核-壳式聚苯乙烯/二氧化硅复合微球及空腔硅球的制备

Preparation of Core-Shell Polystyrene/ Silica Composite Microspheres and Hollow Silica Spheres

利用层层自组装的方法制备了粒径和组成可裁剪、具有核-壳式结构的单分散聚苯乙烯(PS)/二氧化硅(SiO_2)复合微球.对复合微球进行热处理除去有机物中心,制备出壁厚可剪裁的空腔硅球.透射电镜(TEM)照片显示二氧化硅纳米颗粒在中心外生成均匀壳层,而煅烧后则可得到轮廓分明的球形空腔;热重分析(TG)说明复合球体的硅含量随着所组装的纳米二氧化硅的粒径的增加而增加;比较PS、SiO_2、复合球体及热处理后的粉体的红外光谱,可分别验证二氧化硅的成功组装和热处理过程中作为中心的PS的完全去除.在吸附相同层的前提下,随着所选用的二氧化硅纳米粒子(10um,20um,40um)的粒径的增大,复合微球的粒径增大,空腔球体的壁厚增加.

The core-shell polystyrene/silica composite microspheres with tailored dimensions and compositions were prepared by layer-by-layer self-assembling. The polymer cores were removed by calcination and hollow silica spheres with tailored wall thickness were produced. TEM photographs showed that silica nanoparticles formed a uniform shell round the core, which turned into a clear-cut hollow sphere after calcination. TG revealed that silica content within the composite microspheres increased with the assembled nano silica diameter. Both the successful assembly of SiO2 and the complete removal of PS can be verified by FIIR comparison of PS, SiO2, composite microspheres and the powders after heating treatment. With the same number layers of nanoparticles adsorpted on the, latex cores, the larger the selected SiO2 nanoparticles diameter (10nm, 20nm, 40nm), the larger the composite microspheres diameter, and the thicker the hollow spheres' wall.