An Unconventional Route to Hierarchically Ordered Block Copolymers on a Gradient Patterned Surface through Controlled Evaporative Self‐Assembly

A chemically patterned surface was formed by controlled evaporative self-assembly of concentric polymer stripes, followed by the removal of weakly deposited polymer, giving ultrathin polymer stripes with a width gradient on the Si substrate (see picture). A thin film of diblock copolymer hierarchically self-assembled on the ultrathin polymer stripes, giving arrays of nanocylinders perpendicular to the surface of the film.