Effects of conformational chirality on the lamellar morphology in block copolymers

Block copolymer self-assembly for model polymers adopting random-coil conformations has been extensively studied and is well-understood. Recent advances in polymer synthesis have led to the development of a new class of polymer molecules capable of adopting conformational chirality, that can also result in novel chiral morphologies such as helices and single gyroids. In this study, we use particle-based simulations to investigate the phase behavior of model block copolymers exhibiting conformational chirality. A wide range of conformations between random-coil and perfect helices are obtained by tuning the angular and dihedral interactions in a bead-spring model. Conformational chirality of the molecules is quantified by the average helicity and correlated with the average end-to-end distance. The self-assembly of these molecules into the lamellar morphology is investigated and effects of chain helicity and end-to-end distance on the thermodynamics (order-disorder transition) and material properties (domain spacing) are elucidated.