P（St-EA-MAA）模板法制备中空二氧化硅微球

摘要

以种子乳液聚合制得的P（St-EA-MAA）共聚物微球为模板,γ-氨丙基三甲氧基硅烷（APS）为助结构导向剂,正硅酸四乙酯（TEOS）为硅源,制备了P（St-EA-MAA）/SiO2复合微球,经高温煅烧除去聚合物模板,得到了中空二氧化硅微球。热重分析（TGA）表明模板剂的最佳脱除温度为600℃。高分辨透射电镜（HRTEM）观察显示所制得的二氧化硅微球具有典型的中空结构和良好的单分散性,其尺寸主要取决于共聚物微球的大小,通过调节微球模板的尺寸可以有效控制中空微球的大小。N2吸附-脱附曲线显示二氧化硅壁具有丰富的微孔,比表面积、平均孔径和孔容分别为117.87m2/g、1.98nm和0.21cm3/g。在制备复合微球的过程中加入一定量的CTAB可以调整中空微球的壁厚和壁的孔结构,使其比表面积、平均孔径和孔容增加到219.79m2/g、3.89nm和0.25cm3/g。%P（St-EA-MAA） microspheres with different size were synthesized by seed emulsion polymerization of styrene （St）, ethyl acrylate ester （EA） with methacrylic acid （MAA）. The P（St-EA-MAA）/SiO2 composite microspheres were prepared by using N-aminopropyl trimethoxysilane （APS） and tetraethyl orthosilicate （TEOS） as co-structure-directing agent and silicon sources in the presence of the P（St-EA-MAA） microspheres as template, hollow silica microspheres were obtained by removing the P（St-EA-MAA） templates based on calcination. TG analysis shows that the proper temperature for template removal is 600℃. High resolution transmission electron microscopy （HRTEM） results show that silica microspheres are monodispersed with hollow structure, and the diameter of hollow silica microspheres can be adjusted by the size of the P（St-EA-MAA） mi- crospheres. N2 adsorption-desorption isotherms show that the internal surface of hollow silica have rich micropores, and the BET specific surface area, average pore diameter and volume of pores is 117.87m2/g, 1.98nm and 0.21cm3/g, respectively. The introduction of CTAB can change the thickness and structure of the silica shell, and the BET specific surface area, average pore diameter and volume of pores could be increased to 219.79m2/g, 3.89nm and 0.25cm3/g.