Biaxial Nematic Droplets and their Optical Textures: A Lattice Model Computer Simulation Study

Chiccoli, C.; Pasini, Paolo; Feruli, Ivan; Zannoni, Claudio

doi:10.1080/154214091010002

Cited by 16 publications

(11 citation statements)

References 20 publications

(24 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These are interesting properties because optical microscopy (either orthoscopy and conoscopy) is often used as a screening technique for quickly identifying LC phases, Chandrasekhar [13,72] predicted the two-brushes defects to be a signature of N b phases, differently from N u LC which are characterised instead by four-brushes defects. Chiccoli et al [74,42] have theoretically computed the free energy difference between two-and four-brushes defects, and produced optical images from MC computer simulations of a N b lattice model. Such studies have outlined that the presence of topologically stable two-brushes defects is not a universal fingerprint of N b phases because their appearance is related not only to the degree of biaxial orientational ordering but also to the magnitude of elastic constants.…”

Section: Single-site Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Computer simulations of biaxial nematics

Berardi

Muccioli

Orlandi

et al. 2008

J. Phys.: Condens. Matter

Self Cite

120

108

View full text Add to dashboard Cite

Abstract. Biaxial nematic (N b ) liquid crystals are a fascinating condensed matter phase that has baffled for more than thirty years scientists engaged in the challenge of demonstrating its actual existence, and which has only recently been experimentally found. During this period computer simulations of model N b have played an important role, both in providing the basic physical properties to be expected from these systems, and in giving clues about the molecular features essential for the thermodynamic stability of N b phases. However, simulations studies are expected to be even more crucial in the future for unravelling the structural features of biaxial mesogens at molecular level, and for helping in the design and optimisation of devices towards the technological deployment of N b materials. This review article gives an overview of the simulation work performed so far, and relying on the recent experimental findings, focusses on the still unanswered questions which will determine the future challenges in the field.

show abstract

Section: Single-site Modelsmentioning

confidence: 99%

“…Models (and simulations) have been extensively used to study distributions of the nematic directors and topological defects [13,72,73,74,42,75] in N b . Theories for the elastic [76,77,78,79,80,81,82,83,41], flexoelectric [84,85], and rheological [86] behaviour of N b have also been proposed.…”

Section: Order Parameters and Theoriesmentioning

confidence: 99%

Computer simulations of biaxial nematics

Berardi

Muccioli

Orlandi

et al. 2008

J. Phys.: Condens. Matter

Self Cite

120

108

View full text Add to dashboard Cite

show abstract

“…Because of their simplicity, it is possible to simulate systems that contain millions of spins. This allows the study of systems in complex geometries, such as in porous or disordered networks,52 or in device configurations 17, 28…”

Section: Computer Simulation Models Of Liquid Crystalsmentioning

confidence: 99%

“…One of the main limiting factors is the computational cost of atomistic simulations. Even on the largest available computers, it is rarely possible to simulate for longer than a few tens of nanoseconds for 1 000 atoms 52…”

Section: Computer Simulation Models Of Liquid Crystalsmentioning

confidence: 99%

Application and New Developments in Polymer‐Dispersed Liquid Crystal Simulation Studies

Jeon

Yin

Rhee

et al. 2007

Macro Theory & Simulations

View full text Add to dashboard Cite

Cover:The picture on the cover shows a large crowded bottle-brush polymer (top left) with anisotropic excluded volume scaling (top right) and a bottle brush copolymer (bottom right) exhibiting local phase separation showing 1d correlation length behavior (bottom left). Further details can be found in the article by H.-P. Hsu*, W. Paul, and K. Binder on page 660. Contents ReviewCurrently there is significant interest in the use of polymer-dispersed liquid crystals in display materials. Monte Carlo simulations have been used to study PDLCs in a variety of physical situations by different research groups. This article reviews present and past simulation studies of PDLCs. Different molecular simulation techniques applied to such systems are reviewed, along with the new key findings of bulk phase transitions. Some newly developed techniques (e.g., phase separation behavior) in PDLCs are also reported. New directions for future developments in PDLC research are also highlighted.

show abstract

“…Phase diagram along parabolic trajectory has been extensively studied earlier [17,19], and has been used as a prototype for several investigations [37][38][39][40][41]. The dispersion parabola also defines an interesting boundary separating regions of (γ, λ) parameter space: one region that makes the Hamiltonian fully attractive above the parabola and the other which makes it partly repulsive (below the parabola) [32].…”

Section: Introductionmentioning

confidence: 99%

Complex free-energy landscapes in biaxial nematic liquid crystals and the role of repulsive interactions: A Wang-Landau study

2017

View full text Add to dashboard Cite

General quadratic Hamiltonian models, describing interaction between crystal molecules (typically with D 2h symmetry) take into account couplings between their uniaxial and biaxial tensors.While the attractive contributions arising from interactions between similar tensors of the participating molecules provide for eventual condensation of the respective orders at suitably low temperatures, the role of cross-coupling between unlike tensors is not fully appreciated. Our recent study with an advanced Monte Carlo technique (entropic sampling) showed clearly the increasing relevance of this cross term in determining the phase diagram, contravening in some regions of model parameter space, the predictions of mean field theory and standard Monte Carlo simulation results. In this context, we investigated the phase diagrams and the nature of the phases therein, on two trajectories in the parameter space: one is a line in the interior region of biaxial stability believed to be representative of the real systems, and the second is the extensively investigated parabolic path resulting from the London dispersion approximation. In both the cases, we find the destabilizing effect of increased cross-coupling interactions, which invariably result in the formation of local biaxial organizations inhomogeneously distributed. This manifests as a small, but unmistakable, contribution of biaxial order in the uniaxial phase.The free energy profiles computed in the present study as a function of the two dominant order parameters indicate complex landscapes. On the one hand these profiles account for the unusual thermal behaviour of the biaxial order parameter under significant destabilizing influence from the cross terms. On the other, they also allude to the possibility that in real systems these complexities might be indeed inhibiting the formation of a low temperature biaxial order itself -perhaps reflecting the difficulties in their ready realization in the laboratory. 64.70.mf

show abstract

Biaxial Nematic Droplets and their Optical Textures: A Lattice Model Computer Simulation Study

Cited by 16 publications

References 20 publications

Computer simulations of biaxial nematics

Computer simulations of biaxial nematics

Application and New Developments in Polymer‐Dispersed Liquid Crystal Simulation Studies

Complex free-energy landscapes in biaxial nematic liquid crystals and the role of repulsive interactions: A Wang-Landau study

Contact Info

Product

Resources

About