Study of elastic constant ratios in nematic liquid crystals

A technique has recently been proposed for determining the elastic constant ratio K22∕K11 in nematic liquid crystals [E. P. Raynes, C. V. Brown, and J. F. Stromer, Appl. Phys. Lett. 82, 13 (2003)]. This technique has been applied to five nematic materials that cover a range of K33∕K11 elastic constant ratio values. An unusually high value of K22∕K11 is found in one material. High values of the ratio K22∕K11 tended to occur in materials that also have high values of the ratio K33∕K11. The results are validated with independent measurements of K22 from cholesteric helix unwinding.

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