Fig. 3.
EDS spectra and SEM images of AgNP loaded electrospun nanofibers.
The SEM images of electrospun yarns and frequency distribution of their nanofibers are presented in Fig. 4. The SEM images are confirmed that nanofibers were partially oriented and aligned to the yarn axis and the addition of silver nitrate into the electrospinning solution doesn't change the orientation of nanofibers. The average diameter of hybrid yarns and their composed nanofibers are reported in Table 1. As it can be seen in Fig. 4 and Table 1, the diameter of nanofibers and hybrid yarns was decreased as the silver nitrate concentration in electrospinning solutions was increased. The characteristics of electrospun nanofibers also depend on the solution viscosity, conductivity and concentration. The polymer solution properties have a significant effect on the diameter of the resultant nanofibers. The domination of the repulsive forces against the surface tension is the first step in gaining successful electrospinning process and needs enough charges in the solution. Functional groups on polymer backbone, type of solvent, and existence of ionic species in the polymer solution can enhance the conductivity of the polymer solution. In polymer solutions with higher conductivity, more electrical charges will be carried out by electrospinning jet [24], and also more smooth fibers will be formed. It is reported that adding ionic salts to the polymer solution, due to increase the solution charges, will enhance the stretching of solution jet in the electrical field during the electrospinning process. Thus the bead-free and uniform fibers with a smaller diameter will be formed [26].