Hierarchically Organized Structure of Electrospun Nanofibers from Computationally Designed Peptide Bundlemers

Fiber materials made from natural or synthetic polymers can be used as high performance materials exhibiting high stiffness, strength, and/or elongation, all while being light weight. The ability to create a desired internal nanostructure with controllable molecular interactions in the fibers is paramount to a construction of new materials with unique structural features and a remarkable combination of high stiffness, strength, and elongation. Herein, peptides are computationally designed to self-assemble into coiled coil bundles that serve as supramolecular monomers, or “bundlemers”, to create a hierarchical structure for high performance nanofibers. The bundlemers have chemical functionality for desired covalent interactions between bundles to facilitate hierarchical chain growth that displays rigid-rod character. The rigid rods are employed to fabricate uniform nanofibers via electrospinning. The rod chains are observed to be aligned along the fiber axis due to their molecular rigidity and the solution flow during electrospinning process, which impacts the eventual mechanical properties of the nanofibers. The mechanical properties of electrospun rod fibers are investigated as a function of rod length and intra- or inter-chain interactions in the rod chains.