Free surface electrospinning of aqueous polymer solutions from a wire electrode

• Fibers are formed from aqueous solution by free surface electrospinning from a wire.
• Productivity entails liquid entrainment, film breakup, and electrified jetting.
• Changes of equipment design, operation and modeling are presented.
• A productivity model for manufacturing of fibers by this process is validated.

The production of nanofibers from an aqueous solution of poly(vinyl alcohol) by the method of free surface electrospinning from a wire electrode has been examined. The results are interpreted in terms of a previously reported model that was based on the production of fibers from polymeric solutions in ethanol by the same method. Differences in behavior were observed between the processing of aqueous and ethanolic solutions, arising from the more viscoelastic nature of the aqueous solution, the higher surface tension, the fewer number of droplets jetting simultaneously from the wire, and the different electrical current profile observed for jetting from a single droplet. These differences necessitated changes in equipment design, operation of the process, and modeling of productivity. The result is a more robust model for the productivity of fibers by free surface electrospinning from a wire electrode.