影响二氧化硅硅溶胶黏度、固含量及成膜厚度的工艺因素

Factors Affecting Viscosity,Solid Content and Film-Forming Thickness of Silica Gel

为了研究影响硅溶胶一次成膜厚度的因素,以正硅酸乙酯为前驱体,与含有C=C双键的烷氧基硅(KH-570)共同水解,制备出了改性硅溶胶,在薄玻璃片上采用提拉法制备了二氧化硅(SiO2)膜,研究了反应温度、时间及增稠剂LZ-09对SiO2膜层性能及厚度的影响。结果表明:随反应温度增加,膜层厚度也增加,当温度为40℃时,干燥后的膜层不会出现开裂、堆积现象;随反应时间延长,膜厚也增加,当反应时间为2h时,膜层性能最佳;增稠剂的使用能明显提高膜层厚度,当硅溶胶中加入2%(体积分数)增稠剂时,一次性膜厚达到(10±5)μm。

Modified silica gel was prepared via hydrolysis of tetraethyl orthosilicate precursor and alkoxyl silicon KH-570 containing C=C bond.Resultant modified silica gel was prepared into silica films on glass slides by using pulling method.The effects of reaction temperature and time as well as thickener LZ-09 on the thickness and properties of the silica films were investigated.It was found that the thickness of the silica films increased with elevating reaction temperature.The films obtained at 40 ℃ were free of cracks and pileups after drying.At the same time,the thickness of the silica films increased with extending time,and the films obtained at a reaction period of 2 h possessed the best properties.Besides,the introduction of the thickener contributed to greatly increased thickness of the silica films,and the films prepared by single pulling from the silical gel containing 2%thickener was up to (10±5) μm thick.