Square and Rectangular Arrays from Directed Assembly of Sphere-forming Diblock Copolymers in Thin Films

POSTER

Abstract

Patterns of square and rectangular arrays with nanoscale dimensions are scientifically and technologically important. Fabrication of square array patterns in thin films has been demonstrated by directed assembly of cylinder-forming diblock copolymers on chemically patterned substrates, supramolecular assembly of diblock copolymers, and self-assembly of triblock terpolymers. However, a macroscopic area of square array patterns with long-range order has not been achieved, and the fabrication of rectangular arrays has not been reported so far. Here we report a facile approach for fabricating patterns of square and rectangular arrays by directing the assembly of sphere-forming diblock copolymers on chemically patterned substrates. On stripe patterns, a square arrangement of half spheres, corresponding to the (100) plane of the body-centred cubic (BCC) lattice, formed on film surfaces. When the underlying pattern periods mismatched with the copolymer period, the square pattern could be stretched (up to $\sim $60{\%}) or compressed ($\sim $15{\%}) to form rectangular arrays. Monte Carlo simulations have been further used to verify the experimental results and the 3-dimensional arrangements of spheres.

Authors

  • Shengxiang Ji

    University of Wisconsin, Department of Chemical \& Biological Engineering, University of Wisconsin-Madison

  • Umang Nagpal

    University of Wisconsin, Department of Chemical \& Biological Engineering

  • Wen Liao

    University of Wisconsin, Department of Chemical \& Biological Engineering

  • Juan J. de Pablo

    University of Wisconsin - Madison, Chemical and Biological Engineering, University of Wisconsin Madison, Chemical and Biological Engineering, University of Wisconsin-Madison, University of Wisconsin, Department of Chemical \& Biological Engineering, University of Wisconsin, University of Wisconsin-Madison

  • Paul Nealy

    University of Wisconsin, University of Wisconsin, Department of Chemical \& Biological Engineering, Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Department of Chemical and Biological Engineering, University of Wisconsin - Madison, Madison, WI 53706, Department of Chemical and Biological Engineering, University of Wisconsin, Madison WI 53706, University of Wisconsin-Madison