Multistep coating of thick titania layers on monodisperse silica nanospheres
Multistep coating of thick titania layers on monodisperse silica nanospheres
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单分散二氧化硅纳米球上厚二氧化钛层的多步涂覆
DOI：
10.1021/la990220u
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发表时间：
1999-08-17
期刊：
影响因子：
3.9
通讯作者：
Dong, P
中科院分区：
文献类型：
--
作者：
Guo, XC;Dong, P
以正丁醇钛为原料，采用多步法制备了单分散二氧化硅球表面的二氧化钛涂层。利用透射电子显微镜和能量色散x射线荧光光谱对二氧化钛包覆二氧化硅球进行了表征。电泳性能和颗粒的大小分布也被测量。从平均直径为550纳米的单分散二氧化硅球开始，经过5个涂层步骤，二氧化钛涂层的厚度达到46纳米，即125层二氧化钛，相当于54.7%重量的二氧化钛负载。二氧化钛涂层的均匀性是由所得球体的电动力学迁移率与大块二氧化钛颗粒的电动力学迁移率精确一致所证实的。保持了较高的单分散性，直径的相对标准偏差小于5%。经过三步氧化钛包覆后，二氧化硅球的聚集度仅从11.8%略微提高到17.2%。
Titania coating on monodisperse silica spheres was carried out with a multistep method using titanium n-butoxide. Titania-coated silica spheres were characterized with transmission electron microscopy and energy-dispersive X-ray flourescence spectroscopy. Electrophoretic properties and size distributions of the particles were also measured. Starting from monodisperse silica spheres of 550 nm in mean diameter, the thickness of titania coatings achieved with five coating steps was up to 46 nm, or 125 monolayers of titania, equivalent to a titania weight loading of 54.7 wt %. The uniformity of the titania coating was confirmed by the precise agreement in the electrokinetic mobility of the resulting spheres with that of bulk titania particles. High monodispersity was maintained with a relative standard deviation in diameter of less than 5%. The aggregation extent of the coated spheres was only increased slightly from 11.8% for the silica spheres to 17.2% after three steps of titania coating.