单分散SiO_2纳米球的制备及其直径分布研究

Preparation and Diameter Distributions of Monodisperse SiO_2 Nanospheres

通过溶胶凝胶法,以正硅酸乙酯(TEOS)为硅源,乙醇为溶剂,浓氨水为催化剂,制备Si O2纳米球.研究了氨水浓度、水用量以及不同温度条件下Si O2纳米球尺寸的变化.通过扫描电子显微镜(SEM)分析了Si O2纳米球的形貌和直径.实验结果表明,反应温度升高会直接促使Si O2纳米球直径减小,温度由25℃变化至55℃,球直径由280~300nm(57.1%)减少至120~140nm(65%).氨水的用量的增加会增大Si O2纳米球直径,氨水用量翻倍时,球直径由200~220nm(92%)增大至290~310nm(80%).反应体系中水的浓度变大会增加水解速率,但对其尺寸大小影响很小.

Monodisperse Si O2nanospheres(NS)were synthesized by sol-gel method with tetraethyl orthosilicate(TEOS)as silica source, ammonia as catalyst and alcohol as solvent. The influences of ammonia, water and reaction temperatures on sizes of Si O2 NS were studied. The morphology and diameter of Si O2 NS were characterized by Scanning Electron Microscopy(SEM). The results revealed that the NS sizes decreased from 280-300 nm(57.1%)to 120-140 nm(65%)when the temperature rose from 25 ℃ to 55 ℃, then the diameter changed from 200-220 nm(92%)to 290-310 nm(80%)by double the quantity of ammonia. The rate of hydrolysis would be accelerated by adding water, but it gave small influences on the diameter.