Electro-Optical, Spectroscopical and Morphological Properties of Ultraviolet Cured Polymer/Liquid Crystal Films

D. Benaissa(1*), L. Méchernène(2), A. Addad(3), U. Maschke(4)

(1) Laboratoire de Chimie Organique et Macromoléculaire (LCOM - UMR CNRS 8009), Université des Sciences et Technologies de Lille, Bâtiment C6, 59655 Villeneuve d’Ascq Cedex, France., France
(2) Laboratoire de Recherche sur les Macromolécules, Université Aboubakr Belkaïd de Tlemcen, Pôle Chetouane, Faculté des Sciences, 13000 Tlemcen, Algeria., Algeria
(3) ,
(4) Laboratoire de Structure et Propriétés de l'Etat Solide (LSPES - UMR CNRS 8008), Université des Sciences et Technologies de Lille, Bâtiment C6, 59655 Villeneuve d’Ascq Cedex, France., France
(*) Corresponding author


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Abstract


The electro-optical behavior of Polymer Dispersed Liquid Crystal (PDLC) films was studied to understand the relationship between the conditions of preparation in terms of the extent of curing, the morphology, and the response to an external electrical field. The PDLC films were prepared by phase separation of a diacrylate/nematic low molecular weight liquid crystal mixture induced by Ultraviolet (UV) curing as a function of irradiation dose. The polymerization/crosslinking process was monitored by Fourier Transform Infrared Spectroscopy (FTIR) in terms of the radiation dose and LC concentration. The conversion of double bonds of the acrylic monomer shows a rapid increase at low dose values followed by a plateau. The transmission vs voltage curves were investigated as a function of wavelength and sample thickness, and show low transmission in the off-state and high transmission in the on-state. The analysis was accomplished by a proper morphology consideration
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Keywords


Polymer Network; Acrylate; Liquid Crystal; UV Irradiation; Electro-optical Measurements; Infrared Spectroscopy; Morphology; UV-vis Spectroscopy

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