Homeotropic Alignment of Columnar Liquid Crystals in Open Films by Means of Surface Nanopatterning

2007 ◽  
Vol 19 (6) ◽  
pp. 815-820 ◽  
Author(s):  
R. I. Gearba ◽  
D. V. Anokhin ◽  
A. I. Bondar ◽  
W. Bras ◽  
M. Jahr ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Homeotropic Alignment

Mechanism of homeotropic alignment of ferroelectric liquid crystals doped with ferro-fluid and applications

2013 ◽  
Vol 103 (3) ◽  
pp. 034110 ◽  
Author(s):  
Tilak Joshi ◽  
Shri Singh ◽  
Amit Choudhary ◽  
R. P. Pant ◽  
A. M. Biradar
Keyword(s):  
Liquid Crystals ◽  
Ferroelectric Liquid Crystals ◽  
Homeotropic Alignment

Discotic liquid crystals of transition metal complexes, 54: Rapid microwave-assisted synthesis and homeotropic alignment of phthalocyanine-based liquid crystals

2017 ◽  
Vol 21 (07n08) ◽  
pp. 476-492 ◽  
Author(s):  
Toshiyuki Akabane ◽  
Kazuchika Ohta ◽  
Tokihiro Takizawa ◽  
Takehiro Matsuse ◽  
Mutsumi Kimura
Keyword(s):  
Liquid Crystals ◽  
Reaction Time ◽  
Microwave Heating ◽  
Phase Transfer ◽  
Difficult Problem ◽  
Phase Transfer Catalyst ◽  
Microwave Assisted Synthesis ◽  
Aliquat 336 ◽  
Large Area ◽  
Homeotropic Alignment

The most difficult problem on syntheses of the phthalocyanine-based liquid crystals is the long reaction time. In order to shorten the reaction time, we have developed novel Methods A, B and D, for the syntheses of phthalocyanine-based liquid crystals by using microwave heating and/or adding a phase transfer catalysis of Aliquat 336. A series of phthalocyanine derivatives C[Formula: see text]PcZn(1) ([Formula: see text] 10, 12, 14, 16 and 18: a, b, c and e) could be successfully synthesized in a dramatically short reaction time of 30–60 min using Methods A and B by microwave heating. On the other hand, anothor series of the derivatives C[Formula: see text](OH)PcZn (2a–2e) could not be synthesized by microwave heating. Therefore, all these derivatives were synthesized using conventional Method C by oil bath heating, but the reaction took a very long time (22.5–88 h). To shorten the reaction time, we have developed Method D by oil bath heating with adding a phase transfer catalyst of Aliquat 336. In this method, we successfully shortened the reaction time from 88 h to 3 h for the synthesis of the derivative 2a. Thus, the reaction time for oil bath heating can be also greatly shortened by adding the phase transfer catalyst of Aliquat 336. Furthermore, we have established from POM, DSC and temperature-dependent X-ray diffraction measurements that the derivative C[Formula: see text]PcZn (1a) shows a very rare pseudohexagonal columnar (Col[Formula: see text] phase, and that the derivatives C[Formula: see text]PcZn (1b–1e) and C[Formula: see text](OH)PcZn (2b–2e) exhibit spontaneous perfect homeotropic alignment in a large area between two glass plates in their Col[Formula: see text] phases.

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

Homeotropic alignment of liquid crystals on ITO surface using LBL assembly

2018 ◽  
Vol 26 (7) ◽  
pp. 413-418
Author(s):  
Channapura Halappa Chandrashekhar ◽  
So-Jin Park
Keyword(s):  
Liquid Crystals ◽  
Lbl Assembly ◽  
Homeotropic Alignment

Induced Homeotropic Alignment of Nematic Liquid Crystals by Doping Side-on Carbosilane-based Oligomers

2018 ◽  
Vol 47 (9) ◽  
pp. 1180-1183
Author(s):  
Kosuke Kaneko ◽  
Masaki Goto ◽  
Yohei Haketa ◽  
Hiromitsu Maeda ◽  
Tomonori Hanasaki
Keyword(s):  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Homeotropic Alignment

Spontaneous homeotropic alignment of nematic liquid crystals induced by a double-armed side chain liquid crystalline polymethacrylate

2017 ◽  
Vol 656 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Osamu Haba ◽  
Wataru Matsuno ◽  
Nao Nakamura ◽  
Hiroshi Awano ◽  
Tatsuhiro Takahashi ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Nematic Liquid Crystals ◽  
Side Chain ◽  
Homeotropic Alignment

Homeotropic alignment of nematic liquid crystals with negative dielectric anisotropy

2010 ◽  
Vol 405 (8) ◽  
pp. 2118-2121 ◽  
Author(s):  
G. Singh ◽  
G. Vijaya Prakash ◽  
A. Choudhary ◽  
A.M. Biradar
Keyword(s):  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Dielectric Anisotropy ◽  
Homeotropic Alignment

scholarly journals Discotic liquid crystals of transition metal complexes 50: spiranthes-like supramolecular structure of phthalocyanine-fullerene dyads

2014 ◽  
Vol 18 (05) ◽  
pp. 366-379 ◽  
Author(s):  
Aya Ishikawa ◽  
Kenta Ono ◽  
Kazuchika Ohta ◽  
Mikio Yasutake ◽  
Musubu Ichikawa ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Transition Metal Complexes ◽  
Supramolecular Structure ◽  
Liquid Crystalline ◽  
Molecular Design ◽  
Glass Plate ◽  
Helical Structure ◽  
Discotic Liquid Crystals ◽  
One Dimensional ◽  
Homeotropic Alignment

We have synthesized novel liquid crystalline Pc - C 60 dyads (CnS)6PcCu-C60 (n = 14, 16, 18: 1a–1c) by using our developed synthetic method in order to investigate the mesomorphism and alignment behavior. Each of the (CnS)6PcCu-C60 dyads shows perfect homeotropic alignment in the Colho mesophase between two glass plates for n = 14, 16, 18 and also on a glass plate for n = 14, although none of the parent Pc compounds (CnS)8PcCu and the Pc precursors (CnS)6PcCu-OH and (CnS)6PcCu-OFBA shows homeotropic alignment. It may be attributed to the strong affinity between fullerene and glass surface. Although the reason is not so clear at the present time, this is very useful guideline for the molecular design to prepare homeotropic alignment-showing discotic liquid crystals. Very interestingly, the spherical C 60 parts form a helical structure around the column formed by the disk-like Pc parts This supramolecular structure very resembles spiranthes. The spiranthes-like supramolecular structure is compatible with one-dimensional nano-array expecting the high conversion efficiency of solar cells.

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