Probing conformational properties of conjugated polymers in dilute solutions under variable solvent quality via coarse-grained modeling

Abstract

Conjugated polymers (CPs), characterized by rigid conjugation backbones and flexible peripheral side chains, hold significant promise in various organic optoelectronic applications. In this study, we employ coarse-grained molecular dynamics (CG-MD) simulations to investigate the intricate interplay of solvent quality, temperature, and chain architecture (e.g., side-chain length and molecular mass) on the conformational behaviors of CPs in dilute solutions. Our research uncovers distinctive conformational behaviors under varying solvent conditions, highlighting the versatile nature of polymer chains, which can adopt extended configurations in good solvents and transition to aggregated states in poor solvents. Additionally, the mass scaling exponent (Formula presented.), a robust structural descriptor, consistently described CPs behavior across diverse architectures and solvent conditions. Furthermore, our study shows that a CP with longer side-chain exhibits improved solubility, which is further confirmed by experimental observations. Moreover, our analysis of the shape descriptor (Formula presented.) provided valuable insights into the symmetry and dimensionality of CPs under varying solvent conditions. These findings offer a comprehensive understanding of conformational behaviors of CPs in dilute solution, which are helpful in guiding the conformational design of polymer for specific applications.