Enhanced mechanical properties and gelling ability of gelatin hydrogels reinforced with chitin whiskers

Abstract

Gelatin is widely used in the food industry because of its biocompatibility, nonimmunogenicity, and biodegradability. The small diameter, renewability, and low cost of chitin whiskers (CHWs), in addition to good biocompatibility and high stiffness, make them a very promising reinforcing nanofiller for composite materials. In this work, gelatin/CHW nanocomposite hydrogels containing various concentrations of CHWs (0.25–1.0%, w/v) were successfully fabricated. The gelling temperature, dynamic viscoelasticity, compression behavior, pH, and NaCl sensitivity of gelatin hydrogels were determined using dynamically rheological experiments and compression tests. The addition of the CHWs remarkably enhanced the mechanical properties and gelling ability of the gelatin. Scanning electronic microscope images revealed that the pores of the nanocomposite hydrogels containing CHWs were smaller than those of the pure gelatin hydrogels. Moreover, the gelatin nanocomposite hydrogels showed excellent resistance under conditions of strong alkalinity/acidity and high ionic strength. The results suggest that biocompatible gelatin/CHW nanocomposite hydrogels have potential applications in the food industries.