Polymer Miscibility in Capillaries

Abstract

A thermodynamic analysis predicts an increase in miscibility, relative to that in the bulkstate, for a polymer mixture confined in a capillary with a diameter of the order of the sizeof the polymer coils. This is derived by using both the concepts of growing domains and aconsideration of the thickness of polymer-polymer interfaces. The analysis is combinedwith a Monte Carlo lattice simulation that provides results on such confined systems.Intermixing, described in terms of the number of heterocontacts and the dimensions ofthe polymer chains in the capillary parallel and perpendicular to the tubular axis, is investigated.The results confirm that demixing in homogeneous mixtures is hindered, whereasintermixing is enhanced, in the capillary relative to that in the unconfined mixture