Developing environmentally sustainable biodegradable multifunctional bio-composite films is an effective strategy for ensuring food chain security. This study initially prepared inclusion complexes (HP-(3-CD@EGCG) of Hydroxypropyl-(3-cyclodextrin (HP-(3-CD) and EGCG to ameliorate the stability of EGCG. Then HP-(3-CD@EGCG and different ratios of lignin were incorporated into gelatin solution through cross-linking polymerization to prepare an antioxidant, antibacterial and biodegradable composite film (HP-(3-CD@EGCG/Lignin/Gelatin). The results illustrated that HP-(3-CD crosslinked with EGCG and the encapsulation rate of EGCG reached 82.26%, and lignin increased the comprehensive characteristics of the gelatin-based composite films. The hydrophobicity of the composite films increased with increasing lignin concentration, reaching a water contact angle of 117.33 degrees; Furthermore, the mechanical characteristics and UV-light/water/oxygen barrier capacity also increased significantly. The composite films showed excellent antioxidant and antimicrobial properties, which also verified in the preservation of tomatoes and oranges, extending the shelf life of the fruit. It is worth mentioning that lignin has no effect on the biodegradability of the composite film, and the degradation rate in the soil reached 80% on the 10th day. In summary, biodegradable multifunctional environmentally friendly composite films based on gelatin and loaded with lignin and HP-(3-CD@EGCG inclusion complexes are anticipated to be applied in fruit and vegetable preservation.

Conventional food packaging films pose significant environmental hazards. Consequently, there has been a burgeoning interest in biopolymers, leading to numerous studies to develop biodegradable and bioactive films suitable for the food packaging industry. In this study, we present a novel environmentally-friendly chitosan-based film incorporating berberine, a bioactive compound abundant in various plants. Before blending with a chitosan solution, berberine chloride's water solubility was enhanced using 2-hydroxypropyl-beta-cyclodextrin. Fourier transform infrared spectroscopy confirmed the interactions between berberine and chitosan. Scanning electron microscopy and atomic force microscopy analyses demonstrated the even distribution and good compatibility of berberine within the chitosan film. By blending berberine with chitosan, the obtained biopolymer film exhibited improved mechanical properties compared to the control film. Differential scanning calorimetry analysis showed that berberine incorporation reduced the glass transition temperature from 89 degrees C to 68 degrees C. The film also blocked the UV light almost 100%. The addition of berberine decreased the water vapour permeability of the chitosan film while increasing the swelling ratio and water solubility. The berberine-incorporated chitosan film exhibited an antioxidant capacity of 33.7% as measured by the 2,2 diphenyl-1-picrylhydrazyl assay, which was significantly higher than that of the chitosan film, which has 5.92%. The film also demonstrated antimicrobial activity with a reduction in B. cereus and S. typhimurium growth compared to the control. Additionally, the degradation study revealed that the film degraded by 82.5% within ten days under soil. Our findings suggest that the chitosan-berberine film holds promise for applications in the food packaging industry.

Replacing traditional plastics with biodegradable materials, such as poly(butylene adipate-co-terephthalate) (PBAT), is a reliable way to avoid farmland environmental pollution. However, the physical and mechanical properties of PBAT still have much to improve. Adding chain extenders to modify PBAT is one of the primary means. So far, the main chain extenders used are epoxy, anhydride, oxazoline, and isocyanate. In this paper, a blocked isocyanate chain extender with biological cyclodextrin as the skeleton material was designed and prepared(B3H35). When it was added to PBAT for melt blending at high temperature, the active isocyanate groups released by its deblocking reaction wound reacted with the terminal hydroxyl groups or carboxylic acid groups of PBAT to extend the molecular chain of PBAT, and then, a three-dimensional network was constructed based on dynamic hydrogen bonding, molecular entanglement, and physical cross-linking. As a result, the strength and toughness of PBAT improved simultaneously. Compared with pure PBAT, the tensile strength, elongation at break, and toughness of PBAT/B3H35 (2 wt %) increased by 17.7, 8.1, and 31.6%, respectively. In addition, 3,5-dimethylpyrazole, used as a blocking agent in this paper, is also released by deblocking during melt blending and endows PBAT/B3H35 with an excellent nitrification inhibition effect in agricultural soil. The experimental results show that the nitrification inhibition rate of the PBAT/B3H35 (3 wt %) reaches 80.64% after 35 days of landfill, significantly improving the utilization rate of the nitrogen fertilizer, thus reducing greenhouse gas emissions and environmental pollution. Overall, this work provides an idea and direction for designing and preparing functional chain extenders with simultaneous enhancement and toughening effects and nitrification inhibition functions for agricultural materials.

Rechargeable Zinc metal batteries have emerged as promising next-generation energy storage devices, attributed to their affordability, abundant availability, and high safety profile. However, aqueous Zinc anodes encounter challenges such as dendrite formation and electrolyte corrosion. This study addresses these challenges by introducing a biopolymer-based hydrogel electrolyte. The electrolyte is a gelatin (G) hydrogel, enriched with x% beta-cyclodextrin (D) grafted onto chitosan (C), designated as G(DC)(x). It ensures efficient and uniform Zn2+ ion transport through ionic channels to the zinc anode surface, facilitating the formation of parallel, densely arrayed Zn platelets on the anode. This arrangement minimizes the electrolyte-zinc interface area, mitigating interfacial side reactions and preventing dead zinc formation. The enhanced gelatin network endows the hydrogel electrolyte with considerable mechanical strength (1.49 MPa) and extensive stretchability (400 %), effectively inhibiting dendrite growth and penetration. Additionally, the electrolyte demonstrates excellent ionic conductivity at 24.89 mS cm(-1) and a notable transference number of 0.49, synergistically improving the zinc anode's cycling reversibility and lifespan. Symmetric cells using G(DC)2 electrolytes exhibit remarkable cycling stability, exceeding 1200 h at 1 mA cm(-2)/1 mA h cm(-2). Zn-I-2 full cells with G(DC)(2) hydrogel electrolyte show superior cycling performance, maintaining over 300 cycles at 0.1 A g(-1) while retaining excellent mechanical properties. The hydrogel electrolytes, degrading by 85 % in weight within 28 days, also exhibit excellent biodegradability in soil. Consequently, these renewable and biodegradable G(DC)(x) electrolytes present a viable alternative to liquid electrolytes, paving the way for safer, more stable, and eco-friendly zinc metal batteries.