Model calculations for wetting transitions in polymer mixtures

Fundamentals of Phase Separation in Polymer Blend Thin Films

“…Schmidt and Binder extended the work of Nakanshi and Pincus to binary polymer blends in the presence of a single wall [33]. Their results showed that polymer systems should display the same surface phenomena present in simple fluid systems.…”

“…The boundary conditions (4.8) and (4.9) must be satisfied, along with the constraint equation (4.10) via choice of λ, to specify equilibrium profiles φ (z) which also satisfy the Euler-Lagrange equation (4.7) [27,31,33]. Of course, that equilibria must satisfy these requirements is not specific to the Hamiltonian Phase Portrait method in particular.…”

“…(3.24) (often noted as being the only effect on the solution profile due to focus on symmetric blends confined between antisymmetric walls [33,37]) but to effectively apply a field across the film. Of course, the surface energies only act locally at the surfaces, and do not in reality actually apply a field across the film.…”

“…They argued that, for polymer blends, critical/second-order wetting should be impossible to observe, as should extended wetting. Schmidt and Binder studied a semi-infinite binary polymer mixture in contact with a wall preferring one polymer species [33], using a Flory-Huggins-de Gennes free energy functional with an additional term for the bare surface energy, given by equation (2.5). First-order wetting, prewetting and second-order wetting were studied.…”

Avantages de la réflectométrie des neutrons pour l'étude des polymères en couches minces

“…Mais, pour les mélanges isotopiques, ils sont miscibles à des températures hautes et/ou pour des poids moléculaires faibles. La théorie qui décrit ce qui se passe dans la région miscible du diagramme de phases [15] a été démontrée par les expériences de faisceaux d'ions [16] et ses limites étaient testées par la réflectivité de neutrons [17]. Dans la Figure 9(b) nous présentons les données de la réflectivité de neutrons et les meilleurs ajustements pour un mélange de polystyrènes deutéré et protoné, qui est étudié très proche à la transition de séparation de phases [18].…”