Blooming of Block Copolymer Micelles into Complex Nanostructures on a Surface

Self-assembled block copolymer (BCP) nano-structures are of important utility across a wide field. Here, we report a solution-surface sequential self-assembly approach to tailor amphiphilic BCPs in solution and subsequently on a substrate into complex nanostructures. Spherical micelles that formed in solution transform on a substrate sequentially into toroidal micelles, concentric toroidal micelles, and ring clusters upon alternating annealing in solvents that selectively swell the core but poor for the corona. This process is found in both diblock and triblock copolymer systems and appears to be independent of the nature of substrate and gravity. Thus, BCPs micelles with simple shapes can be further manipulated on a surface in a flexible fashion to constructed novel nanostructures.