On the other hand, various re- search groups have used non-covalently bonded organic templates, such as C6 and C16 surfactants [5,17] and alkyltriethoxysilanes [18], to tailor the pore size of intermediate or top layers of mem- branes. At high temperature under oxidizing conditions these organic templates trapped in the gel structure are burnt off, thus producing a cavity with similar dimensions to that of the template molecule [19,20].