Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface

Shvetsov, S. A.; Rudyak, Vladimir Yu.; Emelyanenko, A. V.; Boiko, N. I.; Zhang, Yan Song; Liu, Jui Hsiang; Khokhlov, Alexei R.

doi:10.1016/j.molliq.2018.01.054

Cited by 12 publications

(4 citation statements)

References 27 publications

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“…When the droplets are observed along or perpendicular to the boojum axis they exhibit a cross pattern, while at intermediate angles a variety of patterns exists with respect to the crossed polarizers. [ 87,98 ] Using bright field microscopy one can readily identify the surface defects.…”

Section: The Liquid Crystalline Statementioning

confidence: 99%

Seeing the Unseen: The Role of Liquid Crystals in Gas‐Sensing Technologies

Esteves

Ramou

Porteira

et al. 2020

Advanced Optical Materials

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Fast, real‐time detection of gases and volatile organic compounds (VOCs) is an emerging research field relevant to most aspects of modern society, from households to health facilities, industrial units, and military environments. Sensor features such as high sensitivity, selectivity, fast response, and low energy consumption are essential. Liquid crystal (LC)‐based sensors fulfill these requirements due to their chemical diversity, inherent self‐assembly potential, and reversible molecular order, resulting in tunable stimuli‐responsive soft materials. Sensing platforms utilizing thermotropic uniaxial systems—nematic and smectic—that exploit not only interfacial phenomena, but also changes in the LC bulk, are demonstrated. Special focus is given to the different interaction mechanisms and tuned selectivity toward gas and VOC analytes. Furthermore, the different experimental methods used to transduce the presence of chemical analytes into macroscopic signals are discussed and detailed examples are provided. Future perspectives and trends in the field, in particular the opportunities for LC‐based advanced materials in artificial olfaction, are also discussed.

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Section: The Liquid Crystalline Statementioning

confidence: 99%

Seeing the Unseen: The Role of Liquid Crystals in Gas‐Sensing Technologies

Esteves

Ramou

Porteira

et al. 2020

Advanced Optical Materials

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“…In this case, the tilt angle is in the range

, but there is an azimuthal degeneration of the director orientation ( Figure 1 d). Such boundary conditions are formed at the interface between LC and its own isotropic phase [ 31 , 32 ] or LC and isotropic liquid doped with surfactant [ 33 , 34 , 35 , 36 ]. For LC 5CB a conical anchoring with tilt angles

and

is specified on the solid substrates covered with the polystyrene or polyisoprene, respectively [ 37 ].…”

Section: Introductionmentioning

confidence: 99%

Nematic Structures under Conical Anchoring at Various Director Tilt Angles Specified by Polymethacrylate Compositions

et al. 2021

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Dependence of the director tilt angle of nematic liquid crystal (LC) under conical anchoring from the two-component polymer mixture composition has been studied. We varied the ratio of poly(isobutyl methacrylate) (PiBMA), which specifies a conical anchoring for the nematic liquid crystal LN-396, and poly(methylmethacrylate) (PMMA) assigning a tangential alignment for the same nematic. An oblique incidence light technique to determine a tilt angle has been used. It has been shown that the tilt angle increases from 0∘ to 47.7∘ when PiBMA:PMMA ratio changes in the range 30:70 to 100:0. The specific optical textures viewed under the polarizing microscope and proper orientational structures have been considered for various compositions of the polymer films. An electric field action on the formed orientational structures has been investigated. The obtained results are promising for the application in various electro-optical LC devices with a conical anchoring in which the director tilt angle is a crucial parameter: a controlled diffraction gratings, an electrically operated achromatic rotators of linear light polarization, etc.

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“…Markov chain Monte Carlo simulated annealing is used to find energy-optimal structures of droplets of liquid crystal (LC droplets) droplet structures. It previously showed good results for nematic and cholesteric LC [20,35,39]. The use of MCMC stochastic optimization by simulated annealing [10,30] allows us to almost completely ignore the problem of the trapping into local minima, in contrast to the Newtonian-like iterative methods.…”

Section: Introductionmentioning

confidence: 99%

Efficient Implementation of Liquid Crystal Simulation Software on Modern HPC Platforms

Afanasyev

Lichmanov

Rudyak

et al. 2021

JSFI

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In this paper we demonstrate the process of efficient porting a software package for Markov chain Monte Carlo (MCMC) simulations on a finite cubic lattice on multiple modern architectures: Pascal, Volta and Turing NVIDIA GPUs, NEC SX-Aurora TSUBASA vector engines and Intel Xeon Gold processors. In the studied software, MCMC methodology is used for simulations of liquid crystal structures, but it can be as well employed in a wide range of problems of mathematical physics and numerical methods. The main goals of this work are to determine the best software optimization strategy for this class of algorithms and to examine the speed and the efficiency of such simulations on modern HPC platforms. We evaluate the effects of various optimizations, such as using more suitable memory access patterns, multitasking for efficient utilization of massive parallelism on the target architectures, improved cache hit-rates, parallel workload balancing, etc. We perform a detailed performance analysis for each target platform using software tools such as nvprof, Ftrace and VTune. On this basis, we evaluate and compare the efficiency of the developed computational kernels on different platforms and subsequently rank these platforms by their performance. The results show that NVIDIA GPU and NEC SX-Aurora TSUBASA platforms, although at first glance seem very different, require similar optimization approaches in many cases due to similarities in data processing principles.

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Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface

Cited by 12 publications

References 27 publications

Seeing the Unseen: The Role of Liquid Crystals in Gas‐Sensing Technologies

Seeing the Unseen: The Role of Liquid Crystals in Gas‐Sensing Technologies

Nematic Structures under Conical Anchoring at Various Director Tilt Angles Specified by Polymethacrylate Compositions

Efficient Implementation of Liquid Crystal Simulation Software on Modern HPC Platforms

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