将陶瓷膜与直接沉淀法相结合构成膜反应器,在室温条件下快速制备出三维花瓣状纳米结构碱式碳酸锌粉体。考察了陶瓷膜孔径、膜分散速率以及沉淀反应条件等对碱式碳酸锌粉体形貌的影响,采用XRD、SEM、BET、粒径分析仪等对粉体进行表征。结果表明,随着膜孔径和膜分散速率的减小,粉体粒径减小;粉体粒径随搅拌速率增大,先减小后增大。反应物摩尔配比R(M碳酸氢铵/M乙酸锌)及乙酸锌的初始浓度对粉体形状影响显著,当R由8变化到2时,粉体结构由块状变为条状,再到微球状;当乙酸锌浓度由0.25 mol/L增大到1.0 mol/L时,粉体结构由片平向哑铃状再到花瓣状转变。三维花瓣状结构的碱式碳酸锌粉体粒径约3 m,由厚度约20 nm纳米片组装而成,比表面积达到61.62 m^2/g。
A direct sediment reaction was coupled with a ceramic membrane to construct a membrane reactor, for synthesis of basic zinc carbonate. Flower-like basic zinccarbonatewith nanostructures were successfully prepared at room temperaturerapidly. The effects of membrane pore size, flux and sediment reaction conditions such as stirring rate, molar ratio and initial concentration on particle size and morphology were studied.The products were characterized by SEM, XRD, BET and so on. The results showed that the particle size of basic zinc carbonatedecreased with the decrease of membrane pore size and flux. Under different molar ratio(MNH4HCO3/MZn(CH3COO)2),bulk, strip and sphere powders could be obtained. Plate, dumbbell-like and flower-like basic zinc carbonate with uniform size and morphology were prepared respectively when theconcentration of zinc acetate increased from 0.25 to 1.0mol/L. Flower-like basic zinc carbonate hierarchically structures are assembled by nanosheets of 20 nm and the diameter of the powders is about 3 μm. The specific surface area of prepared basic zinc carbonatecanreachto 61.62m^2/g.