Effects of Solvents on Synthesis and Dispersion of Zircon Powder via Non-Hydrolytic Sol-Gel Route

Abstract

Zircon nano–powder has been synthesized via the non-hydrolytic sol–gel route, using industral zirconium tetrachloride (ZrCl4) and tetraethoxysilane (TEOS) as precursors, lithium fluoride (LiF) as mineralizer, PEG1000 as dispersant. The effects of solvents on the synthesis and dispersion of zircon nano-powder were investigated by means of XRD and TEM. The results indicate that the aprotic solvent N, N-dimethyl formamide (DMF) is not conducive to the nucleophilic substitution reaction, which directly affect the zircon synthesis, and the particles are easy to agglomerate due to the large surface tension; the powder with size of 30nm and good dispersion can be obtained using dichloromethane (CH2Cl2) as solvent; different anhydrous alcohols as solvents influence zircon synthesis, the order of the synthesis ratio is listed as EtOH›propanol (PrOH)› isopropanol (PriOH). Powder particles are larger than 50nm with wide distribution and serious agglomeration when taking PrOH and PriOH as solvents. Nano-zircon with good dispersion and synthesis ratio up to 94.5% can be obtained via using ethanol as solvent.