Biodegradability and antimicrobial activity of chitin nanowhiskers-chitosan films

Abstract

Chitosan has a potential to become a key resources in the development of biodegradable film composites. Chitin Nanowhiskers (CNW) was prepared by hydrolyzing chitin powder with 3M HCl. The CNW/chitosan film was prepared at various CNW contents (1, 2, 3, 4, and 5 percent of weight). CNW was added to improve the strength of chitosan film. CNW/chitosan films were prepared by solution casting method and the biodegradability properties were evaluated in soil burial for 6 days. The biodegradability was determined by weight loss of the films that have been incubated in the soil. It showed that increasing the amount of CNW lead to greater weight loss of the films. The swelling test was done to study the effect of water absorption rate on the physical properties of the film. It showed that addition of CNW reduce the ability of the film to absorb water. Tensile properties were evaluated on the nanocomposite films. It showed that the tensile strength of the nanocomposite films increased as the CNW increased up to 3%. It was found that CNW/chitosan film have antimicrobial activity against food pathogenic bacteria such as E.coli and S.aureus. They can inhibit the growth of these bacteria since clear zone have been detected on the agar plate containing chitosan, 3% CNW/chitosan solution and 5% CNW/chitosan solution. Since the films obtained were transparent and displayed good mechanical properties, the nanocomposite film can be used in membrane and packaging applications.