| In this paper, Nd2O3 nano-particles were prepared by homogeneous precipitation method, technical conditions and kinetics were studied. Besides, the nanometer oxides of other lanthanide (except Pm) and Y had been prepared also. The main contents and results are as follows:The reaction material was prepared by dissolving the raw Nd2O3 in the nitric acid and urea was used as the precipitator, and the Nd2O3 nano-particles were prepared by the homogeneous precipitation. The influence of concentration of Nd3+ and urea, reaction temperature and time, dryness temperature and time, and calcining temperature time on particle size were investigated. The results show that hexagonal, dispersed Nd2O3 nano-particles could be prepared under primary technological conditions.To determine the influence of technical conditions on product diameter, the influence of Nd3+ and urea, reaction temperature and time on average size were investigated by means of uniform design. The results of experiments indicated that the diameter of product was mostly influenced by reaction temperature, followed by reaction time, concentration of Nd3+ and concentration of urea. The optimum conditions were founded: C(Nd3+) =0.24mol/L, C[CO(NH2)2]= 2.27mol/L, reaction temperature = 97.3℃and reaction time=3.41h . Under these conditions, Nd2O3 nano-particles with average diameter of 20nm were obtained.Based on the result of uniform design, the nanometer oxides of other lanthanide (except Pm) and Y had been prepared by homogeneous precipitation method. The results showed that all the nanometer oxides had a form of Re2O3 except Ce, Pr and Tb. Their average diameter decreased with the increase of atomic number. This phenomenon was according with the lanthanide contraction rule.The effects of surfactant as dispersant on the size of the particles were studied. By the characterization of TEM, we found that surfactants reduced the particle size and agglomeration because the surfactant weakened the surface tension and capillary force. Due to the surface electronegative of the particle, cationic surfactant CTAB got better dispersion effect than anionic surfactant SDS. Because of steric effect, macromolecule polymer nonionic surfactants of Tween80, PEG6000 and PVA124 dispersed the precipitations better. While the usage of PEG600 was 4mg/mL, dispersed Nd2O3 particles with average size of 20nm were got.The kinetics of homogeneous precipitation was studied, the activation energy was about 83.25kJ/mol, and the reaction order was 1.62.The TG and DTA techniques were used to research the decomposition kinetics of precursors. The precursors decomposed through two steps. First step: The decomposition mechanism was F(α)1= [-ln(1-α)]1/2. The active energy E1 was 200.72kJ/mol. The pre-exponential factor A1 was 5.08×108 s-1. The second step: The decomposition mechanism was F(α)2= (1-α)-1. The active energy E2 was 187.66kJ/mol. The pre-exponential factor A2 was 4.68×105s-1.
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