光控亲/疏水转换的硅钛核壳型微颗粒制备易清洗防晒霜研究

Preparation and characterization of Si-Ti composite microparticles with UV-induced wettability conversion for easy-clean sunscreen

以简便价廉的溶胶G凝胶法和自组装法制备出一种新型三甲基氯硅烷改性的SiO2GTiO2微颗粒用于防晒霜添加剂.采用透射电镜（TEM）和X射线光电子能谱（XPS）对微颗粒结构和成分进行表征.对纯纳米TiO2和改性前后的SiO2GTiO2复合微颗粒进行紫外吸收测试,结果表明,在190-350nm范围内目标颗粒的紫外吸收能力均显著优于另两种.接触角测试结果表明,目标颗粒在UV光照前为亲油疏水性,UV光照一段时间后转变为亲油亲水性.研究中复合微结构的构建在保证良好紫外屏蔽效果的同时,大大提高了使用的安全性;微颗粒表面UV光控亲/疏水转换能力让使用完毕后的清洗卸妆变得容易,该微颗粒作为防晒霜添加剂具有良好的应用前景.

A new type of SiO2-TiO2 composite microparticles modified with trimethyl chlorosilane has been pre-pared as sunscreen,using the convenient,low-cost sol-gel method and layer-by-layer technique.Transmission electron microscope (TEM)and x-ray photoelectron spectroscopy (XPS)were used to characterize the morphol-ogy and chemical composition of the microparticles.In UV-Vis tests,the modified composite microparticles have showed significantly higher UV absorption than the unmodified and the pure TiO2 particles at 190 to 350 nm.According to contact angle tests,the target microparticles were originally oleophylic and hydrophobic,and became oleophylic and hydrophilic after UV irradiation for several hours.In this study,the employment of com-posite microstructure produced good anti-UV property and also improved safety of use;the ability of UV-in-duced wettability convention on the surface of microparticles made cleaning a lot easier,highlighting the prom-ising application of the novel microparticles for sunscreen preparation.