SOLUTAL SEPARATION UNDER CENTRIFUGATION

We report on experiments and numerical simulations of the centrifugal separation of solutes in aqueous solutions. The experiments are measur ements of solutal concentrations in binary and ternary aqueous mixture s of seven different salts subject to centrifugal accelerations of bet ween 57,000g and 200,000g. The evolution of the concentration profiles are measured and the sedimentation coefficients are determined. We co mpare our experimentally determined coefficients with those predicted by the Svedberg relation. Our numerical simulations of the diffusion a nd sedimentation dynamics of centrifugation agree well with the experi ments and constitute a basis for a nonequilibrium centrifugal separati on scheme.