(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用EDTA 絡(luò)合法在室溫下合成了硫酸鋇微粒。采用X射線衍射(XRD)、傅里葉紅外光譜(FTIR)以及掃描電子顯微鏡(SEM)研究了該硫酸鋇微粒的結(jié)構(gòu)和形貌。研究反應(yīng)條件對硫酸鋇顆粒形貌的影響，計算不同pH 值下Ba-EDTA 絡(luò)合物的條件穩(wěn)定常數(shù)。結(jié)果表明：EDTA 能有效控制硫酸鋇顆粒的大小和形貌；在各種反應(yīng)條件中，pH值對產(chǎn)物形貌的影響最大，pH值為9~10時，得到的硫酸鋇顆粒呈球形且分散性好；SO42−的加入速度對BaSO4顆粒的形貌影響不大，這是由于Ba-EDTA絡(luò)合物控制了Ba2+的釋放速度。FTIR結(jié)果顯示，制備的BaSO4顆粒表面吸附有EDTA的官能團。
關(guān)鍵字: EDTA；硫酸鋇；絡(luò)合反應(yīng)
（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
