Preparation of Zircon Whiskers via Non-Hydrolytic Sol-Gel Process Combined with Molten Salt Method
Zircon whiskers were prepared via non-hydrolytic sol-gel process combined with molten salt method, using Si (OC2H5)4 (TEOS) and ZrCl4 as raw materials, LiF as mineralizer, and Na2WO4 as molten salt. The phase composition, morphology and microstructure of the samples were characterized by X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The influence of introducing molten salt and calcination temperature on the synthesis and morphology of zircon crystals was investigated. The results show that the introduction of Na2WO4 contributes to the one-dimensional preferential growth of zircon. Zircon whiskers elongated along the c-axis, with diameter of ~100nm and aspect ratio of more than 15, are achieved at the temperature of 850 °C, and neither over low nor over high calcination temperature is conducive to the growth of zircon whiskers.