Asymmetry in molecular ordering in the nematic phase: DMR study
- 15 January 1988
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 88 (2) , 1373-1382
- https://doi.org/10.1063/1.454209
Abstract
Deuterium nuclear magnetic resonance (2H-NMR) was performed on the rigid perdeuterated fluorene segment of the compound 2-fluorenyl-4′-tetradecyloxy benzoate (FLOC 14-d9) to unambiguously measure the order parameter U which reflects the degree of asymmetric ordering of the molecule in the nematic liquid crystalline phase. Measurements of U showed this parameter to be finite at all temperatures in the nematic phase indicative of the uniaxial phase U2 described in the Allender–Lee generalized Landau theory. Mixtures of FLOC 14-d9 with compounds consisting of molecules more cylindrical in shape were also studied to examine their effect on the parameter U. Other parameters such as the degree of order S and the orientation of the principal axes of the Maier–Saupe order matrix were measured and are discussed.Keywords
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