Synthesis and Characterization of Zirconia Nanoparticles by Combining Sulfated Hydroxy Zirconyl and Nitrated Hydroxy Zirconyl in Hexagonal Phase Lyotropic Liquid Crystal

摘要

Undoped tetragonal zirconia nanopowders were synthesized by a swollen hexagonal liquid crystal that consisted of a cationic surfactant, a nonionic surfactant TritonX-100, an aqueous solution of sulfated hydroxy zirconyl (SHZ) hydrosol, and nitrated hydroxy zirconyl (NHZ). The stability of the hexagonal phase, used as the reaction template, was determined by polarized optical microscopy and small-angle X-ray scattering. The influence of [Zr4+]/[SO42-] and [Zr4+]/[NO3-] molar ratio (R-s) on the size, particle size distribution, and crystalline phase of zirconia was investigated. The ZrO2 powders and precursor powders were analyzed and characterized by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and laser particle size analyzer. Results showed that the size and particle size distribution of the nanoparticles obtained were greatly affected by the raw materials. The XRD and Raman spectra demonstrated that the presence of SO42- and NO3- ions retarded the tetragonal-to-monoclinic phase transformation of zirconia nanoparticles. The laser particle size analyzer, TEM, and SEM images revealed that the powders prepared via NHZ were small and uniform compared with those via SHZ.