Antimicrobial N-halamine modified polyethylene: characterization, biocidal efficacy, regeneration, and stability

Area of Science:

• Materials Science
• Surface Chemistry
• Food Safety Engineering

Background:

• Microbial cross-contamination is a significant concern in food processing.
• Developing materials with self-regenerating antimicrobial properties is crucial for enhanced hygiene.
• Existing antimicrobial strategies may lack durability or reusability.

Purpose of the Study:

• To develop regenerably antimicrobial N-halamine coatings on polyethylene (PE) surfaces.
• To investigate the stability and reusability of these modified PE materials.
• To assess the efficacy against Listeria monocytogenes for food safety applications.

Main Methods:

• Layer-by-layer (LbL) assembly of polyethyleneimine and poly(acrylic acid) on PE surfaces.
• Application of varying numbers of bilayers (5, 10, 15, 20) to tune N-halamine density.
• Chlorination to activate N-halamine antimicrobial properties.
• Stability testing under repeated chlorination, acidic, and alkaline conditions.

Main Results:

• Modified PE surfaces achieved N-halamine densities ranging from 49.3 to 293.5 nmol cm(-2).
• All variants demonstrated significant reduction (>5 log cycles) of Listeria monocytogenes.
• Antimicrobial activity was regenerated after repeated chlorination cycles (up to 100 cycles).
• Materials remained stable after 300 washing cycles in buffers (pH 3-7) and alkaline detergent.

Conclusions:

• LbL deposition creates robust, regenerably antimicrobial N-halamine surfaces on PE.
• These materials exhibit long-term reusability and stability in harsh chemical environments.
• The technology shows promise for preventing microbial cross-contamination in food processing, enhancing food safety.