Polymer dispersed liquid crystal crystals

C2.2.4.5 POLYMER DISPERSED LIQUID CRYSTAL (PDLC) DISPLAYS... 

Figure C2.2.14. Principle of operation of a polymer-dispersed liquid crystal display. The contours of the liquid...

Similar behaviour has been observed by Emerson and Zannoni [112] in their simulations of polymer dispersed liquid crystal droplets where the solid... 

Refraction of light Polymer dispersed liquid crystals (PDLC), gel and polymer network displays... 

Polymer-dispersed liquid crystals (PDLCs) are made up of nematic liquid crystals dispersed in a solid continuous polymer matrix. These are prepared by mixing a reactive monomer into a non-polymerisable LC medium and then polymerising the reactive monomer to create a polymer matrix, at the same time capturing the LCs as dispersed droplets, greater than 1 pm in diameter, i.e. the wavelength of visible light.3 -33... 

Holographic optical elements can also be made by the preparation of polymer-dispersed liquid crystals using twin lasers in transmission holographic photopolymerisation (see section 5.4.2). They have also been made using photorefractive composites of polymer dispersed liquid crystals (see section 5.6.3). 

The polymer-dispersed liquid crystal was used as a modulating medium in optically controlled modulators instead of the liquid crystal [261-264], The sandwiched structure from polyimide photosensitive film and the polymer dispersed liquid crystal film - i.e. the optically controlled solid state modulator -had the characteristics presented in Fig. 36 [261]. Contrast ratio 35 1, response time > 400 ps, decay time 80 ms and sensitivity 5 x 10 sJcm 2 were obtained. 

Fig. 36. Contrast ratio (/), switch on (2) and switch off (3) times versus voltages for modulator with polymer dispersed liquid crystal. Photocon-ductor-polyimide film. Pulse regime [261]...

Bhargava, R., Wang, S.Q. and Koenig, J. L. (1999) Studying polymer dispersed liquid crystal formation by FTIR spectroscopy 1. monitoring curing reactions. Macromolecules, 32(26), 8982-88. 

Higgins, D.A., J.E. Hall, and A. Xie. 2005. Optical microscopy studies of dynamic within individual polymer-dispersed liquid crystal droplets. Acc. Chem. Res. 38 137-145. 

Mach, P. Rodriquez, S.J. Nortrup, R. Wiltzius, P. and Rogers, J.A. (2001) Monolithically integrated flexible display of polymer-dispersed liquid crystal driven by rubber-stamped organic thin-film transistors. Appl. Phys. Lett., 78, 3592-3594. 

Sheraw, C.D. Zhou, L. Juang, J.R. Gundlach, D.J. Jackson, T.N. Kane, M.G. Hill, I.G. Hammond, M.S. Campi, J. Greening, B.K. Francl, J. and West, J. (2002) Organic thin-film transistor-driven polymer-dispersed liquid crystal displays on flexible polymeric substrates. Appl. Phys. Lett., 80, 1088-1090. 

ICP thin films were used as driving electrodes for polymer-Dispersed Liquid-Crystals (PDLC) display devices. Liquid-crystalline-based display devices, which are commonly made of a liquid-crystal compound sandwiched between two substrates coated with a conducting layer of indium tin oxide (ITO), whose substitution with ICP electrodes could improve the optical and mechanical properties of the display devices. On the way to all-organic displays, PDLC sandwiched between two plastic substrates coated with ICP layers are promising devices for paper-like displays for electronic books which require flexibility, lightness, and low-power consumption. The electro-optical characteristics (transmission properties, drive voltages and switching times) of the PDLC devices depend on the nature of the ICP substrate used [13]. 

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