posted on 2023-12-26, 23:08authored byJunlei Wang, Zhimin Zhao, Hanmeng Yuan, Hongshuai Gao, Yi Nie
Keratin,
a naturally occurring biomaterial, has gained substantial
recognition for its application in various domains. Given its abundant
presence in human hair, the pursuit of efficient methods for dissolving
and extracting keratin is motivated by the dual objectives of maximizing
the utility of human hair and promoting ecological sustainability.
In this work, a series of deep eutectic solvents (DES) were designed
for extraction of keratin from human hair under mild experimental
conditions. The effects of DES structure, molar ratios of HBA to HBD,
dissolution temperature, and time on the dissolving ability of DES
for human hair were investigated in depth. The results showed that
ChCl/MEA can effectively dissolve human hair under mild conditions
(80 °C, 4 h) with a solubility of 84% and a mass percentage of
20%. FT-IR, XRD, SDS-PAGE, and TGA results showed that the structure
of the regenerated keratin was slightly destroyed but still exhibited
stable thermal property. Analysis of the reduced density gradient
(RDG) and surface electrostatic potential (ESP) verified that the
hydrogen bond driven by electrostatic attraction is formed in DESs.
Independent gradient model (IGMH) analysis confirmed that the weak
interaction between human hair and DES is mainly caused by van der
Waals interactions. Additionally, ChCl/MEA displayed an excellent
performance in extracting keratin from human hair even after recycling
for three cycles.