(2d) Designing Colloidal Particles for Complex Self-Assembly Behavior

Colloidal particles, ranging from nanometers to micrometers in size, offer a versatile platform for creating new functional materials with exotic properties and controllable behavior. By encoding explicit short-range interactions, these simple building blocks have been shown to exhibit remarkable self-organization capabilities, spontaneously assembling into well-defined structures. Although the high tunability of particle interactions holds promise for designing desired or even new crystal structure configurations and behavior, our current understanding of the specific interactions that govern self-assembly processes remains limited. In my work, I use molecular dynamics simulations to study the self-assembly of particles interacting via multi-well isotropic pair potentials—proxies for the competing interactions that can come into play in experiments. To both explore and understand the vast parameter space of particle interactions, I developed a new functional form for a particle interaction potential in which all energy wells and maxima can be tuned independently and intuitively. Using rational forward design, I uncovered interactions that will assemble new crystal structure configurations, as well as trends connecting the characteristics of the underlying interaction potential with the resulting self-assembled crystal structures. In the same model systems, I have been studying spontaneous temperature-driven solid–solid phase transitions, which are difficult to observe directly in experiments, but which can be studied in such simulations. I characterize the kinetic pathways of these transitions and show how they may be controlled by the underlying particle interactions. My findings highlight structural diversity and a range of solid–solid phase transitions possible in simulation that are beyond the atomic scale, which can potentially be used to design new soft materials with advanced applications.

Research Interests: My research interests currently span the fields of nanoscale engineering, self-assembly, and crystallography. As a postdoc, I would like to expand my knowledge of physics-based modeling and computational techniques and am particularly interested in topics relating to hierarchical structures or biological self-assembly.