硅溶胶稳定性能的影响因素分析

Analysis of influence factors on silica-sol stability

硅溶胶是二氧化硅微粒分散于水中的胶体溶液，处于热力学不稳定状态。研究了硅溶胶制备过程中水玻璃浓度、混合时间、体系pH值、表面活性剂加入量等因素对其稳定性的影响。结果表明，在水玻璃浓度为（100±50）g／L、混合时间为0．5～2．0h、体系pH值小于3．8或大于9．5的较适宜条件下，可使硅溶胶的胶凝时间达到36．0h。

The silica- sol, a kind of colloid solu- tion, formed by silica particles dispersing in water is in thermodynamically unstable state. The influence factors on silica - sol stability were studied such as water glass concentration, mixing time, pH value of system and level surface active agent. The results showed that under the appropriate conditions of water glass concentration of （ 100 ± 50） g/L, mixing time of 0.5 - 2.0 h, system pH value below 3.8 or above 9.5, the gelation time for silica- sol reached 36.0 h.