%0 Journal Article %T Fractionation of polydisperse systems: multi-phase coexistence %A R. M. L. Evans %J Physics %D 1999 %I arXiv %R 10.1103/PhysRevE.59.3192 %X The width of the distribution of species in a polydisperse system is employed in a small-variable expansion, to obtain a well-controlled and compact scheme by which to calculate phase equilibria in multi-phase systems. General and universal relations are derived, which determine the partitioning of the fluid components among the phases. The analysis applies to mixtures of arbitrarily many slightly-polydisperse components. An explicit solution is approximated for hard spheres. %U http://arxiv.org/abs/cond-mat/9901283v1