(692e) Design of Block Copolymers to Form Chiral Mesophases (single gyroid) Using Particle-Based Simulations

The self-assembly of chiral mesophases using block copolymers can arise from either achiral or chiral building blocks. In this talk, we will focus on using achiral triblock copolymers to produce the single gyroid morphology, resulting in a chiral structure. The selection of the building blocks should promote the formation of an alternating gyroid, providing a facile route towards the single gyroid. In this talk, we investigate the self-assembly of model achiral block copolymers into gyroid morphologies using coarse-grained molecular simulation. The interaction parameters of the triblock were chosen to be non-frustrated, to energetically favor the alternating gyroid. While successful, the formation of the morphology is found to be limited to a narrow volume fraction window in the phase diagram. We show that by co-assembling the triblock with a selective homopolymer, the volume fractions can be widely tuned. Finally, the geometric topology and net chirality are quantified, and the impact of chain packing and distribution is also elucidated.