Shear-induced sphere-to-cylinder transition in diblock copolymer thin films

Young Rae Hong, Douglas H. Adamson, Paul M. Chaikin, Richard A. Register

    Research output: Contribution to journalArticlepeer-review


    Applying sufficiently strong shear to thin films of a sphere-forming polystyrene-polyisoprene diblock copolymer is shown to induce an order-order transition to cylinders. The transformation is not continuous or epitaxial, as the intercylinder spacing is ca. 10% greater than the spacing between close-packed lines of spheres. The transition is facilitated when the block copolymer has a composition which places it close to the "zero-field" (no shear) sphere/cylinder phase boundary; the shear-induced transformation is more difficult and less effective for a polymer further from this boundary. Applying a modest shear stress to a polymer close to the boundary distorts the hexagonal lattice formed by the spheres without forming cylinders; the mechanical anisotropy produced by this distortion is sufficient to permit a film containing only a single layer of spherical domains to align in shear.

    Original languageEnglish (US)
    Pages (from-to)1687-1691
    Number of pages5
    JournalSoft Matter
    Issue number8
    StatePublished - 2009

    ASJC Scopus subject areas

    • General Chemistry
    • Condensed Matter Physics


    Dive into the research topics of 'Shear-induced sphere-to-cylinder transition in diblock copolymer thin films'. Together they form a unique fingerprint.

    Cite this