ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
A self-consistent field approach is used to investigate the partial to complete wetting transition for an A:B polymer blend at coexistence where polymers A and B have equal numbers of segments, N. The surface free energy, Fs, is modeled using the quadratic form suggested by Schmidt and Binder [J. Phys. II (France) 46, 1631 (1985)], namely, Fs=−μφ1−0.5gφ12, where μ and g are the surface equivalents of the bulk chemical potential and interaction energy, respectively, and φ1 is the surface volume fraction of the surface preferred component (A). For selected values of g and the bulk volume fraction of A, φ∞, the volume fraction profile and A surface excess, z*, are calculated as a function of increasing μ. The first and second order wetting transitions are indicated by a discontinuity and divergence, respectively, of z* and φ1. In our simulations, at high values of φ∞ only first order transitions are detected for both N=100 and N=1000. However, both first and second order wetting transitions are observed for low values of φ∞ depending on the value of g. The latter results contrast with those of Carmesin and Noolandi [Macromolecules 22, 1689 (1989)], who found that only first order wetting transitions are possible polymer mixtures. However, our results are in agreement with recent Monte Carlo simulations carried out by Wang and Binder [J. Chem. Phys. 94, 8537 (1991)] and Pereira and Wang [J. Chem. Phys. 104, 5294 (1996)]. © 1997 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.473222
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