Towards Understanding How the Solution Environment Impacts Crystal Morphology

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.