Phase behavior of flexible and semiflexible polymers in solvents of varying quality
arXiv:1905.06789 · doi:10.1063/1.5110393
Abstract
The interplay of nematic order and phase separation in solutions of semiflexible polymers in solvents of variable quality is investigated by density functional theory (DFT) and molecular dynamics (MD) simulations. We studied coarse-grained models, with a bond-angle potential to control chain stiffness, for chain lengths comparable to the persistence length of the chains. We varied both the density of the monomeric units and the effective temperature that controls the quality of the implicit solvent. For very stiff chains only a single transition from an isotropic fluid to a nematic is found, with a phase diagram of "swan-neck" topology. For less stiff chains, however, also unmixing between isotropic fluids of different concentration, ending in a critical point, occurs for temperatures above a triple point. The associated critical behavior is examined in the MD simulations and found compatible with Ising universality. Apart from this critical behavior, DFT calculations agree qualitatively with the MD simulations.
References in corpus (9)
- Strong scaling of general-purpose molecular dynamics simulations on GPUs
- Critical behavior of active Brownian particles
- Chain length dependence of the polymer-solvent critical point parameters
- Precise Simulation of Near-critical Fluid Coexistence
- Anomalous fluctuations of nematic order in solutions of semiflexible polymers
- Depletion induced isotropic-isotropic phase separation in suspensions of rod-like colloids
- Asymmetric Fluid Criticality II: Finite-Size Scaling for Simulations
- Self-organisation of semi-flexible rod-like particles
- Structure Function of Polymer Nematic Liquid Crystals: A Monte Carlo Simulation