偶联剂改性纳米硅溶胶的接枝率及稳定性

为改善纳米硅溶胶与有机物间的亲和性及分散稳定性,用硅烷偶联剂对碱性纳米硅溶胶进行表面接枝改性。分析了偶联剂用量、反应温度和反应时间对接枝率、分散稳定性及微观形貌的影响。结果表明,偶联剂KH560更适合做碱性纳米硅溶胶的表面改性剂,且制备的改性纳米硅溶胶表面可接枝KH560;从接枝率变化梯度来看,KH560用量对接枝率影响最大,当KH560含量为12.5%、反应时间为5h、反应温度为60℃时,改性接枝率及Zeta电位绝对值最高,分别为7.37%和55.6mV。

Grafting Ratio and Stability of Nano Silica Sol Modification with Silane Coupling Agent

Surface modification of nano silica sol was performed so as to improve nano silica sol dispersion stability and affinity with organics.The influence of amount of silane coupling agent,reaction temperature and time on degree of grafting,dispersion stability and microstructure of modified silica sol were investigated.T he results indicate that alkaline nano silica sol is more suitable to be modified by silane coupling agent KH560.What's more,silane coupling agent KH560 was successfully grafted on surface of nano silica sol.The amount of silane coupling agent KH560 has greatest influence on degree of grafting in consideration of gradient of degree of grafting.Degree of grafting and absolute value of Zeta potential is 7.37% and 55.6mV respectively w hen amount of silane coupling agent K H 560 is 12.5%,reaction time is 5h and reaction temperature is 60℃.