Out-of-plane orientational dynamics of polymer liquid crystals under flow

The nonplanar orientational dynamics of polymer liquid crystals is investigated using a continuum theory based on Hamiltonian mechanics. The initial out-of-plane orientation is generated through the application of a magnetic field which naturally appears in the Hamiltonian of the system. Our analysis begins at the instant the magnetic field is turned off and the flow is started. It is found that the orientational pattern is varied and rich in transitions. The ''kayaking'' states and the shear-plane tumbling states are found to be the dominant attractors for the majority of the parameter space. Also, this theory has an inbuilt nonaffine parameter which is found to have an important effect on the nature of the final stable orientations. (C) 1996 Society of Rheology.