Simulating the nematic-isotropic phase transition of liquid crystal model via generalized replica-exchange method

In this work, the advantages of applying the temperature and pressure replica-exchange method to investigate the phase transitions and the hysteresis for liquid-crystal fluids were demonstrated. In applying this method to the commonly used Hess–Su liquid-crystal model, heat capacity peaks and points of phase co-existence were observed. The absence of a smectic phase at higher densities and a narrow range of the nematic phase were reported. The identity of the crystalline phase of this system was found to a hexagonal close-packed solid. Since the nematic-solid phase transition is strongly first order, care must be taken when using this model not to inadvertently simulate meta-stable nematic states at higher densities. In further analysis, the Weighted Histogram Analysis Method was applied to verify the precise locations of the phase transition points.

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Investigating the solid-liquid phase transition of water nanofilms using the generalized replica exchange method

The Journal of Chemical Physics ◽

10.1063/1.4896513 ◽

2014 ◽

Vol 141 (18) ◽

pp. 18C525 ◽

Cited By ~ 9

Author(s):

Qing Lu ◽

Jaegil Kim ◽

James D. Farrell ◽

David J. Wales ◽

John E. Straub

Keyword(s):

Phase Transition ◽

Liquid Phase ◽

Replica Exchange ◽

Exchange Method ◽

Liquid Phase Transition ◽

Solid Liquid ◽

Replica Exchange Method

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Dissipative structures induced by photoisomerization in a dye-doped nematic liquid crystal layer

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2017.0382 ◽

2018 ◽

Vol 376 (2135) ◽

pp. 20170382 ◽

Cited By ~ 1

Author(s):

I. Andrade-Silva ◽

U. Bortolozzo ◽

C. Castillo-Pinto ◽

M. G. Clerc ◽

G. González-Cortés ◽

...

Keyword(s):

Phase Transition ◽

Liquid Crystal ◽

Nematic Liquid Crystal ◽

Dissipative Structures ◽

Input Power ◽

Isotropic Phase ◽

Crystal Layer ◽

Liquid Crystal Layer ◽

Nematic Liquid Crystal Layer ◽

Interface Propagation

Order–disorder phase transitions driven by temperature or light in soft matter materials exhibit complex dissipative structures. Here, we investigate the spatio-temporal phenomena induced by light in a dye-doped nematic liquid crystal layer. Experimentally, for planar anchoring of the nematic layer and high enough input power, photoisomerization processes induce a nematic–isotropic phase transition mediated by interface propagation between the two phases. In the case of a twisted nematic layer and for intermediate input power, the light induces a spatially modulated phase, which exhibits stripe patterns. The pattern originates as an instability mediated by interface propagation between the modulated and the homogeneous nematic states. Theoretically, the phase transition, emergence of stripe patterns and front dynamics are described on the basis of a proposed model for the dopant concentration coupled with the nematic order parameter. Numerical simulations show quite a fair agreement with the experimental observations. This article is part of the theme issue ‘Dissipative structures in matter out of equilibrium: from chemistry, photonics and biology (part 2)’.

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