Shape-Driven Colloidal Crystal--Crystal Transitions

Mimicking nature's ability to control energy and information in next-generation reconfigurable synthetic materials is a key challenge. Meeting this challenge with colloidal materials is promising because of recent developments in building block synthesis and the understanding of bulk assembly mechanisms. However, it is not understood, generally, how to drive bulk reconfiguration with building block reconfiguration, such as shape change. Here, we study the thermodynamics of shape-change-driven bulk colloidal crystal--crystal phase transitions. We find, depending on the local environment of the building block self-assembled structures and the difference between the two crystal structures, that a shape driven reconfiguration between crystal structures can be a first-order transition, or can occur without any thermodynamic phase transition whatsoever.