Novel nanocomposite polylactic acid films with Curcumin-ZnO: structural, thermal, optical and antibacterial properties

Abstract

In this work, biodegradable polylactic acid (PLA)/Curcumin/ZnO nanocomposite films were prepared by using the film casting method at room temperature. Zinc Oxide nanoparticles (NPs) were prepared in a green method using Bambusa arundinacea leaves extract. Scanning electron microscopy results showed that curcumin and ZnO NPs were uniformly dispersed in the PLA matrix. X-ray diffraction analysis showed that addition of curcumin converts semi-crystalline PLA into amorphous. The photoluminescence spectra of PLA/Curcumin showed a broad emission band in green color. After adding ZnO NPs, the spectra showed a redshift in the emission peak with a gradual decrease in the intensity with increasing weight percentage. The energy band gap values are calculated by Tauc's plot for all PLA nanocomposite films. The antibacterial activity was not observed in pure PLA film whereas the PLA nanocomposite films exhibited antibacterial activity against both gram -ve and gram ​+ ​ve bacteria. The antibacterial activity was increased by incorporating the curcumin and ZnO NPs concentrations. The present study provides a simple procedure to prepare large-area PLA nanocomposite films with good antibacterial activity.

Keywords

• Poly lactic acid
• Curcumin
• ZnO Nanoparticles
• Photoluminescence
• Antibacterial activity