Liquid crystal/glass interface effects on the orientation of lyotropic liquid crystals in magnetic fields

1978 ◽  
Vol 56 (16) ◽  
pp. 2178-2183 ◽  
Author(s):  
Fred Y. Fujiwara ◽  
Leonard W. Reeves
Keyword(s):  
Magnetic Field ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Cylindrical Tube ◽  
Lyotropic Liquid Crystals ◽  
Crystal Glass ◽  
Type I ◽  
Type Ii ◽  
Glass Interface ◽  
Interface Effects

Lyotropic mesophases of both positive (type I) and negative (type II) diamagnetic anisotropy have been prepared. The deuterium magnetic resonance signal from D2O in the sample bas been studied during the process of orientation in a magnetic field. A type II mesophase oriented by a magnetic field in a cylindrical tube perpendicular to the lines of force does not achieve a uniform distribution of directors in a plane perpendicular to the field. The re orientation of a type I mesophase after an initial displacement of the director at an angle to the field has been studied. Previous equations derived for thermotropic liquid crystals are applicable but the velocity of re-orientation was found to be an inverse function of the radius, for nmr tubes of less than 4 mm in diameter, indicating that liquid crystal/glass interface effects are important.

Type I CM-type II DM transitions of lyotropic liquid crystals

1981 ◽  
Vol 103 (7) ◽  
pp. 1641-1647 ◽  
Author(s):  
Bruce J. Forrest ◽  
Leonard W. Reeves
Keyword(s):  
Liquid Crystals ◽  
Lyotropic Liquid Crystals ◽  
Type I ◽  
Type Ii

scholarly journals Aligning lyotropic liquid crystals with unconventional organic layers

2017 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Eva Otón ◽  
Morten Andreas Geday ◽  
Caterina Maria Tone ◽  
José Manuel Otón ◽  
Xabier Quintana
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Chem Phys ◽  
Water Soluble ◽  
Lyotropic Liquid Crystals ◽  
Sunset Yellow ◽  
Lab On Chip ◽  
Wide Range ◽  
Homeotropic Alignment ◽  
Alignment Layers

Lyotropic chromonic liquid crystals (LCLC) are a kind of LCs far less known and more difficult to control than conventional thermotropic nematics. Nevertheless, LCLCs are a preferred option -often the only one- for applications where hydrophilic materials must be employed. Being water-soluble, LCLC can be used in numerous biology related devices, for example in target detection in lab-on-chip devices. However, their properties and procedures to align them are still less explored, with only a very limited number of options available, especially for homeotropic alignment. In this work, novel organic alignment layers and alignment properties have been explored for selected LCLCs. Non-conventional organic alignment layers were tested and new suitable procedures and materials for both homogeneous and homeotropic alignments have been found. Full Text: PDF ReferencesS.L. Hefinstine, O.D. Lavrentovich, C.J. Woolverton, "Lyotropic liquid crystal as a real-time detector of microbial immune complexes", Lett. Appl. Microbiol. 43, 27 (2006). CrossRef M.A. Geday, M. Ca-o-García, J.M. Escolano, E. Otón, J.M. Otón, X. Quintana, Conference on Liquid Crystals CLC'16, Poland (2016).M.A. Geday, E. Otón, J.M. Escolano, J.M. Otón, X. Quintana, Patent WO 2015193525 (2015). DirectLink Yu.A. Nastishin et al., "Optical characterization of the nematic lyotropic chromonic liquid crystals: Light absorption, birefringence, and scalar order parameter", Phys. Rev. E, 72 (4) 41711 (2005). CrossRef A. Mcguire, et al., "Orthogonal Orientation of Chromonic Liquid Crystals by Rubbed Polyamide Films", Chem. Phys. Chem. 15 (7) (2014). CrossRef J. Jeong, et al., "Homeotropic Alignment of Lyotropic Chromonic Liquid Crystals Using Noncovalent Interactions", Langmuir 30(10) 2914 (2014). CrossRef J.Y. Kim, H.-Tae Jung, "Macroscopic alignment of chromonic liquid crystals using patterned substrates", Phys. Chem. Chem. Phys. 18, 10362 (2016). CrossRef E. Otón, J.M. Escolano, X. Quintana, J.M. Otón, M.A. Geday, "Aligning lyotropic liquid crystals with silicon oxides", Liq. Cryst. 42 (8) 1069 (2015). CrossRef H.S. Park, et al., "Condensation of Self-Assembled Lyotropic Chromonic Liquid Crystal Sunset Yellow in Aqueous Solutions Crowded with Polyethylene Glycol and Doped with Salt", Langmuir 27, 4164 (2011). CrossRef H.S. Park, et al., "Self-Assembly of Lyotropic Chromonic Liquid Crystal Sunset Yellow and Effects of Ionic Additives", J. Phys. Chem. B 112, 16307 (2008). CrossRef R Caputo et al., "POLICRYPS: a liquid crystal composed nano/microstructure with a wide range of optical and electro-optical applications", J. Opt. A: Pure Appl. Opt. 11, 024017 (2009). CrossRef

Fabrication and Characterizes of TiO2 Nanomaterials Templated by Lyotropic Liquid Crystal

2011 ◽  
Vol 399-401 ◽  
pp. 532-537
Author(s):  
Li Hua Liu ◽  
Ying Bai ◽  
Fu Min Wang ◽  
Ning Liu
Keyword(s):  
Aqueous Solution ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nonionic Surfactant ◽  
Formation Mechanism ◽  
Lyotropic Liquid Crystals ◽  
Lyotropic Liquid Crystal ◽  
Micro Structure ◽  
Ft Ir ◽  
Rod Structures

TiO2 nanomaterials were synthesized in lyotropic liquid crystal formed by nonionic surfactant TritonX-100 and TiOSO4 aqueous solution with NH3•H2O as precipitator. The lyotropic liquid crystals were characterized by means of POM and Low-angle XRD. FT-IR, TGA, XRD, TEM were used to characterize the TiO2 samples. It was found that all the lytropic liquid crystal were in lamellar liquid crysal phase and after casting the micro-structure of the LLC phase, the TiO2 samples were self-assemble to form lamellar, sphere and rod structures. According to the characterization results, possible formation mechanism was proposed.

A pirfenidone loaded spray dressing based on lyotropic liquid crystals for deep partial thickness burn treatment: healing promotion and scar prophylaxis

2020 ◽  
Vol 8 (13) ◽  
pp. 2573-2588 ◽  
Author(s):  
Jintian Chen ◽  
Hui Wang ◽  
Liling Mei ◽  
Bei Wang ◽  
Ying Huang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Lyotropic Liquid Crystals ◽  
Lyotropic Liquid Crystal ◽  
Burn Treatment ◽  
Partial Thickness ◽  
Partial Thickness Burn

This study develops a HA combined lyotropic liquid crystal based spray dressing loaded with pirfenidone for wound healing and scar prophylaxis.

scholarly journals Stable and Metastable Patterns in Chromonic Nematic Liquid Crystal Droplets Forced with Static and Dynamic Magnetic Fields

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 138 ◽  
Author(s):  
Jordi Ignés-Mullol ◽  
Marc Mora ◽  
Berta Martínez-Prat ◽  
Ignasi Vélez-Cerón ◽  
R. Santiago Herrera ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Boundary Conditions ◽  
Isotropic Phase ◽  
Director Field ◽  
Line Defects ◽  
The One ◽  
Bulk Structures ◽  
Microscopy Images

Spherical confinement of nematic liquid crystals leads to the formation of equilibrium director field configurations that include point and line defects. Driving these materials with flows or dynamic fields often results in the formation of alternative metastable states. In this article, we study the effect of magnetic field alignment, both under static and dynamic conditions, of nematic gems (nematic droplets in coexistence with the isotropic phase) and emulsified nematic droplets of a lyotropic chromonic liquid crystal. We use a custom polarizing optical microscopy assembly that incorporates a permanent magnet whose strength and orientation can be dynamically changed. By comparing simulated optical patterns with microscopy images, we measure an equilibrium twisted bipolar pattern within nematic gems that is only marginally different from the one reported for emulsified droplets. Both systems evolve to concentric configurations upon application of a static magnetic field, but behave very differently when the field is rotated. While the concentric texture within the emulsified droplets is preserved and only displays asynchronous oscillations for high rotating speeds, the nematic gems transform into a metastable untwisted bipolar configuration that is memorized by the system when the field is removed. Our results demonstrate the importance of boundary conditions in determining the dynamic behavior of confined liquid crystals even for configurations that share similar equilibrium bulk structures.

Nonlinear total reflection at a lyotropic liquid crystal/glass interface

1988 ◽  
Vol 21 (10S) ◽  
pp. S184-S186 ◽  
Author(s):  
M Bertolotti ◽  
E Fazio ◽  
A Ferrari ◽  
C Sibilia
Keyword(s):  
Liquid Crystal ◽  
Total Reflection ◽  
Lyotropic Liquid Crystal ◽  
Crystal Glass ◽  
Glass Interface

Magnetic field-induced type I → type II transition in a semimagnetic superlattice

1990 ◽  
Vol 8 (2) ◽  
pp. 171-174 ◽  
Author(s):  
E. Deleporte ◽  
J.M. Berroir ◽  
G. Bastard ◽  
C. Delalande ◽  
J.M. Hong ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Type I ◽  
Type Ii

Novel Dichroic Polarizing Materials and Approaches to Large-Area Processing

1998 ◽  
Vol 508 ◽  
Author(s):  
Yuri. A. Bobrov ◽  
Sean M. Casey ◽  
Leonid. Y. Ignatov ◽  
Pavel I. Lazarev ◽  
Daniel Phillips ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Liquid Crystal Display ◽  
Substrate Surface ◽  
Continuous Production ◽  
Lyotropic Liquid Crystals ◽  
Large Area ◽  
Rigid Plastic ◽  
Coating Materials ◽  
Wide Range

AbstractWe have developed new polarizing coating materials and processes which enable the fabrication of polarizers for large-area liquid-crystal displays. The polarizing materials are novel discotic surfactants which self-assemble in aqueous solutions to provide a stable liquid-crystalline phase within a wide range of concentrations and temperatures. These lyotropic liquid crystals in an aqueous medium can be spread on a substrate surface by a variety of techniques including a knife-like doctor blade, a rolling cylinder, or a roll-to-roll method. Under the shearing force applied during deposition, the liquid crystals align on the substrate forming a dichroic polarizer. This alignment process allows continuous production of large-area polarizing films at low cost compared with the current technology that requires stretching of the films. Thin coatings can be applied to flexible plastic films, glass, or rigid plastic substrates. Direct coating of the polarizing material on glass eliminates several process steps in liquid-crystal display production since lamination of the polarizing film is no longer required. These new polarizing films have a high optical performance including a polarizing efficiency of above 98% and a dichroic ratio as high as 7.7.

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