摘要
采用先共水解正硅酸乙酯和乙醇锗混合溶液、后以胺类化合物作为凝胶催化剂的方法制备了GeO2/SiO2复合氧化物湿凝胶,再将湿凝胶经超临界流体干燥获得了相应的复合氧化物气凝胶。对气凝胶的场发射扫描电镜和高分辨透射电镜分析表明,气凝胶为存在致密纳米团簇的网络结构。电子能谱分析表明,致密的纳米颗粒由富含GeO2的溶胶颗粒堆积而成,网络结构则主要以SiO2为主,这说明在"一锅法"制备复合气凝胶的过程中,GeO2将优先形成nm量级的颗粒而掺杂到SiO2气凝胶网络中。
A ＂one pot＂ procedure of synthesis of GeO2/SiO2 binary composite aerogel was presented.The precursors of GeO2 and SiO2 were vigorously stirred into homogenous mixture in alcohol solution and the stoichiometric calculation water was added to co-hydrolyze the solution at 0 ℃.After the clear sol obtained,ammonium was introduced into the sol to gelatinize the system.The solvent in gel pores was removed by supercritical CO2 to prepare composite aerogels.The as-synthesized aerogels were characterized by field-emission scanning electron microscopy（FESEM）,high-resolution transmission electron microscopy（HRTEM） and Brunauer-Emmett-Teller（BET） N2 isothermal adsorption method.The FESEM micrograph shows that,the aerogels are made up of 3D networks,in which olive-like nanoparticles are planted.The HRTEM micrograph and energy density spectrum indicate that the particles are GeO2 rich,while the networks are mainly constituted of silica.The specific surface area obtained from adsorption/desorption properties by BET method is 467.17 m^2/g,which indicates that mesopores are dominant and macropores are far fewer.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2010年第5期1035-1038,共4页
High Power Laser and Particle Beams
基金
国家高技术发展计划项目
高温高密度等离子体国家重点实验室基金项目(9140C6806020609)
