Bacteriostatic Activity of LLDPE Nanocomposite Embedded with Sol–Gel Synthesized TiO2/ZnO Coupled Oxides at Various Ratios

Abstract

Metal oxide-polymer nanocomposite has been proven to have selective bactericidal effects against the main and common pathogens (Gram-positive <i>Staphylococcus aureus</i> (<i>S. aureus</i>) and Gram-negative <i>Escherichia coli</i> (<i>E. coli</i>)) that can cause harmful infectious diseases. As such, this study looked into the prospect of using TiO₂/ZnO with linear low-density polyethylene (LLDPE) to inactivate <i>S. aureus</i> and <i>E. coli</i>. The physical, structural, chemical, mechanical, and antibacterial properties of the nanocomposite were investigated in detail in this paper. The production of reactive species, such as hydroxyl radicals (^•OH), holes (h⁺), superoxide anion radicals (O₂^•¯), and zinc ion (Zn²⁺), released from the nanocomposite were quantified to elucidate the underlying antibacterial mechanisms. LLDPE/25T75Z with TiO₂/ZnO (1:3) nanocomposite displayed the best performance that inactivated <i>S. aureus</i> and <i>E. coli</i> by 95% and 100%, respectively. The dominant reactive active species and the zinc ion release toward the superior antibacterial effect of nanocomposite are discussed. This work does not only offer depiction of the effective element required for antimicrobial biomedical appliances, but also the essential structural characteristics to enhance water uptake to expedite photocatalytic activity of LLDPE/metal oxide nanocomposite for long term application.