溶胶-凝胶法制备的SiO2涂层抗原子氧侵蚀性能研穷

Erosion resistance of SiO2 protective coatings prepared by sol-gel process in atomic oxygen environment

以正硅酸乙酯（TEOS）为原料，在乙醇共溶剂和盐酸催化剂条件下，采用溶胶-凝胶方法制备SiO2胶体溶液，通过旋涂法在Kapton基体上制备了SiO2薄膜。采用自己研制的空间综合环境地面模拟设备对试样进行了原子氧暴露实验，测试表明溶胶-凝胶制备的SiO2涂层抗原子氧侵蚀性能优异，抗原子氧侵蚀性能比聚酰亚胺基体提高了2个数量级以上。经FTIR和XPS分析表明在原子氧暴露后涂层表面生成了一层SiO2，它阻止了原子氧对基体材料的进一步侵蚀。涂覆涂层后基体的光学性能没有受到影响。实验证明溶胶-凝胶制备抗原子氧侵蚀的防护涂层是一种行之有效的方法。

The tetraethoxysilane （TEOS） precursor is hydrolyzed with ethanol as co-solvent under various concentrations of hydrochloric acid catalyzer to prepare the SiO2 solution through sol-gel process. Highly transparent, uniform and corrosion resistant SiO2 coatings were fabricated by spin-coating of such pre-polymer solutions onto Kapton substrates followed by aging and during of resultant gels. The coatings irradiated by atomic oxygen generated in a ground simulation facility were investigated by scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS） and fourier transform infrared spectroscopy （FTIR）. The experimental results clearly demonstrate that this kind of coatings provided a good protection from AO attack. The erosion yield of the coatings was 1.5 × 10^-26 cm^/atom, decreased by two orders of magnitude compared with the value of 3.0×10^-24 cm^3/atom of the polyimide film. This SiO2 layer significantly retarded the penetration of oxygen atoms, preventing further degradation of the bulk polymer. The coatings had no influence on the optical property of the substrate materials. The results demonstrate that the coatings prepared by sol-gel technique can protect the polymer from atomic oxygen erosion and can be used easily for space application.