Investigation of Functionalized Surface Charges of Thermoplastic Starch/Zinc Oxide Nanocomposite Films Using Polyaniline: The Potential of Improved Antibacterial Properties

• Main Authors: Korakot Charoensri, Chatchai Rodwihok, Duangmanee Wongratanaphisan, Jung A. Ko, Jin Suk Chung, Hyun Jin Park
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Polymers
• Subjects: thermoplastic starch; Functionalized ZnO NPs; Polyaniline; positive surface charge; antibacterial activity
• Online Access: https://www.mdpi.com/2073-4360/13/3/425

Improving the antibacterial activity of biodegradable materials is crucial for combatting widespread drug-resistant bacteria and plastic pollutants. In this work, we studied polyaniline (PANI)-functionalized zinc oxide nanoparticles (ZnO NPs) to improve surface charges. A PANI-functionalized ZnO NP surface was prepared using a simple impregnation technique. The PANI functionalization of ZnO successfully increased the positive surface charge of the ZnO NPs. In addition, PANI-functionalized ZnO improved mechanical properties and thermal stability. Besides those properties, the water permeability of the bionanocomposite films was decreased due to their increased hydrophobicity. PANI-functionalized ZnO NPs were applied to thermoplastic starch (TPS) films for physical properties and antibacterial studies using Escherichia coli (<i>E. Coli</i>) and Staphylococcus aureus (<i>S. aureus</i>). The PANI-functionalized ZnO bionanocomposite films exhibited excellent antibacterial activity for both <i>E. Coli</i> (76%) and <i>S. aureus</i> (72%). This result suggests that PANI-functionalized ZnO NPs can improve the antibacterial activity of TPS-based bionanocomposite films.