Surface modification of magnesium hydroxide by γ-aminopropyltriethoxysilane

  • Wei Luo (罗 伟)
  • Qi-ming Feng (冯其明)Email author
  • Le-ming Ou (欧乐明)
  • Kun Liu (刘 琨)


Magnesium hydroxide(MH), which is commonly used as a halogen-free flame retardant filler in composite materials, was modified by silanization reaction with γ-aminopropyltriethoxysilane (γ-APS) in aqueous solution at different pH values (pH range from 8.0 to 12.0). The surface properties of grafted γ-APS on MH surface as a function of solution pH value were studied using elemental analysis, Fourier transform infrared spectroscopy and zeta potential measurement. The results show that hydrolysis and condensation of γ-APS are activated in alkaline solution and lead to multilayer adsorption of γ-APS molecules on the surface of MH. The type of adsorption orientation of γ-APS on MH surface is a function of coverage density that is altered by changing solution pH value. At low coverage density (e.g. 55 nm−2), γ-APS molecules are preferentially adsorbed to the surface with the silicon moiety towards the surface, and increasing coverage density (e.g. 90 nm−2) leads to parallel orientation. At an even higher coverage density (e.g. 115 nm−2), γ-APS molecules bond to the surface with the amino moiety towards the surface.

Key words

magnesium hydroxide γ-aminopropyltriethoxysilane surface modification orientation 


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Copyright information

© Central South University Press and Springer-Verlag GmbH 2008

Authors and Affiliations

  • Wei Luo (罗 伟)
    • 1
  • Qi-ming Feng (冯其明)
    • 1
    Email author
  • Le-ming Ou (欧乐明)
    • 1
  • Kun Liu (刘 琨)
    • 1
  1. 1.School of Resources Processing and BioengineeringCentral South UniversityChangshaChina

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