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An investigation on structure and texture of silica-magnesia xerogels

  • Rodrigo Brambilla
  • Cláudio Radtke
  • João H. Z. Dos Santos
  • Márcia S. L. Miranda
Original Paper

Abstract

Silica-magnesia xerogels were prepared by reacting tetraethoxysilane (TEOS) and magnesium chloride (MgCl2) under acidic conditions. The TEOS/MgCl2 molar ratio was varied from 1:0 to 0:1. The xerogels were characterized by a set of complementary techniques, namely, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), nitrogen adsorption, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). Magnesium contents of silica-magnesia xerogels were between 1.3 and 16.0 wt%. Increasing TEOS/MgCl2 molar ratio affords higher homogeneity and crystallinity. The presence of low Mg content (<5%) increases specific surface area compared to bare silica. A cubic grain morphology was observed for xerogels with higher Mg content.

Keywords

Silica-magnesia Mixed oxide Xerogel Sol–gel 

Notes

Acknowledgments

CNPq is thanked for the grant. Capes and FAPERGS are thanked for partial financing.

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Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Rodrigo Brambilla
    • 1
  • Cláudio Radtke
    • 1
  • João H. Z. Dos Santos
    • 1
  • Márcia S. L. Miranda
    • 2
  1. 1.Instituto de QuímicaUFRGSPorto AlegreBrazil
  2. 2.Braskem S.A.III Pólo PetroquímicoTriunfoBrazil

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