Polymer phase separation on lattice patterned surfaces

We demonstrate the self-organization of phase-separated polymer microstructures on two-dimensionally chemically patterned surfaces. Pattern replication is expected when both the blend composition ratio matches the surface patterning area ratio, and the pattern periodicity matches the natural phase separation length scale. By varying film thickness and blend composition, we show that ordered morphologies also result for contrary situations, resulting in the formation of a rich variety of hierarchically-ordered microstructures. This hierarchy suggests that non-equilibrium structures generated by incomplete phase separation of blend components are locked in by rapid solvent quenching during casting.