Towards Understanding How the Solution Environment Impacts Crystal Morphology

晶体形态对离子晶体的力学、流变性和催化性能起着决定性的作用。因此，已经作出了相当大的努力来建立简单和廉价的方法来控制晶体的哪些面被暴露。从溶液或熔体中结晶特别有吸引力，因为它适合大规模合成并允许材料的可回收性。然而，在我们对分子尺度上是什么控制着晶体形态的理解上，还有很大的差距。在这个项目中，分子动力学模拟将用于阐明控制离子晶体生长的微观过程。特别是，我们的目的是解释实验观察报告从立方体到八面体的盐晶体的形态变化在改变过饱和或引入添加剂。这将在溶液中极性晶体表面的最新理论框架的背景下完成。我们还将利用分子模拟的最新进展，使离子吸附到表面的精确建模，以及使晶体在恒定化学势下生长的技术。

Crystal morphology plays a determining role in the mechanical, rheological, and catalytic properties of ionic crystals. As such, considerable effort has been made to establish simple and inexpensive approaches to control which facets of a crystal are exposed. Crystallization from solution or the melt is particularly appealing, as it is amenable to large scale synthesis and permits recyclability of materials. There are major gaps, however, in our understanding of what controls crystal morphology at the molecular scale. In this project, molecular dynamics simulations will be used to shed light on the microscopic processes that control the growth of ionic crystals. In particular, we aim to explain experimental observations that report changes in morphology of salt crystals from cubes to octahedra upon changing the supersaturation or introduction of additives. This will be done within the context of a recent theoretical framework for polar crystal surfaces in solution. We will also exploit recent advances in molecular simulations that allow accurate modeling of ion adsorption to surfaces, along with techniques that allow crystals to grow at constant chemical potential.