Subproject for SiS; CAREER: Visualizing single-chain conformation and dynamics of bottlebrush polymers in the bulk state.

This proposal will address the fundamental question of how molecular architecture affects the structure and dynamics of polymer chains in the melt. Specifically, bottlebrush polymers will be investigated, which have attracted substantial attention for applications such as photonic materials and drug delivery, but an understanding of their fundamental physics is still incomplete. This work will close the knowledge gap through direct imaging of bottlebrush conformations in the melt using single-molecule super-resolution microscopy, an emerging optical microscopy technique in materials science that can non-invasively obtain real-space and real-time images with nanoscale resolution. The capabilities of this method are perfectly matched to the demands of the problem, which enables our work to directly visualize the structure and dynamics of bottlebrush polymers, thus answering academically interesting and technologically relevant questions such as how the molecular shape depends on polymer parameters, and how the nature of entanglement differs from models of linear polymer dynamics. All of these questions are ones where other techniques such as scattering, rheology, and simulation can only probe indirectly.