Porosity and mechanical properties of mesoporous thin films assessed by environmental ellipsometric porosimetry

Cédric Boissière (1) , David Grosso (1) , Sophie Lepoutre (1) , Lionel Nicole (1) , Aline Brunet Bruneau (2) , Clément Sanchez (1)

1 LCMCP (site Paris VI) - Laboratoire de Chimie de la Matière Condensée de Paris (site Paris VI)
2 INSP - Institut des Nanosciences de Paris

Mesoordered silica thin films with cubic structures were prepared by evaporation induced self-assembly (EISA) with two types of structuring agent (CTAB and block copolymer F127). A complete and accurate description of these films was obtained by combining 2D-SAXS analyses, variable angle spectroscopic ellipsometry, and a specially designed environmental ellipsometric porosimetry (EEP) experiment. The EEP analysis is rapid and cheap and operates at ambient pressure and temperature. This latter experiment was performed with water and produced a set of water adsorption−desorption isotherms. A modified Kelvin equation, coupled with a modelisation of pores contraction, enabled the determination of the structural parameters of films porous networks:  ellipsoidal pore diameters, porous volume, and surface area. Young moduli of films in the direction perpendicular to the substrates were calculated from these parameters.

Domaines: Matériaux

Cédric Boissière, David Grosso, Sophie Lepoutre, Lionel Nicole, Aline Brunet Bruneau, et al.. Porosity and mechanical properties of mesoporous thin films assessed by environmental ellipsometric porosimetry. Langmuir, 2005, 21, pp.12362-12371. ⟨10.1021/la050981z⟩. ⟨hal-00022622⟩