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Effects of Electric Fields on Cholesterol Nonanoate Liquid Crystals

1966; Taylor & Francis; Volume: 2; Issue: 1-2 Linguagem: Inglês

10.1080/15421406608083067

0369-1152

John Hubert Muller,

Molecular spectroscopy and chirality

Abstract Effects of strong electric fields upon cholesteric liquid crystals have been studied. Increased intensity of light selectively scattered from the plane texture at d.c. and up to 3 kc have been found, as well as a temperature-dependent minimum in the average intensity as a function of frequency. An effect somewhat like hysteresis is shown by retention of the acquired brightness in the absence of field. Curious effects such as three classes of dark spots, some of which metamorphose into bars, light maltese crosses, and bright cross-hatchings are regularly observed. These effects taken together with the conditions of their appearance imply strong alignment such that the selective reflection of the cholesteric mesophase is greatly enhanced by the increased ordering of the planes of reflection within the mosphase. The complicated a.c. electric field effects are given a detailed, qualitative explanation.