Light scattering from spheroids in shear flows. I. The orientation correlation

Abstract

The time dependent orientation distribution function for ellipsoids of revolution (a,b,b) in shear flow is obtained as an expansion in terms of the parameter r=[1−(b/a)²]/[1+(b/a)²]. Our results reduce to Peterlin’s steady state results at infinite time (t=∞). Using this distribution, the orientation correlation function and its contribution to the light spectrum of polarized light are calculated. The results for the correlation function as an expansion in r lead also simultaneously to an expansion in the ratio σ of the shear rate to the Brownian rotation diffusion coefficient, σ=γ/D. The expansion procedure is thus valid for reasonably high shear rates in the case of nearly spherical spheroids (r≪1) or for small shear rates but large values of r (‖r‖?1, rods and disks).