Armstrong Emma, Yeandel Stephen R, Harding John H, Freeman Colin L
Department of Materials Science and Engineering, Sir Robert Hadfield Building, University of Sheffield, Mappin Street, Sheffield S1 3JD, U.K.
Information School, The Wave, University of Sheffield, 2 Whitham Road, Sheffield S10 2AH, U.K.
Langmuir. 2025 Apr 1;41(12):8092-8105. doi: 10.1021/acs.langmuir.4c04738. Epub 2025 Mar 18.
This work uses a recently proposed methodology to calculate the free energies of calcite and aragonite interfaces with water. This method properly includes the entropic contributions, ignored or approximated in previous work. By including this entropic component, we show that the aqueous calcite {101̅4} surface has a lower free energy than any of the aragonite surfaces. This resolves the discrepancies in previous simulation work that suggested that an aragonite nucleus would be more stable than a calcite one. Our analysis of the water structure highlights the generally greater entropic contribution to the interfacial free energy at the aragonite/water interface than at the calcite one. These methods are applied to a range of temperatures to examine how the solution temperature alters the interfacial energies. Our results are then discussed in the context of calcium carbonate nucleation and polymorph-morphology selection under different environmental conditions.
这项工作采用了最近提出的方法来计算方解石和文石与水界面的自由能。该方法恰当地纳入了先前工作中被忽略或近似处理的熵贡献。通过纳入这一熵分量，我们表明方解石的 {101̅4} 水合表面的自由能低于任何文石表面。这解决了先前模拟工作中存在的差异，先前的模拟工作表明文石核比方解石核更稳定。我们对水结构的分析突出了与方解石/水界面相比，文石/水界面的界面自由能通常具有更大的熵贡献。这些方法被应用于一系列温度，以研究溶液温度如何改变界面能。然后，我们在不同环境条件下碳酸钙成核和多晶型形态选择的背景下讨论了我们的结果。
