Jiarui Liu,Jiachang Feng,Zhefeng Xu,Jinsong Zhang,He Wang
Natural antibacterial food packaging materials endowed with environmental responsiveness are garnering substantial research interest in sustainable food preservation. This study reports the development of a pH-responsive antimicrobial composite film through encapsulation of eugenol—a natural phenolic compound—within zeolitic imidazolate framework-8 (ZIF-8). The engineered eugenol@ZIF-8 system demonstrated pH-dependent release characteristics, with cumulative release reaching 32.2% at pH 6 versus merely 0.61% at pH 7 over 4 h. Subsequent integration of this nanocarrier into a polyvinyl alcohol (PVA)/hydroxypropyltrimethyl ammonium chloride chitosan (HACC) matrix yielded a multifunctional composite film for active food packaging applications. The characterization of film revealed that while eugenol@ZIF-8 incorporation slightly compromised mechanical strength (tensile resistance decreased by 18.7%) and flexibility (elongation at break reduced to 54.3% of control), it significantly enhanced hydrophobicity (water contact angle increased to 92.5°) and thermal stability (decomposition temperature elevated by 34 °C). The composite film demonstrated synergistic antibacterial efficacy through the combined action of Zn2+ions, ZIF-8 nanostructures, and eugenol, achieving 88% inhibition againstE. coli.Practical validation through fresh noodle preservation trials confirmed the material’s effectiveness, with the optimized formulation (PVA-HACC-2% eugenol@ZIF-8, PHEZ2) extending shelf life by >5 days compared to conventional packaging. This work establishes a novel strategy for engineering intelligent ZIF-based packaging systems that respond to food spoilage microenvironments, offering significant potential for reducing food loss.
Shuchun Gan,Bo Xu,Xiong Zhang,Jianhao Zhao,Jianhua Rong
Physically cross-linked double-network (DN) hydrogels are capturing more and more attention due to their good mechanical properties and self-recovery ability. However, they usually suffer from complicated preparation process and fussy performance regulation, which severely limit their applications in many fields. Herein, we fabricated a physically cross-linked poly(vinyl alcohol)-(2-hydroxypropyltrimethyl ammonium chloride chitosan) (PVA-HACC) DN hydrogels without organic solvents or toxic cross-linking agents via a simple two-step method of freezing/thawing and immersion processing. The effects of immersion time and concentration of Na 3 Cit solution on the structures and mechanical properties of the hydrogels were investigated. The obtained hydrogels exhibited excellent mechanical properties including high elastic modulus (1.44 MPa), high strength (a maximal tensile fracture stresses of 4.14 MPa and a maximal compressive stresses of over 70 MPa at 98% strain), and superior fracture toughness (17.09 MJ/m 3 ). In addition, good self-recovered property and anti-fatigue performance were realized for the hydrogels owing to the reversible HACC ionic networks. The preparation of PVA-HACC DN hydrogels offers a new guidance for the design and synthesis of environmentally friendly DN hydrogels with outstanding mechanical properties and broad application prospects.
危险品化学品经营许可证（带存储）