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Preparation of Holographic Gratings of Liquid Crystals Dispersed in Polyurethane Acrylates under Controlled Reaction Conditions

✍ Scribed by Eun Hee Kim; Byung Kyu Kim


Publisher
John Wiley and Sons
Year
2006
Tongue
English
Weight
360 KB
Volume
7
Category
Article
ISSN
1439-4235

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✦ Synopsis


Abstract

Transmission gratings of holographic polymer‐dispersed liquid crystals (HPDLC) are prepared under controlled reaction conditions by adding various amounts of chain‐transfer agent (CTA). The resulting films have a higher gel content with lower cross‐link density, less dark reaction, less grating shrinkage with much smoother LC/polymer interfaces, smaller induction period, and fast saturation of diffraction efficiency, which shows a maximum of 95 % with 1 % CTA. An optimum LC content of 35 % is verified on the basis of morphology and reaction kinetics.