Synthesis of submicron-sized titania-coated silica particles with a sol-gel method and their application to colloidal photonic crystals

Eiichi Mine, Mitsuaki Hirose, Masaki Kubo, Yoshio Kobayashi, Daisuke Nagao, Mikio Konno

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

A previously proposed method for preparing monodispersed titania particles was extended to preparation of titania-coated silica spherical particles. The core silica particles with an average size of 264 nm were prepared with Stöber method. The titania-coating was performed in ethanol/acetonitrile solvent in the presence of silica particles by a sol-gel method with the use of titanium tetraisopropoxide (TTIP) and methylamine (MA) catalyst. Average size of the silica-titania particles decreased from 457 to 292 nm with an increase in concentration of silica particles. Coefficient of variation for the particle size was less than 5%. Colloidal crystals could be fabricated with a dip-coating technique and a sedimentation process, respectively. Measurements of reflectance revealed peaks based on the Bragg diffraction. Those peaks red-shifted with an increase in titania shell thickness because of a high refractive index of titania. Annealing at high temperature transformed crystal structure of titania shell from amorphous to anatase (500°C) and rutile (1000°C), which led to red-shift of reflection peak because of an increase in refractive index of titania due to the crystallization.

Original languageEnglish
Pages (from-to)91-95
Number of pages5
JournalJournal of Sol-Gel Science and Technology
Volume38
Issue number1
DOIs
Publication statusPublished - 2006 Apr 1

Keywords

  • Coating
  • Colloidal crystal
  • Monodispersed particle
  • Silica
  • Sol-gel method
  • Titania

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Chemistry(all)
  • Biomaterials
  • Condensed Matter Physics
  • Materials Chemistry

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