2000/07/24 by M. Mueller, Marcus Müller, E. V. Albano +3 · 1 citation
Engineering · Materials Science · Mathematics · Physics and Astronomy · #Antisymmetric relation #Block Copolymer Self-Assembly #Condensed matter physics #Critical point (mathematics) #Geometry #Materials science #Mathematics #Phase (matter) #Phase Equilibria and Thermodynamics #Phase diagram #Phase transition #Physics #Quantum mechanics #Theoretical and Computational Physics #Thermodynamics #Tricritical point #Triple point #Wetting #Wetting layer #Wetting transition #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.62.5281
Phys.Rev.E in print
arxiv created 2000/07/24 · openalex publication_date 2000/10/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the phase behavior of a symmetric binary polymer blend that is confined in a thin film. The film surfaces interact with the monomers via short-range potentials. We calculate the phase behavior within the self-consistent field theory of Gaussian chains. Over a wide range of parameters we find strong first-order wetting transitions for the semi-infinite system, and the interplay between the wetting/prewetting behavior and the phase diagram in confined geometry is investigated. Antisymmetric boundaries, where one surface attracts the A component with the same strength as the opposite surface attracts the B component, are applied. The phase transition does not occur close to the bulk critical temperature but in the vicinity of the wetting transition. For very thin films or weak surface fields one finds a single critical point at straight phi(c)=1 / 2. For thicker films or stronger surface fields the phase diagram exhibits two critical points and two concomitant coexistence regions. Only below a triple point there is a single two-phase coexistence region. When we increase the film thickness the two coexistence regions become the prewetting lines of the semi-infinite system, while the triple temperature converges toward the wetting transition temperature from above. The behavior close to the tricritical point, which separates phase diagrams with one and two critical points, is studied in the framework of a Ginzburg-Landau ansatz. Two-dimensional profiles of the interface between the laterally coexisting phases are calculated, and the interfacial and line tensions analyzed. The effect of fluctuations and corrections to the self-consistent field theory are discussed.