采用乳化液膜法制备出草酸锌微细颗粒,乳化液膜体系以煤油为油相,以含量高于95%的二-(2-乙基己基)磷酸酯为载体,选取丁二酰亚胺类表面活性剂T155为膜相稳定剂,内、外水相分别为草酸和硝酸锌溶液,外水相Zn^2+透过膜相与内水相草酸结合生成草酸锌微细颗粒。反应在40min时基本平衡,Zn^2+萃取率达到90%。实验考察了反应条件对产物粒径的影响,研究表明,粒径随表面活性剂用量的增加、油水比(O/A)的增大而减小,外水相Zn^2+浓度的降低可以有效地减小颗粒的粒径。TG、SEM和XRD分析证明合成产物是含两个结晶水的均匀草酸锌颗粒。将制得样品在500℃下煅烧2 h得到粒径均匀的六方纤锌矿晶系ZnO颗粒。
The zinc oxalate fine particles were prepared by using an emulsion liquid membrane (ELM) system with kerosene as solvent, P204 as extractant (cation carder), and T155 as surfactant. Zinc ions were extracted from the external phase and stripped into the internal phase to form zinc oxalate particles. The reaction reached equilibrium after 40min and the extraction ratio of zinc ions was 90%. The effects of reaction conditions on the size of particles were investigated. In the range of experiments, the size of particles decreased with increasing surfactant concentration and O/A ratio. The decrease of zinc ions concentration could effectively reduce particle size. Instrumental analysis, such as scanning electron microscopy (SEM), x-ray diffraction (XRD) and thermogravimeter (TG), confirmed that zinc oxalate particles were synthesized. The zinc oxide particles were obtained by calcining zinc oxalate particles at 500℃ for two hours.