Microphase separation in bottlebrush polymers under poor-solvent conditions

Molecular-dynamics simulations are used to study the structure of bottlebrush polymers with rigid backbones, for various grafting densities, side chain lengths, and varying solvent quality. While we confirm different states of the bottlebrush proposed by Sheiko et al. (Eur. Phys. J. E, 13 (2004) 125) we find that the transition between stretched and collapsed brushes occurs in a rather gradual manner. The pearl-necklace structure occurring at intermediate grafting densities and rather low temperatures has a pronounced medium-range order along the backbone.