Liquid Crystal Influenced Self-assembly in Mesogenic Polymer and Liquid Crystal Blends

2004 ◽  
Vol 856 ◽  
Author(s):  
Lanfang Li ◽  
Carmen Otilia Catanescu ◽  
Liang-Chy Chien
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Self Assembly ◽  
Polymer Network ◽  
Monomer Concentration ◽  
Curing Temperature ◽  
Low Molecular Weight ◽  
Photo Polymerization ◽  
Anisotropic Elastic ◽  
Polymerization Conditions

ABSTRACTIn this work, we found that by performing photo-polymerization of the mesogenic monomer RM257 in liquid crystals, well organized polymer walls were formed through out the cell by self-assembly of the polymer within the anisotropic host – the liquid crystal. The polymerization conditions, which were parameterized as UV intensity, photo-reactivity (characterized by photo initiator concentration), curing temperature, monomer concentration and mesophase of the liquid crystal host, were systematically varied. Different liquid crystal host also raised some difference in polymer network. We believe this kind of morphology comes from spinodal decomposition and the anisotropic elastic property of the liquid crystal host. It is found that for RM257 and low molecular weight nematic liquid crystals a monomer concentration of 5% is sufficient to use liquid crystal hosts to work as templates for well structured polymer walls.

Uv Curable Liquid Crystals and Their Application

1996 ◽  
Vol 425 ◽  
Author(s):  
H. Takatsu ◽  
H. Hasebe
Keyword(s):  
Liquid Crystals ◽  
Light Scattering ◽  
Liquid Crystalline ◽  
Room Temperature ◽  
Polymer Network ◽  
Driving Voltage ◽  
Uv Curable ◽  
Good Thermal Stability ◽  
Photo Polymerization ◽  
Smectic A

AbstractSome classes of liquid crystalline monoacrylates having no methylene spacers in a side chain have been prepared. The liquid crystalline monoacrylates have effects to reduce the driving voltage and the hysteresis for a light scattering display of Polymer Network liquid crystals prepared by photo-polymerization-induced phase separation.By photo-polymerization of a chiral monoacrylate monomer in a nematic liquid crystalline host including a black dichroic dye, a polarizer free reflective Spiral Polymer Aligned Nematic (SPAN) Guest Host (GH) LCD exhibiting a low driving voltage has been fabricated. The effect of the spiral polymers made of some kinds of chiral monoacrylates for a Super Twisted Nematic (STN) LCD using SPAN liquid crystals is discussed.UV-curable liquid crystals showing nematic phases at room temperature have been developed. By in situ photo-polymerization, the UV-curable liquid crystals can be utilized for the retardation film with high quality and good thermal stability. The fabrication of various kinds of retardation film using the UV-curable liquid crystals is discussed.UV-curable liquid crystals having isotropic-nematic-smectic A phase sequence have been developed and the photo-polymerization at the state of their uniaxially oriented smectic A phases at room temperature is discussed. The polymerized film is optically uniaxial and transparent without light scattering.

scholarly journals Supramolecular self-assembly and physical-gel formation in disc-like liquid crystals: a scalable predictive model for gelation and an application in photovoltaics

RSC Advances ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 6335-6345
Author(s):  
Sehrish Iqbal ◽  
Ammar A. Khan
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Predictive Model ◽  
Self Assembly ◽  
Gel Formation ◽  
Discotic Liquid Crystal ◽  
Physical Gel

The application of triphenylene-based discotic liquid crystal derivatives as physical gelators is investigated.

Photo-Induced Properties of Liquid Crystal Molecules on Alternately Assembled Charged Azobenzene Dyes and Polyelectrolyte Films Using Attenuated Total Reflection Method

1999 ◽  
Vol 598 ◽  
Author(s):  
Akira Baba ◽  
Takashi Kato ◽  
Jun Ishikawa ◽  
Futao Kaneko ◽  
Kazunari Shinbo ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Self Assembly ◽  
Surface Plasmon Polariton ◽  
Hybrid Cell ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Low Molecular Weight ◽  
Reflection Method ◽  
Linearly Polarized ◽  
Plasmon Polariton

ABSTRACTIn this report, we describe the photo-induced in-plane alignment of nematic liquid crystal (LC) molecules, 5CB, in a hybrid cell with alternate self-assembled films of low-molecular weight azobenzene dye and polyelectrolyte on gold electrodes using the attenuated total reflection (ATR) measurement method. The molecular self-assembly process was also investigated by the ATR method. Reflectivities due to excitations of the surface plasmon polariton (SPP) were observed in the ATR properties of the LC cell. In-plane switching of the LC molecules adjacent to the aligning layer was evaluated from the ATR curves after irradiation of linearly polarized visible light to the LC cell. The sensitivity of the ATR method gives information on the alignment, tilt angle, and extent of LC reorientation in the bulk. Thus, the importance of using the molecular self-assembly processes of individual polyion-dye pairs for fabrication of new photo-aligning layers is emphasized.

Swelling dynamics of liquid crystal elastomers swollen with low molecular weight liquid crystals

2004 ◽  
Vol 69 (2) ◽  
Author(s):  
Yusril Yusuf ◽  
Yukitada Ono ◽  
Yusuke Sumisaki ◽  
P. E. Cladis ◽  
Helmut R. Brand ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Low Molecular Weight ◽  
Liquid Crystal Elastomers

Orientation, interaction and laser assisted self-assembly of organic single-crystal micro-sheets in a nematic liquid crystal

Soft Matter ◽  
2015 ◽  
Vol 11 (38) ◽  
pp. 7674-7679 ◽  
Author(s):  
M. V. Rasna ◽  
K. P. Zuhail ◽  
U. V. Ramudu ◽  
R. Chandrasekar ◽  
J. Dontabhaktuni ◽  
...  
Keyword(s):  
Experimental Study ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Single Crystal ◽  
Nematic Liquid Crystal ◽  
Self Assembly ◽  
Nematic Liquid Crystals ◽  
Directed Assembly ◽  
Orientation Interaction ◽  
Organic Single Crystal

In this paper we report first experimental study on the orientation, interaction and directed-assembly of single crystal micro-sheets in nematic liquid crystals.

The Influence of 4,4’-bis[6-(acryloyloxy)-hexyloxy]biphenyl Contents on the Electro-Optical Properties of Polymer Stabilized Liquid Crystals

2013 ◽  
Vol 634-638 ◽  
pp. 2523-2526
Author(s):  
Hui Chang ◽  
Wen Juan Fan ◽  
Xiao Li Liu ◽  
Hong Ying Huo
Keyword(s):  
Optical Properties ◽  
Liquid Crystals ◽  
Response Time ◽  
Polymer Network ◽  
Contrast Ratio ◽  
Monomer Concentration ◽  
Helical Structure ◽  
Switching Process ◽  
Polymer Stabilized ◽  
Structure Of Liquid

The polymer stabilized liquid crystals (PSLC) films was prepared subsequently based on the mesogenic diacrylate monomer 4,4’-bis[6-(acryloyloxy)-hexyloxy]biphenyl (BAB6). The effects of BAB6 on the morphology of polymer network as well as the electro-optical properties of the PSLC films were investigated. The helical structure of liquid crystals was observed in the morphology of polymer network by SEM. Further, a single switching process was observed at lower monomer concentration in this study compared with the former publication. When BAB6 concentration reached 7 %, the response time and contrast ratio of PSLC film were 7 ms and 16.8, respectively.

scholarly journals Synthesis, Self-Assembly and Photoresponsive Behavior of Liquid Crystals Based on Azobenzene

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1560
Author(s):  
Yaming Wu ◽  
Yuhai Liu ◽  
Jianxiang Chen ◽  
Runmiao Yang
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Self Assembly ◽  
Driving Force ◽  
1H Nmr Spectroscopy ◽  
Uv Light ◽  
Light Exposure ◽  
Scanning Calorimetry ◽  
Stimulus Response ◽  
Cis Isomer

A new amphiphilic surfactant (C4-Azo-C5-HDA) was formed by liquid crystals (LCs) based on azobenzene, whose structures were characterized by 1H-NMR spectroscopy. The reversible hydrogelation upon changes in temperature and light exposure was also studied. Under the irradiation of UV light, the trans-isomer of C4-Azo-C5-HDA rapidly photoisomerized to the cis-isomer, resulting in rapid disruption of the gel. The thermotropic liquid crystal behavior of the gelator was investigated via Differential Scanning Calorimetry (DSC) and Polarizing Optical Microscopy (POM). The biocompatibility experiment of multi-stimulus response of the liquid crystal provides a potential driving force for the development of biomaterials.

scholarly journals Adjacent functional group effects on the assembly of columnar liquid crystals

2020 ◽  
Vol 98 (7) ◽  
pp. 379-385
Author(s):  
Carson O. Zellman ◽  
Danielle Vu ◽  
Vance E. Williams
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Self Assembly ◽  
Room Temperature ◽  
Functional Group ◽  
The Self ◽  
Clearing Temperature ◽  
Crystal Phases ◽  
Potential Strategy ◽  
The Impact

Although the impact of individual functional groups on the self-assembly of columnar liquid crystal phases has been widely studied, the effect of varying multiple substituents has received much less attention. Herein, we report a series of dibenzo[a,c]phenazines containing an alcohol or ether adjacent to an electron-withdrawing ester or acid. With one exception, these difunctional mesogens form columnar phases. The phase behavior appeared to be dominated by the electron-withdrawing substituent; transition temperatures were similar to derivatives with these groups in isolation. In most instances, the addition of an electron-donating group ortho to an ester or acid suppressed the melting temperature and elevated the clearing temperature, leading to broader liquid crystal thermal ranges. This effect was more pronounced for derivatives functionalized with longer chain hexyloxy groups. These results suggest a potential strategy for controlling the phase ranges of columnar liquid crystals and achieving room temperature mesophases.

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