While equilibrium block-copolymer morphologies are dictated by energy-minimization effects, the semi-ordered states observed experimentally often depend on the details of ordering pathways and kinetics. Here, we explore reordering transitions in thin films of block-copolymer cylinder-forming polystyrene-block-poly(methyl methacrylate). We observe several transient states as films order towards ...

Directed self-assembly of block copolymers has been used for fabricating various nanoscale patterns, ranging from periodic lines to simple bends. However, assemblies of dense bends, junctions and line segments in a single pattern have not been achieved by using sparse templates, because no systematic template design methods for achieving such complex patterns existed. To direct a complex patter...

Block copolymer thin films with distinct morphologies are prepared by spin casting a nominally lamellar assay of poly(styrene-block-ethylene oxide) from a variety of solvents with and without salt doping. The 3-D morphologies of free-standing thin-film regions, which are obtained by casting directly onto holey substrates, are investigated in detail using various energy-filtering transmission el...

We present a straightforward method for the preparation of a novel donor–acceptor block copolymer based on an acceptor block with pendant phenyl-C71-butyric methyl ester (PC71BM) and a regioregular poly(3-hexylthiophene) (P3HT) as a donor. First, a hydroxyl-functionalized polystyrene copolymer with an azide end group was synthesized via nitroxide-mediated radical polymerization (NMRP) and was c...