水溶液体系中钐离子(III)对草酸钙结晶过程影响效应的研究

进行了水溶液体系中三价稀土离子(Sm^3＋)对草酸钙(CaC₂O₄)结晶过程影响效应的研究. 采用微量热法、X射线衍射(XRD)以及扫描电镜(SEM)法, 研究了Sm^3＋对草酸钙结晶过程动力学的影响效应及对草酸钙晶体晶型、形貌、尺寸的调控作用. 微量热研究结果表明, Sm^3＋对草酸钙结晶过程的影响包括对晶体初期成核以及晶体生长过程的影响, 在适宜的浓度(约2.50×10^－5 mol•L^－1)下达到对晶体成核与生长的最佳抑制效果; XRD研究结果表明, Sm^3＋的加入有利于草酸钙二水合物(COD)的生成; SEM形貌研究表明, Sm^3＋对草酸钙晶体的形态、尺寸产生非常显著的调控作用.

Effects of Sm3+ on the Crystallization of Calcium Oxalate in Pure H2O System

In this paper the control effects of lanthanide ion (Sm^3＋) on the crystallization of calcium ox-alate (CaC₂O₄) in pure H₂O system were investigated. By microcalorimetry, the effects of Sm^3＋on the crystallization kinetics of CaC₂O₄ were studied. Moreover, the control effects of Sm^3＋on the crystal structure, morphology, and size were investigated by X-ray diffraction (XRD) and scanning elec-tromicroscopy (SEM). The microcalorimetric results showed that the effects of Sm^3＋were not only on the initial nucleation of CaC₂O₄ but also on the crystal growth, and the optimal inhibition effects can be obtained only at appropriate concentration of Sm^3＋ (～2.50×10^－5 mol•L^－1). The XRD results showed that under given condi-tions, the addition of Sm^3＋ favors the formation of dihydrate (COD). The SEM results showed that the addition of Sm^3＋ causes significant controls on the crystal shape and size of CaC₂O₄, namely crystals with different morphologies and different sizes will be obtained as the concentration of Sm^3＋ varies.