Preparation of PE Based Composite Films With Dual Antibacterial Agents via Co-Extrusion Method and Their Potential in Active Food Packaging

Abstract

Graphitic carbon nitride (g-C₃N₄) exhibits antibacterial potential but suffers from a low specific surface area and insufficient reactive sites. This study designed a biohybrid antimicrobial agent by loading thermally exfoliated g-C₃N₄ nanosheets onto high-surface-area calcined shell powder (CSP), which provided abundant active sites. Blow-molded PE films incorporating optimized g-C₃N₄/CSP hybrids (mCNB) were fabricated. At a 1:2 g-C₃N₄:CSP ratio (CNB-1:2), synergistic antibacterial effects achieved inhibition zones of 18.3 mm (Escherichia coli) and 18.6 mm (Staphylococcus aureus) under visible light. Antibacterial efficacy increased with mCNB content, reaching inhibition rates of 96.63% (E. coli) and 96.96% (S. aureus) for mCNB-10.0/PE. Mechanical properties peaked at 2.5% mCNB loading, with longitudinal/transverse tensile strength of 19.6/18.4 MPa and Young's modulus of 235.9/198.7 MPa. This work can provide a green route for the development of antimicrobial materials in plastic films, leveraging eco-friendly composite design for high-performance active packaging with light response.