Computer simulations of conformational behavior of bottlebrush polymers with van der Waals and reversible interactions

Bottlebrush polymers (BBPs) have attracted considerable attention due to their unique properties and applications. Understanding their structural organization is particularly important as the conformation of BBPs is strongly correlated to their self-assembly behavior in solution and ability to encapsulate or interact with other molecules. Developing a clear connection between molecular architecture and morphology provides critical design rules for developing BBPs as functional polymer materials. Using coarse-grained molecular dynamics simulations, we investigate structural properties of cyclic and linear BBPs with hydrophilic and hydrophobic sidechains in aqueous solution. We will discuss different conformational regimes of linear and cyclic heterograft BBPs including a dumbbell-like structure and a spherical unimolecular micelle with a single hydrophobic core surrounded by a hydrophilic corona. We will also discuss the conformations of BBPs with sidechains functionalized with association end-groups. By relating structural transitions to side-chain chemistry and topology, these results demonstrate that heterograft BBPs offer a variety of conformations controlled by the side-chain length and composition that can be broadly exploited in a variety of polymeric material applications, including encapsulation of hydrophobic moieties for drug and gene delivery or stimuli-responsive soft materials.