Log in

Relevant bibliographies by topics / Nematic layer / Journal articles

Journal articles on the topic 'Nematic layer'

To see the other types of publications on this topic, follow the link: Nematic layer.

Author: Grafiati

Published: 30 May 2022

Last updated: 31 May 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Nematic layer.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

SORIA, S., D. SCHUHMACHER, G. MAROWSKY, R. BARBERI, F. CIUCHI, S. PAUS, and T. RASING. "PROBING ALIGNMENT OF LIQUID CRYSTALS ON SILANE DERIVATIVES BY SECOND HARMONIC GENERATION." Journal of Nonlinear Optical Physics & Materials 10, no. 02 (June 2001): 133–42. http://dx.doi.org/10.1142/s0218863501000486.

Full text

Abstract:

We studied surface second-harmonic generation from thin films of 4'-n-pentyl-4-cyano-biphenyl (5CB) nematic liquid crystal (NLC) deposited onto layers of several silanes dipped on conductive glasses. We also studied a new liquid crystalline polymer deposited onto silanized substrates. The cinnamoyl side groups of this polymer can be aligned by linearly polarized UV light. The average orientation and surface order of the nematic were determined by Fourier analysis of the reflected and transmitted angular dependent second harmonic signal. The aim was to check the possible use of these materials as a control layer for the anchoring properties of nematics.

APA, Harvard, Vancouver, ISO, and other styles

2

POLAT, ÖMER, ARIF NESRULLAJEV, and ŞENER OKTIK. "EFFECT OF THICKNESS OF LIQUID CRYSTALLINE LAYER ON THE THERMOTROPIC AND THERMODYNAMICAL PROPERTIES OF NEMATIC-ISOTROPIC LIQUID AND ISTROPIC LIQUID-NEMATIC PHASE TRANSITIONS." International Journal of Modern Physics B 20, no. 23 (September 20, 2006): 3383–94. http://dx.doi.org/10.1142/s0217979206034765.

Full text

Abstract:

In this work, effect of thickness of the liquid crystalline layer on the morphologic, thermotropic and thermodynamical properties of the nematic–isotropic liquid and isotropic liquid–nematic phase transitions in Shiff based liquid crystals has been investigated. The shift of temperatures of the nematic–isotropic liquid and isotropic liquid–nematic phase transitions to the lower temperatures and the widening of linear and temperature widths of the heterophase regions of these phase transitions by the increase in the thickness of liquid crystalline layer have been found. The effect of thickness of liquid crystalline layer on morphologic, thermotropic and thermodynamical properties of liquid crystals under investigations is connected with change of interaction energy between liquid crystalline molecules and reference surfaces.

APA, Harvard, Vancouver, ISO, and other styles

3

Andrade-Silva, I., U. Bortolozzo, C. Castillo-Pinto, M. G. Clerc, G. González-Cortés, S. Residori, and M. Wilson. "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 376, no. 2135 (November 12, 2018): 20170382. http://dx.doi.org/10.1098/rsta.2017.0382.

Full text

Abstract:

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)’.

APA, Harvard, Vancouver, ISO, and other styles

4

Jaworowicz, Katarzyna, Katarzyna A. Brzda¸kiewicz, Mirosław A. Karpierz, and Marek Sierakowski. "Spatial Solitons in Twisted Nematic Layer." Molecular Crystals and Liquid Crystals 453, no. 1 (September 2006): 301–7. http://dx.doi.org/10.1080/15421400600653688.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Budagovsky, Ivan, Aleksey Kuznetsov, Sergey Shvetsov, Mikhail Smayev, Alexander Zolot’ko, Alexey Bobrovsky, Natalia Boiko, and Valery Shibaev. "Phase Structure Recording in a Nematic Side-Chain Liquid-Crystalline Polymer." Polymers 12, no. 2 (February 6, 2020): 356. http://dx.doi.org/10.3390/polym12020356.

Full text

Abstract:

Dye-doped nematic side-chain liquid-crystalline polymers possess extraordinary large optical nonlinearity and ability to store the induced orientational deformations in a glassy state, which makes them a very promising material for photonic applications. In this study, the phase structures were generated and recorded in the bulk of a 50-μm layer of a nematic liquid-crystalline side-chain polymer, containing polyacrylate backbone, spacer having five methylene groups, and phenyl benzoate mesogenic fragment. The polymer was doped with KD-1 azodye. The director field deformations induced by the light beam close to the TEM01 mode were studied for different geometries of light–polymer interaction. The phase modulation depth of 2π was obtained for the 18-μm spacing between intensity peaks. The experimental data were analyzed based on the elastic continuum theory of nematics. The possibility to induce and record positive and negative microlenses in the polymer bulk was shown experimentally.

APA, Harvard, Vancouver, ISO, and other styles

6

Braun, F. N., T. J. Sluckin, and E. Velasco. "Director distortion in a nematic wetting layer." Journal of Physics: Condensed Matter 8, no. 16 (April 15, 1996): 2741–54. http://dx.doi.org/10.1088/0953-8984/8/16/003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Son, Seung-Rak, and Jun Hyup Lee. "Vertical Alignment of Nematic Liquid Crystals Based on Spontaneous Alignment Layer Formation between Silver Nanowire Networks and Nonionic Amphiphiles." Crystals 10, no. 10 (October 9, 2020): 913. http://dx.doi.org/10.3390/cryst10100913.

Full text

Abstract:

The vertical arrangement of nematic liquid crystals (LCs) in displays can be generally achieved by introducing a polyimide material onto indium tin oxide electrodes. However, this method requires multiple coating and deposition processes as well as high curing temperature, restricting the potential applicability to flexible displays. Thus, we herein propose the facile approach for homeotropic alignment of nematic LCs based on spontaneous alignment layer formation between silver nanowire networks and nonionic amphiphiles. The silver nanowires as transparent electrode materials were spin-coated on glass substrate and 4-(4-heptylphenyl)benzoic acids as nonionic amphiphiles were doped into the LC medium. The nonionic amphiphiles were spontaneously bonded to the polyvinylpyrrolidone capping layer of silver nanowire networks through polar interactions, creating the self-assembled alignment layer of nonionic amphiphiles on silver nanowire electrodes. In addition, the alkyl chains of the amphiphiles interacted with the LC molecules, leading to stable directional LC alignment along vertical direction. The electro-optical characteristics of the manufactured LC cell were comparable to those of conventional device including polyimide layer and indium tin oxide electrode. Overall, the combination of silver nanowire electrode and nonionic amphiphiles presents a new way to achieve the vertical alignment of nematic LCs without polyimide layer.

APA, Harvard, Vancouver, ISO, and other styles

8

Sullivan, Donald E., and Reinhard Lipowsky. "On the free energy of nematic wetting layers." Canadian Journal of Chemistry 66, no. 4 (April 1, 1988): 553–56. http://dx.doi.org/10.1139/v88-094.

Full text

Abstract:

The contributions to the free energy of a nematic wetting layer as a function of its thickness l are analyzed. The longest-range contribution is due to distortion of the nematic director across the film, resulting from different preferred molecular orientations at the two interfaces bounding the film. Van der Waals forces as well as the decaying tails of the interfacial order-parameter profiles yield contributions to the free energy of successively shorter range. These effects lead to crossovers between different scaling régimes for variation of the mean wetting-layer thickness with temperature. Experimental implications of the results are described.

APA, Harvard, Vancouver, ISO, and other styles

9

Kozhevnikov, E. N., and Y. V. Samoilova. "SPATIALLY MODULATED STRUCTURES IN NEMATIC LIQUID CRYSTAL UNDER OSCILLATORY COUETTE FLOW AT ULTRALOW FREQUENCIES." Vestnik of Samara University. Natural Science Series 18, no. 6 (June 9, 2017): 113–23. http://dx.doi.org/10.18287/2541-7525-2012-18-6-113-123.

Full text

Abstract:

The distortion of homeotropic structure of nematic liquid crystal under the inﬂuence of periodic shear at ultralow frequencies is theoretically described. It is shown that periodic shear action results in spatially modulated structure in NLC layer. Threshold shear amplitude and spacial periodicity of new molecular orientational structure are found on the base of nonlinear nematic liquid crystal hydrodynamic equations using Galerkin method. Theoretical analysis shows that at low frequencies threshold shear amplitude does not depend on frequency and the spatial period of the order of NLC layer thickness. Theoretical results are compared with experimental data.

APA, Harvard, Vancouver, ISO, and other styles

10

ZHOU, XUAN, and ZHIDONG ZHANG. "THE RELAXATION OF TWISTED CHIRAL NEMATIC LIQUID CRYSTALS WITH SIDE-CHAIN POLYMERIC LAYER." International Journal of Modern Physics B 27, no. 22 (August 12, 2013): 1350118. http://dx.doi.org/10.1142/s021797921350118x.

Full text

Abstract:

A generalized form of surface dissipation function, for the description of the relative motion of the nematic director with respect to the polymer side chains in twisted chiral nematic samples is proposed, and the relaxation time of such samples are investigated, using the perturbation analysis method proposed by Alexe-Ionescu et al. Our results show that the presence of both the surface dissipation and the polymer side chains increase the relaxation time.

APA, Harvard, Vancouver, ISO, and other styles

11

ZHANG, ZHIDONG. "A STUDY OF TWO PARTICLE CLUSTER APPROXIMATION FOR NEMATIC LIQUID CRYSTAL FILMS." Modern Physics Letters B 09, no. 21 (September 10, 1995): 1361–67. http://dx.doi.org/10.1142/s0217984995001352.

Full text

Abstract:

A two-particle cluster variation theory is presented here to treat the inhomogeneous nematic phase. This theory is used to study nematic liquid crystal films. The internal energy per molecule in each layer is calculated and results are in agreement with those of the simulation. It is found that within the two-particle cluster theory, the surface excess free energy in both the nematic phase and the isotropic phase increases with the temperature. This behavior is in contradiction with that of the simulation and the mean field theory.

APA, Harvard, Vancouver, ISO, and other styles

12

Klämke, W., and W. Haase. "X-ray Studies on Layer Stacking and Ordering in a Liquid Crystalline Disubstituted Biphenylcyclohexane." Zeitschrift für Naturforschung A 43, no. 10 (October 1, 1988): 885–88. http://dx.doi.org/10.1515/zna-1988-1008.

Full text

Abstract:

Abstract X-ray measurements on disubstituted biphenylcyclohexanc BCH 52 show a crystalline smectic B phase with an ABCA layer stacking in bulk samples when cooled from the nematic to the smectic phase. No temperature dependence of this stacking can be seen. When cooling freely suspended thin films (below 20 μm) from the nematic to the smectic B phase, the obtained X-ray reflexes indicate an arrangement of the molecules in an orthorhombic F like stacking.

APA, Harvard, Vancouver, ISO, and other styles

13

Jin, Zhao Hui, Ying Guo, Hua Jing Gao, and Kazuo Kasatani. "Amplified Spontaneous Emission from the Oriented NK-2014-Doped Nematic Liquid Crystal Layer." Advanced Materials Research 554-556 (July 2012): 23–26. http://dx.doi.org/10.4028/www.scientific.net/amr.554-556.23.

Full text

Abstract:

Although lasing has been observed in the solid state for numerous organic molecules emitting at visible wavelengths, this is few case in the infrared. We show amplified spontaneous emission (ASE) in the near infrared (913-930 nm) from the layer of a cyanine dye-doped 4-cyano-4'-pentylbiphenyl (5CB) for laser power above 0.08 GW/cm2, the layer was prepared with the solution of 1,1',3,3,3',3'- hexamethyl-4,4',5,5'-di-benzo-2,2'-indotricarbocyanine perchlorate (NK-2014) dissolved in 5CB. Oriented NK-2014 molecules in nematic liquid crystal (NLC) must have very high amplified spontaneous emission efficiency.

APA, Harvard, Vancouver, ISO, and other styles

14

Parsouzi, Z., Shokir A. Pardaev, C. Welch, Z. Ahmed, G. H. Mehl, A. R. Baldwin, J. T. Gleeson, et al. "Light scattering study of the “pseudo-layer” compression elastic constant in a twist-bend nematic liquid crystal." Physical Chemistry Chemical Physics 18, no. 46 (2016): 31645–52. http://dx.doi.org/10.1039/c6cp06292j.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Kalugin, A. G., and D. V. Pavlov. "On Periodical Solutions in Nematic Liquid Crystal Layer." Liquid Crystals and their Application 17, no. 2 (June 26, 2017): 62–66. http://dx.doi.org/10.18083/lcappl.2017.2.62.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Sheng, Ping, Bo-Zang Li, Minyao Zhou, Thomas Moses, and Y. R. Shen. "Disordered-surface-layer transition in nematic liquid crystals." Physical Review A 46, no. 2 (July 1, 1992): 946–50. http://dx.doi.org/10.1103/physreva.46.946.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Kothekar, Natasha, D. W. Allender, and R. M. Hornreich. "Surface-layer phase transitions in nematic liquid crystals." Physical Review E 49, no. 3 (March 1, 1994): 2150–54. http://dx.doi.org/10.1103/physreve.49.2150.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Gaisina (Mukhamedyarova), Guzal A., and Ayrat D. Galimbekov. "Investigation of the dielectric parameters of nematic liquid crystals in the boundary layers." Butlerov Communications 61, no. 3 (March 31, 2020): 43–48. http://dx.doi.org/10.37952/roi-jbc-01/20-61-3-43.

Full text

Abstract:

This article presents the results of a study of the dielectric properties of thin liquid crystal layer systems. To study the dielectric parameters of nematic liquid crystals in the boundary layers, the frequency and temperature dependences of the real (ε') and imaginary (ε'') parts of the dielectric constant were determined. We studied samples that are in macroscopic layers and samples located in flat capillary layers (d ~ 0.1 μm). In both cases, the measurement is performed by the same method, namely, the method of temporary dielectric spectroscopy. The entire procedure for measuring, recording, accumulating and processing data was carried out automatically. In this case, the results of dielectric measurements could be presented both in the frequency and time domains. For measurements, a plane-parallel measuring cell made of brass and titanium electrodes was used. It should be noted that the surface of a solid body has a strong influence on the phase state of liquids and liquid crystals in the boundary layer. For example, in such a layer, liquid molecules acquire a mesophase ordering. In the case of NLC, the nematic potential increases and, as a result, the temperature of the nematic-isotropic phase transition increases. However, a shift in the bleaching temperature in the NLC mixture studied by us did not appear due to the smallness of the effect. The substance enclosed in the microspace between the surfaces of the mica has a higher dielectric constant than the corresponding bulk sample. Moreover, such a difference is observed both in the isotropic and in the nematic phases. This can be explained as follows. In a thick layer, a dipole-dipole intermolecular interaction takes place, which reduces the effective dipole moment of the molecules.

APA, Harvard, Vancouver, ISO, and other styles

19

Gao, Boxuan, Jeroen Beeckman, and Kristiaan Neyts. "Design and Realization of a Compact Efficient Beam Combiner, Based on Liquid Crystal Pancharatnam–Berry Phase Gratings." Crystals 11, no. 2 (February 23, 2021): 220. http://dx.doi.org/10.3390/cryst11020220.

Full text

Abstract:

We demonstrate a laser beam combiner based on four photo-patterned Pancharatnam–Berry (PB) phase gratings, which is compact and has high diffraction efficiency for incident circularly polarized light. The nematic liquid crystal mixture E7 is used as anisotropic material, and the thickness of the layer is controlled by spacers. The beam combiner can bring two parallel laser beams closer to each other while remaining parallel. This work shows the potential to realize components based on flat optical LC devices.

APA, Harvard, Vancouver, ISO, and other styles

20

Lee, Sunyoung, Yooseong Yang, Sunchul Kwon, and Youngsuk Jung. "Influence of side chains on the self-alignment capability of electroluminescent polyfluorenes." Soft Matter 12, no. 7 (2016): 1983–88. http://dx.doi.org/10.1039/c5sm02927a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Hinov, H. P. "Electrooptic behaviour of a nematic MBBA layer with a thick interfacial surfactant layer." Crystal Research and Technology 22, no. 3 (March 1987): 455–59. http://dx.doi.org/10.1002/crat.2170220327.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Kalugin, A. G. "Orientational instability of a lyotropic nematic liquid crystal layer." Moscow University Mechanics Bulletin 71, no. 2 (March 2016): 39–41. http://dx.doi.org/10.3103/s0027133016020035.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Komitov, Lachezar, Sven T. Lagerwall, Ameia Sparavigna, Bengt Stebler, and Alfredo Strigazzi. "Surface Transition in a Nematic Layer with Reverse Pretilt." Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals 223, no. 1 (January 1992): 197–217. http://dx.doi.org/10.1080/15421409208048252.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Chu, Fan, Li-Lan Tian, Rui Li, Xiao-Qing Gu, Xiang-Yu Zhou, Di Wang, and Qiong-Hua Wang. "Adaptive nematic liquid crystal lens array with resistive layer." Liquid Crystals 47, no. 4 (September 5, 2019): 563–71. http://dx.doi.org/10.1080/02678292.2019.1662502.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Brzdąkiewicz, K., W. K. Bajdecki, A. Kozanecka, and M. A. Karpierz. "Reorientational Nonlinear Phenomena in Thin Nematic Liquid Crystals Layer." Acta Physica Polonica A 99, no. 1 (January 2001): 183–92. http://dx.doi.org/10.12693/aphyspola.99.183.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Sparavigna, Amelia, Lachezar Komitov, Bengt Stebler, and Alfredo Strigazzi. "Static Splay-Stripes in a Hybrid Aligned Nematic Layer." Molecular Crystals and Liquid Crystals 207, no. 1 (October 1991): 265–80. http://dx.doi.org/10.1080/10587259108032105.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Hwang, Shug-June, Yi-Ming Shieh, and Kuo-Ren Lin. "Liquid Crystal Microlens Using Nanoparticle-Induced Vertical Alignment." Journal of Nanomaterials 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/840182.

Full text

Abstract:

The nanoparticle-induced vertical alignment (NIVA) of the nematic liquid crystals (LC) is applied to achieve an adaptive flat LC microlens with hybrid-aligned nematic (HAN) mode by dropping polyhedral oligomeric silsesquioxane (POSS) nanoparticle solution on a homogeneous alignment layer. The vertical alignment induced by the POSS nanoparticles resulted in the formation of a hybrid-aligned LC layer with concentric nonuniform distribution of the refractive index in the planar LC cell, which subsequently played the role of the lens, even in the absence of any applied voltages. The dimensions of the concentric HAN structure significantly depend on the volume of the microdroplet and the POSS concentration. The focus effect of this flat microlens was observed while electrically controlling its focal length using the applied voltages from −50 mm to −90 mm.

APA, Harvard, Vancouver, ISO, and other styles

28

Nassrah, Ameer R. K., István Jánossy, Viktor Kenderesi, and Tibor Tóth-Katona. "Polymer–Nematic Liquid Crystal Interface: On the Role of the Liquid Crystalline Molecular Structure and the Phase Sequence in Photoalignment." Polymers 13, no. 2 (January 7, 2021): 193. http://dx.doi.org/10.3390/polym13020193.

Full text

Abstract:

We provide experimental evidence for the influence of the molecular structure of the nematic liquid crystal (NLC) on the photoalignment process in three dimensions at the interface with a polymer layer. In particular, the experimental findings are explained through the presence (or absence) of the π−π aromatic interactions between the NLC and the polymer. The influence of the nematic-to-smectic A phase transition on the photocontrol is also addressed. Furthermore, we demonstrate that the photo-induced reorientation scenarios can be eventually connected to conformational changes in the photosensitive polymer.

APA, Harvard, Vancouver, ISO, and other styles

29

Ibrahim, I. H., and W. Haase. "Thermal and X-Ray Studies of 1,6-Bis-[4-(trans-4-n-propylcyclohexyl) phenyl]-hexane and 3,5-Bis-[4-(trans-4-n-propylcyclohexyl) phenyl]-1,2,4-thiadiazol." Zeitschrift für Naturforschung A 42, no. 7 (July 1, 1987): 774–76. http://dx.doi.org/10.1515/zna-1987-0719.

Full text

Abstract:

The liquid crystalline phases of the title compounds have been investigated by differential scanning calorimetry, optical microscopy and X -ray diffraction methods. Transition temperatures and transition enthalpies of these compounds have been determined. The diffraction photographs in the nematic phase of the first compound showed diffraction patterns corresponding to two coexisting mass density fluctuations with commensurate wavelengths, whereas a single diffraction pattern was observed in the nematic phase of the second compound. The thermal and X -ray data showed that the first compound has a quasi-smectic layer structure.

APA, Harvard, Vancouver, ISO, and other styles

30

Nassrah, Ameer R. K., István Jánossy, Viktor Kenderesi, and Tibor Tóth-Katona. "Polymer–Nematic Liquid Crystal Interface: On the Role of the Liquid Crystalline Molecular Structure and the Phase Sequence in Photoalignment." Polymers 13, no. 2 (January 7, 2021): 193. http://dx.doi.org/10.3390/polym13020193.

Full text

Abstract:

We provide experimental evidence for the influence of the molecular structure of the nematic liquid crystal (NLC) on the photoalignment process in three dimensions at the interface with a polymer layer. In particular, the experimental findings are explained through the presence (or absence) of the π−π aromatic interactions between the NLC and the polymer. The influence of the nematic-to-smectic A phase transition on the photocontrol is also addressed. Furthermore, we demonstrate that the photo-induced reorientation scenarios can be eventually connected to conformational changes in the photosensitive polymer.

APA, Harvard, Vancouver, ISO, and other styles

31

Lapanik, Valeri I., Anatoly P. Lugovsky, and Sergei N. Timofeev. "Physico-chemical and electro-optical properties of liquid crystals doped with chemically modified nanocline minerals." Journal of the Belarusian State University. Physics, no. 3 (October 7, 2020): 76–88. http://dx.doi.org/10.33581/2520-2243-2020-3-76-88.

Full text

Abstract:

The object of study is nematic and smectic (ferroelectric) liquid crystals containing chemically modified nanoclay based on montmorillonite. The aim of the work is to develop new composite materials with improved physico-chemical and electro-optical properties. During the study, chemical methods were developed for modification of the surface of nanoclay; the mesomorphic, dielectric, and electro-optical properties of nematic and ferroelectric compositions doped with a nanoclay with a modified surface are studied. On the basis of experimental data, the regularities of the influence of functional groups grafted onto the surface of nanoclay on the mesomorphic, dielectric and electro-optical properties of nematic and ferroelectric compositions are established. It has been shown experimentally that the addition of a small amount of nanoclay to a nematic and ferroelectric liquid crystal material can significantly improve the electro-optical response time and reduce the threshold and saturation voltage values. For ferroelectric liquid crystals, the addition of nanoclay leads to an increase in the tilt angle in the layer and an increase in spontaneous polarization.

APA, Harvard, Vancouver, ISO, and other styles

32

Mirri, Giorgio, Miha Škarabot, and Igor Muševič. "In situ laser-imprinted surface realignment of a nematic liquid crystal." Soft Matter 11, no. 17 (2015): 3347–53. http://dx.doi.org/10.1039/c5sm00282f.

Full text

Abstract:

We present a new method for the in-plane realignment of nematic liquid crystals in already fully assembled cells with uni-directionally rubbed polyimide as an aligning layer. This method can be applied to obtain twisted and planar μm-sized domains.

APA, Harvard, Vancouver, ISO, and other styles

33

Chen, Lu-Jian, Bin Luo, Wen-Song Li, Can Yang, Tao Ye, Sen-Sen Li, Xiao-Zhong Wang, Yuan-Jing Cui, Han-Ying Li, and Guo-Dong Qian. "Growth and characterization of zeolitic imidazolate framework-8 nanocrystalline layers on microstructured surfaces for liquid crystal alignment." RSC Advances 6, no. 9 (2016): 7488–94. http://dx.doi.org/10.1039/c5ra25794h.

Full text

Abstract:

The coverage of zeolitic imidazolate framework-8 (ZIF-8) nanocrystals deposited on patterned sol–gel films is significantly affected by the surface morphology. The ZIF-8 layer can induce vertical alignment of a typical nematic liquid crystal (LC) E7.

APA, Harvard, Vancouver, ISO, and other styles

34

PALTO, S. P., M. I. BARNIK, A. V. ARBUZOV, B. A. UMANSKII, and L. M. BLINOV. "A NEMATIC REPLICA OF A HOLOGRAPHIC POLARIZATION GRATING: MODELING OF THE IDEAL AND A CORRUGATED SURFACE." Journal of Nonlinear Optical Physics & Materials 15, no. 01 (March 2006): 23–32. http://dx.doi.org/10.1142/s0218863506003141.

Full text

Abstract:

When a nematic liquid crystal layer is brought in contact with a photosensitive polymer, on which a holographic grating is recorded by two laser beams with opposite circular polarization, due to a spatial modulation of the direction of the local optical axis, the photopolymer modulates the anchoring conditions for NLC in a similar way. As a result, a similar grating is induced in NLC with the enhanced diffraction efficiency and specific diffraction properties controlled by electric field.6 Here we show that, even in the case of a typical finite value of the anchoring energy, the numerical modeling confirms the characteristic asymmetric diffraction of the circularly polarized reconstructing beam and exchange by energy between the zero and first-order diffracted beams. Some other properties, such as reduced diffraction efficiency, appearance of higher diffraction orders and too-large optical phase retardation of a nematic cell at the areas occupied by gratings, can also be modeled by assuming some corrugation of the surface.

APA, Harvard, Vancouver, ISO, and other styles

35

Xing, Hong Yu, Wen Jiang Ye, Nai Fu Wu, Li Bin Si, and Zhi Dong Zhang. "Determination of Director Profile in the Vertical Alignment Nematic Liquid Crystal Cell by the Full Leaky Guided Mode Technique." Solid State Phenomena 181-182 (November 2011): 265–68. http://dx.doi.org/10.4028/www.scientific.net/ssp.181-182.265.

Full text

Abstract:

By means of the full leaky guided mode technique, the transmittance of the full leaky waveguide geometry which consists of pyramid, matching fluid of refractivity, the vertical alignment nematic liquid crystal cell are investigated experimentally. The experimental curves with different voltages between polarization-conserving transmittance Tss and the internal angle (the angle of incidence for which light is incident on the vertical alignment liquid crystal cell) are obtained. Comparing these experimental curves with the theoretical curves obtained from multi-layer optics theory, the director profile of vertical alignment nematic liquid crystal cell for different voltages is determined.

APA, Harvard, Vancouver, ISO, and other styles

36

Nádasi, Hajnalka, Ralf Stannarius, Alexey Eremin, Atsuki Ito, Ken Ishikawa, Osamu Haba, Koichiro Yonetake, Hideo Takezoe, and Fumito Araoka. "Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers." Physical Chemistry Chemical Physics 19, no. 11 (2017): 7597–606. http://dx.doi.org/10.1039/c6cp08461c.

Full text

Abstract:

We systematically studied the photoinduced anchoring transition in a nematic liquid crystal containing azo dendrimers. The transition was driven by photoisomerisation of the dendrimer adsorbed at the glass substrate. We investigated the relation between the spectral content of the illumination light and the anchoring energy of the liquid crystal.

APA, Harvard, Vancouver, ISO, and other styles

37

Galstian, Tigran, and Karen Allahverdyan. "Focusing unpolarized light with a single-nematic liquid crystal layer." Optical Engineering 54, no. 2 (February 5, 2015): 025104. http://dx.doi.org/10.1117/1.oe.54.2.025104.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Zambra, V. "Vortex and glass bead interaction in nematic liquid crystal layer." Journal of Physics: Conference Series 1043 (June 2018): 012005. http://dx.doi.org/10.1088/1742-6596/1043/1/012005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Kozhevnikov, E. N. "Domain structure in a nematic layer under oscillatory Couette flow." Crystallography Reports 47, no. 3 (May 2002): 501–6. http://dx.doi.org/10.1134/1.1481942.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Cattaneo, L., P. H. J. Kouwer, A. E. Rowan, and Th Rasing. "Sub-millisecond nematic liquid crystal switches using patterned command layer." Journal of Applied Physics 113, no. 1 (January 7, 2013): 014503. http://dx.doi.org/10.1063/1.4773108.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Kalugin, A. G. "Orientation instability of the layer of a nematic liquid crystal." Fluid Dynamics 51, no. 1 (January 2016): 81–85. http://dx.doi.org/10.1134/s0015462816010099.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Geršak, Rok, and Simon Čopar. "Interactions on the Interface between Two Liquid Crystal Materials." Crystals 10, no. 5 (May 14, 2020): 393. http://dx.doi.org/10.3390/cryst10050393.

Full text

Abstract:

In liquid crystal applications, boundary conditions are essential to ensuring suitable bulk molecular orientation and a deterministic response to external fields. Be it confinement to a droplet or a shell, a glass plate, or an interface with air or another liquid, proper surface alignment must be ensured—mechanically by rubbing, by chemical treatment that adds a layer of aligning molecules, by using photoalignment or even by leaving the surface untreated, using the intrinsic properties of the substrate itself. The anchoring can be classified as unidirectional (perpendicular homeotropic, or at oblique angles), or degenerate (planar or pre-tilted). However, if both substances at the interface are anisotropic, more diverse behaviour is expected. Here, we present a numerical simulation of a nematic droplet in a nematic host, and investigate behaviour of the director field and defects at the interface for different interfacial couplings. Finally, we compare the simulations to experimental images of discotic droplets in a calamitic nematic host.

APA, Harvard, Vancouver, ISO, and other styles

43

Buttsworth, D. R., S. J. Elston, and T. V. Jones. "Direct Full Surface Skin Friction Measurement Using Nematic Liquid Crystal Techniques." Journal of Turbomachinery 120, no. 4 (October 1, 1998): 847–53. http://dx.doi.org/10.1115/1.2841798.

Full text

Abstract:

New techniques for the direct measurement of skin friction using nematic liquid crystal layers are demonstrated. Skin friction measurements can be made using a molecular rotation time technique or an equilibrium orientation technique. A mathematical model describing the molecular dynamics of the nematic liquid crystal layer has been introduced. Theoretical results from the proposed mathematical model are in excellent agreement with the current experimental measurements. It is thus demonstrated that the present model captures the essential physics of the nematic liquid crystal measurement techniques. Estimates based on the variance of the liquid crystal calibration data indicate that skin friction measurements to within ±4 percent should certainly be possible. The techniques offer the considerable advantage of simplicity, without any compromise on the accuracy, relative to other surface shear stress measurement techniques. The full surface measurement capacity of the equilibrium orientation technique is demonstrated by measuring the skin friction distribution around a cylindrical obstruction in a fully developed laminar flow.

APA, Harvard, Vancouver, ISO, and other styles

44

Romeo, Maurizio. "Density–orientation coupling for a microcontinuum approach to nematic liquid crystals subject to electric field." Continuum Mechanics and Thermodynamics 33, no. 3 (January 17, 2021): 835–49. http://dx.doi.org/10.1007/s00161-020-00961-6.

Full text

Abstract:

AbstractA microcontinuum description of compressible liquid crystals is examined accounting for a constitutive model based on mass microdensity. As a first point, we discuss the effectiveness of the micropolar theory on compressible continua, which is limited to static problems. Then, by a micromorphic representation of mass density, we show the consistence of some classical constitutive models for compressible nematic liquid crystals and remark their connection with the microinertia tensor. After the analysis of a constitutive micropolar model, we discuss a static problem for a layer of compressible nematic liquid crystal in a planar configuration. The effects of an applied electric potential are considered remarking the coupling of density distribution with the molecular orientation.

APA, Harvard, Vancouver, ISO, and other styles

45

Zhang, Boyu, Sixiang Zhao, Yingying Yu, Ming Li, Liancheng Zhao, and Liming Gao. "Circularly Polarized Light Detection by Chiral Photonic Cellulose Nanocrystal with ZnO Photoconductive Layer in Ultraviolet Region." Nanomaterials 11, no. 11 (November 16, 2021): 3098. http://dx.doi.org/10.3390/nano11113098.

Full text

Abstract:

Circularly polarized light (CPL) detection and polarization state recognition are required for a wide range of applications. Conventional polarization detection with optical components causes difficulties for miniaturization and integration. An effective design strategy is proposed for direct CPL detection with chiral material. Here, we realized direct CPL detection based on the combination of chiral photonic cellulose nanocrystal (CNC) and ultraviolet-sensitive ZnO photoconductive material. The CNC layer deposited by evaporation-induced self-assembly established the left-handed chiral nematic structure with a photonic bandgap (PBG) to recognize left-handed CPL (LCPL) and right-handed CPL (RCPL) at specific wavelengths. The PBG of CNC layer has been modulated by the adjustment of chiral nematic pitch to match the semiconductor bandgap of ZnO film in ultraviolet region. The photocurrents under RCPL and LCPL are 2.23 × 10−6 A and 1.77 × 10−6 A respectively and the anisotropy factor Δgpc of 0.23 is acquired for the CPL detection based on the chiral photonic CNC. This design provides a new approach to the detection of CPL polarization state with competitive performance.

APA, Harvard, Vancouver, ISO, and other styles

46

Palermo, Giovanna, Rossella Grillo, Luigia Pezzi, Thomas Bürgi, Nelson Tabiryan, Luciano De Sio, and Cesare Umeton. "Photo-Aligned Nematic Liquid Crystals Enable the Modulation of Thermoplasmonic Heating." Applied Sciences 11, no. 14 (July 7, 2021): 6272. http://dx.doi.org/10.3390/app11146272.

Full text

Abstract:

We experimentally demonstrate that the plasmonic heat delivered by a single layer of homogeneously distributed gold nanoparticles (AuNPs), immobilized on a glass substrate, can be optically tuned by taking advantage of the properties of an organic layer based on azobenzene and nematic liquid crystal (NLC) molecules. The effect, which exploits the dependence of the NLC refractive index value on the molecular director orientation, is realized using the polarization-dependent, light-induced molecular reorientation of a thin film of photo-aligning material that the NLC is in contact with. The reversibility of the optically induced molecular director reorientation of the NLC enables an active modulation of the plasmonic photo-induced heat.

APA, Harvard, Vancouver, ISO, and other styles

47

Yusuf, Yusril, Shohei Yamaguchi, Shinya Kawano, Hirotaka Okabe, Simon Krause, Heino Finkelmann, P. E. Cladis, and Shoichi Kai. "Polar Liquid Crystal Elastomers Cross Linked Far from Thermodynamic Phase Transitions: Dislocation Loops in Smectic Clusters." Advances in Condensed Matter Physics 2013 (2013): 1–11. http://dx.doi.org/10.1155/2013/752060.

Full text

Abstract:

Nematic networks with three different concentrations of polar and nonpolar mesogens and the same concentration of a novel cross-linking agent give rise to unusual liquid single crystal elastomers (LSCEs) that are transparent monodomain nematic networks with smectic clusters. The largest spontaneous length change is observed in the sample with 70 mol% of the polar mesogen which also has the highest glass transition temperature and smectic clusters with a slowly increasing but nearly constant layer spacing on cooling from 90°C to 25°C. X-ray scattering intensity from smectic clusters with layer spacings that monotonically increase on cooling first increases to a maximum atT*~60∘C corresponding to clusters of about 30 layers. BelowT∗, the scattering intensity decreases as the number of layers in a cluster decreases. To account for this surprising nonlinear behavior that correlates with nonlinear features of the networks’ macroscopic spontaneous shape change and birefringence, a model is proposed where dislocations form in the layers atT∗. BelowT∗, more dislocations form to break down the layer structure. The possibility of dislocation formation atT∗independent of mesogenic concentrations is attributed to a conformational change in the crosslinker which is present at the same concentration in the three LSCEs.

APA, Harvard, Vancouver, ISO, and other styles

48

Pavlov, Ihor, Andrey Rybak, Andrii Dobrovolskiy, Viktor Kadan, Ivan Blonskiy, Fatih Ö. Ilday, Zoya Kazantseva, and Igor Gvozdovskyy. "The alignment of nematic liquid crystal by the Ti layer processed by nonlinear laser lithography." Liquid Crystals 45, no. 9 (January 31, 2018): 1265–71. http://dx.doi.org/10.1080/02678292.2018.1429027.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Uetani, Kojiro, Shogo Izakura, Takaaki Kasuga, Hirotaka Koga, and Masaya Nogi. "Self-Alignment Sequence of Colloidal Cellulose Nanofibers Induced by Evaporation from Aqueous Suspensions." Colloids and Interfaces 2, no. 4 (December 12, 2018): 71. http://dx.doi.org/10.3390/colloids2040071.

Full text

Abstract:

Cellulose nanopapers fabricated by drying aqueous colloidal suspensions of cellulose nanofibers (CNFs) have characteristic hierarchic structures, which cause the problem that their optical properties, including their transparency or haze, vary due to the drying processes affecting CNF alignment. It is unclear when and how the colloidal CNFs align in the evaporation–condensation process from the randomly dispersed suspension to form the nanopaper. In this study, we found that the CNFs undergo a self-alignment sequence during the evaporation–condensation process to form chiral nematic nanopaper by observing the birefringence of the drying suspensions from both the top and side for two suspensions with different initial CNF concentrations. The layer structures of the CNFs first form on the surface by condensation of the suspension, owing to water evaporation from the surface. The thickness of the layered structure then increases and the CNFs begin to align within each layer plane, finally forming chiral nematic structures. A birefringence difference also occurs for dried nanopapers with similar transparency or haze because of the initial CNF concentration.

APA, Harvard, Vancouver, ISO, and other styles

50

Snively, C. M., and J. L. Koenig. "Structure/property relationships in nematic liquid crystal/polymer alignment layer interactions." Journal of Molecular Structure 521, no. 1-3 (March 2000): 121–26. http://dx.doi.org/10.1016/s0022-2860(99)00429-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!