Session D3 - Polymer-templated Nanostructures.
INVITED session, Monday afternoon, March 03
Ballroom C, Austin Convention Center
Block copolymers self-assemble into a wide range of morphologies where, due to the interconnectivity of the blocks, the size scale of the microdomain morphology is limited to the tens of nanometer length scale. Directed self-assembly, where an external field or coupled fields are used to define the orientation of the morphology, are necessary to make full use of the nanoscopic size and exceptionally high packing density of the morphological elements. Here, two simple routes are demonstrated wherein a well-defined alignment and orientation of the cylindrical microdomains of diblock copolymers can be achieved by use of solvent evaporation. For a pinned droplet, the outward flow of solution to the pinning line causes the cylindrical domains to orient parallel to the flow directions over very large lateral area. Simple solvent evaporation, on the other hand, causes the propagation of an ordering front from the surface, through the copolymer film, thereby strongly orienting the microdomain normal to the surface and to a long-range lateral ordering. This work was done in collaboration with M.Misner, T.Xu, S.H.Kim, D.H.Kim, M.Kimura and Z.Lin and was supported by the NSF supported MRSEC and NIRT at the University of Massachusetts, the US Army, the DOE Office of Energy Science, and HOMRC at Seoul National University.