文献类型：期刊文献

英文题名：Investigation of amorphous calcium carbonate's formation under high concentration of magnesium: The prenucleation cluster pathway

作者：Zhang, Jie[1];Zhou, Xiaqing[1];Dong, Chunhua[1];Sun, Yuzhu[1];Yu, Jianguo[1]

机构：[1]East China Univ Sci & Technol, Natl Engn Res Ctr Integrated Utilizat Salt Lake R, Shanghai 200237, Peoples R China

年份：2018

卷号：494

起止页码：8

外文期刊名：JOURNAL OF CRYSTAL GROWTH

收录：;EI(收录号：20182005191481);WOS:【SCI-EXPANDED(收录号:WOS:000432749700002)】；

基金：The authors would like to thank the financial support from Natural Science Foundation of China (NSFC, No. U1507105), National Sci-Tech Support Plan (No. 2015BAB10B01), National Key R&D Program (No. 2016YFC0401203) and China Scholarship Councilamad and Chao Li for contribution to the language editing of this manuscript and Yimei Wu for the help with experiments.

语种：英文

外文关键词：Impurities; Free energy barrier; Supersaturated solutions; Amorphous calcium carbonate; Magnesium

摘要：This paper investigates the formation of amorphous calcium carbonate under high magnesium concentration (Mg/Ca = 6) via several novel methods. While feeding calcium chloride solution into the mixed solution of magnesium chloride and sodium carbonate, a large amount of calcium ions (>0.13 mol/L) stably coexisted with the amorphous calcium carbonate in the solution. The calcium concentration detected by the calcium ion selective electrode was proportional to the calcium concentration added. Surprisingly, the ratio of magnesium to calcium in the amorphous calcium carbonate was just 0.07, and the concentration of calcium continued to increase in the solution after the formation of the amorphous calcium carbonate. We propose that stable prenucleation cluster formed in the solution, which stably coexisted with the amorphous calcium carbonate because of the incorporation of hydrated magnesium ions. The high dehydration free energy barrier of magnesium ions led to its slow dehydration. Also, the hydroxide ion helped to bypass the high dehydration free energy barrier. This research indicates the possible significant role of prenucleation cluster pathway in the calcium carbonate crystallization. (C) 2018 Elsevier B.V. All rights reserved.