二氧化硅溶胶反应物的配比对性能的影响研究

Effect of reaction matters proportioning of silica sol on its properties

以正硅酸乙酯为前驱体，硝酸作为催化剂，制备了SiO2溶胶．研究了催化剂、水以及乙醇的加入量对溶胶性质的影响，用粘度、凝胶时间、粒径等对溶胶的性能进行了表征．结果表明，当pH〈2时，随着pH的升高，溶胶的粘度减小，凝胶时间增大，SiO2胶粒的粒径则减小；随着水量的不断增加，溶胶的粘度先增大后减小，凝胶时间则先减小后增加，当水酯比（摩尔比）Rw=7．0～8．0时，溶胶的粘度达到最大、凝胶时间达到最小，而SiO2胶粒的粒径则随着水量的增加不断增大：随著乙醇加入量的增加，溶胶体系的粘度降低，凝胶时间延长，二氧化硅粒平的粒径减小．

Silica sol was prepared using TEOS as the precursor and HNO3 as the catalyst. The effects of the amount of catalyst, water and ethanol on the properties of silica sol were investigated. The properties of silica sol were characterized by viscosity, gelation time and particle sizes. The results show that when pH is less than 2, the viscosity of silica sol decreases, gelation time increases and the particle size decreases with the pH increased. As the mol ratio of water to TEOS Rw increases, the viscosity of silica sol firstly increases and then decreases, and gelation time firstly decreases and then increases. When Rw is 7.0-8.0, the viscosity of silica sol reaches its maximum, and the gelation time achieves its minimum, and the particle size of sol increases with the water amount increased. As the ethanol amount increases, the viscosity of silica sol decreases, gel time increases and the particle size decreases.