Mechanical properties comparison of phenylsilsesquioxane–methylsilsesquioxane hybrid films by indentation

Abstract

Sol–gel derived phenylsilsesquioxane (PhSiO_3/2)–methylsilsesquioxane (MeSiO_3/2) films were prepared on soda-lime-silicate (SLS) glass substrates by dropping and spreading method. The mechanical properties of the pure MeSiO_3/2 and 20PhSiO_3/2·80MeSiO_3/2 (in mol %) films were measured as a function of heat treatment times and temperatures using a nanoindentation test with a Berkovich indenter. The relative residual depth (ξ_r) of films decreased and the film hardness (H_M) significantly increased with increasing heat treatment times and temperatures. The mechanical properties of the films well reflect the changes in the chemical structures and the evolution of siloxane networks with the heat treatment.