Demixing by a Nematic Mean Field: Coarse-Grained Simulations of Liquid Crystalline Polymers

Polymers

Monica Olvera de la Cruz¹  Su-Mi Hur²  Julio C. Armas-Pérez²  Juan J. de Pablo³  Abelardo Ramírez-Hernández³ 

[1] Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA;Institute for Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA;Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA;

关键词: liquid crystalline polymers;    coarse grained models;    polymer blends;   

DOI  :  10.3390/polym9030088

来源: DOAJ

【 摘 要 】

Liquid crystalline polymers exhibit a particular richness of behaviors that stems from their rigidity and their macromolecular nature. On the one hand, the orientational interaction between liquid-crystalline motifs promotes their alignment, thereby leading to the emergence of nematic phases. On the other hand, the large number of configurations associated with polymer chains favors formation of isotropic phases, with chain stiffness becoming the factor that tips the balance. In this work, a soft coarse-grained model is introduced to explore the interplay of chain stiffness, molecular weight and orientational coupling, and their role on the isotropic-nematic transition in homopolymer melts. We also study the structure of polymer mixtures composed of stiff and flexible polymeric molecules. We consider the effects of blend composition, persistence length, molecular weight and orientational coupling strength on the melt structure at the nano- and mesoscopic levels. Conditions are found where the systems separate into two phases, one isotropic and the other nematic. We confirm the existence of non-equilibrium states that exhibit sought-after percolating nematic domains, which are of interest for applications in organic photovoltaic and electronic devices.

【 授权许可】

Unknown