Rapid dissolution of β-chitin and hierarchical self-assembly of chitin chains in aqueous KOH/urea solution

Abstract

The rapid dissolution of β-chitin and the hierarchical self-assembly of chitin chains have long attracted research attention from the perspectives of both fundamental sustainable chemistry and potential applications in materials chemistry. Here, we describe the hierarchically corrugated board structure of β-chitin, as well as its rapid dissolution and hierarchical self-assembly in aqueous KOH/urea solution. The β-chitin crystal form promotes dissolution efficiency, and as determined by the spectral results, the chitin chains tend to interact with solvent molecules, which leads to total dissolution without derivatization. Subsequently, during neutralization, the self-assembled chitin chains propagate into chitin nanofibrils with a characteristic right-handed helical structure and lengths of several micrometers. At a higher chitin concentration, these chitin nanofibrils form an interconnected nanofibrous network structure, resulting in a temperature-sensitive solution and even the formation of gels of crystalline α-chitin.