Free-standing membranes from the chemical exfoliation of mesoporous amorphous titania thin film

Abstract

Thin films are typically bound to their substrate, limiting their integration on rough, porous, curved or chemically/thermally sensitive surfaces. Instead of employing tedious and expensive back-etching processes, specific chemical routes can enable the exfoliation of such thin structures. Herein, we demonstrate that an alkaline treatment can exfoliate a hybrid thin film comprising amorphous titania embedded in well-ordered block-copolymer micelles, which can be redeposited elsewhere. We provide sufficient evidence of the preservation of pore ordering and the importance of neutralizing the solution to spare the system from the redissolution of the titania species.