Bimodal distribution in branched polymer solutions

Overview & Synopsis

We study the swelling of one very large molecule made of N monomers in a mixture of a good solvent and shorter polymers of P units of the same chemical species. All the macromolecules are branched. The total concentration is larger than the contact concentration C* of the short chains. When P decreases, the radius of gyration of the probe chain crosses-over from a N 1/3 behaviour typical of concentrated solutions to a N 1/2 law characteristic of dilute solutions. The cross-over occurs around a value P* ∼ N5/6. The monomer correlation functions are also studied.