has successfully been formed on a macroporous support by prefilling the support pores with poly(vinyl alcohol). The ordered mesoporous silica thin film with narrow pore size distribution was synthesized via a sol-gel route. These thin films have a number of potential applications, including in membrane-based separation processes, as catalysts, and as chemical sensors. (S.-M. Yang et al., August 5, Adv. Mater. 2002, 14, 1078-1081)