Mesoscopic interpretation of Fokker-Planck equation describing time behavior of liquid crystal orientation

Starting out with the mesoscopic mass balance for liquid crystals we derive the balance equation for the orientation distribution function (ODF) of the molecules which is of Fokker-Planck type. Comparison of this mesoscopic generated Fokker-Planck equation to well-known statistically induced balance equations of the ODF results in a slip relation between the rotation of the liquid crystal and the angular velocity of molecules of different orientations. The difference between these two angular velocities is caused by the torque of the meanfield, by the velocity gradient, by the alignment, and by the non-isotropy of the ODF. (C) 1997 American Institute of Physics.