【摘要】 以CaCl₂-NH₃-CO₂为反应体系,采用分散鼓泡碳化法制备出单分散纯球霰石型碳酸钙微球。用扫描电镜（SEM、FE-SEM）、透射电镜（TEM）、X射线衍射（XRD）等手段对样品进行了表征。考察了反应初始pH、反应终止p H、反应初始温度、二氧化碳气体流速等因素对产物颗粒形貌和粒径的影响,并探讨了球霰石微球的形成机理。实验结果表明,与直接鼓泡碳化法相比,分散鼓泡碳化法形成的二氧化碳气泡数量多、大小均匀,能增大溶液中二氧化碳的过饱和度,有利于制备高纯度的单分散球霰石微球;反应初始温度低、二氧化碳气体流速大,均有利于球霰石的生成。最佳反应条件:反应初始pH为10.0,反应终止pH为7.0,二氧化碳气体流速为1 L/min。更多还原

【Abstract】 The monodispersed pure vaterite microspheres were synthesized by disperse bubbling carbonization using the reaction system of CaCl₂-NH₃-H₂ O and characterized by SEM,FE-SEM,TEM and XRD.The effects of several factors such as the initial pH,final pH,initial reaction temperature and flow rate of CO₂ gas on the morphology and particle size of products were investigated.The formation mechanism of vaterite microspheres was also discussed.The experiment results demonstrate that much more CO₂ bubbles with uniform size are produced by dispersed bubbling carbonization which can increase the supersaturation of CO₂ in solution compared with the direct bubbling carbonization.It is helpful to prepare monodisperse vaterite microspheres with high purity.Low initial temperature and high flow rate of CO₂ gas also improve the produce of vaterite.The optimum conditions are as follows: initial pH of 10.0,final pH of 7.0,flow rate of CO₂ gas of 1 L/min.更多还原