Nanocellulose/ZIF-8/Calcium Hybrid Films for Sustainable Food Preservation

With the progressive depletion of petroleum resources and the worsening greenhouse effect, the demand for sustainable materials has become increasingly urgent. In this study, a composite film was fabricated using waste tobacco stems as the raw material by integrating the TEMPO oxidation process with the in situ growth of metal–organic frameworks (MOFs) and subsequent Ca2+ cross-linking. The incorporation of ZIF-8 significantly enhanced the film’s thermal stability, hydrophobicity, and water vapor barrier performance. Compared with pure cellulose nanofiber (CNF), the ZIF-8-loaded composite film exhibited a markedly higher water contact angle (68.2°) and tensile strength (130.54 MPa). The structural characteristics of the films were comprehensively analyzed using FTIR, XRD, and XPS. Moreover, the composite film demonstrated outstanding antibacterial activity, with the addition of Ca2+ facilitating the sustained release of antibacterial agents. The film effectively extended the postharvest storage life of grapes. Owing to its multifunctional properties, the ZIF-8/CNF-Ca composite film shows great potential as a biodegradable alternative to conventional plastic packaging materials.