sol-gel synthesis, and thin film coating methods in the 1980s. The second generation of silica membranes started in the late 1990s, mainly due to the advent of nanotechnology that employed a large number of templates to produce nonmaterial with tailored pore sizes. The third generation of silica membranes started around 2005 and is associated with the development of metal oxide membranes led by Asaeda's and Tsar’s groups from Hiroshima University in Japan and Diniz da Costa's group at the University of Queensland in Australia. The challenge is to design large membrane modules for gas separation that takes place at high temperatures and pressures.
