Synthesized Of Cerium Carbonate Via Polymer Controlled Nonclassical Crystallization And Properties Of Cerium Oxide Particles

Baiyunebo rare earth ore in Inner Mongolia Baotou is the top ore in the world, light rare earth accounts for over 98%, of which 50% are cerium oxide. To turn the resource advantages into economic advantages, new light rare earth material shall be vigorously developed, and its application shall be expanded. However, its application in many fields requires special properties of particles, such as particle morphology, size, structure, dispersion, surface properties. These properties will determine its application. Therefore, it is much necessary to explore more simple and controllable preparation method. The biological mineralization method is introduced in the material synthesis. Self-assembling on a mesoscopic scale is achieved by interaction of polymer and inorganic added to create material with unique properties and microstructure characteristics. In this paper, sodium polystyrene sulfonate(PSS), poly allyl ammonium chloride(PAH), nonylphenols oxygen vinyl ether(NPnEO) synthesis of long chain polymers were used as nanocrystal self-assembling regulation agent to study the effect of polymer on nucleation and growth of precursor of carbonate crystal particles of rare earth oxide particle. In addition, the interaction of polymer and crystallization unit is also studied, as well as the effect of polymer on self-assembling to find out the mechanism of self-assembling of nanoparticles controlled by the polymer. The physical and chemical properties of particle obtained after calcination with controllable morphologies and properties are characterized to study its peroperties on oxygen storage, polishing, catalytic and glass additives. Based on the characterization of application properties, the regulation improvement to the mode of preparation is performed to obtain the controllable synthesis process to meet the application requirements. The major works are as follow:1. Study on properties of cerium carbonate and cerium oxide particle synthesized under sodium polystyrene sulfonate template control of gas phase method. Using gas diffusion technique (gas phase) and PSS as the important additives of precursor morphology (this morphology is inherited by cerium oxide particles) to research the method for cerium oxide particles with synthesized sphere and mesopore; and the mechanism of self-assembling by nanocrystals under the action of PSS precursor via non-typical crystallization was studied. Performance test showed particles of spherical cerium oxide obtained with small particle size, high specific surface area and volume of pores, suitable as catalyst.2. Study on properties of carbonate and cerium oxide particle synthesized under polyallyl ammonium chloride template control of gas phase method. Using gas diffusion technique (gas phase) and PAH as the template control agent, the optimum conditions of the synthesis of spherical cerium particles were studied; and the effect of different drying methods on of CeO2 particle size was studied. Performance test showed spherical cerium oxide particles obtained with small particle size and high specific surface area, a better photomask polishing powder than the ultrafine CeO2 we studied for industrialized production of co-precipitation method for ammonia and oxalate.3. Study on properties of cerium carbonate and cerium oxide particle synthesized under polyallyl ammonium chloride template control of liquid phase method. In this experiment, the traditional liquid phase synthesis method was used, polyelectrolyte poly allyl ammonium chloride by using cationic (PAH) as the template, directionally control of crystal growth, the final synthesis by six prism sheet composed of petal shaped cerium carbonate precursor and cerium oxide particles. Single factor experiments were performed by changing the feeding mode, PAH concentration and reaction temperature respectively, the optimum preparation conditions of petal shaped cerium carbonate precursor and cerium oxide crystals were determined; The PAH regulation mechanism was studied in detail. CeO2 particles propertiy on absorbing UV was also studied, the petal shaped CeO2 has a strong absorption and reflex action to UV, and the absorption interval changed significantly, red shifting from area UVB to area UVA.4. Preparation of cerium carbonate by nonylphenol ethoxylates control and its application in glass. Using nonionic organic polymer nonylphenol polyoxyethylene ether as the template agent, the effects of nonylphenol concentration, CeCl3 concentration, feeding mode and pH value on the morphology of cerium carbonate particles were studied, cerium carbonate with regular spindle shape, uniform size (about 6μm), and evenly scattering is obtained. The regulation mechanism of polyoxyethylene nonyl phenyl ether to cerium carbonate morphology was studied, and it has been applied to the glass to improve the performance.