2005 Volume 113 Issue 1315 Pages 210-215
The simple polymerization of methyltriethoxysilane (MTES) has been achieved by the co-hydrolysis with chemically modified tantalum or niobium alkoxides, at room temperature, within 0.5 h and under a slight catalyst. The addition of the transition metal alkoxides into MTES is found to accelerate the formation of siloxane bonds, which was confirmed by 29Si- nuclear magnetic resonance measurement. The siloxane condensation degree of the obtained sol was found to be approximately 80%. The self-supported crack-free hybrid films could be obtained by using this solution. Crack-free ceramic films of 90 mm diameter and 0.2 mm thickness were also obtained by the pyrolysis of the above-described hybrid films. The solutions could also be used as coating precursors, allowing smooth and homogeneous coating films without cracks or pores to be obtained by the dip coating of sol to the various substrates. The adhesion between the coating films and substrates showed large values even for organic substrates, which was evaluated by a cross cut tape test. Scratch hardness was also high.
