Abstract
A simple electro-optical technique was developed for measuring the rotational viscosity of nematic liquid crystals. These results were then used to confirm the newly developed Osipov-Terentjev (OT) theory [M. A. Osipov and E. M. Terentjev, Z. Naturforsch. A 44, 785 (1989)]. Another theory frequently used, the Diogo-Martins theory [A. C. Diogo and A. F. Martins, Mol. Cryst. Liq. Cryst. 66, 133 (1981)], is also used for comparison. By comparing the OT theory with experimental results of some Leslie coefficients, the activation energy, mean-field potential, fourth order of the nematic order parameter, and molecular length-to-width ratio of a liquid-crystal compound are obtained. The mean-field coupling constant is found to be about 1.8 , which is somewhat lower than the Maier-Saupe theoretical value of 4.5 .
- Received 23 April 1990
DOI:https://doi.org/10.1103/PhysRevA.42.2219
©1990 American Physical Society