Recently, Dr. Ding Beibei from the School of Food Science and Technology of Wuhan University of Light Industry and Associate Professor You Jun and Professor Zhang Qunchao of Hubei University collaborated on the “Pseudosolvent Intercalator of Chitin:Self-Exfoliating into Sub-1 nm Thick Nanofibrils for Multifunctional Chitinous Materials”, published the latest research results in the top journal Advanced Materials (Adv. Mater.2021, 2007596, IF2020=27.398) in the field of materials, reporting an efficient, The self-exfoliation technology of chitin nanofibers with low energy consumption and adjustable surface properties is expected to promote the industrial application of waste food resources shrimp/crab shells and the innovative development of the Hubei aquatic food industry chain. This research work was funded by the Open Project of the Hubei Provincial Key Laboratory of Agricultural Products Processing and Transformation.
”quasi-solvent” mediated chitin nanofibers Self-stripping
It is understood that there are hundreds of thousands of tons of crab and shrimp shells discarded after consumption in our country every year. This is not only a serious waste of resources, but also a serious problem in the living environment. Heavy burden. The content of chitin in shrimp and crab shells is as high as 40%. Chitin nanofibers are one-dimensional nanomaterials extracted from chitin. They have biocompatibility, high crystallinity (70~85%), and solvent resistance (solubility parameters up to 41). (J/cm3) 0.5), low thermal expansion coefficient (10 ppm/K), biodegradability, high specific surface area and many other excellent properties. It has broad application prospects in frontier fields such as food and medicine, flexible display and energy storage. However, the highly ordered multi-layer structure and strong cohesion (hydrogen bond, van der Waals force) make it difficult for the closely packed chitin nanofibers to be peeled off. So far, all methods for extracting chitin nanofibers in liquid phase require high-energy-consuming and strong mechanical post-processing (such as high-pressure homogenization, ball milling, cell disruption, etc.) to achieve liquid phase stripping of nanofibers. The cost is still high and it is difficult to meet industrialization. Production requirements.
In order to overcome the technical bottleneck of high energy consumption, the author of this article first designed and defined the “quasi-solvent” (DMSO/KOH) of chitin. The “quasi-solvent” can selectively destroy the strong interaction between the chitin nanofibers, weaken the cohesion, and promote the pre-dissociation of the tightly packed nanofibers under the premise of avoiding molecular-level dissolution, so as to realize the liquid phase self-dissociation of the chitin nanofibers. Peel off. This method does not need to use any strong mechanical processing equipment, not only can extract ultra-fine nanofibers with adjustable length and close to 100%yield from shrimp and crab shells, but also applicable to squid bones and pen tubes. Compared with other methods, the reported technology has significant advantages in terms of productivity, aspect ratio, energy consumption, productivity, and structural control. These nanofibers can be further assembled into nanopaper, hydrogel, and hydrogel with excellent mechanical properties. Materials such as aerogel have a wide range of potential applications in the fields of food packaging, electronics and energy.