Zakharov A V, Domenici V, Veracini C A, Dong R Y
Saint Petersburg Institute for Machine Sciences, Russian Academy of Sciences, Saint Petersburg 199178, Russia.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 Jan;73(1 Pt 1):011711. doi: 10.1103/PhysRevE.73.011711. Epub 2006 Jan 27.
The five nematiclike viscosity coefficients corresponding to the Smectic-C* (SmC*) phase are calculated by a combination of the existing statistical-mechanical approach and NMR theory, based on a rotational diffusion model for two ferroelectric smectogens. The order parameter S2, the smectic tilt angle Theta, and the rotational diffusion coefficient D(perpendicular), corresponding to molecular tumbling in the SmC* phase, for the ferroelectric smectogens 4-[4'-(1-methylheptyloxy)]biphenyl'-(10-undecenyloxy)benzoate and (S)-[4-(2-methylbutyl)phenyl]-4'-n-octylbiphenylcarboxylate have been obtained by means of 2H NMR spectroscopy and these data have been used to calculate viscosity quantities. For practical purposes a specific form of the functional dependence of S4 on S2 is used. As the main result, our calculations also predict a laminar flow regime in a high shear flow for these liquid crystal compounds.
