The diameter, morphology and alignment of the MEW-processed fibers were characterized using field emission scanning electron microscopy (FESEM) (Hitachi S-4800, Hitachi Ltd., Japan). Before imaging, all samples were sputter coated with a thickness of 5 nm Au/Pd to create a conductive surface (Cressington 208HR, Ted Pella Inc, USA). An accelerating voltage of 5 kV was applied for imaging and ≈50 fibers were analysed using ImageJ software to determine the average fiber diameter for each sample.