precipitation fractionation

of polymers
A process in which a @M03667@ material, consisting of @M03667@ differing in some characteristic affecting their @S05740@, is separated from solution into fractions by successively decreasing the solution @P04792@ of the solvent, resulting in the repeated formation of a two-phase system in which the less soluble components concentrate in the @P04745@.
Purple Book, 1st ed., p. 68 [Terms] [Book]