scholarly journals Electrical properties of a liquid crystal dispersed in an electrospun cellulose acetate network

2018 ◽  
Vol 9 ◽  
pp. 155-163 ◽  
Author(s):  
Doina Manaila Maximean ◽  
Octavian Danila ◽  
Pedro L Almeida ◽  
Constantin Paul Ganea
Keyword(s):  
Liquid Crystal ◽  
Cellulose Acetate ◽  
Indium Tin Oxide ◽  
Electric Energy ◽  
Equivalent Model ◽  
Electrical Characteristics ◽  
Impedance Measurements ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed ◽  
Crystal Composite

Electro-optical devices that work in a similar fashion as PDLCs (polymer-dispersed liquid crystals), produced from cellulose acetate (CA) electrospun fibers deposited onto indium tin oxide coated glass and a nematic liquid crystal (E7), were studied. CA and the CA/liquid crystal composite were characterized by multiple investigation techniques, such as polarized optical microscopy, dielectric spectroscopy and impedance measurements. Dielectric constant and electric energy loss were studied as a function of frequency and temperature. The activation energy was evaluated and the relaxation time was obtained by fitting the spectra of the dielectric loss with the Havriliak–Negami functions. To determine the electrical characteristics of the studied samples, impedance measurements results were treated using the Cole–Cole diagram and the three-element equivalent model.

scholarly journals Atomic Layer-Deposited Al-Doped ZnO Thin Films for Display Applications

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 539 ◽  
Author(s):  
Dimitre Dimitrov ◽  
Che-Liang Tsai ◽  
Stefan Petrov ◽  
Vera Marinova ◽  
Dimitrina Petrova ◽  
...  
Keyword(s):  
Thin Films ◽  
Liquid Crystal ◽  
Indium Tin Oxide ◽  
Near Infrared ◽  
Atomic Layer ◽  
Optical Transmittance ◽  
Flexible Polymer ◽  
Polymer Dispersed ◽  
Infrared Spectral ◽  
Aluminum Doped Zinc Oxide

The integration of high uniformity, conformal and compact transparent conductive layers into next generation indium tin oxide (ITO)-free optoelectronics, including wearable and bendable structures, is a huge challenge. In this study, we demonstrate the transparent and conductive functionality of aluminum-doped zinc oxide (AZO) thin films deposited on glass as well as on polyethylene terephthalate (PET) flexible substrates by using an atomic layer deposition (ALD) technique. AZO thin films possess high optical transmittance at visible and near-infrared spectral range and electrical properties competitive to commercial ITO layers. AZO layers deposited on flexible PET substrates demonstrate stable sheet resistance over 1000 bending cycles. Based on the performed optical and electrical characterizations, several applications of ALD AZO as transparent conductive layers are shown—AZO/glass-supported liquid crystal (LC) display and AZO/PET-based flexible polymer-dispersed liquid crystal (PDLC) devices.

PHASE TRANSITION INVESTIGATIONS IN POLYMER/LIQUID CRYSTAL COMPOSITE MATERIALS

1999 ◽  
Vol 13 (21) ◽  
pp. 759-767 ◽  
Author(s):  
DOINA MANAILA-MAXIMEAN ◽  
MAURIZIO FURLANI ◽  
RODICA BENA ◽  
BENGT-ERIK MELLANDER ◽  
CONSTANTIN ROSU ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Liquid Crystal ◽  
Composite Films ◽  
Scanning Calorimetry ◽  
Polymer Dispersed Liquid Crystal ◽  
Polarized Microscopy ◽  
Polymer Dispersed ◽  
Thermally Stimulated Depolarization ◽  
Crystal Composite ◽  
Polymer Liquid Crystal

We prepared polymer dispersed liquid crystal (PDLC) composite films using polymethyl methacrylate (PMMA) and the ferroelectric liquid crystal (LC) Felix 015/000 (Hoechst) by the solvent-induced phase separation method. We studied the phase transitions by the thermally stimulated depolarization currents (TSDC) method and by differential scanning calorimetry (DSC), for the composite film and the corresponding liquid crystal. Polarized microscopy was also used to characterize the phase transitions. When the LC is mixed with the PMMA, its characteristic transition temperatures are shifted down a few degrees and the current peaks revealed by the TSDC method are broadened due to the dispersion of microdroplets and the consequential presence of a large interface between the LC and the polymer matrix.

Holographic Polymer Dispersed Liquid Crystals: Effect of Partial Matrix Fluorination on Electro-Optical and Morphological Properties

2001 ◽  
Vol 709 ◽  
Author(s):  
Michael D. Schulte ◽  
Stephen J. Clarson ◽  
Lalgudi V. Natarajan ◽  
C. Allan Guymon ◽  
Timothy J. Bunning
Keyword(s):  
Liquid Crystal ◽  
Low Voltage ◽  
Morphological Properties ◽  
Acrylate Monomer ◽  
Polymer Dispersed Liquid Crystal ◽  
Morphological Studies ◽  
Polymer Dispersed Liquid Crystals ◽  
The Matrix ◽  
Polymer Dispersed ◽  
Morphological Differences

ABSTRACTHolographic polymer dispersed liquid crystal (H-PDLC) films with partially fluorinated matrices were investigated. Electro-optical and morphological studies revealed that fluorinated composites were substantially different from non-fluorinated analogues. The addition of a fluorinated monofunctional acrylate monomer to a pentaacrylate-derived polymer matrix resulted in improved diffraction efficiency. These findings suggest that the partial fluorination of the host polymer decreases the compatibility between the matrix and liquid crystal phase. Morphological differences between fluorinated films and non-fluorinated control specimens were verified using low-voltage, high-resolution scanning electron microscopy (LVHRSEM).

Side-chain liquid-crystal epoxy polymer binders for polymer-dispersed liquid crystals

1992 ◽  
Vol 25 (1) ◽  
pp. 133-137 ◽  
Author(s):  
Liang Chy Chien ◽  
C. Lin ◽  
David S. Fredley ◽  
James W. McCargar
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Epoxy Polymer ◽  
Side Chain ◽  
Polymer Binders ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed
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