Preparation of CH₃SiO_3/2-SiO₂ Self-sustained Film From Sol-Gel Method

A sol-gel derived self-sustained film with large size and considerable thickness ranging from 50 to 1000μm was prepared using 0.2 Si（OEt）4 and 0.8 CH₃Si（OEt）₃ as precursors. A hydrophobic plastic plate was selected as the film forming substrate. The film was originally formed on the substrate, and then separated from it and post-treated. The effects of TEOS on the film properties and on the inhibition of the crystalline precipitate formation from MTES solution were studied in detail with the aid of XRD. The results pointed out that the addition of certain amount of TEOS into MTES may greatly suppress the formation of the crystalline precipitates, which is inevitable for pure MTES solution. From AFM used for surface morphology investigation, a mean roughness of about 0.2nm, was determined. Various parameters that may influence the film properties were discussed finally. It is pointed out that a moderate evaporation rate of solvent from the film is essential for preparing a high quality self-sustained film.