纳米SiO_2在水性介质中的分散稳定性研究

Research on Dispersion and Stability of SiO2 Nano-particles in Water Medium

纳米SiO2特殊的性能使其在很多领域都得到了广泛的应用,而纳米SiO2能否在水性介质中稳定分散将会影响产品的最终质量。本实验选择了九水合硅酸钠和聚丙烯酰胺作为分散剂,并通过激光粒度分析仪和沉降实验对纳米颗粒的分散稳定性进行评价。发现高速研磨能够使聚丙烯酰胺充分地吸附到纳米颗粒表面,聚丙烯酰胺能使纳米SiO2颗粒在水溶液中保持良好的分散稳定性,但是,聚丙烯酰胺的加入量过饱和反而会引起纳米SiO2颗粒的团聚,九水合硅酸钠和聚丙烯酰胺结合起来使用可以发挥协同效应,从而显著改善纳米SiO2颗粒在水溶液中的分散稳定性。

The special performances of SiO2 nano-particles make it widely applicated, but dispersion of nanoparticles in water medium will affect the quality of products. Sodium silicate and PAM were selected as dispersants, laser diffi＇action-based particle size analyzer and settlement experimentation were used to evaluate dispersion and stability of nano-particles. The results indicate that high speed lapping can make polyacrylamide （PAM） adequately adsorb to the surface of nano-particles, PAM can make SiO2 nano-particles be capable of derpersing stably in aqueous solution, but the stability of SiO2 suspension will be destroyed when the added amount of PAM exceed the saturation adsorption, the combination of sodidm silicate nanahydrate and PAM can gave play to bond cooperativity, then effectively improve dispersion and stability of SiO2 nano-particles in aqueous solution.