摘要：
首先以正硅酸乙酯(TEOS)为硅源和氨水为催化剂,于无水乙醇介质中通过溶胶?凝胶法制备亚微米球形二氧化硅(SiO2),再以乙烯基三乙氧基硅烷(VTES)为修饰剂,通过后嫁接法在其表面引入乙烯基,制备了表面乙烯基化的 SiO2微球(V-SiO2).探讨了上述2个步骤中工艺条件对产物粒径和形貌的影响,并用热重(TG)、扫描电镜(SEM)、傅里叶变换红外光谱(FTIR)、接触角测量仪对微球进行了表征.结果表明:SiO2的制备过程中,水、无水乙醇、氨水和TEOS用量分别为0.8、1.5、0.03 ~ 0.07和0.05 ~ 0.10 mol,陈化12 ~ 36 h,可得到亚微米级微球.SiO2微球的粒径随氨水和TEOS用量的增加而增大,随陈化时间延长而变得均匀.VTES 用量越大,接枝时间越长,SiO2微球表面乙烯基的接枝量越大,但接枝阻力亦增加大.SiO2微球经过表面接枝后,表面粗糙度增大,对水的接触角可高达近140°.%Vinyl-functionalized submicron SiO2 particles (V-SiO2) were prepared by two steps: firstly, submicron SiO2 particles were made with tetraethyl orthosilicate (TEOS) as predecessor and ammonia water as catalyst in absolute ethanol by sol–gel method; secondly, vinyl groups were introduced on the surface of the submicron SiO2 particles via post-synthesis grafting with vinyl triethoxy silane (VTES) as a modifier. The effects of process conditions in two steps on the particle size and morphology were studied,. The particles were characterized by thermogravimetry (TG), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and contact angle measurement. The results showed that in the first step, submicron SiO2 particles can be prepared with 0.8 mol H2O, 1.5 mol absolute ethanol, 0.03-0.07 mol ammonia water, 0.05-0.1 mol TEOS after being aged for 12-36 hours. The particle size of submicron SiO2 particles is increased with the increasing of TEOS amount, and becomes more uniform with the extending of aging time. In the second step, the higher the amount of VTES is and the longer the grafting time goes, the more the vinyl groups grafted on the surface of submicron SiO2 particles will be, but the higher the hindrance to grafting will grow. The surface of V-SiO2 microspheres is more rough than that of SiO2 microspheres, and has a water contact angle of up to 140°.
