Chitosan/clay bionanocomposites: Structural, antibacterial, thermal and swelling properties

Abstract

In this study, Na+Montmorillonite (C Na), Nanoclay 1-135 (C 10A) and Nanoclay 1-140 (C 15A) were used as nanofiller in the preparation of chitosan biopolymer/clay nanocomposites. For this purpose, a dilute acetic acid solution was used as solvent for dissolving and dispersing the chitosan and the clays, respectively, and chitosan/C Na, chitosan/C 10A and chitosan/C 15A bionanocomposites were synthesized. Bionanocomposites were prepared by the solution induced intercalation method with various percentages of the three clay types. Then, the properties of the bionanocomposites were investigated as the loading of the clays was varied: 1%, 3%, 5%, and 7%. The characterization of the composites was done chemically by FTIR, physically by XRD and SEM, and thermally by TGA/DTA. Also, swelling tests of the clay and bionanocomposites were carried out. In addition, their antimicrobial properties were investigated towards Staphylococcus aureus and Escherichia coli. The highest antimicrobial activity was found for the chitosan/C 10A biocomposite. It was observed that the thermal stability of the bionanocomposites increased with increasing amount of clay added to chitosan. All the chitosan/clay biocomposites were observed by XRD and SEM, which revealed exfoliation behavior.