Molecular Simulation of acid-induced crystal dissociation

酸诱导晶体解离的分子模拟

• 批准号: 415210974
• 负责人: Professor Dr. Dirk Zahn
• 金额: --
• 依托单位: Computer-Chemie-Centrum (CCC)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/415210974?language=en
• 关键词: Molecular; Simulation; acid; induced; crystal

While molecular simulation techniques for studying crystal nucleation and growth experienced significant progress in the past 10 years, the inverse process of crystal dissociation received much less attention. This particularly holds for the investigation of dissolving solids by the help of acids – which combines several challenges that so far render such processes elusive to current modelling approaches. On the one hand, the study of proton transfers calls for quantum calculations that limit the accessible time and length scales of the simulation models. However, statistical significance implies extended sampling of large numbers of possible reaction events and sufficiently large simulation models to address rough surfaces, including the formation of notches and the back-propagation of steps during crystal dissociation. The aim of the present proposal is to transfer the Kawska-Zahn method originally formulated for crystal nucleation and growth to the study of the acid-induced dissolving of solids. This shall provide the efficient prediction of suitable protonation sites, quantum/classical modelling of reactive events and efficient sampling of cascades of dissociation trajectories – thus allowing in-depth mechanistic investigations based on dissolving nm-sized layers. Method development shall be accompanied by application to two rather different classes of systems. As demonstrators we wish to explore the dissociation of calcium carbonates, phosphates and molecular crystals in water as functions of pH, as relevant to sanitary cleaning, biomineral shaping and the uptake of pharmaceutical compounds in the intestinal system.

在过去的10年里，研究晶体成核和生长的分子模拟技术取得了重大进展，但晶体解离的逆过程却很少受到关注。这特别适用于通过酸的帮助溶解固体的研究-这结合了几个挑战，到目前为止，这些挑战使得这种过程难以实现当前的建模方法。一方面，质子转移的研究需要量子计算，这限制了模拟模型的可访问时间和长度尺度。然而，统计显著性意味着大量可能的反应事件和足够大的模拟模型的扩展采样，以解决粗糙的表面，包括形成的切口和反向传播的步骤在晶体解离。本提案的目的是将最初用于晶体成核和生长的Kawska-Zahn方法转移到固体酸诱导溶解的研究中。这将提供合适的质子化位点的有效预测，反应事件的量子/经典建模和解离轨迹级联的有效采样-从而允许基于溶解纳米级层的深入机制研究。方法开发应伴随着对两类不同系统的应用。作为示范者，我们希望探索碳酸钙，磷酸盐和分子晶体在水中的解离作为pH值的函数，与卫生清洁，生物矿物成型和肠道系统中药物化合物的吸收有关。