| 反相微乳液法制备纳米SiO2的研究 |
| Preparation of Nanosized SiO2 Particles in a Reverse Microemulsion System |
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| 摘要: 在壬基酚聚氧乙烯5醚(NP-5)/环己烷/氨水的反相微乳液体系中，进行正硅酸乙酯(TEOS)的水解、缩合反应，得到粒径在30～50 nm的单分散纳米SiO2胶体。红外光谱法(FTIR)及透射电子显微镜(TEM)观察证明了纳米SiO2粒子的生成。反相微乳液体系相图的研究表明，水相为氨水比纯水有较窄的W/O型微乳区。氨水微乳液是碱催化TEOS水解、缩合制备纳米SiO2粒子的适宜体系。当体系中TEOS的浓度增大时，粒子的粒径随之增大。降低NP-5 |
| 关键词: 反相微乳液 纳米SiO2 正硅酸乙酯 水解-缩合 |
| 基金项目: |
| Abstract: The nanosized (30～50 nm), monodispersed silica particles were prepared by hydrolysis and condensation reactions of tetraethyl orthosilicate (TEOS) in a polyoxyethylene nonylphenyl ether (NP-5)/cyclohexane/aqueous ammonium hydroxide reverse microemulsion system. Nanosize silica particles were characterized by FTIR and TEM. The ternary phase diagram investigations show that introduction of ammonia into the NP-5/cyclohexane/water microemulsion system results in a decrease in area of the W/O type microemulsion region. The aqueous ammonia microemulsion is a proper system to catalyse hydrolysis and condensation reactions of TEOS for synthesising nanosized SiO2 particles. The particle sizes increase with the concentration of TEOS. A decreased size and narrowed distribution of SiO2 particles was obtained with the decrease of CNP-5 while keeping CCH2O constant, which shows that whether or not each micelle can nucleate individually is a dominant factor for the particle numbers. Meanwhile, water in reverse micelles transits from bound water to free water gradually, subsequently the possibility of micelle-nucleation increases and the ratio of final particle numbers over initial micelle numbers increases. Ammonia concentration plays an important role in controlling particle morphology. With relatively high ammonia concentration, the particle size increases, and the size distribution becomes narrow. |
| Keywords: reverse microemulsion nanosize SiO2 particle tetraethyl orthosilicate hydrolysis-condensation |
| 投稿时间：2005-04-02 修订日期：2005-06-30 |
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| 王丽丽,贾光伟,许湧深.反相微乳液法制备纳米SiO2的研究[J].无机化学学报,2005,21(10):1505-1509. |
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