Selective optical properties of induced cholesteric containing dispersed network polymer

G.M. Zharkova, I.V. Samsonova, L.A. Kutulya*, V.V. Vashchenko*, S.A. Streltzov, V.M. Khachaturyan

Institute of Theoretical and Applied Mechanics, Sibirian Division of Russian Academy of Sciences, 4/1 Institutskaya str., Novosibirsk, 630090, Russia
*Institute for Single Crystals. National Academy of Sciences of Ukraine, 60 Lenin Ave., Kharkiv, 61001, Ukraine

Received November 13, 1999

In this paper, selective optical reflection properties of liquid crystal (LC) composites obtained by dispersing of network polyvinylpyrrolidone of low-concentration in the induced cholesteric liquid crystals are discussed. Induced cholesteric LC on the base of nematic liquid crystals (4-alkyl- and 4-alkyloxy-4'-cyanobiphenyl derivatives) containing chiral non-mesogenic dopants (CD) of 4-alkyloxy substituted of 1R,4R-2-(4-phenylbenzylidene)-p-menthane-3-one series with variable terminal alkyl substituent length have been investigated. CD used high helical twisting power allowed to obtain induced cholesteric LC systems possessing selective light transmission in visible spectral region. Selective light transmission spectra measured revealed that polymer addition does not effect induced helical pitch and its temperature dependence. The influence of small polymer concentrations on spectral order parameter of a cholesteric LC sample and its selective transmission is shown.

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