催化条件对SiO_2静电自组装薄膜光学性质的影响

Effect of catalysts on optical anti-reflective characteristic of SiO_2 films prepared by electrostatic self-assembly method

用NH3·H2O催化和先后经HCl、NH3·H2O、HCl依次分步催化分别制备了SiO2溶胶。在低折射率的玻璃基片上用静电自组装(electrostaticselfassemblymultilayer,ESAM)法制备了聚电介质PDDA与SiO2的光学增透薄膜。研究了制备SiO2溶胶的催化条件对SiO2的光学增透薄膜在可见光区透光特性的影响。用傅立叶红外光谱仪(FTIR)、X光电子能谱(XPS)、透射电镜(TEM)对薄膜进行了组成和结构分析,用721分光光度计测试薄膜的透光性能。结果显示,两种薄膜都使基片的透过率得到大大增加。NH3·H2O催化SiO2溶胶制备的SiO2光学增透膜使基片在波长为520nm处透过率达到99.2%,相对于HCl与NH3·H2O分步催化制备的薄膜强,但薄膜的耐刮伤能力较相对较差。

SiO2 sols were prepared with two kinds of catalysis conditions, the first with ammonia water, the second with hydrochloric acid, ammonia water and hydrochloric acid in succession. PDDA/SiO2 organic/inorganic complex films were fabricated by electrostatic self-assembly multi-layer (ESAM) method on low refractive index glass substrates. Then SiO2 optical anti-reflective films were prepared through heat treatment with complex films. The compositions and microstructures of the films were studied by X photoelectron spectrum spectrometer (XPS), Fourier transform infrared spectrophotometer (FT-IR) and transmission electron microscope (TEM). The compositions of the films mainly consist of SiO2 and the microstructures were porous and particle sizes were lower than 100 nm. The light transmittance was observed with 721 spectrophotometer. The results show that the visible light transmittance of the two kinds of samples was largely improved compared with the naked substrates. But the maximum visible light transmittance of the sample, prepared with SiO2 sol catalyzed by NH3&middotH2O, attains 99.2% at wavelength 520 nm and was higher than the other kind of sample.