Figure 1

SEM images of PA6 nanofibers (A), PA6/PPy nanofibers (B,C), and TEM image of PPy hollow fibers (D). The morphological images of the PA6 ENF and PA6/PPy NFM were obtained with a scanning electron microscope (SEM; Hitachi S-3000 N). A transmission electron microscopy (TEM) system was employed to examine the core-shell structure of the PA6/PPy NFM. PA6 nanofibers had smooth surface and the average diameter was about 200 nm. While for PA6/PPy nanofibers, the average diameter increased to 220 nm, and the surface became coarse. The cross-section of PA6/PPy nanofibers and TEM image indicated that the PA6 610 nanofibers were coated with the PPy, forming a core-shell structure.