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PO: Polymerphysik
PO 11: Poster: LC-Polymere und Ferroelektrizität
PO 11.3: Poster
Wednesday, March 11, 1998, 15:25–17:15, P1
Light Scattering Studies of Polymer Dispersed Liquid Crystals — •L. Leclercq1, U. Maschke2, B. Ewen1, X. Coqueret3, L. Mechernene3, and M. Benmouna3 — 1MPI f"ur Polymerforschung, Ackermannweg 10, D- 55128 Mainz — 2Université de Lille 1, F-59655 Villeneuve d’Ascq — 3Université Aboubakr Belkaid, Tlemcen, Algeria
Polymer dispersed liquid crystals (PDLCs) are promising new materials for electro-optical applications such as switchable windows and flexible displays. In their most common form, PDLC films consist of low molecular weight liquid crystal (LC) dispersed as micron sized droplets in a solid polymer matrix. Polymerization induced phase separation initiated by electron beam radiation was used to obtain well defined PDLC films [1]. The PDLC material was prepared from a blend of an eutectic nematic LC mixture E7 and a polyester acrylate- based polymer as a precursor of the matrix. PDLC film performance may depend strongly on the angular distribution of the light scattered by the films. The light transmission and scattering properties of the obtained PDLC films were investigated in the opaque (field off) and transparent (field applied) state. Measurements of samples with supra-microsized droplets show Rayleigh-Gans-Debye (RGD) behavior and are sensitive to variations in droplet size. Theoretical calculations of scattering from a nematic droplet in the RGD-regime agree well with experiments.
[1] U. Maschke et al.; J. Appl. Polym. Sci. Vol. 56, 1547 (1995)