(747e) Solvent-Induced Conformation Transition of Bottlebrush Copolymers By Coarse-Grained Molecular Dynamics Simulations

Bottlebrush polymers (BBPs) are linear macromolecules with a highly grafted backbone and long side-chains of polymers. Bottlebrush copolymers, a special class of BBPs, consisted of side-chains with multiple types of polymers. They can self-assemble into a variety of nanostructures, which can be applied in drug delivery and medical imaging. The overall conformations of BBPs and their self-assembled structures can be altered by solvents. Here, to understand the effect of solvents on the conformations of side-chains and backbone of bottlebrush copolymers, we have performed coarse-grained (CG) molecular dynamics (MD) simulations of bottlebrush copolymers with polystyrene (PS) and poly(acrylic acid) (PAA) as side chains in different solvents, i.e. dimethylformamide (DMF) and water. The CG models of bottlebrush copolymers were developed by varying the positions of PS and PAA side-chains with 30 monomers (30-mer). Specifically, bottlebrush copolymers with three different types of grafting positions were studied in pure DMF, pure water, and their binary mixtures. The structure of these bottlebrush copolymers was characterized by the radius of gyration and end-to-end distance. The structure of solvents around the side-chains and backbones of the bottlebrush copolymers was explored by calculating the radial distribution functions (RDFs).