(581i) Simultaneous in-Film Polymerization with Self-Assembly for on-Demand Manipulation of Polymer Functionality

Qiang, Z., Northwestern University
Akolawala, S., Northwestern University
Shebek, K., Northwestern University
Wang, M., Northwestern University
Self-assembly of polymers has emerged as a next-generation patterning technique due to its advantages of low cost and spontaneous nanoscale order. One key requirement for nanostructured polymer films for practical applications is the ability to generate complex geometries including different shapes and diverse sizes across one substrate surface. The constraints on previous strategies indicate a limited control of the polymer chemistry within defined locations on a polymer film.

In this talk, we will demonstrate a photo-controlled in-film polymerization process in the presence of monomer vapor for synthesizing homopolymers in self-assembled BCP films. The homopolymers blend with BCP films and alter the nanopatterns by changing the underlying polymer chemistry and composition. Identical photopolymerization conditions with lower UV power intensity causes more expansion of domains due to addition of higher molecular weight homopolymers. As these altered nanostructures are thermodynamically favored, this method can be adapted and combined with other techniques for alignment control and ordering improvement. The region of in-film polymerization can be modulated by the location of irradiation using photomasks for obtaining distinct morphologies on one substrate. We will also discuss how to understand these nanostructural re-arrangements kinetics using advanced techniques such as super-resolution single-molecule microscopy. With successful integration of polymer chemistry and self-assembly physics, in-film polymerization provides true on-demand synthesis for exact hierarchical control over the resulting morphology, functionality, and properties.