Applications of deep eutectic solvents in the extraction, dissolution, and functional materials of chitin: research progress and prospects

As a recyclable and inexhaustible renewable resource, chitin is one of the most abundant polysaccharides in nature. It has excellent biocompatibility, biodegradability, and non-toxicity and has been widely used in food packaging, tissue engineering, and other fields. Deep eutectic solvents (DESs) are regarded as a new generation of green solvents due to their excellent biocompatibility and stability. Recently, the use of DESs to process chitin has also received widespread attention. In this review, we first introduced DESs and chitin, then discussed the relationship between the properties of DESs and the applications in the extraction, dissolution, and functional materials of chitin. In addition, the related applications are classified and introduced. The opportunities and challenges for DESs when dealing with chitin systems are also summarized. Deep eutectic solvents (DESs) as sustainable solvents for chitin extraction, dissolution, and functional materials.