Soft Condensed Matter, Debye Institute for Nanomaterials Science, Department of Physics and Astronomy, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
Langmuir. 2010 Jun 15;26(12):9297-303. doi: 10.1021/la100188w.
We describe a general one-pot method for coating colloidal particles with amorphous titania. Various colloidal particles such as silica particles, large silver colloids, gibbsite platelets, and polystyrene spheres were successfully coated with a titania shell. Although there are several ways of coating different particles with titania in the literature, each of these methods is applicable to only one type of material. The present method is especially useful for giving the opportunity to cover many types of colloidal particles with titania and forgoes the use of a coupling agent or a precoating step. We can produce particles with a smooth titania layer of tunable thickness. The monodispersity, which improves during particle growth, and the high refractive index of titania make these particles potential candidates for photonic crystal applications. We also describe various ways of fabricating hollow titania shells, which have been intensively studied in the literature for their applications in electronics, catalysis, separations, and diagnostics. Note that our method initially produces amorphous shells on the particles, but these can be easily turned into crystalline titania by a calcination step. We also find that the growth of titania is a surface-reaction-limited process.
我们描述了一种通用的一步法，用于将胶体颗粒涂覆上无定形的二氧化钛。各种胶体颗粒，如二氧化硅颗粒、大银胶体、水铝石薄片和聚苯乙烯球，都成功地被二氧化钛壳层覆盖。虽然文献中有几种涂覆不同颗粒的二氧化钛的方法，但这些方法中的每一种都仅适用于一种类型的材料。本方法特别适用于有机会用二氧化钛覆盖多种类型的胶体颗粒，并且省去了偶联剂或预涂覆步骤。我们可以生产出具有可调厚度的光滑二氧化钛层的颗粒。在颗粒生长过程中提高的单分散性和二氧化钛的高折射率使得这些颗粒成为光子晶体应用的潜在候选者。我们还描述了各种制造空心二氧化钛壳的方法，这些方法在文献中因其在电子、催化、分离和诊断方面的应用而得到了广泛研究。请注意，我们的方法最初在颗粒上产生无定形壳，但通过煅烧步骤可以很容易地将其转化为结晶二氧化钛。我们还发现，二氧化钛的生长是一个表面反应限制过程。
