Highly Oriented and Ordered Arrays from Block Copolymers via Solvent Evaporation


  • This work was funded by the US Department of Energy, Office of Energy Sciences, the National Science Foundations sponsored Materials Research Science and Engineering Center at the University of Massachusetts, the Hyperstructured Organic Materials Research Center at Seoul National University and the Films & Film Products Research Laboratories and Special Purpose Overseas Study Program of Toray Industries, Inc. and the Keck Foundation. We thank B. Ocko, O. Gang, and A. Gibaud for assistance with the GASAXS measurements and C. Harrison, D. E. Angelescu, M. Trawick, R. Register, and P. Chaikin of Princeton University for providing us with IDL-based software to analyze block copolymer patterns.


A simple process of solvent evaporation is shown to produce highly ordered arrays of cylindrical microdomains in block copolymers with long-range lateral order (see Figure). Solvent evaporation in thin films is unidirectional, producing a self-assembly directed normal to the film surface, akin to a zone refinement. Further control over the size and separation distance of the domains can be achieved with cosolvents.