Molecular Crystals and Liquid Crystals, Vol.577, No.1, 116-126, 2013
A Novel Method for the Formation of Lithium Aluminosilicate and Lithium Aluminosilicate-Alumina Matrix Composites by Silicothermal Reaction of Li-Geopolymers
Li-geopolymer precursors containing silicon were fabricated by a solid-state method and fired in nitrogen at 1100 degrees C-1400 degrees C to produce lithium aluminosilicate (LAS), the amount and crystallinity of which was independent of the silicon used, as shown by X-ray diffraction and solid-state magic angle spinning nuclear magnetic resonance (MAS NMR). LAS/Al2O3 composites were formed by adding -Al2O3 to the Li-geopolymer precursor and firing under nitrogen at 1400 degrees C. Although no nitride phases were formed under these reaction conditions, scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) showed a small amount of unreacted silicon in the fired samples, suggesting that it may be possible to adapt this procedure to produce LAS-nitride composites.