溶胶-凝胶法制备 SiO2微球及其表征

文中采用溶胶-凝胶法，以正硅酸乙酯（TEOS）为硅源，氨水为催化剂，醇为溶剂，制备了 SiO2微球，并研究了正硅酸乙酯添加方式、溶剂类型、反应温度对其形貌和粒径的影响。通过 SEM，XRD，FT - IR，UV - Vis 测试分析 SiO2微球的形貌、结构、成分以及光学性能。结果表明，正硅酸乙酯水解对醇溶剂有选择性，乙醇作为溶剂合成 SiO2的分散性和球形较好，溶剂类型对 SiO2紫外吸收影响不大，SiO2对200~250 nm 紫外线吸收最强。逐步滴定法更利于 SiO2的合成，而 TEOS 添加方式对其非晶化程度影响不大。温度变化会影响氨水催化效率，进而会影响生成 SiO2的粒径。

Synthesis and characterization of SiO2 particles by sol-gel method

SiO2 particles were synthesized by sol-gel method,using tetraethoxy silane（TEOS）as silica source, ammonia as catalyst and alcohol as solvent. The influence of different adding methods,alcohols and reaction tem-peratures on SiO2 particles was studied. The morphology,structure,composition and absorption spectra of the as-obtained SiO2 particles were characterized by SEM,XRD,FT - IR and UV - Vis spectroscopy. The results re-vealed that hydrolysis of tetraethoxy silane is selective to alcohol solvent,dispersity and sphericity of SiO2 are best using ethanol as solvent,different kinds of solvents do not have a certain effect on the ultraviolet rays absorbance of SiO2 and the biggest absorbance is 200 ~ 250 nm. Gradual dropwise additon method is much more beneficial to the formation of SiO2 ,different addition manners of TEOS do not influence the non-crystalline. The catalytic effi-ciency of ammonia will be affected because of different temperatures,the particle size will change with the change of the reaction temperature.