Preparation and characterization of silicon hydride oxide: a fully hydrophobic solid

Abstract

Silicon hydride oxide, a white solid with composition Si₂H₂O₃, has been prepared by hydrolysis and condensation of triethoxysilane HSi(OC₂H₅)₃. This material is amorphous to XRD. The surface area is 195 m² g⁻¹. It is stable from the point of view of its chemical composition up to 550 K, as shown by TG-DTA analysis. IR spectra show that the amount of silanol groups at its surface is negligible. The interaction with polar organic compounds such as acetone is very weak and shows no significant hydrogen bonding. Its adsorption capacity towards hexane is definitely higher, while its adsorption capacity for water is smaller than for typical silica. This material appears as a highly hydrophobic silica-like solid. At temperatures higher than 673 K Si–H bonds progressively disappear and SiOH groups appear, in parallel to a significant decrease in surface area.