(中南大学 冶金科学与工程学院，长沙 410083)
摘 要: 采用EDTA 络合法在室温下合成了硫酸钡微粒。采用X射线衍射(XRD)、傅里叶红外光谱(FTIR)以及扫描电子显微镜(SEM)研究了该硫酸钡微粒的结构和形貌。研究反应条件对硫酸钡颗粒形貌的影响，计算不同pH 值下Ba-EDTA 络合物的条件稳定常数。结果表明：EDTA 能有效控制硫酸钡颗粒的大小和形貌；在各种反应条件中，pH值对产物形貌的影响最大，pH值为9~10时，得到的硫酸钡颗粒呈球形且分散性好；SO42−的加入速度对BaSO4颗粒的形貌影响不大，这是由于Ba-EDTA络合物控制了Ba2+的释放速度。FTIR结果显示，制备的BaSO4颗粒表面吸附有EDTA的官能团。
关键字: EDTA；硫酸钡；络合反应
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Barium sulfate particles were synthesized in the presence of EDTA at room temperature. X-ray diffractometry (XRD), Fourier transform infrared resonance(FTIR) and scanning electron microscopy (SEM) were used to characterize the structure and morphology of BaSO4 particles. The effect of the preparation parameters on the particles size distribution and morphology were investigated. The complexation stability constant of Ba-EDTA at different pH values was calculated. The results show that the size and morphology of BaSO4 particles can be effectively controlled by additing EDTA in the precipitation process. Among all the operation conditions, the pH value has significant effect on the particle size. The obtained barium sulfate particles are spherical and well dispersed at pH=9−10. The feeding rate of SO42− has less effect on the morphology of BaSO4, the reason is that Ba-EDTA complex controls effectively the reactivty of Ba2+ in the solution. The FTIR result dacates that the surface of the prepared BaSO4 absorbs the functional group of EDTA.
Key words: EDTA; barium sulfate; complexation reaction
