Nowadays, thanks to the electrospinning process, polymeric fibers in nanoscale diameters (10–500 nm) are easily producible. During the last decade, the electrospinning technique has been greatly investigated and developed. One of the most important fields of study on the electrospinning process is the influence of effective parameters on electrospun nanofibers and nanoweb properties. In this study, using polyamide-6 (PA-6)/formic acid polymer solution, three important parameters of the electrospinning process, including polymer solution concentration, needle-tip-to-collector distance, and needle length, were precisely studied. The solution concentration is a very important parameter that affects the nanowebs’ homogeneity and nanofibers’ diameter evenness. Scanning electron microscopy (SEM) analysis of the electrospun nanowebs showed that among five polymer solution concentrations (5, 10, 15, 20, and 25 wt%), 25 wt% was more suitable and provided the homogeneity and reproducibility of PA-6 nanowebs. It has been found that the needle-tip-to-collector distance had a considerable influence on the nanofibers’ diameter and the nanoweb collection zone. Morphological investigation and statistical studies showed that the nanofibers’ diameter increased with the reduction of the needle-tip-to-collector distance. Moreover, the average diameter of the nanoweb collection zone decreased by the reduction of this distance. The effect of needle length on the nanofibers’ morphology and nanowebs’ collection zone was investigated. Statistical analysis of the obtained results revealed that the increase of needle length significantly increased the average nanofibers’ diameter. Inversely, the diameter of the nanoweb collection zone reduced when needle length increased. All previously mentioned studies helped to define the optimal electrospinning condition to produce the bead-free, non-branched, and homogeneous PA-6 electrospun nanofibers and nanowebs.

Electrospinning is a common method used to produce nanofiber from almost all types of polymers. By changing effective parameters of this process, especially polymer solution concentration, it is possible to produce nanoweb that consists of nanofibers with different averages of diameter. Here, the effect of nanofibers’ diameter on textural properties (water absorption time and pore size) of polyamide-6 nanoweb has been studied. In this way, three nanowebs with nanofibers’ average diameter of 111, 151, and 318 nm were electrospun from three different concentrations of 15, 20, and 25 wt%, respectively. Contact angle measurement and mercury porosimetry were used to investigate the nanowebs’ water absorption properties and porosity (pore size). The results from the water absorption test demonstrated that the absorption time of a 2 µL water droplet was remarkably shorter for electrospun nanoweb with larger nanofiber diameter. Nanowebs electrospun from 15 and 20 wt% concentrations had roughly the same absorption regime, while for 25 wt% the absorption regime was totally different. Mercury porosimetry of electrospun nanowebs revealed that the pore size in the nanoweb structure decreased by decreasing average diameter of nanofibers. The results of this study showed that contact angle measurement and mercury porosimetry tests could be used as complementary methods to scanning electron microscopy and atomic force microscopy and presented as promising methods to study the textural and physical properties of electrospun nanowebs.