Positioning and Aligning Electrospun PAN Fibers by Conductive and Dielectric Substrate Patterns

During electrospinning, the flying nanofibers can be attracted by conductive areas such as copper tape on a nonconductive substrate, especially in case of magnetic nanofibers. The question arises, however, whether the conductivity or any other physical properties of these areas are responsible for this effect. Here, electrospinning polyacrylonitrile (PAN) on nonconductive polypropylene (PP) substrates is reported, modified with conductive copper tape as well as with diverse coatings with varying dielectric constants. The results show that in case of non-magnetic PAN fibers, especially BaTiO3 with its high dielectric constant strongly, attracts the fibers formed during electrospinning, which can be explained by local modification of the electric field due to the introduced dielectric. This process can be used to tailor the nanofiber mat thickness depending on the position.