Solvent-induced ordering in thin film diblock copolymer/homopolymer mixtures

A new way to control the characteristic dimensions CA morphologies in polymer systems is demonstrated with a mixture of a block copolymer and a small amount of homopolymer. Controlled solvent annealing and casting produces long-range order over large areas for the blends (see Figure), and through the selective removal of the homopolymer, almost defect-free arrays of nanoscopic holes are produced in the block copolymer film.