Temperature and time-dependent self-assembly and gelation behavior of chitin in aqueous KOH/urea solution
Junchao Huang, Yi Zhong, Ang Lu, Lina Zhang, Jie Cai
Abstract
Chitin is the most abundant natural glycosaminoglycan that is derived from marine crustaceans and has enormous potential in biomedical applications because of its high similarity in chemical structure to the component of extracellular matrix. However, the key challenge remains the discovery of appropriate solvents for dissolving chitin and the limited understanding of the solution properties of chitin solutions, which hampers its development and applications. An aqueous KOH/urea solution was demonstrated to be a high-efficiency, energy-saving, and “green” solvent for chitin dissolution. Herein, we report the self-assembly and gelation behavior of chitin in aqueous KOH/urea solution using atomic force microscopy, fluorescence microscopy, rheology, wide-angle X-ray diffractometry, and differential scanning calorimetry. The molecular conformation, aggregate structure, and macroscopic solution properties of chitin in aqueous KOH/urea solution are affected by the temperature, chitin concentration, molecular weight, and aging time of the chitin solution. Understanding the self-assembly and gelation behavior of chitin solutions will enable accurate manipulation of the properties of chitin-based materials in potential applications such as structural materials, biomedicine, textile, and so on.