Counter diffusion self assembly synthesis of ordered mesoporous silica membranes

We report the synthesis of ordered mesoporous silica membranes in macroporous supports by a novel acid catalyzed counter diffusion self assembly (CDSA) method. Effect of pore size, morphology and surface chemistry of the support on the formation of oriented mesoporous silica plugs has been studied. Hydrophobically modified small pore alumina supports (0.3 mu m) show good quality silica membranes as sub-millimeter plugs. Preliminary observations on straight pored hydrophilic and hydrophobic track etch polycarbonate membranes supports (pore diameters 5 mu m and 8 mu m respectively) indicate the formation of ordered mesoporous silica plugs within the support pores, as seen by results of scanning electron microscopy and X-ray diffraction studies. Experimental results suggest that the pore size and morphology of the support play a vital role in the formation of these ordered mesoporous silica plugs, while surface chemistry seems affect the quality of the plugs formed.