Some photographs showing dissolving process of the feathers in
the IL system are given in under the temperature of 90 C,
with 20 wt.% of water in IL–water, weight ratio of liquid/
feather = 20, and 10 wt.% Na2SO3. The branches of feathers dissolved
very quickly and at about 20 min these parts were mainly
dissolved. At 40 min, the main residual feathers were the stalks
and usually they were totally dissolved at 60 min.