CONSERVATIVE DICHROISM OF A SHEARED SUSPENSION IN THE RAYLEIGH-GANS LIGHT-SCATTERING APPROXIMATION

Calculations of the conservative linear dichroism and of the average particle orientation angle are carried out for dilute suspensions subjected to transient simple shear flow in the absence of Brownian motion and in the presence of weak Brownian motion. For both situations, only small differences in the features associated with the particle orientation statistics of the simulation occur between the Rayleigh and the Rayleigh-Gans calculations over a wide range in particle geometry. In particular, the calculation of the average particle orientation angle is found to be insensitive to the choice of light scattering treatment. Generally, we infer from these simulations that the additional complexity of the Rayleigh-Gans treatment is usually not warranted for the analysis of typical rheo-optical data from dilute suspensions.