Block copolymer self-assembly can be used to create solid ordered nanostructures in thin or bulk films, as well as well-defined nano-objects in solution assembly. In combination with sacrificial porogens, the co-assembly of block copolymers creates ordered nanoporous polymers with homogenous porosity. While the casting of block copolymers on solid substrates yields substrate-bound films, their preparation in emulsion drops can lead to freely dispersed polymeric particles with internal ordered nanostructure. However, the self-assembly of block copolymers in single emulsion drops is typically limited to submicron particles. Complex emulsions enable the formation of large, thin polymeric films freely dispersed in liquids in the form of microcapsules. Here we report the combination of the microfluidic fabrication of double emulsion drops with the nanoscale co-assembly of amphiphilic block copolymers with a sacrificial porogen. The co-assembly of di- and triblock copolymers with removable small molecule additives inside the oil phase of homogeneous water-in-oil-in-water double emulsion droplets is described. The obtained microcapsules with controllable diameters of 100s of microns exhibit thin polymeric shells with ordered nanostructures and well-defined nanopores with pore sizes in the 10s of nanometers. Self-assembled nanoporous morphologies include three-dimensionally ordered, bicontinuous gyroid networks, and one-dimensional hexagonally packed cylinders. The challenges in using amphiphilic block copolymers in water-in-oil-in-water double emulsions are also discussed.

Block copolymer self-assembly in microfluidically produced double emulsion droplets

256th National Meeting (2018)

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