6533b7d1fe1ef96bd125c23f
RESEARCH PRODUCT
Orientational ordering transitions of semiflexible polymers in thin films: A Monte Carlo simulation
Kurt BinderViktor A. IvanovE. A. AnMarcus MüllerWolfgang PaulM. R. StukanA. S. RodionovaJulia A. Martemyanovasubject
chemistry.chemical_classificationPhase transitionMaterials scienceCondensed matter physicsCapillary actionMonte Carlo method02 engineering and technologyPolymer021001 nanoscience & nanotechnology01 natural sciencesCondensed Matter::Soft Condensed MatterchemistryLiquid crystalCritical point (thermodynamics)0103 physical sciencesVolume fractionThin film010306 general physics0210 nano-technologydescription
Athermal solutions (from dilute to concentrated) of semiflexible macromolecules confined in a film of thickness D between two hard walls are studied by means of grand-canonical lattice Monte Carlo simulation using the bond fluctuation model. This system exhibits two phase transitions as a function of the thickness of the film and polymer volume fraction. One of them is the bulk isotropic-nematic first-order transition, which ends in a critical point on decreasing the film thickness. The chemical potential at this transition decreases with decreasing film thickness ("capillary nematization"). The other transition is a continuous (or very weakly first-order) transition in the layers adjacent to the hard planar walls from the disordered phase, where the bond vectors of the macromolecules show local ordering (i.e., "preferential orientation" along the x or y axes of the simple cubic lattice, but no long-range orientational order occurs), to a quasi-two-dimensional nematic phase (with the director at each wall being oriented along either the x or y axis), while the bulk of the film is still disordered. When the chemical potential or monomer density increase, respectively, the thickness of these surface-induced nematic layers grows, causing the disappearance of the disordered region in the center of the film.
year | journal | country | edition | language |
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2011-05-31 | Physical Review E |