Recently, ionic liquids (ILs) have received recognition as green
and promising materials for potential applications in various fields
because they are typically non-volatile, non-flammable, chemical
and thermal stability and remarkable solubility [12–16]. They
have also been termed as ‘designer solvents’ as their properties
can be manipulated by a careful choice of cation/anion
according to the requirements. Ionic liquids exhibit excellent
solubility characteristics because of their special structures compared
to the traditional molecular solvents. Some recent works
have been reported regarding the dissolution and regeneration
of keratin fibers in ionic liquids. Xie et al. [17] reported the
dissolution and regeneration of wool keratin fibers in 1-butyl-3-
methylimidazolium chloride (BMIMCl) ionic liquid. Hameed et al.
[18] prepared natural wool/cellulose blends in BMIMCl and the
films were formed subsequently from the coagulated solutions. In
fact, the costs of ionic liquids are obviously higher than that of inorganic
reagents, but they can be reused and improve the efficiency of
whole process, leading to lower the overall cost. Separation of keratin
from hydrophilic ionic liquids after reaction is an inconvenient
and troublesome problem.