Numerical self-consistent field theory of multicomponent polymer blends in the Gibbs ensemble

A new computational technique is presented for the investigation of multicomponent polymer phase behavior based on a Gibbs ensemble formulation of self-consistent field theory. Calculations in the Gibbs ensemble allow the simulation of two or more coexisting phases in the absence of an interface by enabling the exchange of volume and matter between phases to locate equilibrium. The theory underlying our numerical method is developed with an intensive formulation to allow the representation of each constituent phase or mesophase by a single representative unit cell. The phase coexistence of a binary blend consisting of an AB diblock copolymer with an A homopolymer was calculated and found to agree with previously reported results obtained in the grand canonical ensemble.