Preparation of core-shell SiO2/Fe3O4 nanocomposite particles via sol-gel approach

Bing Liu, De Ping Wang, Wen Hai Huang, Ai Hua Yao, Ioku Koji

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13 Citations (Scopus)

Abstract

Core-shell structural SiO2/Fe3O4 nanocomposite particles with adjustable magnetic properties were prepared via a sol-gel process, in which the hydrolysis and condensation of TEOS were conducted on the surface of Fe3O4 nanoparticles under the aid of basic catalyst. The effects of the volume ratio of alcohol to water, the concentrations of ammonium and TEOS on the appearances and properties of the nanocomposite particles were investigated. The mechanism of the formation of SiO2/Fe3O4 nanocomposite particles was analyzed. Results show that silica shell is mainly formed from the aggregative growth of silica primary particles on the surface of Fe3O4 nanoparticles. With increasing the concentration of TEOS in the range of 0-0.02mol/L, the silica shell thickness increases on the condition of 0.3mol/L of NH4OH and 4:1 ratio of alcohol to water. Although the saturation magnetization of the nanocomposite particles decreases with the thickness of silica shell increasing, the coercive force of the particles is almost unchanged. And more, the nanocomposite particles remain favorable superparamagnetism.

Original languageEnglish
Pages (from-to)33-38
Number of pages6
JournalWuji Cailiao Xuebao/Journal of Inorganic Materials
Volume23
Issue number1
DOIs
Publication statusPublished - 2008 Jan 1
Externally publishedYes

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Keywords

  • Core-shell structure
  • Magnetite
  • Silica
  • Sol-gel

ASJC Scopus subject areas

  • Materials Science(all)
  • Inorganic Chemistry

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