Determination of hydrolysis ratio of silicic ester on the surface of coated films by X-ray photoelectron spectroscopy (XPS)

The hydrolysis ratio of silicic ester on the surface of coated films was an alyzed quantitatively by X-ray photoelectron spectroscopy using monochromat ized AlKalpha X-rays. Alkoxy groups were selectively decomposed on irradiat ion of non-monochromatized Mg K-alpha X-rays to coated silicate films. This phenomenon could be used for determination of the number of alkoxy groups bonded to one silicon atom. This method was applied to evaluate the hydroly sis ratio of various silicic ester coating films. A good correlation was ob tained between hydrolysis ratio which was measured by XPS and water contact angle which indicate hydrophilicity of the surface of coated films.