Study On The Synthesis Of ZnO Nanoparticles By Homogeneous Precipitation Method

ZnO nanoparticles is new high functional inorganic materials with many unique properties and extensive uses. In this article the chelating precipitation method and the converting precipitation method were chosed to synthesis ZnO nanoparticles on the basis of the theory of synthesis of nanoparticles by precipitation.Uniform and dispersed ZnO nanoparticles were prepared by the two methods because Zn2+ of conformation crystal was flee slowly and the supersaturation was well controlled.The problem which ZnO nanoparticles are wide size and agglomerative was solved.The effects of different ratio of reactants,different solvent of oxalic acid agitating,drying,ploymer,ZnSO4 concentration on ZnO powders were studied in the experiment of synthesis of ZnO nanoparticles by the chelate precipitation method. ZnO nanoparticles were 100nm on the average ,narrow size and dispersed under the condition of 0.3mol/l ZnSO4,1:2 mol ratio between ZnSO4 and tartaric, not agitating,ethanol solution of oxalic acid with little PEG and drying by azetropic distillation of butanol.The effects of the dosage and kind of ploymer , surfactant,washing means,drying,roasting temperature,reactant concentration on ZnO powders were studied in the experiment of synthesis of ZnO nanoparticles by the converting precipitation method. ZnO nanoparticles were 35nm on the average ,narrow size and dispersed under the condition of 1.25mol/l ZnSO4 with little PVA,1:1 NH3.H2O, 0.5mol/l(NH4)2CO3 with little SDBS,washing with 0.1 M NH3.H2O,drying by vacuum and freezing and roasting at 400C for an hour. Reactant concentration and reactive temperature have great effects on ZnO powders .Under the condition of different reactant concentration and reactive temperature ,the optimal experimental conditionshave been investigated on the basis of the theory of orthogonal test.ZnO nanoparticles were characterized by the means of SEM,TEM,XRD technique.After surface modification of ZnO nanoparticles by titance coupling agent ,the product were more dispersed because their surface were associated with organics anion.The effects of the dosage of titance coupling agent on surface modification of ZnO nanoparticles were studied, the optimal dosage of titance coupling agent(9%) have been investigated.