Non-native block copolymer morphologies via blending and layering

Self-assembly of block copolymers efficiently yields nanoscale morphologies. Yet the most easily-accessible morphologies—such as lamellae and cylinders—are comparatively simple. Future materials will equire nanostructures more complex than those afforded by the canonical diblock-copolymer equilibrium phase diagram. This talk will discuss non-equilibrium strategies for generating non-native morphologies. Blending of copolymer chains can be used to stabilize otherwise high-energy configurations, opening the door to a new set of morphologies. Additional control can be applied by using directed assembly strategies. Chemical templates can select among competing morphologies in the blends, alongside the usual pattern registration. Layering of copolymer thin films provides an additional control mechanism. Layering essentially 'primes' the system into a contrived initial state, forcing the system to evolve through a set of non-equilibrium morphologies during annealing. Finally, we will discuss how the complex and high-dimensional parameter spaces associated with these strategies can be efficiently explored using autonomous experimentation, wherein machine-learning algorithms guide discovery.