Ordered mesoporous and macroporous inorganic films and membranes

This article reviews synthesis, structures and emerging applications of ordered inorganic meso- and macroporous films and membranes. Thin films or membranes of these groups of porous materials can be prepared by various techniques commonly used for film formation from liquid solution, including solvent evaporation, in situ growth from solution and other alternative methods. Although these techniques allow control over the thickness and pore structures in thin films or membranes, they currently offer limited control over the pore alignment relative to the substrate surface. The ordered mesoporous and macroporous thin films and membranes are highly promising for a range of potential applications in separations, chemical sensing, heterogenous catalysis, microelectronics and photonics as insulating layers of low dielectric constant and photonic bandgap materials. Furthermore, functionalization of the internal pore surfaces in these films and deposition of functional nanoparticles within the pores offer numerous new possibilities for molecular engineering of catalytic, photonic, and magnetic materials for advanced nanotechnological applications based on quantum confinement effect. (C) 2004 Elsevier B.V. All rights reserved.