posted on 2024-01-01, 14:03authored byYaling He, Yang Liu, Jie Luo, Xiangzhao Mao, Wen-Can Huang
The
deep eutectic solvent (DES) extraction method is
considered
a promising alternative to the acid/base method in chitin extraction.
However, DESs face challenges such as inefficient extraction at room
temperature and limited recyclability due to low molecular mobility.
In this study, a novel ternary DES composed of N-methylurea, N-methylacetamide, and acetic acid is developed and applied
for chitin extraction. Compared to previous DESs, this novel DES not
only has significantly reduced melting point (−16.82 °C)
and viscosity (7.38 mPa·s at 25 °C) but also exhibits remarkably
high extraction efficiency at room temperature, with demineralization
and deproteinization reaching 99.07 and 92.67%, respectively. Furthermore,
this DES can be repeatedly used without significant changes in viscosity.
The results of repeated cycles of use demonstrated that the demineralization
and deproteinization remained at 89.78 and 86.84%, respectively, even
after 10 cycles of reuse. Experimental and simulation results suggest
that the formation of strong hydrogen bonds between the component
molecules of the DES disrupts the regular packing of the components
in their crystalline state and allows for more flexible and dynamic
interactions. This disruption leads to a less ordered structure, which
contributes to the decrease in melting point and increase in molecular
mobility.