Green Fabrication of High-Performance Chitin Nanowhiskers/PVA Composite Films with a “Brick-and-Mortar” Structure

Abstract

Chitin is a biobased and renewable biopolymer which consistents with the green and sustainable development. However, the strong inter-and intra-molecular hydrogen bonding interactions of chitin endow it with very poor solubility and processability, which extremely limit its broad application. In this work, a simple "building block reorganization" strategy has been developed to prepare chitin-based composite film with a "brickand-mortar" structure. After successively experiencing salt-induced "preaggregation" and alkali-induced "hydrogen bonds remolding", the mixture of chitin nanowhiskers (ChNWs) and poly(vinyl alcohol) (PVA) was processed into high strength and transparent composite film with ChNWs as "bricks" and PVA as "mortar". The hydrogen-bond remolding process had successfully promoted the interactions between ChNWs and PVA, and optimized the microscopic "brick-and-mortar" structure, therefore resulting in much improved mechanical properties, water resistance, and barrier properties of the composite films. Moreover, the whole process for preparing the composite films was carried out in aqueous medium at room temperature, which makes it a promising candidate for green processing of natural polysaccharide.

Phosphine Oxide-Containing Multifunctional Polymer via RAFT Polymerization and Its High-Density Post-Polymerization Modification in Water

“…The poor solubility of the polymer in water was due to the strong hydrogen-bond interaction among the polymer moieties (−P­(O)­CH 2 OH) and also to hydrophobic polystyrene-like backbones. The similar phenomenon was also found when dissolving other hydroxyl-rich polymers such as cellulose, polyvinyl alcohol, − and chitin in water . The main-chain of hydroxyl-rich polymers was stabilized by strong and complex intramolecular and intermolecular hydrogen-bond networks.…”

“…The similar phenomenon was also found when dissolving other hydroxyl-rich polymers such as cellulose, 51 polyvinyl alcohol, 52−54 and chitin in water. 55 The main-chain of hydroxyl-rich polymers was stabilized by strong and complex intramolecular and intermolecular hydrogen-bond networks. The existence of hydrogen-bond interaction was studied by variable temperature FT-IR spectroscopy (Figure S10).…”

Nanochitin: Chemistry, Structure, Assembly, and Applications

“…In particular, the films exhibited low coefficient of thermal expansion (Figure b) . Biocompatible poly­(vinyl alcohol) has been integrated with nanochitin in environmentally friendly films for improved performance. ,− …”

Recent developments of polysaccharide‐based double‐network hydrogels

“… 64 . Shi et al 65 reported a “building block reorganization” strategy to prepare chitin‐based DN film. In this system, chitin nanowhiskers (ChNWs) and PVA served as “bricks” and “mortar”, respectively.…”

“…61 and the "bottom-up" method (e.g., wet-spinning method, 62 self-assembly method, 63 and dissolution-regeneration method, etc.). 64 Shi et al 65 reported a "building block reorganization" strategy to prepare chitin-based DN film. In this system, chitin nanowhiskers (ChNWs) and PVA served as "bricks" and "mortar", respectively.…”