Fiber Engineering Trifecta of Spinnability, Morphology, and Properties: Centrifugally Spun versus Electrospun Fibers

Designing application-ready fibers involves multifaceted challenges related to correlating the formulation properties and processing parameters to the fiber engineering trifecta of spinnability, morphology, and properties. Here, we characterize the influence of macromolecular and solvent properties on the trifecta for poly(ethylene oxide) (PEO) fibers produced using a bespoke centrifugal force spinning (CFS) setup and matched processing parameters. We illustrate the influence of changing solvent on spinnability, morphology, and properties (thermal and mechanical) by varying the acetonitrile (AcN) fraction in the spinning dope formulated with PEO dissolved in AcN/H2O mixtures. We contrast the numerical values of measured diameter, tensile strength, elongation-at-break, and crystallinity of centrifugally spun PEO fibers with the published data sets for electrospun fibers using the Berry number (or the overlap parameter) as the ordinate. We compile, analyze, and replot ES and CFS data sets obtained for various solvents, PEO (Mw and c), and processing parameters. Even though distinct forces determine the jet trajectory and fiber formation for ES and CFS, we find that centrifugally spun PEO fibers emulate electrospun fiber properties, morphology, and spinnability. We discuss the mechanism underlying volatile-entangled spinnability, displayed here by PEO solutions in certain AcN/H2O mixtures, in contrast to extensibility-enriched spinnability of multicomponent formulations, enabled by the addition of an ultrahigh Mw polymer fraction.