Figure 1.

Morphology of milkweed fibers: (a) naturally occurring in the wild; (b) SEM image of a fiber surface at low magnification showing its hollow structure; (c) SEM image of the outer surface; (d) inter surface of the fiber showing a rough surface which is naturally covered by waxes; and (e) high-resolution AFM images of the original milkweed fiber surface showing the morphology of the waxes on the fiber surface. From this image, the three-dimensional rugosity index is calculated using AFM-IR software. The arrows in (c,d) show the presence of wax inside and outside the fiber surface.