Long-acting antibacterial nanochitin/nanocellulose bioplastic packaging film

Abstract

Ensuring antimicrobial safety and durability remains a critical challenge in bioplastic packaging. In this study, a silver-loaded lignin/laponite antimicrobial agent (Lap@LAg) with outstanding long-term antibacterial properties was synthesized and subsequently incorporated with nanocellulose and nanochitin to fabricate a bioplastic film (CTF/Lap@LAg). The lignin-coated silver nanoparticles (AgNPs) were effectively immobilized on the laponite and uniformly dispersed throughout the matrix. The combined effects of laponite's confinement and electronegativity, along with the encapsulation capability of lignin, conferred prolonged antibacterial activity to Lap@LAg, achieving over 99.99 % bacteriostatic efficacy against E. coli and S. aureus. Furthermore, Lap@LAg demonstrated a remarkable long-lasting antibacterial effect, effectively protecting wood powder from mold contamination for 14 days. Moreover, the electrostatic and hydrogen bonding interactions among nanocellulose, nanochitin, and laponite, coupled with their multidimensional interwoven structure, imparted exceptional mechanical strength (Increased by 57.2 %) and superior barrier properties (WVP 0.082 g⋅mm/m²⋅d⋅kPa, OTR 0.077 cm³/m²⋅24h⋅0.1 MPa) to the film. This study provides valuable insights into the design of safe and long-lasting antibacterial bioplastic packaging.