Ion-assisted collection of Nylon-4,6 electrospun nanofibers

In electrospinning, electrostatic interaction between charged fibers and the collection substrate can result in poor and non-uniform coverage, particularly when electrically insulating substrates are used, because they are prone to surface charge accumulation. Charged electrospun Nylon-4,6 nanofiber coatings were deposited onto substrates of varying size, conductivity and morphology. The density and uniformity of the nanofiber coatings were significantly enhanced, both on insulating and on conducting substrates, by a new method based on rapid sequential deposition of charged nanofibers and oppositely charged ions onto substrates that were mounted onto a rotating collecting electrode (mandrel) located between an electrospinning source and a focused ion source. Sequential fiber/ion deposition presumably led to surface charge neutralization or reversed charging, and minimization of electrostatic fiber/substrate interactions. An electrostatics model was developed to interpret the experimental results. It was also theoretically argued that any degree of ion charging will induce continuous fiber accumulation.