Materials
2.1.1. Keratin feather fiber
Keratin feather fiber is obtained from Featherfiber
Corporation (Nixa, MO). The keratin feather fiber is
cleaned and separated from the quill fraction according
to a process developed and patented by the USDA [33].
The feather fiber is semi-crystalline and has an average
diameter of 5 lm. Feather fiber has an experimentally
determined density of 0.89 g/cm3 [15]. Hong and Wool