Block copolymers are promising materials for nanoscale applications, such as conducting membranes and nanoporous templates, due to their ability to self-assemble into periodically ordered structures. To controllably obtain desirable nanostructures for various applications, it is essential to study the factors that affect the block copolymer self-assembly. The tendency for block copolymers to phase separate into various nanostructures is generally governed by the segregation strength and volume fraction of the copolymer blocks. One area of current project in our group is using tapered block copolymers to investigate the effects of interfacial composition on segregation strength between copolymer blocks. In tapered block copolymers, the composition profile is modified along the polymer backbone by introducing a transition region between two pure blocks that tapers from one component to another. This interfacial manipulation between blocks provides control over the segregation strength in our nanoscale phase-separated materials independent of molecular weight and block constituents. In this work, we are studying the effect of the tapered interface on the domain spacing behavior of salt-doped poly(styrene-b-oligo(oxyethylene) methacrylate) (PS-POEM). We synthesized tapered PS-POEM block copolymers with a range of taper lengths and salt doping levels, and we determined the domain spacing of salt-doped block copolymers using scattering and microscopy techniques. We also estimated the influence of salt doping on the thermodynamics of our tapered and non-tapered block copolymers.

Interfacial modification effects on the self-assembly of lithium-doped block copolymers

245th National Meeting (2013)

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