In this study, nylon-6 nanofiber mats containing Fe2+ ions were fabricated via electrospinning. The resultant electrospun nylon-6/FeCl2 nanofiber mats were characterized by SEM, TEM, Fourier transform IR spectroscopy, wide angle XRD and DSC. Unique morphological features, such as spider's-web-like morphologies, were observed and became evident with increasing additive Fe2+ ions. The metastable form was predominant in the as-spun nylon-6 nanofibers. The relative intensity of such form gradually decreased with increasing additive Fe2+ ions, indicative of transformation of the crystalline structure in the electrospun nylon-6/FeCl2 nanofibers due to strong molecular interactions between the nylon-6 backbone and the additive Fe2+ ions. The effects of additive Fe2+ ions on the mechanical properties of both nonwoven nanofiber mats and single nanofibers were investigated. In particular, Young's modulus of nylon-6/FeCl2 single nanofibers gradually increased from 1.46 to 5.26 GPa with increasing additive Fe2+ ions. (c) 2013 Society of Chemical Industry