scholarly journals Thermo-Chromic Response of Polymer Stabilized Cholesteric Liquid Crystal for Thermal Imaging

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Rishi Kumar
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Thermal Imaging ◽  
Cholesteric Liquid Crystal ◽  
Helical Structure ◽  
Cholesteric Liquid Crystals ◽  
Polymer Stabilized

Cholesteric liquid crystal (Ch-LC) exhibits many remarkable optical properties due to formation of a macroscopic helical structure. A low amount of monomer (5wt.%) is dispersed into cholesteric liquid crystal and get polymerized under UV radiations to form polymer stabilized cholesteric texture (PSCT). The thermo-chromic response made this device suitable for the developing applications in thermal imaging. Temperature based measurements of PSCT exploits the key property of some polymer stabilized cholesteric liquid crystals (PSCLC) to reflect definite colors at specific temperatures. The selective color of PSCT texture shifts with raise in temperature from 30oC to 85oC, which can be utilized in thermal imaging applications.

Thermal and electrical wavelength tuning of Bragg reflection with ultraviolet light absorbers in polymer-stabilized cholesteric liquid crystals

2018 ◽  
Vol 6 (45) ◽  
pp. 12377-12385 ◽  
Author(s):  
Amid Ranjkesh ◽  
Tae-Hoon Yoon
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Electric Field ◽  
Ultraviolet Light ◽  
Bragg Reflection ◽  
Cholesteric Liquid Crystal ◽  
Wavelength Tuning ◽  
Cholesteric Liquid Crystals ◽  
Light Absorbers ◽  
Polymer Stabilized

A dual thermal and electrical polymer-stabilized cholesteric liquid crystal has been fabricated by using ultraviolet light absorbers. The Bragg reflection can be autonomously controlled by temperature and manually by an electric field.

scholarly journals Enhanced Bandwidth Broadening of Infrared Reflector Based on Polymer Stabilized Cholesteric Liquid Crystals with Poly(N-vinylcarbazole) Used as Alignment Layer

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2238
Author(s):  
Limin Zhang ◽  
Qiumei Nie ◽  
Xiao-Fang Jiang ◽  
Wei Zhao ◽  
Xiaowen Hu ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Electric Field ◽  
Cholesteric Liquid Crystal ◽  
Critical Role ◽  
Cholesteric Liquid Crystals ◽  
Smart Window ◽  
Alignment Layer ◽  
Thermal And Electrical Properties ◽  
Polymer Stabilized

Alignment layer plays a critical role on liquid crystal (LC) conformation for most LC devices. Normally, polyimide (PI) or polyvinyl alcohol (PVA), characterized by their outstanding thermal and electrical properties, have been widely applied as the alignment layer to align LC molecules. Here, we used a semi-conductive material poly(N-vinylcarbazole) (PVK) as the alignment layer to fabricate the cholesteric liquid crystal (CLC) device and the polymer-stabilized cholesteric liquid crystals (PSCLC)-based infrared (IR) reflectors. In the presence of ultraviolet (UV) irradiation, there are hole–electron pairs generated in the PVK layer, which neutralizes the impurity electrons in the LC–PVK junction, resulting in the reduction in the built-in electric field in the LC device. Therefore, the operational voltage of the CLC device switching from cholesteric texture to focal conic texture decreases from 45 V to 30 V. For the PSCLC-based IR reflectors with the PVK alignment layer, at the same applied electric field, the reflection bandwidth is enhanced from 647 to 821 nm, ranging from 685 to 1506 nm in the IR region, which makes it attractive for saving energy as a smart window.

Research on Non-Electric Readout Infrared Thermal Imaging Detection Technology Based on the Liquid Crystal

2011 ◽  
Vol 181-182 ◽  
pp. 293-296
Author(s):  
Chang Long Cai ◽  
Ya Zhang ◽  
Xiao Ling Niu ◽  
Wei Guo Liu
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Thermal Imaging ◽  
Optical Rotation ◽  
Cholesteric Liquid Crystals ◽  
Isotropic Liquid ◽  
Infrared Thermal Imaging ◽  
Detection Technology ◽  
Imaging Detection

Liquid crystal, as a condensed matter, is a phase state between crystal and isotropic liquid. On the one hand, it has mobility and continuity as a liquid, and on the other hand, it has arranging ordering as a crystal, then it has many unique properties. Because the factors, such as heat, electric field, magnetic field, pressure, and so on, will easily influence the arranging of liquid crystal molecular, so once it is excited externally, its optical properties will be changed. At present, most research on the theory and application of liquid crystal mainly focus on the display. Thermo-optic effect is defined as the phenomenon that the optical properties of liquid crystal change with the changing of temperature. At the phase transition point, the thermo-optic effect of liquid crystal is very obvious. In this paper, non-electric readout infrared thermal imaging detection technology based on the optical rotation property of the cholesteric liquid crystals is mainly researched. Through the research, the cholesteric liquid crystals’ light curves, gray value curves and CCD image were obtained under different temperatures; it proved that using the optical rotation property of cholesteric liquid crystals to achieve the infrared imaging of hot objects is possible.

scholarly journals Fabrication of multicolored patterns based on dye-doped cholesteric liquid crystals

2019 ◽  
Vol 18 (7) ◽  
pp. 1638-1648 ◽  
Author(s):  
Linlin Xu ◽  
Hanbing Zhang ◽  
Jie Wei
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Fluorescence Enhancement ◽  
Cholesteric Liquid Crystal ◽  
Cholesteric Liquid Crystals ◽  
Dual Mode

We developed a type of dye-doped cholesteric liquid crystal, which were used for fluorescence enhancement and dual-mode multicolor patterns.

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.

Optical Properties of Polymer Stabilized Cholesteric Liquid Crystals

2002 ◽  
Vol 277 (1) ◽  
pp. 75-83 ◽  
Author(s):  
V. Laux ◽  
F. Roussel ◽  
J.-M. Buisine
Keyword(s):  
Optical Properties ◽  
Liquid Crystals ◽  
Cholesteric Liquid Crystals ◽  
Polymer Stabilized

scholarly journals Applications of Natural Purple from Dolabella auricularia: Colouration of Cholesteric Liquid Crystals

2016 ◽  
Vol 50 ◽  
pp. 1-6
Author(s):  
Yuki Kudo ◽  
Hiromasa Goto
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Cholesteric Liquid Crystal ◽  
Optical Microscope ◽  
Hydroxypropyl Cellulose ◽  
Cholesteric Liquid Crystals ◽  
Optical Texture ◽  
Sea Hare ◽  
Crystal Mixture

Hydroxypropyl cellulose (HPC) as a cholesteric liquid crystal was coloured with purple ink from Dolabella auricularia as a sea hare. Optical texture of the liquid crystal mixture was confirmed with a polarising optical microscope.

Electrically tunable infrared reflector with adjustable bandwidth broadening up to 1100 nm

2016 ◽  
Vol 4 (16) ◽  
pp. 6064-6069 ◽  
Author(s):  
Hitesh Khandelwal ◽  
Michael G. Debije ◽  
Timothy J. White ◽  
Albertus P. H. J. Schenning
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Ethylene Glycol ◽  
Cholesteric Liquid Crystals ◽  
Anisotropic Liquid ◽  
Polymer Stabilized ◽  
Bandwidth Broadening

A tunable infrared reflector has been fabricated using polymer stabilized cholesteric liquid crystals containing a negative dielectric, anisotropic liquid crystal and a long and flexible ethylene glycol twin crosslinker.

scholarly journals Nanoscale hyperspectral imaging of tilted cholesteric liquid crystal structures

Soft Matter ◽  
2019 ◽  
Vol 15 (15) ◽  
pp. 3256-3263 ◽  
Author(s):  
Aurélie Jullien ◽  
Adriana Scarangella ◽  
Umberto Bortolozzo ◽  
Stefania Residori ◽  
Michel Mitov
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Crystal Structures ◽  
Hyperspectral Imaging ◽  
Spectral Properties ◽  
Cholesteric Liquid Crystal ◽  
Cholesteric Liquid Crystals

In tilted cholesteric liquid crystals, hyperspectral imaging reveals the correlation between the bandgap spectral properties and spatial twists.

Textural Spectral Characteristics of the Cholesteric Liquid Crystal

2010 ◽  
Vol 428-429 ◽  
pp. 241-246
Author(s):  
Jia Ling Wang ◽  
Xin Du ◽  
Jia Lv ◽  
Tian Chi Yu ◽  
Zhi Xin Fan
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Cholesteric Liquid Crystal ◽  
Spectral Characteristics ◽  
Optoelectronic Devices ◽  
Liquid Crystal Displays ◽  
Transmission Property ◽  
Large Crystal ◽  
Important Significance

For the cholesteric liquid crystal (hereinafter short for Ch-LC) possesses special optical properties, it has specific applications in the area of liquid crystal displays and optoelectronic devices. Specimens of Ch-LCs in planar and focal conic texture stably are prepared. The photographs of textures are shot by polarizing microscope and transmittance spectrums of different textures are measured by spectrophotometer. It is found that the specimen in focal conic texture with large crystal domains has the well transmission property. The experiment has an important significance for applications of liquid crystals.

Sign in / Sign up

Export Citation Format

Share Document