Designed synthesis of large-pore mesoporous silica–zirconia thin films with high mixing degree and tunable cubic or 2D-hexagonal mesostructure

Abstract

Mesoporous oxide thin films with a mixed silica/zirconia framework were reproducibly synthesised for the first time by a two-step dip-coating method. Different synthesis strategies were developed for the Si-rich and Zr-rich regions. These optical quality films are highly organised and oriented, stable, and exhibit amorphous mixed frameworks presenting good dispersion of both cations at the molecular level. Si inclusion in zirconia matrices modifies the inorganic network, improving the thermal stability of the mesostructure. A ‘library’ of varied compositions [0 ≤ f_Si = [Si]/([Si] + [Zr]) ≤ 0.3; 0.7 ≤ f_Si = [Si]/([Si] + [Zr]) ≤ 1] and tunable mesostructures (cubic Im3m, 2D-hexagonal p6m, local hexagonal, lamellar) has been established with F127, P123 and Brij 58 as templates, opening the way to using different PEO-based polymers to fine-tune the pore sizes.