| Abstract: 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 ISL(low ionic strength) condition and oriented clusters under ISH(high ionic strength) condition. Crystals with two layers arrangement were obtained in micelle ordered PC-H2O system under ISL 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. |
