Clarifying the gel-to-glass transformation in Al2O3-SiO2 systems

Shujiang Liu, Vittorio Boffa, D.L. Yang, Z.K. Fan, F.P. Meng, Yuanzheng Yue

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3 Citations (Scopus)


In this paper, we clarify the gel-to-glass (G-G) transformation behavior of the sol-gel derived xAl 2O 3-(100 − x)SiO 2 (x = 0, 10, 20 and 30 mol) systems by differential scanning calorimetry, X-ray diffraction, infrared (IR) spectroscopy and transmission electron microscopy. The SiO 2-Al 2O 3 gels exhibit lower G-G transition temperature than the pure SiO 2 reference gel. Adding Al 2O 3 to the SiO 2 gel can suppress the dependence of glass transition temperature (T g) on hydroxyl concentration, and this effect is attributed to the highly cross-linked structure in alumina-silica gels. In addition, the Al-rich phase separates from the Si-rich matrix phase, and such immiscibility increases with increasing Al 2O 3 content. This behavior is similar to that of the melt-quenched alumina-silica glasses.

Original languageEnglish
JournalJournal of Non-Crystalline Solids
Pages (from-to)77-83
Number of pages7
Publication statusPublished - 2018



  • Gel-to-glass transformation
  • Glass transition
  • Immiscibility
  • SiO -Al O gel

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