NSF Award
2214590
Nontechnical Abstract<br/><br/>Crystallization—the spontaneous ordering of atoms, molecules, or other small particles—has fascinated humankind for centuries. The study of crystallization has led to fundamental developments in our understanding of matter, for example, how water freezes to become ice. Crystallization is also central to a wide variety of important industries, ranging from microelectronics to pharmaceuticals. Yet, despite the ubiquity of crystallization in both fundamental and applied science, many mysteries regarding the dynamics of crystallization remain. The scientific objective of this research project is to understand the dynamic pathways by which crystals form and to use that understanding to develop new methods for making macroscopic single crystals with exotic materials properties. The research will reveal new fundamental knowledge about the physics of crystallization and lay the foundation for programmable nanomaterials of the future, which could find applications in optical communications, light-harvesting, and other next-generation technologies. The research project also trains students in the interdisciplinary field of soft condensed matter physics and engages the public in conversations about science. More specifically, the research team is developing student-led, student-focused summer programs designed to provide undergraduate students with practical hands-on training in the laboratory, while also promoting diversity and inclusion by creating a community of researchers and reinforcing group cohesion. The team is also creating outreach activities with a local science museum focused on enhancing interest and scientific literacy in the surrounding community.<br/><br/>Technical Abstract<br/><br/>The goal of this research project is to understand the fundamental thermodynamic and kinetic driving forces that govern the dynamic pathways to crystallization, and to develop practical strategies for controlling those pathways to create new optical metamaterials from DNA-coated colloids. The proposed research is organized around two specific studies. In the first study, the research team is exploring how the kinetics of nucleation and growth emerge from the pair-interaction potential, as well as the details of the parent fluid phase and the child crystal phase. The research team uses an experimental approach combining droplet-based microfluidics with optical microscopy to systematically quantify the full dynamic evolution of hundreds of experiments running in parallel. They are also developing a suite of theoretical tools based on the statistical mechanics of multivalent interactions, classical nucleation theory, and classical theories of crystal growth to uncover microscopic information about the crystallization pathways and to create a data-driven framework to guide the design of their experiments. In the second study, the research team is utilizing their fundamental understanding of nucleation and growth to create rational nonequilibrium protocols for forming single crystals with prescribed structures, which could be used in future applications in photonics and plasmonics. Here they draw inspiration from traditional industrial practices, such as slow temperature ramps, temperature cycling, multistep nucleation and growth protocols, and seeded nucleation. While existing studies have focused primarily on expanding the diversity of static structures that form in equilibrium, the research team is working to understand the rich dynamical pathways by which those structures self-assemble and to develop new approaches to control those pathways in order to assemble macroscopic programmable materials from colloids.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
