Highly ordered hexagonal arrays of hybridized micelles from bimodal self-assemblies of diblock copolymer micelles

We demonstrate the formation of highly ordered hexagonal arrays of hybridized polystyrene-poly(4-vinyl pyridine), PS-PVP, micelles with controllable size by solvent annealing techniques. Because the formation of hybridized micelles was prohibited in the mixture solutions of two different-sized PS-PVP micelles, single-layered films with bimodal self-assemblies of small and large micelles were fabricated from the mixture solutions by adjusting their mixing ratios. When the single-layered films were solvent annealed by saturated vapor of tetrahydrofuran (THF), on the other hand, small and large PS-PVP micelles in the bimodal self-assemblies merged together to form hybridized micelles. In addition, the hybridized micelles arranged themselves in a highly ordered hexagonal array, the diameter and center-to-center distance of which were precisely adjusted by varying the mixing ratio of small to large micelles in the bimodal assemblies.