Bottlebrush polymers, networks, and devices*

A bottlebrush polymer consists of a long linear backbone densely grafted with many relatively short linear side chains. Analogous to sausages versus spaghetti, a bottlebrush polymer, in some cases, essentially resembles a 'fat' linear polymer and is difficult to entangle. The unique molecular architecture of bottlebrush polymers makes them a platform for designing soft (bio)materials with properties that are inaccessible to their linear counterparts. In this talk, I will describe our recent efforts to understand and apply bottlebrush polymers. First, I will introduce a new theoretical framework for the molecular structure of bottlebrush polymers. Corroborated with experiments, we discover that, in some instances, the bottlebrush backbone can fold to store length, a phenomenon opposite to all previous understandings of bottlebrush polymers. Second, I will demonstrate how the use of foldable bottlebrush polymers as network strands provides a universal strategy for decoupling stiffness and extensibility—two fundamental mechanical properties that are inherently negatively correlated in polymer networks. Finally, I will discuss the applications of bottlebrush-based polymers as a new class of soft materials for additive manufacturing of functional structures and devices.