Cholesteric liquid crystals recordings

C.d. and u.v.-visible spectra are reported for solutions of the antitumour triterpenoid tingenone in aqueous sodium deoxycholate,83 and c.d. curves have been recorded for morphine and related alkaloids in cholesteric liquid crystals.84... 

In order to record the spectrum of light reflected from the cholesteric liquid crystal, it is better to use a thin slab of the same mixture confined between a microscope glass slide and a cover glass. In such a sample, the orientation of the liquid crystal can be efficiently improved by a gentle back-and-forth gliding motion of the cover glass. After this action, the cholesteric helix is orthogonal to the slab. 

Because electrostatic fields can be created and controlled by a variety of methods, including electron beam scanning, the method described here may be suitable for color recording on picture screens. The main disadvantages of this screen are thermal and electrical hysteresis phenomena of the cholesteric liquid crystal layer. 

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