Transient SANS studies of rodlike micelles on a time scale of 100 ms

Time-dependent anisotropic small-angle neutron scattering (SANS) patterns of rodlike micelles in a shear gradient Γ, suddenly changing its value from zero to a constant value, are presented. The time resolution of the experiment was 100 ms. By an analysis of the steady-state pattern a rotational diffusion coefficient D of ~ 2 s⁻¹ is deduced. Furthermore it is shown that in a well aligned sample the SANS pattern is sensitive to the rod length distribution in spite of correlation peaks which are caused by repulsive inter-micellar interaction.