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

Abstract

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 (E. coli) and Staphylococcus aureus (S. aureus). The PANI-functionalized ZnO bionanocomposite films exhibited excellent antibacterial activity for both E. coli (76%) and S. aureus (72%). This result suggests that PANI-functionalized ZnO NPs can improve the antibacterial activity of TPS-based bionanocomposite films.

Current Knowledge on the Oxidative-Stress-Mediated Antimicrobial Properties of Metal-Based Nanoparticles

“…It has been described that the negatively charged molecules composing both Gram-positive and Gram-negative cell walls promote the interaction between NPs and the bacterial membrane. These negatively charged molecules have a strong affinity for the positive ions released by most NPs, including AgNPs [27], AuNPs [28], CuNPs [6,29], ZnONPs [30,31], α-Fe 2 O 3 metal-based NPs [32], and TiO 2 [33], leading to the electrostatic attraction of NPs to the bacterial surface that induces a disruption of the bacterial cell wall and an increase in its permeability (Figure 1) [34]. It was determined that positively charged AgNPs are strongly attracted to the surface of the bacteria, which increases antibacterial activity [27].…”

Preparations, Properties, and Applications of Polyaniline and Polyaniline Thin Films—A Review

“…Clean substrates are immersed for 10 s following immersion in high temperature of the water using proportional variety, and the strategy is repeated. These methods are tempered using an air annealing chamber at 450 °C [ 88 , 89 ].…”

Recent Advances in Functional Polymer Materials for Energy, Water, and Biomedical Applications: A Review

“…[18][19][20][21][22][23][24]. Functionalization of polymeric surfaces is generally provided chemically either via covalent bonds and low energy interactions [25][26][27], or by non-covalent physical attraction, such as the adsorption of pollutants [28,29], antibacterial biomaterials [30][31][32], and drug delivery systems [33][34][35]. Covalent chemical functionalization remains the most interesting and the most advantageous.…”