Angular-dependent rotational friction in anisotropic liquids

Hydrodynamical arguments are used to derive an expression for the angular-dependent rotational friction, appropriate for the description of the rotational dynamics of molecules in liquid-crystal phases characterized by anisotropic viscosities and orientational torques. The solutions of the corresponding Fokker—Planck equation, obtained under conditions of diffusional motion, show significant variations in the time dependence of the dipole correlation functions