镁离子调控无定形碳酸钙制备一水碳酸钙结晶过程  

Crystallization Pathway of Monohydrocalcite via Amorphous Calcium Carbonate Regulated by Magnesium Ion

作　　者：蔡豪 汪琦航 邹朝勇 CAI Hao;WANG Qihang;ZOU Zhaoyong(State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,武汉430070

出　　处：《无机材料学报》2024年第11期1275-1282,共8页Journal of Inorganic Materials

基　　金：国家重点研发计划(2021YFA0715700);国家自然科学基金(21905217);中国博士后科学基金资助项目(2023TQ0254);中央高校基本科研业务费专项资金资助(2023IVA097)。

摘　　要：无定形碳酸钙(Amorphous Calcium Carbonate,ACC)在生物矿化中具有重要作用,其结晶过程受到了人们广泛的关注。镁离子(Mg^(2+))能够有效调控ACC的结晶转变过程,但其调控ACC转变为一水碳酸钙(Monohydrocalcite,MHC,CaCO_(3)·H_(2)O)晶体的作用机制并不清楚。本研究使用Mg^(2+)作为添加剂,采用自动电位滴定系统,原位研究了ACC到MHC的转变过程,发现Mg^(2+)能够提升ACC的稳定性,抑制方解石和球霰石的形成。ACC向MHC转变的过程中,首先发生部分溶解,随着Ca^(2+)被消耗,溶液中Mg/Ca摩尔比提高。Mg^(2+)进一步吸附在ACC颗粒表面,抑制ACC表面溶解,促使其从内部溶解,形成富含Mg^(2+)的中空结构以及尺寸更小的纳米颗粒。随后,MHC通过颗粒聚集的方式结晶生长。这些结果解释了Mg^(2+)调控ACC通过非经典结晶方式转变为MHC的机理,加深了对以ACC为前驱体的生物矿化机制的理解。Amorphous calcium carbonate(ACC)plays a crucial role in biomineralization which crystallization process has attracted significant attention.Magnesium ions(Mg^(2+))can effectively regulate the crystallization of ACC,but the mechanism by which it controls the transformation of ACC into monohydrocalcite(MHC,CaCO_(3)·H_(2)O)is not well understood.In this study,Mg^(2+)was used as an additive,and the transformation process from ACC to MHC was investigated in situ using an automatic potentiometric titration system.It was found that Mg^(2+)can enhance the stability of ACC and inhibit the formation of calcite and vaterite.During the transformation of ACC to MHC,partial dissolution firstly occurred,and the molar ratio of Mg/Ca in the solution increased with the consumption of Ca^(2+).Mg^(2+)further adsorbed onto the surface of ACC particles,inhibiting surface dissolution of ACC and promoting internal dissolution of ACC,resulting in the formation of hollow structures rich in Mg^(2+)and smaller-sized nanoparticles.Subsequently,MHC crystallized and grew through particle aggregation.These results elucidate the mechanism by which Mg^(2+)regulates the transformation of ACC into MHC through a non-classical crystallization pathway,enhancing an understanding of the biomineralization mechanism from ACC precursor.

关 键 词：生物矿化 无定形碳酸钙 镁离子 一水碳酸钙 晶体生长 

分 类 号：TB321[一般工业技术—材料科学与工程]