Multiple scattering suppression in static light scattering by cross-correlation spectroscopy

Cross-correlation techniques have been used successfully to suppress multip le scattering in dynamic lightscattering experiments on turbid samples. Thi s allows dynamic information to be obtained straightfowardly by processing the remaining single scattering. Here we show that cross-correlation techni ques can also be used to suppress multiple scattering in static light-scatt ering measurements. We use the two-color dynamic lightscattering method and exploit the fact that the amplitude of the time-dependent part of the meas ured intensity cross-correlation Function depends on the ratio of Che singl e-scattered intensity to the total (single + multiple) scattered intensity. The method is illustrated by measurements of the static structure factors of concentrated suspensions of "hard-sphere" colloids. Good agreement is fo und with those calculated in the Percus-Yevick approximation [S1063-651X(99 )15310-8].