A new era of chitin synthesis and dissolution using deep eutectic solvents- comparison with ionic liquids

Chitin is a value-oriented mucopolysaccharide natural source that found its application in various biomedical fields. The primary source of chitin mass production is the tons and tons of biomass waste produced in the fish industry. Recent advancements in the efficient utilization of biowastes is offering a promising step towards the green chemistry and sustainable development. There are several techniques adopted for the efficient extraction of chitin. Traditionally, chemical isolation of chitin is done using harsh chemicals. The ionic liquids(ILs) have replaced them and now being swapped by more environment-friendly Deep Eutectic Solvents(DES). The purity, crystallinity, and yield of the extracted chitin vary with the reagents, methods adopted, and biomass source used. Many researchers have studied chitin derivatives, chitosan, chitin hydrogels, and nanofibers/nanowhiskers of chitin and found them suitable for applications both in biomedical and non-biomedical fields. This review is a comparative analysis of dissolution and extraction strategies of chitin using Ionic Liquids and Deep Eutectic Solvents.