Study of PDCLC Materials Using Fabry Perot Scattering Technique
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Polymer dispersed cholesteric liquid crystals (PDCLCs) consist of liquid crystal (nematic and Cholesteric) droplets that are dispersed in a solid polymer matrix. PDCLCs are a relatively new class of materials that hold promise for many applications ranging from switchable windows to projection displays. These materials, which are simply a combined application of polymers and liquid crystals, are the focus of extensive research in the display industry.
Cholesteric liquid crystasls are often considered to exhibit a modified nematic phase, the molecules they contain being parallel, but characterized by a continual rotation of the direction of molecular alignment (Director). This unusual twisting often causes the appearance of bright colors when cholesteric liquid crystals diffract light . The mixtures of PDCLCs with room temperature nematic liquiod crystal TL205 doped with Cholesteryl materials having different liquid crystal concentrations and polymer PN393 were investigated. The concentration of cholesteric liquid crystal played crucial role in the properties of PDCLCs. The phase transition temperatures (PTTs) of the samples thus prepared were studied using Fabry Parol scattering studies (FPSS), Optical Polarising Microscope (OPM) and Differential Thermal Analysis (DTA).
KeywordsPolymer dispersed cholesteric liquid crystal director cholesteric liquid crystals optical polarizing microscopy differential thermal Analysis Fabry Perot Scattering Studies
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- 1.http://nobelprize.org/educational_games/physics/liquid_crystals/history/Google Scholar
- 2.Crooker, P.P. in Chirality in Liquid Crystals (eds Kitzerow, H.-s & Bahr, C) 186–222, Springer, New York, ChemPort (2001).Google Scholar
- 3.http://plc.cwru.edu/tutorial/enhanced/files/pdlc/prep/prep.htmGoogle Scholar
- 7.J.B. Nephew, T.C. Nihei,and S.A. Carter, 80, No 15, Physical Review Letters, (1998).Google Scholar
- 9.S.J. Gupta, “New mesophase transitions in cholesteryl chloride using an optical method” in Indian Journal of Pure and Applied Physics, 37, 620 (1999).Google Scholar
- 11.Gupta S.J., et al, “Phase Transition Temperatures of LCs using Fabry-Perot Etalon” Molecular Crystals; Liquid Crystals, Procs of ILCC2000, Japan 364–368 (2000).Google Scholar
- 14.Dierking and S.T. Lagerwall, Journal of liquid crystalsGoogle Scholar
- 15.S.R. Renn and T.C. Lubensky, physics review A382132 (1988)Google Scholar