The electro-optic properties of colloidal silica filled nematics |
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| Authors: | N J Diorio Jr M R Fisch J W West |
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| Institution: | 1. Institute of Organic Chemistry, Technische Universit?t Berlin , Stra?e des 17. Juni 135, D-1000, Berlin, 12, F. R. Germany;2. Sektion Chemie der Martin-Luther-Universit?t Halle-Wittenberg , Mühlpforte 1, DDR-4010, Halle, G.D.R. |
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| Abstract: | The optical and electro-optical properties of filled nematic liquid crystals, nematic systems with added colloidal silica nanoparticles (? 6%), have been studied. The macroscopic near IR birefringence of cells constructed from these materials was measured for wavelengths between 2 and 5 mum, and a wavelength independent value of 0.16 was obtained. The visible optical behaviour of cells formed with untreated ITO substrates using both filled nematic, and filled nematic and dichroic dyes was similar to those observed in polymer dispersed liquid crystals. At an electric field of 1–2 V μm -1, the cells were highly transmitting, while at low fields they were highly scattering. The effects of colloidal silica nanoparticle concentration, cell thickness, electric field and substrate preparation (rubbed polyimide versus no surface treatment) on the electro-optical behaviour of these cells were studied. |
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