Chitosan/Clay biocomposite films with enhanced physico-chemical, mechanical and antimicrobial properties

Chitosan (CS) is a biopolymer known for its outstanding biocompatibility, biodegradability, and antibacterial properties. On the other hand, Clays are natural inorganic materials and have good rheological and thermal properties. Therefore, it is expected that the biocomposite prepared from both these materials may have numerous intriguing properties. In this work, we report the preparation of chitosan (CS)/bentonite (BNTN) and chitosan (CS)/silica (Si) biocomposite films and characterizations of those via various analytical techniques such as X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared (FT-IR) Spectroscopy, Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Ultraviolet/Visible (UV/Vis) Spectroscopy and Universal Testing Machine (UTM). Swelling tests of prepared biocomposite films were also carried out in distilled water to evaluate their property towards packaging applications. The synthesized biocomposite films exhibit appreciable antimicrobial activity against Escherichia coli and Bacillus subtilis bacteria using the agar well diffusion method. Additionally, it has been noted that compared to the films of the other two biocomposites, the CS/BNTN biocomposite films showed greater tensile strength, swelling capacity and antimicrobial activity.