AgNP-Zeolite integrated into cellulose nanofibers for enhanced ethylene scavenging performance

Postharvest accumulation of ethylene accelerates ripening and senescence, significantly reducing the shelf-life. This work developed a multifunctional ethylene-scavenging system utilizing silver nanoparticle (Ag NP)-functionalized TEMPO-oxidized cellulose nanofibers (TCNFs) combined with varying the zeolite loadings. A dual-side coating strategy was employed: one side of the paper substrate was coated with one to three layers of alginate to enhance barrier performance, while the opposite side was coated with Ag NP-functionalized TCNFs containing 1-20% zeolite to provide ethylene scavenging and antibacterial properties. In-situ incorporation of Ag NPs into TCNF matrix improved suspension stability, reflected by an increase in ζ-potential to -31.3 ± 0.46 mV. Morphology and distribution of nanoparticles were analyzed using STEM and TEM techniques. SPR band at 424.13 nm and XRD reflections characteristics of face-centered cubic silver confirmed the formation of metallic Ag⁰. FTIR analysis confirmed the incorporation of zeolite into the Ag NP-TCNF network. The paper coated with 20% zeolite in the Ag NP-functionalized TCNFs exhibited the highest ethylene scavenging capacity, removing 0.8 ± 0.06 μL of ethylene (at 60 bar) per gram of coated paper, equivalent to 13.13 μL per gram of zeolite, corresponding to 50.05 μL/L ethylene elimination. The coated papers displayed significant improvements in barrier performance: grease resistance increased from a kit value of 1 (uncoated) to 12, the water vapor transmission rate decreased from ⁓1400 to 350 g·m^-2·day^-1, and air resistance rose from 28 to ⁓1800 Gurley seconds. They exhibited pronounced antibacterial activity of ⁓ 99% against Bacillus subtilis and Escherichia coli.