The spontaneous self-assembly of block copolymers (BCPs) into periodic nanoscopic domains can be exploited in applications like antireflective surface nanotexturing, nanofiltration membrane fabrication, or as a platform for nanolithography. A common thread that often limits the use of BCP self-assembly is slow ordering kinetics, which can result in poor quality, defective patterns. Here we discuss the enhanced ordering kinetics in thin film ternary blends of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) block copolymers with low molecular weight (&lt; 10% of the BCP molecular weight) PS and PMMA homopolymers. These “wet brush” homopolymers distribute more uniformly within the BCP domains and can even decrease the domain interfacial tension. Previously, we have shown that blending dramatically increases the power law exponent governing the development of long-range order during thermal annealing in lamellae-forming BCP thin films. More recent investigations of cylinder forming ternary blends using in situ grazing incidence small angle X-ray scattering (GISAXS) show that blends exhibit significantly faster early stage ordering and faster domain reorientation than the unblended BCP in films thicker than one monolayer. This ternary blending strategy is also compatible with solvent vapor annealing, where it can be used to promote rapid self-assembly of ultrahigh molecular weight lamellar PS-b-PMMA (&gt; 1000 kg/mol). Finally, we discuss the development of a new user tool at the Center for Functional Nanomaterials that uses electrospray deposition to create thin film multicomponent “libraries” on a single substrate; such a capability will enable rapid, systematic investigation of thin film blends of solution-deposited functional materials.

Rapid self-assembly in ternary “wet brush” block copolymer/homopolymer blend thin films

2019 Spring National Meeting

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