Dissolving and Efficient Fractionation of Chitin and
Synchronous Preparation of Calcium Lactate from Crayfish Shell Waste
Using Amino Acid-Based Deep Eutectic Solvents
posted on 2024-01-18, 15:07authored byLong Zhang, Jiake Wang, Boxiang Zhan, Yongqi Deng, Lifeng Yan
Chitin
is a natural biomass material with wide sources and high
application potential, but the solvents for dissolving chitin are
very limited. In this work, ternary alkaline deep eutectic solvents
(DESs) containing amino acids, urea, and 1,8-diazabicyclo [5.4.0]
undec-7-ene (DBU) were prepared, which can successfully achieve the
dissolution of chitin and can be recycled. By adjusting the type of
amino acids and the amount of DBU, the maximum solubility of chitin
can reach 6.0 wt %. In addition, unlike the reported acidic DES system,
this new ternary alkaline DES not only efficiently extracted chitin
from crayfish shell waste but also efficiently prepared calcium lactate
(CL), which successfully realized the effective recycling of calcium
resources. Through 11 sets of extraction conditions, proteins in the
crayfish shell were effectively removed, and the yields of chitin
and CL remained above 85 and 90%, respectively. Finally, chitin nanofibers
were successfully prepared by ultrasonic treatment with extracted
regenerated chitin. Further processing of the chitin nanofibers can
yield chitin films with high transparency and high tensile strength
(63.2 MPa). It provides a novel DES system to dissolve chitin and
an environmentally friendly utilization strategy to efficiently extract
chitin and prepare CL from crayfish shell waste, thereby producing
high-performance functional materials.