Preparation of Composite Materials from Self-Assembled Chitin Nanofibers.

Jun-Ichi Kadokawa

doi:10.3390/polym13203548

Abstract

Although chitin is a representative abundant polysaccharide, it is mostly unutilized as a material source because of its poor solubility and processability. Certain specific properties, such as biodegradability, biocompatibility, and renewability, make nanofibrillation an efficient approach for providing chitin-based functional nanomaterials. The composition of nanochitins with other polymeric components has been efficiently conducted at the nanoscale to fabricate nanostructured composite materials. Disentanglement of chitin microfibrils in natural sources upon the top-down approach and regeneration from the chitin solutions/gels with appropriate media, such as hexafluoro-2-propanol, LiCl/N, N-dimethylacetamide, and ionic liquids, have, according to the self-assembling bottom-up process, been representatively conducted to fabricate nanochitins. Compared with the former approach, the latter one has emerged only in the last one-and-a-half decade. This short review article presents the preparation of composite materials from the self-assembled chitin nanofibers combined with other polymeric substrates through regenerative processes based on the bottom-up approach.

Highlights

The conversion of biomasses into value-added materials as alternatives to petroleumbased conventional materials has increasingly attracted much attention based on views revolving around the environmental aspects of the earth [1]
Compared with the above top-down approach, bottom-up techniques for the fabrication of nanochitins have only emerged in the last one-and-a-half decade [25,26]
chitin nanofibers (ChNFs) with other polymeric components at the nanoscale has been further conducted to fabricate ChNF-based nanocomposite materials for improving properties and providing new functions [27]. This short review article presents an efficient approach for the preparation of the nanostructured composite materials, ranging from the self-assembled ChNFs combined with other polymeric components, to the facile regenerative processes based on the bottom-up approach, where CNFs and other constituent materials are merged to create new materials with properties different from the individual components

Summary

Introduction

The conversion of biomasses into value-added materials as alternatives to petroleumbased conventional materials has increasingly attracted much attention based on views revolving around the environmental aspects of the earth [1]. Chitin is one of the most abundant polysaccharides comparable to cellulose and, has been expected to be used as a biomass source in bio-based practical materials. It is an aminopolysaccharide consisting of repeating β(1→4)-linked N-acetyl-D-glucosamine units (Figure 1), which occurs mainly in the exoskeletons of crustacean shells, such as crab and shrimp shells, in nature [2,3,4]. Compared with the above top-down approach, bottom-up techniques for the fabrication of nanochitins have only emerged in the last one-and-a-half decade [25,26] Such techniques have mainly been achieved by the simple regeneration from chitin solutions/gels, resulting in self-assembled ChNFs (Figure 2b).

Chemical

Preparation of Composite

Preparations of ChNF-reinforced

Findings

Conclusions and Outlook