(415c) Synthesis and Processing of High-Strength and High-Toughness Crystalline 2-D Covalent Organic Frameworks

Poly-aramid fibers (such as Kevlar) are among the strongest and toughest synthetic materials ever created. Poly-aramids are linear polymers comprised of rigid, aromatic molecules joined by amide linkages, and the combination of chain rigidity along with intermolecular hydrogen bonding provides lightweight and low-density fibers with unusually high tensile modulus and strength. However, these exceptional mechanical properties cannot be easily translated to thin films and coatings. 2-D COFs are macromolecules with a two-dimensional structure and an overall planar conformation, and recent work has shown that 2-D COFs with interlayer hydrogen bonding interactions have the potential to be used in high-strength films and coatings. In this talk, I will present the design, synthesis, processing, and characterization of 2-D COFs designed to have strong interlayer bonding. We demonstrate the synthesis of a series of polyimide and polyamide COFs, the characterization of mechanical properties through in situ testing, and novel synthesis and processing strategies for scaling up the preparation of 2-D COF films.