Berlin 2018 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 46: Poster Session IV

CPP 46.42: Poster

Mittwoch, 14. März 2018, 11:00–13:00, Poster A

Modeling morphologies with liquid crystalline order in copolymers with conjugated blocks — •Jianrui Zhang, Kurt Kremer, and Kostas Daoulas — Max Planck Institute for Polymer Research, Mainz, Germany

Block copolymers (BCP) with conjugated blocks are interesting for organic electronics. Because of the π-π stacking interactions between aromatic rings in the backbone and short side chains, conjugated blocks can form liquid crystals (LC) with collective planar order or crystalline phases. Therefore, the phase behavior of BCP with conjugated blocks is significantly more complex comparing to classical BCP and their properties are less understood. Here we investigate the effects of collective planar order on conformational and structural properties of these materials. For this purpose, we employ a generic model, where conjugated blocks can create collective planar order characterized by biaxial nematic symmetry. We consider diblock copolymers consisting of one flexible and one conjugated block, and restrict our study to the simplest case -- lamellar phase. First Monte Carlo (MC) simulations in the canonical ensemble are used to locate approximately the region of the parameter space where lamellae are formed. Then variable box-shape MC simulations are performed to find optimized lamellae with uniform stress. The optimized lamellae comprise alternating amorphous and biaxial layers, formed by flexible and conjugated blocks respectively. Interestingly, we find that different biaxial layers have the same preferred chain alignment direction but different π-stacking directions. This observation indicates decorrelation between biaxial layers.