In the first method, the silane compound is hydrolyzed in an organic solvent selected from aromatic hydrocarbons such as toluene and xylene, hydrocarbons such as hexane and octane, ketone compounds such as methyl ethyl ketone and methyl isobutyl ketone, ester compounds such as ethyl acetate and isobutyl acetate, and alcohols such as methanol, ethanol, isopropanol, butanol, isobutanol and t-butanol