Electric-field induced alignment of nanoparticle-coated channels in thin-film polymer membranes

Microscopic phase separation in immiscible polymer melts can be significantly altered by the presence of dispersed nanoparticles and externally applied electric fields. Inducing order or directionality to the resulting microstructure can lead to novel materials with efficient synthesis. Here, the coupled morphology of an immiscible binary polymer blend with dispersed nanoparticles in a thin-film geometry is investigated under the influence of an applied electric field using a unique mesoscale computational approach. For asymmetric binary blends (e.g., 70-30), the resulting microstructure consists of columnar channels of the B-phase perpendicular to the major plane of the film (aligned with the electric field), with the particles segregated along the channel interfaces. The simulations reveal the variability of the average channel diameter and the interfacial arrangement of the particles. The high density of exposed particles makes these structures viable candidates for catalytically active porous membranes or macromolecular manipulation devices.