乙烯基三(β-甲氧基乙氧基)硅烷原位改性纳米SiO2的制备与表征

摘要

以正硅酸乙酯为原料,通过改进的St(o)ber法制备纳米SiO2悬浮液,利用乙烯基三(β-甲氧基乙氧基)硅烷对纳米SiO2粒子进行原位表面改性,考察偶联剂用量、反应时间和反应温度对产品亲油化度和吸水率的影响,利用红外光谱、紫外-可见分光光度计、透射电镜和水接触角等手段对改性前后的样品进行表征.结果表明,改性纳米SiO2的分散性得到改善,疏水性明显增强；较优的合成条件确定为:改性剂用量为总反应溶剂用量的8％,78℃回流反应6h.%Abstraet:SiO2 nano-particles suspension was synthesized by modified sol-gel method with tetraethyl orthosilicate as raw materials.SiO2 nanoparticles were in-situ modified by vinyltris (β-methoxyethoxy) silane.The effect of factors,such as mass fraction ofvinyltris (β-methoxyethoxy) silane,reaction time,reaction temperature on the oil-affinity degree and water-sorption ratio was investigated.The samples before and after modification were characterized by UV-Vis,FTIR,TEM and water contact angle.The results show that dispersion properties of the modified SiO2 nano-particles are improved obviously and the hydrophobicity is also increased apparently.The optimum surface modification conditions are determined that the dosage ofvinyltris (β-methoxyethoxy) silane is 8％ of total solvent dosage,reflux reaction time is 6 h at 78 ℃.