CONFORMATION OF A POLYMER-CHAIN DISSOLVED IN A CRITICAL FLUID

The problem of a polymer chain immersed in a critical fluid, e.g. a mi xture of low molecular weight solvent close to its critical point, is studied and reformulated in a field theoretic framework. The starting point is a path integral formulation of the polymer chain which intera cts with the solvent molecules. If the critical solvent is approximate d by a Gaussian model all classical results are recovered, i.e. the po lymer chain collapses close to the critical point. These results becom e modified at the critical point where non-classical exponents determi ne the precise form of the fluctuation induced interaction potential b etween two monomers of the chain, and so its conformation.