Difference between revisions of "Surfactant-Assisted Synthesis of Uniform Titania Microspheres and Their Clusters"
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Revision as of 19:19, 29 November 2012
Under Construction 11/28/12
Authors: HK Yu, G Yi, J Kang, Y Cho, VN Manoharan, DJ Pine, and S Yang.
Publication: HK Yu, G Yi, J Kang, Y Cho, VN Manoharan, DJ Pine, and S Yang. (2008) "Surfactant-assisted synthesis of uniform titania microspheres and their clusters." Chem. Mater. 20 pp. 2704-2710.
This work focuses on creating uniform microspheres of titania using a surfactant-assisted synthesis method. The motivation for making clusters has to do with their unique optical properties. The spheres can also be doped with a Europium compound to create phosphorescence sources.
Colloids with sizes comparable to the wavelength of light interact strongly with light, and thus exhibit interesting and potentially useful optical properties. One such use could be as light scatterers in displays, etc. Titania is the material used in this study, because it has a relatively high refractive index. Titania microspheres are hard to create with uniformity and repeatability, so a new synthesis route was developed using surfactants to stabilize growing microspheres.
Explanation of Experimental Methods
The titania microspheres were made from a precursor solution of 0.46% titanium butoxide, ethylene glycol, a stabilizing surfactant, and acetone.
Various surfactants were experimented with, including Tween 20, SDS, CTAB, and Pluronic P123.
To create monodispersed 650nm micropheres,2.03mM Tween 20 was added to 12mL of acetone. Then 1.2mL of a mixture of 0.46% titanium butoxide in ethylene glycol was added. The titanium butoxide concentration in acetone was then 1.46mM. After one day, precipitate formed. Unreacted precursors and acetone were removed using solvent exchange. The precipitate was redispersed in ethanol.
 HK Yu, G Yi, J Kang, Y Cho, VN Manoharan, DJ Pine, and S Yang. (2008) "Surfactant-assisted synthesis of uniform titania microspheres and their clusters." Chem. Mater. 20 pp. 2704-2710.