Planar-Model Calculation of the Twist Viscosity, for Nematic Liquid Crystals

孫瑪琍(M. L. Sun)；黃幸美(H. M. Huang)

Chinese Journal of Physics

15卷3期（1977 / 10 / 01）

162 - 171

英文

One of the Leslie coefficients: the twist viscostiy γ, which'’measures the frictional torque opposing orientational motion, is calculated in the mean field approximation. The formalism employed parallels Kirkwood's statistical calculation of transport coefficients for ordinary isotropic liquids. The magnitude and temperature dependence ofγobtained are in qualitative agreement with experiment, even though the model used considers only one planar angle. The theory predicts a linear dependence of 7 on the molecular length and a square-root dependence on temperature for fixed order parameter. The prediction should be tested by experimental measurements performed on a homologous series of nematics.