纳米二氧化硅包覆有机硅弹性体微球的制备

Preparation of Silicone Elastomer Microspheres Coated by Nano-SiO_2

以亲水性纳米Si O2和少量阳离子表面活性剂为乳化剂制得硅油Pickering乳液,再通过硅氢加成反应制备了表面包覆纳米Si O2的有机硅弹性体微球。研究了实验条件对产物的影响,结果表明,当Si O2质量分数高于0.5%时即可得到稳定的Pickering乳液,当Si O2质量分数为3%、十六烷基三甲基溴化铵浓度为2×10-4mol/L时得到的乳液最稳定。反应前后液滴粒径与微球粒径均无明显变化,纳米Si O2颗粒均匀包覆在有机硅微球表面。单因素实验结果表明,当催化剂用量为20×10-6、反应温度为80℃、反应时间为80 min时,乙烯基硅油的转化率较高。

Pickering emulsion was prepared with hydrophilic nano-SiO2 and a little cationic surfactant used as the emulsifiers. Silicone elastomer microspheres coated by SiO2 were prepared by hydrosilylation of polymethylhydrosiloxane （PMHS） and the vinyherminated the experiment conditions on the production were studied. polydimethylsiloxane （ Vi - PDMS）. The effects of Results showed that when the mass fraction of SiO2 was higher than 0.5%, a stable Pickering emulsion was obtained. When the mass fraction of SiO2 was 3% and the concentration of CTAB was 2 × 10 -4 mol/L, the Picketing emulsion had the best stability. Before and after the reaction, the diameter of the droplet and microspheres had no significant change. The nano-SiO2 particles were uniformly coated on the surface of the silicone microspheres. Single factor experimental results showed that when the dosage of catalyst was 20 × 10 -6, 80℃ of the reaction temperature, 80 min of reaction time, the conversion rate of vinyl silicone oil was higher.