摘要
以正硅酸乙酯、水、乙醇为原料,硝酸为催化剂,制备了SiO_2溶胶.研究了pH值、水量、乙醇量、反应温度、反应时间以及溶胶陈化温度等因素等对SiO_2溶胶稳定性的影响,以便实现对二氧化硅溶胶稳定性的控制.实验结果表明,随着体系pH值的升高、乙醇量的增大,溶胶的凝胶时间延长,溶胶的稳定性也增强.随着体系水量的增加,溶胶的稳定性先减小后增大,在水酯摩尔比R_W= 7.2时,溶胶的稳定性达到最小;随着反应温度的升高、反应时间的延长,溶胶的稳定性降低;采用较低的陈化温度有利于提高溶胶的稳定性.在溶胶粘度发生急剧变化之前溶胶是相对稳定的.
Silica sol was prepared using TEOS, water, ethanol as the materials and nitric acid as the catalyst. The effects of pH, the amount of water and ethanol, reaction temperature, reaction time and the aging temperature of sol on the silica sol stability were investigated. The effects of the above factors can be used to control the stability of the silica sols. The results show that the gelation time of silica sol is prolonged and the stability is increased as the pH and the ethanol amount increase. As the water amount increase, the silica sol stability firstly is decreased and then increased, and when Rw which is the mol ratio of water to TEOS is 7.2, the sol stability becomes minimal. The stability of the silica sol is decreased with the reaction temperature and the reaction time increase. Lower aging temperature can increase the silica sol stability. The silica sol is relatively stable before the viscosity changes greatly.
出处
《西安工程科技学院学报》
2007年第5期623-627,共5页
Journal of Xi an University of Engineering Science and Technology
基金
陕西省教育厅自然科学专项基金(05JK208)
西安工程大学校管基金(04XG12)
