The development of biodegradable and recyclable food packaging materials derived from biomass is a promising solution to mitigate resource depletion and minimize ecological contamination. In this study, lignin nanoparticles (LNPs) were effectively produced from bamboo powder using an eco-friendly recyclable acid hydrotrope (RAH) strategy. A sustainable CA/LNPs nanocomposite film was then designed by incorporating these LNPs into a casein (CA) matrix. The LNPs served as nucleation templates, inducing ordered hydrogen bonding and close packing of the CA chains. The addition of 5 wt% LNPs significantly enhanced the mechanical properties of the film, with tensile strength enhanced to 21.42 MPa (219.7 % improvement) and elastic modulus rising to 354.88 MPa (220.3 % enhancement) compared to pure CA film. Notably, the resultant CA/LNPs nanocomposite film exhibited recyclable recasting characteristics, maintaining a reasonable mechanical strength even after three recasting cycles. The incorporation of LNPs also decreased the water solubility of the pure CA film from 31.65 % to 24.81 % indicating some interactions are taking place, while endowing the film with superior UV-blocking ability, achieving nearly complete absorption in the 200-400 nm range. Moreover, the inherent properties of LNPs imparted improved antibacterial and antioxidant activities to the CA/LNPs nanocomposite film. Owing to its comprehensive properties, the CA/LNPs nanocomposite film effectively extended the storage life of strawberries. A soil burial degradation test confirmed over 100 % mass loss within 45 days, highlighting excellent degradability of the films. Therefore, the simple extraction of LNPs and the easily recovery of p-TsOH provide significant promise and feasibility for extending the developed methodologies in this work to rapidly promote the produced films in fields such as degradable and packaging materials.

Biodegradable mulch films are essential for reducing plastic pollution in agriculture; however, current production methods often rely on complex and costly chemical processes. This study presents an innovative, ecofriendly approach to developing fully biodegradable mulch films using untreated vegetable stalks and sodium alginate through a simple blending method. By eliminating the need for pretreatment, this process significantly reduces energy consumption and maximizes agricultural waste utilization. The optimized film formulation (30 % vegetable stalk, 3 % solution, 40 % glycerin) demonstrated excellent mechanical and barrier properties, including tensile strength (6.8 MPa), elongation at break (29 %), water vapor permeability (1.88 x 10-12 g & sdot;cm-1 & sdot;Pa-1 & sdot;s-1), and UV-blocking efficiency (98.5 %), and thermal insulation and moisture retention properties. Rheological analysis showed that the addition of vegetable stalks impacted the film-forming solution's properties, enhancing processing and application performance. Additionally, the films facilitated seed germination and maintained functionality on the surface of moist soil, while rapidly degrading when buried in moist soil. Life Cycle Assessment confirmed that the biodegradable films significantly reduce environmental impacts, supporting their potential for widespread adoption in sustainable agricultural practices. This study provides a scalable and cost-effective strategy for converting agricultural residues into high-performance biodegradable films, addressing the need for sustainable solutions in agriculture and environmental protection.

To enhance the mechanical properties and water resistance of chitosan (CS) films while imparting additional functionalities, this study incorporated a hydrophobic deep eutectic solvent (DES) composed of menthol and pyruvic acid into the CS matrix. At an optimal DES content of 15 %, compared to pure CS films, the elongation at break increased by 77 %, while swelling degree and solubility decreased by 94.44 % and 60.71 %, respectively. The lowest water vapor permeability (11.55 x 10-11 g & sdot;m- 1 & sdot;s- 1 & sdot;Pa- 1) demonstrated enhanced moisture barrier properties. These improvements were attributed to the synergistic effects of hydrogen bonding and ionic crosslinking, reinforcing the network structure and restricting water penetration while maintaining molecular mobility. The films also exhibited excellent ultraviolet-shielding (ultraviolet C transmittance of 3 %) with high transparency, making them suitable for light-sensitive packaging. Additionally, they achieved complete biodegradation in soil within 10 weeks, highlighting their potential as sustainable alternatives to petroleumbased plastics. This study presents a novel approach to enhancing bio-based packaging materials through hydrophobic DES, expanding their applications in sustainable food and pharmaceutical packaging.

Biodegradable mulch film is considered a promising alternative to traditional plastic mulch film. However, biodegradable mulch film-derived microplastics (BMPs) in the environment have been reported as carriers for herbicides. Particularly in agricultural settings, limited attention has been given to the abiotic and biological aging processes of BMPs, as well as the herbicides adsorption mechanisms and associated health risks of BMPs. This study investigated the adsorption behaviors and mechanisms of mesotrione on both virgin and aged polylactic acid (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) BMPs, and further evaluated their bioaccessibilities in gastrointestinal fluids. A variety of physical and chemical methods, including scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), revealed increased roughness, generation of oxygen-containing functional groups, and higher O/C ratios of PLA/ PBAT BMPs after ultraviolet (UV) and microbial aging processes. Both UV aging and microbial aging significantly enhanced the adsorption levels of mesotrione on PLA and PBAT BMPs by approximately two-fold, driven by pore filling, hydrogen bonding, and it-it conjugation. The adsorption capacity of mesotrione on BMPs decreased with the pH from 3.0 to 11.0, which was involved by electrostatic interactions. In addition, salt ionic strength (Na+, Ca2+, Mg2+, Fe3+) generally inhibited the adsorption due to ions competition for adsorption sites. Notably, mesotrione exhibited high bioaccessibility when adsorbed onto BMPs, with aged BMPs exhibiting greater desorption quantities in gastrointestinal fluids compared to virgin BMPs. These findings provide effective insights into the potential health threats posed by BMPs carrying herbicides in the environment and offer applicable guidance for managing and remediating composite pollution involving BMPs and adsorbed contaminants.

Electronic waste (e-waste) from nonbiodegradable products present a significant global problem due to its toxic nature and substantial environmental impact. In this study novel electrically conductive biodegradable films of uncured natural rubber (NR) incorporating graphite platelets and chitosan were developed via a latex aqueous microdispersion method. Chitosan was added as a dispersing and thickening agent to encourage the uniform distribution of graphite in the NR matrix at loadings of 20-60 parts per hundred rubbers (phr). FTIR confirmed interactions between NR, graphite, and chitosan. FE-SEM and Synchrotron XTM analyses demonstrated uniform graphite dispersion. The result of XRD revealed the greatest crystallinity at 86.9% with 60 phr graphite loading. Mechanical properties testing indicated a significant increase in Young's modulus to 58.2 MPa, or about 470-fold improvement over the pure NR film. The composite films demonstrated improved thermal and chemical resistance, and their electrical conductivity could rise dramatically to 1.22 x 10-5 S cm-1 at 60 phr graphite loading, or about six orders of magnitude higher than pure NR film. The composite films exhibit antibacterial activity against Staphylococcus aureus and some inhibition against Escherichia coli. In addition, the NR composite films exhibited biodegradability ranging from 16.7% to 25.1% after three months of soil burial, declining with increased graphite loading. These results demonstrate the potential of NR-graphite composites as conductive materials for flexible electronics, such as thin-film electrodes in energy storage devices and sensors.

Having porous structure, large surface area, and high carbon content of biochar facilitates interface bonding of polylactic acid (PLA) composites, but uneven dispersion by its irregular morphology is becoming a new challenge in damaging properties. Based on this, the novelty of this study is using carbon quantum dots (CQDs) to overcome the performance defects of caused PLA composites by biochar while the ultimate goal is to reveal the influence mechanism of CQDs on structure, characteristics, and properties of PLA composites based on disclosing the forming mechanism of CQDs. It was found that adding CQDs accelerated the degradation of PLA from the results of Phosphate Buffer Saline (PBS) degradation, hydrolysis, and soil degradation. PLA/CQDs composite films also showed better thermal properties due to the excellent thermal stability of CQDs, and nucleation effect of CQDs should be responsible for the improvement of PLA crystallization. Additionally, having good activity, regular morphology, and uniform size of CQDs facilitated uniform dispersion and good interface combination in PLA system and thereby improved the tensile strength, tensile modulus, and elongation at break simultaneously. As a comparison, the tensile strength, tensile modulus, and elongation at break of 1 wt% PLA/CQDs composite films are 55.00 MPa, 1.76 GPa, and 9.84 %, this provides a promising, sustainable, and eco-friendly solution for reinforcing PLA composites.

Mulching films serve various functions, such as temperature regulation, moisture retention, and weed suppression. They can substantially increase crop yields and are widely adopted in agricultural practices. However, the use of traditional plastic mulch films is limited by their difficult recycling processes and poor biodegradability, leading to soil contamination and negatively affecting crop growth. Consequently, eco-friendly alternatives are gaining attention as replacements for conventional petroleum-based films in agricultural applications. Enhancing the performance of these eco-friendly films remains a crucial challenge. Traditional polyvinyl alcohol (PVA) films have inherent limitations, including low mechanical strength and poor water resistance. In this work, a PVA/sodium alginate (SA)/glycerol (GLY)/glutaraldehyde (GA) film was prepared that is biodegradable, demonstrates superior mechanical properties, and offers exceptional transparency through glutaraldehyde crosslinking. The impact of GA on films was examined using characterization techniques. The findings revealed that the composite film has a uniform, compact surface with no observable holes or aggregation. The mechanical performance and water vapor barrier properties (WVP) of the film were significantly enhanced after GA crosslinking. The tensile strength and elongation at the break of the PVA/SA/GLY/GA film reached 33.73 MPa and 362.89%, respectively. This work offers a straightforward approach to the development of sustainable agricultural materials.

In food packaging industry, plastic was the most commonly used material for packaging, which caused serious pollution to the marine and soil environment. The researches on biodegradable films development from biodegradable polymers was arise, which was expected to ensure the quality and safety of food as much as possible. Biodegradable materials for films included polysaccharides and proteins of different biological sources, and synthetic materials. This review discussed the molecular characteristics and film-forming properties of natural polymer materials of polysaccharides from halobios, plant and microorganism, protein from animal, plant, milk. In addition, the effects of polymerization degree, crystallinity, and film-forming process of synthetic materials (polycaprolactone, polyvinyl alcohol, polylactic acid) on film performance was studied. In order to improve the practicality of biodegradable films in food packaging, many methods were explored to enhance the physical performance of the films. The enhancement strategies including: introduction of nanoparticles, chemical modification, and blending with other polymers, which can effectively enhance the mechanical properties and water vapor barrier performance of biodegradable films. Furthermore, it will provide a reference for future research interest that to development biodegradable food packaging films with high mechanical and barrier properties.

The generation of polyethylene mulch film (PEMF) has promoted the rapid development of agriculture, while the non-degradability of it has caused the serious damage for the ecological environment. Currently, the biodegradable mulch film is considered as the most promising green substitutes for petroleum-based PEMF, owing to its environmental friendliness and biodegradability. Hence, this study fabricated a biodegradable mulch film (PSGA) through the crosslink (the esterification/amidation reactions and hydrogen bonds) between polylactic acid waste liquid (PLAWL) and sodium alginate (SA)/gum arabic (GA). Then attapulgite (ATP) was added to improve the mechanical properties. Therein, PLAWL was a kind of waste liquid from the fabrication process of polylactic acid (PLA) based on straw. At the same time, PSGA had similar insulation and water retention performance to PEMF and great UV resistance, thermal stability, and hydrophilicity surface. Additionally, pot experiment showed that PSGA could significantly promote the growth of Chinese white cabbage and the degradability ratio of that could reach 50% in a month. The total amounts of Rhizobiaceae (Ensifer and Allorhizobium-Neorhizobium-Pararhizobium, fixing free nitrogen gas and providing nitrogen nutrients for plants) in soil with PSGA was 12%, which was obviously higher than that in blank (4.5%). Therefore, this study provides a high-value recycling route for industrial waste liquid, offering an alternative solution to PEMF.

Herin, a biodegradable bioplastic composite packaging film was prepared by utilizing bamboo powder partially in replace of plastic. Bamboo powder lignocellulose and polybutylene adipate terephthalate (PBAT) resin granules were mixed together with certain percentage to form bamboo-plastic complex, and then through hotpressed to obtain the bamboo/PBAT bioplastic composite films. The effect of bamboo powder content on overall properties of the composite film was systematically investigated. Results showed that the addition of bamboo powder could greatly improve the mechanical properties of composite films, especially the tensile strength and elastic modulus increased by 18.90 %, 251.58 %, respectively. Besides, the bioplastic composite film exhibited superior water resistance including the high water contact angle value of 108.13 degrees, low water absorption rate (2.38 %), and water absorption thickness expansion rate (1.08 %) with 10.0 % bamboo powder content. Notably, the enhanced bonding between bamboo powder and PBAT contributed to the excellent gas barrier performance (1.48 x 10- 2 cm3 & sdot;m/(m2 & sdot;24 h & sdot;0.1 MPa)). With the increase of bamboo powder addition, the melt flow rate of the composite was increased, indicating the improved processing performance. More importantly, the bamboo/PBAT bioplastic composite film showed good packaging preservation ability for strawberry and excellent biodegradability in soil, presenting feasible and green alternatives to biodegradable plastic food packaging material.