Environment-responsive antibacterial paper based on polyvinyl alcohol (PVA)/ SiO₂ coating for on-demand ClO₂ release...

Antibacterial packaging can effectively preserve postharvest fruits by reducing microbial contamination. In this study, an environment-responsive ClO₂-releasing Antibacterial paper has been developed, achieved by coating the base paper with polyvinyl alcohol (PVA), nano silica and NaClO₂. The release of ClO₂ was sustained and regulated by the environmental humidity and CO₂ concentration. The coating formulation was optimized through single-factor experiments, yielding in a NaClO₂ loading efficiency of 78.8 %. Although the coating treatment decreased the tensile strength of paper, it notably improved its smoothness, tear resistance, and elongation at break. Release behavior studies showed that higher humidity and CO₂ levels accelerated ClO₂ release, with sustained release lasting up to 35 days under conditions of 23 °C, 3 % CO₂, and 98 % RH. When applied to postharvest preservation of strawberry and hawthorn-fruits with different respiration rates-the storage quality of both was significantly enhanced. Decay rates were reduced by 52.63 % and 77.78 %, respectively, while fruit appearance, firmness, soluble solids content, and organic acid levels were effectively maintained. By intelligently responding to the high humidity and high CO₂ microenvironment generated by postharvest fruit respiration, the prepared Antibacterial paper enables controllable ClO₂ release, offering advantages such as simple preparation, environmental friendliness, adaptability to fruits with varying respiration rates, and remarkable preservation efficacy. This study presents a practical new technological solution for intelligent postharvest preservation of fruits and vegetables, holding significant potential for extending shelf life and reducing postharvest losses.