From gas-liquid to liquid crystalline phase behavior via anisotropic attraction: A computer simulation study in three and two dimensions

The partial phase behavior of a continuum molecular model for self-assembling semiflexible equilibrium polymers is studied via Monte Carlo and Molecular Dynamics simulation. We investigate the transfer from ordinary gas-liquid coexistence to the appearance of liquid crystallinity driven by excluded volume interaction between rod-like aggregates. The transfer between the two types of phase behavior is governed by a tunable anisotropic attractive interaction between monomer particles. The relation to dipolar fluid models, which are also known to form reversible chains, is discussed. In two dimensions, depending on the strength of the anisotropy, we find the formation of reversible networks as well as stiff rod-like aggregates. The phase transition observed in the presence of the network structures is compared to predictions of the Tlusty-Safran defect model.