Characteristics of organic-inorganic hybrid sols prepared from colloidal silica and multifunctional organoalkoxysilanes

The characteristics of organic-inorganic hybrid coatings that were prepared well from surfacemodified silicate sols were studied. The surface-modified silicate sols were fabricated in a two-step sol-gel process involving nano-silicates and silanes by varying the type of silane and the reaction time. The synthesized oraganosilane-treated silicate hybrid sols were confirmed using Fouriertransform infrared (FT-IR) spectroscopy. The viscosity of the sols increased with increasing number of alkoxy functional groups in the organoalkoxysilane and the transmittance of the sol solutions decreased with increasing reaction time. The thermal stability of the hybrid coatings increased with increasing amount of inorganic components. The surface roughness of the coatings depended highly on the homogeneity of the sol solutions. In addition, the contact angle of the hybrid coatings increased as the length of the alkyl chain decreased. Importantly, stabilized hybrid sols and coatings with well-controlled surface and thermal propreties were successfully fabricated by controlling the organoalkoxysilanes and the reaction time.