Fabricating Chitin Paper from Self-Assembled Nanochitins

Herein, we report the fabrication of paperlike chitin sheets (chitin paper) by the extensive entanglement of self-assembled nanochitins formed using a bottom-up approach involving stepwise regeneration from a solution of chitin in a deep eutectic solvent composed of 1-allyl-3-methylimidazolium chloride and thiourea, with additives such as benzylamine. The successful process involves preliminary sedimentation, promoted addition of the additives to the solution, with subsequent dispersive regeneration with methanol. The appearance of the regenerated chitins, namely, sheet or powder, depends on the amount of benzylamine used. The nanoscale morphology of the chitin paper was confirmed by scanning electron microscopy, and it depends on the additive used. The mechanical properties of the chitin paper were evaluated by tensile testing and compared with those of cellulose filter paper.