SiO_2空心微球及其丙烯酸树脂复合薄膜的光学性能

Optical Properties of SiO_2 Hollow Spheres and Corresponding PA/h-SiO_2 Composite Films

以聚合物模板法合成了粒径介于200~2 000 nm之间的SiO2空心微球（h-SiO2）,并将h-SiO_2加入到丙烯酸树脂中形成复合薄膜,分别测试了空心微球及复合薄膜的紫外-可见-近红外区内的光学性能.以TEM、SEM、紫外-可见-近红外光谱仪等仪器对空心微球的结构、形貌及光学性能进行了表征,详细讨论了h-SiO2的粒径,表面粗糙度对光学性能的影响.应用FDTD（时域有限差分法）方法对光束在通过空心微球后的电场强度进行模拟计算,得到与实验数据吻合的模拟结果.研究表明,直径为900 nm、加入占单体3.9%的MTC时所得到的h-SiO2光反射能力最强,对近红外和可见光的反射率达到85%以上,紫外光反射率也高于80%,并且加入此h-SiO_2的丙烯酸树脂复合膜遮盖力也较好,可见光区光透过率低于10%.

Silica hollow spheres （h-SiO2） with the diameter ranged from 200 nm to 2000 nm have been synthesized by polymer-templated method. Optical properties of both h-SiO2 and corresponding PA/h-SiO2 composite films were systematically studied. TEM, SEM, UV-VIS-IR spectrophotometer were used to analysis the morphology and the optical property of the products. It was found that both the diameter and surface roughness of h-SiO2 have crucial impact on the optical properties of h-SiO2 and the PA/h-SiO2 composite films. Besides, the electric filed distribution in the PA/h-SiO2 film with three tangent h-SiO2 was modeled by the finite difference time domain （FDTD） method and the simulation results showed similar principle with the experimental data. After all, the 900 nm h-SiO2 which was prepared from the PS template with 3. 9 % MTC performs best. These spheres could reflect over 85% visible as well as near infrared light, while the reflectivity could also be over 80% in UV region, which could probably replace TiO2 in high-hiding coatings.