In Situ Homeotropic Alignment of Nematic Liquid Crystals Based on Photoisomerization of Azo-Dye, Physical Adsorption of Aggregates, and Consequent Topographical Modification

2013 ◽  
Vol 25 (24) ◽  
pp. 3365-3370 ◽  
Author(s):  
Sudarshan Kundu ◽  
Myong-Hoon Lee ◽  
Seung Hee Lee ◽  
Shin-Woong Kang
Keyword(s):  
Liquid Crystals ◽  
Azo Dye ◽  
Physical Adsorption ◽  
Nematic Liquid Crystals ◽  
Homeotropic Alignment

scholarly journals Nanocomposites of Polyaniline and Cellulose Nanocrystals Prepared in Lyotropic Chiral Nematic Liquid Crystals

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Dawei Zhang ◽  
Lihong Zhang ◽  
Bingzhe Wang ◽  
Guangzhe Piao
Keyword(s):  
Liquid Crystals ◽  
Cellulose Nanocrystals ◽  
Nematic Liquid Crystals ◽  
Weight Ratio ◽  
Asymmetric Reaction ◽  
Reaction Field ◽  
Electron Microscopies ◽  
Chiral Nematic ◽  
Before And After

Stable lyotropic chiral nematic liquid crystals (N*-LCs) of cellulose nanocrystals (CNs) were prepared via hydrolysis using sulfuric acid. The lyotropic N*-LCs were used as an asymmetric reaction field to synthesize polyaniline (PANI) onto CNs by in situ polymerization. As a primary step, we examined the mesophase transition of the N*-LCs of CNs suspension before and after in situ polymerization of aniline (ANI) by polarizing optical microscopy. The structure of nanocomposites of PANI/CNs was investigated at a microscopic level using Fourier transform infrared spectroscopy and X-ray diffraction. Influence of the CNs-to-ANI ratio on the morphology of the nanocomposites was also investigated at macroscopic level by scanning electron and transmission electron microscopies. It is found that the weight ratio of CNs to aniline in the suspension significantly influenced the size of the PANI particles and interaction between CNs and PANI. Moreover, electrical properties of the obtained PANI/CNs films were studied using standard four-probe technique. It is expected that the lyotropic N*-LCs of CNs might be available for an asymmetric reaction field to produce novel composites of conjugated materials.

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

scholarly journals Dual wavelength in situ photoalignment for stable planar alignment of nematic liquid crystals

2018 ◽  
Vol 8 (8) ◽  
pp. 2366 ◽  
Author(s):  
Vineet Kumar ◽  
Aboozar Nasrollahi ◽  
Vijay Kumar Baliyan ◽  
Heung-Shik Park ◽  
Myong-Hoon Lee ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Dual Wavelength

scholarly journals Electrically Controlled Diffraction Grating in Azo Dye-Doped Liquid Crystals

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1051 ◽  
Author(s):  
Chuen-Lin Tien ◽  
Rong-Ji Lin ◽  
Chi-Chung Kang ◽  
Bing-Yau Huang ◽  
Chie-Tong Kuo ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Electric Fields ◽  
Azo Dye ◽  
Nematic Liquid Crystals ◽  
Polarized Light ◽  
Dielectric Anisotropy ◽  
Linear Effect ◽  
Periodic Distribution ◽  
The Difference

This research applies the non-linear effect of azo dye-doped liquid crystal materials to develop a small, simple, and adjustable beam-splitting component with grating-like electrodes. Due to the dielectric anisotropy and optical birefringence of nematic liquid crystals, the director of the liquid crystal molecules can be reoriented by applying external electric fields, causing a periodic distribution of refractive indices and resulting in a diffraction phenomenon when a linearly polarized light is introduced. The study also discusses the difference in the refractive index (Δn), the concentration of azo dye, and the rising constant depending on the diffraction signals. The experimental results show that first-order diffraction efficiency can reach ~18% with 0.5 wt % azo dye (DR-1) doped in the nematic liquid crystals.

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

Photoexcitation and diffusion of azo dye molecules in nematic liquid crystals

1998 ◽  
Author(s):  
Bendaoud Saad ◽  
Marie-Marguerite Denariez-Roberge ◽  
Tigran V. Galstian
Keyword(s):  
Liquid Crystals ◽  
Azo Dye ◽  
Nematic Liquid Crystals ◽  
Dye Molecules ◽  
And Diffusion

scholarly journals Highly Stable, Pretilted Homeotropic Alignment of Liquid Crystals Enabled by In Situ Self-Assembled, Dual-Wavelength Photoalignment

2020 ◽  
Vol 2 (7) ◽  
pp. 2017-2025
Author(s):  
Vineet Kumar ◽  
Zhiqiu Ye ◽  
Haodong Jiang ◽  
Yue Shi ◽  
Ke Li ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Dual Wavelength ◽  
Homeotropic Alignment ◽  
Self Assembled
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