Synergistic effect of combining metallic and mineral nanoparticles on the improvement of the performance of active poly(butylene adipate‐co‐terephthalate) packaging films

Abstract

Active ternary nanocomposite films based on poly(butylene adipate‐co‐terephthalate) (PBAT), ZnO nanoparticles (NPs), and cloisite (C15A, C30B) were fabricated through solvent casting. The structural and morphological characteristics of these hybrid metal‐oxide‐clay nanocomposites were analyzed using Fourier transform infrared spectroscopy, X‐ray diffraction, atomic force microscopy, and UV‐visible spectrophotometry. Due to the synergistic effect resulting from the combination of ZnO and cloisites, PBAT‐based nanocomposite films have demonstrated a significant improvement in their mechanical and barrier properties. Hardness recorded increase of 87.75% and 41.05%, while Young's modulus showed improvement of 218.13% and 102.68% for PBAT/ZnO/C15A and PBAT/ZnO/C30B films, respectively, compared to the pure PBAT matrix. Additionally, an enhancement in water vapor barrier properties was estimated at 81.28% for PBAT/ZnO/C15A film and 90.88% for PBAT/ZnO/C30B, in comparison with the PBAT alone. Furthermore, the incorporation of clay into the PBAT/ZnO matrix led to a notable slowdown in the release rate of Zn2+ ions, mainly attributed to the entrapment of ZnO NPs within the Cloisite galleries. As these particles dissolve into Zn2+ ions, they undergo a gradual diffusion process through the clay sheets. In addition, the simultaneous presence of both types of nanofillers exhibited a more pronounced antibacterial effect compared to that induced by ZnO NPs alone. However, it is noteworthy that antibacterial performance was closely linked to the type of clay used. Indeed, the PBAT/ZnO/C15A film demonstrated complete inhibition of in vitro bacterial growth within just 3 to 4 days, whereas the PBAT/ZnO/C30B film did not exhibit the same level of effectiveness.Highlights Development of active PBAT/ZnO/clay packaging films. ZnO NPs entrapped in clay galleries yielded slow Zn2+ ion diffusion. Synergistic combination of ZnO and Cloisite NPs exhibits strong antibacterial activity. The antibacterial performance is directly linked to the type of clay used.