Comprehensive Comparison Between Mechanical Properties of Nanofiber Matrix and Single Nanofibers

The development of electrospun nanofibers for using in different applications requires a comprehensive understanding of the mechanical properties of a single nanofiber and nanofiber layer. Here, we studied the mechanical properties of nanofiber layer and single nanofiber of polycaprolactone (PCL)/functionalized multiwall carbon nanotubes (F-MWCNTs) composite structures. Scanning electron microscopy (SEM) showed morphology and diameter of composite nanofibers with various CNT concentrations. Moreover, the tensile testing was used for measuring mechanical properties of both nanofiber layer and single nanofibers by distinct procedures. Our results clearly showed that the mechanical properties of single nanofibers had a significant difference with those of nanofiber layer. By increasing the F-MWCNT concentration up to 3 wt%, Young’s modulus and tensile strength of the nanofiber layer increased. However, Young’s modulus and tensile strength of single nanofiber increased with addition of F-MWCNTs up to 1 wt% and further increase in concentration led to a decrease in the modulus and tensile strength of single nanofiber.Moreover, the toughness and elongation-at-break of the nanofiber layer and single nanofiber showed different trends. Taken together, considering the mechanical properties of nanofibers in different scales, help us to design an appropriate structures for various applications.