6533b863fe1ef96bd12c78a8
RESEARCH PRODUCT
Phase behavior of flexible and semiflexible polymers in solvents of varying quality.
Sergei A. EgorovArash NikoubashmanKurt BinderJiarul Midyasubject
Persistence lengthMaterials science010304 chemical physicsGeneral Physics and AstronomyThermodynamicsFOS: Physical sciencesCondensed Matter - Soft Condensed Matter010402 general chemistry01 natural sciences0104 chemical sciencesMolecular dynamicsCritical point (thermodynamics)Liquid crystalPhase (matter)0103 physical sciencesSoft Condensed Matter (cond-mat.soft)Ising modelDensity functional theoryPhysical and Theoretical ChemistryPhase diagramdescription
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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2019-05-16 | The Journal of chemical physics |