锌基复合气凝胶的微观结构

Microstructure of zinc-based composite aerogels

以ZnCl2为前躯物,不同相对分子质量的聚丙烯酸为模版剂,环氧丙烷作为催化剂,超临界干燥成功制得了锌基复合气凝胶。运用场发射扫描电镜、高分辨透射电子显微镜和N2等温吸附测试对气凝胶的微观结构进行了表征。结果表明,制备的锌基复合气凝胶呈现三维网络状结构,其三维结构是由大量微小颗粒组成,颗粒的粒径为nm量级,为介孔材料。选用相对分子质量为1800的聚丙烯酸作为模版剂制备的气凝胶的微观结构最好,无明显的塌陷和团聚现象,其比表面积为236 m2/g,平均孔径分布在11 nm左右,总的孔体积为0.179 cm3/g。

The zinc-based composite aerogel was prepared by the sol-gel method using ZnC12 as precursor, polyacrylic acid （800,1800,5000） as template, and propylene oxide as initiator. The characterization of aerogels was carried out by fieldemission scanning electron microscope （FESEM）, high-resolution transmission electron microscopy （HRTEM）, and N2 adsorption/de sorption. The results suggested that the zinc-based composite aerogel made by polyacrylic acid （1800） had perfectly three-dimen sional networks and the skeletal was composed of particles in nanometer and had a high surface area about 236 m2/g. The N2 ad sorption/desorption showed the aerogel had an average pore-diameter of 11 nm and a total pore volume of 0. 179 cm^3/g.