均匀沉淀法可控制备氯化镉氨配合物

Controlled Synthesis of Diammine Cadmium Chloride by Homogeneous Precipitation Method

以金属氯化物为反应原料,以尿素为沉淀剂,以醇为溶剂,采用均匀沉淀法制备了多种过渡金属盐氨配合物。以氯化镉氨配合物为典型的研究对象,考察了尿素含量、反应时间和温度等参数对所得产物尺寸及形貌的影响,通过X射线粉末衍射(XRD)、热重-差示扫描量热法(TG-DSC)、扫描电子显微镜(SEM)和激光粒度分析仪(LPSA)对所得产物物相组成、热稳定性、形貌及粒子尺寸分布等进行了表征。实验结果表明所得产物为二氯化二氨合镉Cd(NH_3)_2Cl_2。产物粒子的尺寸随着尿素含量的增加而增大,反应时间较短有利于得到单分散且呈多面体的Cd(NH_3)_2Cl_2,随着反应时间的延长,所得Cd(NH_3)_2Cl_2颗粒团聚严重;随着反应温度的升高,所得产物粒子形貌变化不大且几乎没有团聚现象,产物粒子的尺寸均一性更好。

In the present work,many complexes of transition metal chloride and ammonia were prepared by homogeneous precipitation method,in which metal chloride was used as raw material,urea as precipitant and alcohol as solvent.The effects of urea concentration,reaction time and temperature on the size and morphology of the products were investigated by taking cadmium chloride as a typical research object.The compositions,thermal stability,morphology and particle size distribution of the product were characterized through X-ray diffraction(XRD),thermogravimetric analysis-differential scanning calorimetry(TG-DSC),scanning electron microscopy(SEM)and laser particle size analyzer(LPSA).The product identified to be diammine cadmium chloride Cd(NH3)2Cl2.With the increase of the urea concentration,the size of the product particles increased correspondingly.The shorter reaction time was benificial to obtain monodisperse and polyhedral Cd(NH3)2Cl2particles and they seriously agglomerated once the reaction time was prolonged.The morphology of the product particles changed little and barely agglomerated with the increase of the reaction temperature.Furthermore,the size uniformity of the product particles was better at higher temperature.