卵磷脂-水体系中草酸钙模拟生物矿化的研究

草酸钙通常以三种水化物的形式存在：热力学稳定的一水草酸钙（以下简称COM），亚稳态的二水草酸钙（以下简称COD）和三水草酸钙（以下简称COT）。前人研究已经表明引起草酸钙不同水化物成核、生长以及聚集的因素，不仅仅在于钙离子和草酸根离子浓度的过量，而且与晶体成长所处环境包括离子种类、浓度、环境等有关。有关表面活性剂对草酸钙结晶过程的影响，例如SkriticD．小组做了大量的研究工作犤１～３犦。他们指出草酸钙晶体的成核、生长、组成以及晶体结构同表面活性剂水溶液的状态间存在着复杂的相关性犤１犦。本文选用卵磷脂（P…

The Study of Mimetic Biomineralization of Calcium Oxalate in PC-H2O System

In this paper, the mimetic biomineralization of CaC₂O₄ in lecithin-water(PC-H₂O) ordered systems has been discussed. First, the effect of the aggregation state of PC aqueous solutions on the crystal structure of CaC₂O₄ has been studied. In all experiments, the only precipitated crystal forms obtained are calcium oxalate monohydrate(COM) and calcium oxalate dihydrate(COD). It have been shown that the relative amount of COD in PC-H₂O systems is much higher than that of in H₂O system, and furthermore the aggregation state of PC influences the composition of coprecipitations to some extent. When PC distributing in aqueous solution as single molecules, it acts as inhibitor of COM , and then favors the formation of COD. While PC in micelle existence, the relative amount of COM increases , but is still lower than that of in H₂O system . And when PC aggregates as vesicles, COD forms predominantly. Second, the morphology of CaC₂O₄ obtained in different reaction systems under different conditions has been also investigated. In H₂O system, we observed thin, plate-like crystals with serrated edges under IS_L(low ionic strength) condition and oriented clusters under IS_H(high ionic strength) condition. Crystals with two layers arrangement were obtained in micelle ordered PC-H₂O system under IS_L condition. And in vesicle ordered PC-H₂O system, clusters with butterfly-like shape were observed. The results obtained revealed a complex depen-dence of calcium oxalate formation,crystal growth, structure and morphology on the aggregation state of PC-H₂O systems.