Preparation, Characterization, and Antimicrobial Activity of Chitosan/Kaolin Clay Biocomposite Films

Abstract

AbstractChitosan (CS) is a polycation found in nature that exhibits many good properties. Kaolin (KAO) clay is a natural inorganic filler and is being used in medicine, ceramic, food additives, etc. Therefore, the mixing of two such biomaterials, a natural polycation (CS) and natural filler (KAO clay) may lead to a biocomposite, chitosan/kaolin (CS/KAO) clay, with many interesting properties. In this study, the composites of CS and KAO clay are prepared by mixing the solution of CS (in dilute acetic acid) with KAO clay at various weight ratios. FT‐IR, UV/Vis, X‐Ray diffraction, SEM, UTM, TGA, and DSC analyses are used to investigate these biocomposites thoroughly. Agar well diffusion method has been used to determine the antibacterial activities of different concentrations of the CS‐ KAO clay against gram ‐positive (Bacillus subtilis) and gram‐ negative (Escherichia coli) bacteria. The biocomposites exhibited antibacterial activities against tested microrganisms. In addition, swelling tests of the biocomposites are also carried out. The CS/KAO clay biocomposite films show better tensile strength than CS film. It is observed that dispersed KAO clay improves the thermal stability and enhances the hardness of the matrix systematically with the increase of its loading.