Directed self-assembly of Janus Bottlebrush Polymers from A-Branch-B Diblock Macromonomers

Recent advances in polymerization strategies have facilitated the synthesis of precisely controlled polymer architectures. Bottlebrush block copolymers BBCPs is a distinct structure that is characterized by side-chains densely grafted on a linear backbone. BBCPs exhibit novel properties such as reduced entanglement density, improved micro-phase separation, and dense functionality. Here, we study a particular form of BBCPs constituting of a series of tethered AB linear diblock chains. Hence, the A and B blocks phase separate with the backbone serving as an interface. The added constraint imposed by the polymer backbone on the equilibrium spacing of the neighboring AB diblocks directly manifests itself in the resulting morphologies. Simulations using self-consistent field theory SCFT reveal the structural effects on the characteristics of micro-phase separation. In particular, the effect of grafting density on domain spacing and effective segregation. In addition, the self-assembly of BBCPs under confinement shows distinct orientation preferences compared to its linear AB counterpart. Free energy calculation reveals regions of stability of different orientations based on segregation strength and molecular architecture. ”