Conformational Statistics of Ribbon-like Chains

The chemistry of conjugated polymers and ladder polymers endows them with anisotropic bending stiffnesses in their backbones, giving rise to "ribbon-like" structures that the existing statistical polymer models do not fully capture. Here, we analyze a generalization to the worm-like chain (WLC) model, called the ribbon-like chain (RLC) model, which permits such conformational anisotropy and highlights the importance of backbone twisting stiffness. The free-chain Green function is solved, and the basic chain conformational properties are evaluated. The effects of anisotropic bending stiffness on the tangent and normal correlations, the radius of gyration, and the instantaneous chain shape are clearly revealed. Finally, parametrization, extension, and applications in the study of conjugated polymers are discussed.