Keratin was extracted from chicken feathers by using a hydrophobic ionic liquid (IL), 1-hydroxyethyl-3-
methylimidazolium bis(trifluoromethanesulfonyl)amide ([HOEMIm][NTf2]). Extracted keratin has good
solubility in water while the ionic liquid is immiscible with water, and therefore the extracted keratin
could be easily separated from the reaction system by water. The effects of ionic liquid, NaHSO3, reaction
temperature and time were investigated and extracting conditions were optimized. The maximum yield
of keratin was up to about 21% with mass ratio of feathers to NaHSO31:1 and mass ratio of feathers to
ionic liquid 1:40 at 80 ◦C for 4 h. Moreover, there was no obvious loss in the yield after ionic liquid was
reused for five batches under optimized conditions. In addition, the recovery of ionic liquid was about
95% each time. The results indicated that [HOEMIm][NTf2] was very efficient as catalyst and solvent for
dissolving feathers and could be easily recovered due to its hydrophobicity