Study On Preparation Of Neodymium Oxide Powders By Microemulsion Method

Preparation of nano-Neodymium oxide using reverse microemulsion systems hasbecome a technology of promising applications, due to its many advantages such asprecise controllable on the morphology and grain size, mild operating condition, and lowrequirements on the equipment, etc.In this paper TritonX-100/alkanol/petroleum ether/water reverse microemulsionsystems and CTAB/alkanol/petroleum ether/water reverse microemulsion systems werepreparated, microstructure of microemulsion and the maximum water solubilizationcapacities of water-in-oil （W/O） microemulsions were studied by measuring the electricalconductivity and watching. Effects of the alkanol chain length, the content of alkanol andthe composition of emulsifier, the mass ratio for emulsifier to oil and the concentration ofthe dispersed phase on the microstructure and water solubilization capacity of W/Omicroemulsions were analyzed according to the electrical conductivity diagram and thepseudo-ternary phase diagram, and the formulas of microemulsions with different watercontent were given. Then several typical W/O microemulsion systems were used toprepare Nd₂O₃nanoparticles, effects of some factors such as the water content, thereaction time, the concentration of Nd（NO₃）₃solution and the washing condition on thegrain size and morphology of nanoparticles were analyzed. The powders werecharacterized by the scanning electron microscope （SEM）, thermogravimetry-differentialthermal analysis （TG-DTA） and the X-ray powder diffraction （XRD） measurements.Results showed that, for the TritonX-100/petroleum ether/alkanol/water W/Omicroemulsion systems, pentanol is better cosurfactant. when the mass ratio of pentanol toTritonX-100is0.5, and W/O microemulsions with different water content can be preparedin a broader range. The change of the concentration of neodymium nitrate and ammonialiquor have little effect on the dispersed phase solubilization capacity. It’s found that thegrain size of nano-Neodymium oxide increase gradually with the solubilization capacity ofneodymium nitrate and ammonia liquor increasing, the mass ratio of emulsifier to oilincreasing and the decreasing concentration of Nd（NO₃）₃solution whenTritonX-100/petroleum ether/alkanol/neodymium nitrate（ammonia liquor） W/Omicroemulsions was used to prepare Nd₂O₃nanoparticles. The morphologys ofNeodymium oxide nanoparticles are oval-like approximately. When the reaction time islonger, the crystallinity of nanoparticles is higher. Nd₂O₃nanoparticles are dispersedhomogeneously in the condition of washing precipitate with ethanol compared. Nd₂O₃nanoparticles obtained in the condition of washing precipitate with ethanol are dispersedhomogeneously. For the CTAB/alkanol/petroleum ether/water W/O microemulsionsystems, n-Butyl alcohol is better cosurfactant. The microemulsion system formulatedwith pentanol as cosurfactants displays the greatest water solubilization capacity. However, Neodymium oxide powders preparated from CTAB/alkanol/petroleum ether/water W/Omicroemulsion systems agglomerate more seriously.