Study of PDLC and PDCLC Mixtures using Various Techniques
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Polymer Dispersed Liquid Crystal (PDLC) and Polymer Dispersed Cholesieric Liquid Crystal (PDCLC)fdms were prepared by thermal-induced phase separation method. PDLC and PDCLC films are analyzed using Fabry Parol Scattering Studies (FPSS), Differential Thermal Analysis (DTA) and Fourier Transform Infra-red (FTIR) Spectroscopy. Changes in the structure, phase transition temperatures (PTTs) and clearing temperatures i.e. the temperature at which the material becomes isotropic are listed. FTIR spectrometer is used to find the structural changes due to the addition of cholesteric material to PDLC. DTA technique is used to corroborate the results obtained using the FPSS technique.
Present studies reveals that the PDCLC samples are a homogeneous mixture at the room temperature. Transmission intensity and hence the homogeneity of the samples is seen to be maximum for the PDCLC sample containing 80% (80% TL205+20% Cholesteryl Pelargonate) + 20%PN393. Approximate range of percentage transmission decreases as the concentration of the cholesteric material increases.
KeywordsPolymer dispersed cholesteric liquid crystal differential thermal Analysis Fabry Perot Scattering Studies Fourier Transform Infra-red (FTIR) Spectroscopy
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- 2.J.B. Nephew, T.C. Nihei, and S.A. Carter 80, 15, Physical Review Letters, (1998).Google Scholar
- 5.H.K.D.H. Bhadeshia, University of Cambridge, Materials Science & Metallurgy “Thermal Analysis Techniques”.Google Scholar
- 6.W.P. Brennan and A.P. Gray, Instrumentation Division. Perkin-Elmer Corp. Norwalk, Conn.06856, Thermal Analysis: Application study of Liquid Crystals by DSC; 13 (1974).Google Scholar
- 7.Introduction to Fourier Transform Infrared Spectrometry, Thermo Nicolet corporation, USA, (2001).Google Scholar
- 10.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
- 12.J.L. West and R. Ondris-Crawford, 3785 J. Appl. Phys. 70(7), 1 October (1991).Google Scholar
- 13.Interpretation of Infrared Spectra, A Practical Approach, John Coates, Coates Consulting, Newtown, USA.Google Scholar
- 14.I. Dierking and S.T. Lagerwall, liquid Crystals, 26(1), 83–95, (1999).Google Scholar