Properties of thin films prepared from nano boehmite and organoalkoxysilane

Abstract

We investigated the properties of inorganic-organic hybrid thin films prepared by sol-gel reaction. Inorganic-organic hybrid materials have created very effective coating agents possessing advantages of both inorganic and organic materials. Sol solutions were synthesized by using two kinds of nanosized boehmite and methyltrimethoxysilane (MTMS) in variation with the amount of MTMS at different reaction time. Boehmite nano sol of spherical and fibrous shapes was used as inorganic material, and MTMS was used as organic material. The identifications of crystal pattern and morphology of boehmite nano sol powder were observed by X-ray diffraction and transmission electron microscopy. Coating sols were prepared from boehmite sol and MTMS by sol-gel reaction. In order to understand physical and chemical properties of sols prepared from boehmite and MTMS, thin films were fabricated on glass substrate by dip-coating process. Surface hydrophobicity, roughness, thickness, thermal resistance and electrical resistivity of boehmite/MTMS thin films were investigated. The contact angle of thin films increased with increasing the amount of MTMS and reaction time. Surface roughness of thin films decreased with increasing the amount of MTMS and decreasing reaction time. The thermal degradation of thin films occurred approximately at 400 degC. Surface electrical resistivity increased with increasing the amount of MTMS.