ИСТИНА

A new promising class of ordered block copolymer morphologies in thin films we call diamond-like morphologies (DLM) is theoretically described in detail. This class comprises the cubic morphologies possessing diamond symmetry Fd m3 as well as its tetragonal and orthorhombic generalizations. The characteristic property of the DLM is that the corresponding percolation cluster contains both perpendicular and parallel (with respect to the substrate) intertwining channels, which is expected to improve noticeably the permeability efficiency of such quasi-isotropic morphologies as compared to the anisotropic lamellar and cylindrical ones. Using the methods of weak segregation theory (WST) and self-consistent field theory (SCFT) we find relationships between the microscopic parameters of the ternary ABC symmetric block copolymers of a specified composition and their morphology in thin films. The effects of confinement (film width) and the film walls selectivity are analyzed and the corresponding phase diagrams are built. The key theoretical prediction is that the way the selectivity is distributed over the film substrate makes a drastic difference in the selectivity influence on the various phases’ stability: the homogeneous selectivity distribution enhances the lamellae stability whereas a simple 1D (lamellar) selectivity modulation could enhance the DLM stability. The corresponding preliminary phase diagram is built in the plain (the film width – the selectivity pattern period).