共水解法制备GeO2/SiO2复合气凝胶初步研究
Synthesis of GeO2/SiO2 binary composite aerogel by cohydrolysis
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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。Abstract: 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
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Key words:
- composite aerogels /
- icf /
- backlight target /
- olive-like nanoparticles
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