Structural and Morphological Transformation of NaX Zeolite Crystals at High Temperature
Well-shaped octahedral crystals of NaX zeolite of a large size of 30μm were synthesized by a hydrothermal method in a mother solution having a 3.5Na2O : Al2O3 : 2.1SiO2 : 593~2000H2O composition. Thermal treatment of NaX zeolite crystals results in the formation of an intermediate amorphous phase (T < 1000oC) and crystalline phase of aluminium silicate at temperature above 800 and 900oC. Environmental scanning electron microscopy (ESEM), High resolution Transmission Electron Microscopy (HRTEM), X-ray powder diffraction (XRD), Fourier transform infrared(FT-IR) spectroscopy, DTA/TGA and BET analysis were used to characterize the initial materials and the obtained products after various heat treatments.
Wei Pan and Jianghong Gong
Y. M. Kim and I. J. Kim, "Structural and Morphological Transformation of NaX Zeolite Crystals at High Temperature", Key Engineering Materials, Vols. 336-338, pp. 405-408, 2007