Block copolymer micelles: From delicate liquids to tough plastics
Frank Bates, of University of Minnesota, presents a seminar in Chemical and Biomolecular Engineering.
Block copolymers belong to a broad class of soft materials that includes soaps, lipids and other amphiphilic compounds. These macromolecules assemble into micelles with molecular dimensions on the order of 5 to 50 nm in size when mixed with excess solvent that preferentially solvates one block type. This presentation explores two different aspects of block copolymer micelle formation. The fundamental thermodynamic and kinetic factors that control micelle shape and dynamics will be discussed based on small-angle x-ray and neutron scattering and cryogenic electron microscopy results. These concepts have been exploited in developing a newly commercialized technology that provides immense improvements in the fracture toughness of thermosetting epoxy plastics.