Effect of adding LiCl on PEO electrospun nanofibers

Electrospinning is a straightforward method to produce continuous polymer fibers. We can get fibers which diameters range in the sub-micron, with the action of an external electric field imposed on a polymer solution or melt. In this paper, inorganic salt (LiCl) was added to polyethylene oxide (PEO) /deionized water (DI water) solution in order to study the effect of two main solution parameters on electrospinning: solution viscosity and electrical conductivity. By adding different contents of LiCl, viscosity of the solution hardly changed, while the electrical conductivity dramatically increased. As a result, the bigger size of the nanofibers was obtained and a bimodal distribution of fiber sizes disappeared. Some interesting morphology, such as doubling phenomenon and "garland" structure, has been seen in the electrospun nanofibers. In addition, in the electrospinning process, with the increase of the salt in the solution, some vertical stand-up short-fibers appeared on the collector. Furthermore, a connective filament phenomenon appeared between the needle tip and the collector distance (TCD) as well.