(781b) Twisted Peanut-Shaped Poly (Vinyl Pyrrolidone) Ribbons Generated by Electrospinning

Qing Du¹, Hong Yang^1,2,*, David Harding³

¹ Department of Chemical Engineering, University of Rochester, Rochester, NY 14627, U.S.A.

² Department of Chemical and Biomolecular Engineering, University of Illinois at Urban-Champaign, Urbana, IL 61801, U.S.A.

³ Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14623, U.S.A.

Interesting twisted peanut-shaped ribbons of poly (vinyl pyrrolidone) (PVP) have been fabricated by Magnetic-Field-Assisted Electrospinning (MFAE) method. The relative humidity has been found to significantly influence the morphology of PVP fibers. The morphology changes from aligned fibers to twisted ribbons, when the relative humidity decreases. The percentage of twisted ribbon increases dramatically as well.  At the same time, the cross-section of the electrospun fibers changes continuously from circle, ellipse, to peanut shape. In addition, the ultimate elongation of fibers also changes with the relative humidity due to the variation of morphology of the fibers. The formation of twisted ribbons is explained by the synergy of the bending instability of electrospinning and the rigidity of polymer materials during the MFAE. We will offer insight on the effect of the relative humidity on the extent of twisting and shape of the cross-section, which is an important but overlooked factor in the electrospinning process.