QUASI-ELASTIC LIGHT-SCATTERING FROM SOLUTIONS OF LOLLIPOP-SHAPED PARTICLES

An expression is derived for the field correlation function of the light scattered from a solution of lollipop‐shaped particles. Such particles are a tractable model of certain bacteriophages. They are assumed to consist of an ellipsoidal head containing optically anisotropic scattering material and a tail which does not scatter. Because of the tail, Brownian rotational movement occurs around a center of rotational friction which is at a distance r0 from the center of the head. The dependence of the field correlation function C(τ) on the rotational diffusion coefficient DR is given by the factor ΣlBl exp[−l(l + 1)DRτ]. It is shown that the tail causes the coefficients Bl to be different from zero for all values of l. Therefore, C(τ) contains a term proportional to exp(−2DRτ), which is not present when r0 = 0. We give plots of Bl for various combinations of parameters. It turns out that dynamic light scattering may be used to measure r0. Copyright © 1979 John Wiley & Sons, Inc.