Advanced Materials

Enhancement in the Orientation of the Microdomain in Block Copolymer Thin Films upon the Addition of Homopolymer


  • This work was supported by the National R & D project for Nano Science and Technology (M1-0214-00-0230), the Department of Energy, Office of Basic Energy Sciences under contract DE-FG02-96ER45612, National Science Foundation under partnership in Nanotechnology (CTR-9871782), and the Material Research Science and Engineering Center at the University of Massachusetts. Small angle X-ray scattering was performed at PLS beam line supported by POSCO and KOSEF.


Cylindrical microdomains in thin films of mixtures of polystyrene-block- poly(methyl methacrylate) and poly(methyl methacrylate) (PMMA) homopolymer are oriented normal to the film surface (see Figure). Confining the PMMA homopolymer to the microdomains increases the persistence of microdomain orientation over large distances; thus, aspect ratios up to ∼10 are achievable without the use of an external field.