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.

Functional membranes that are both robust and porous with selective wettability find widespread application in oil/water separation processes. This study used polyacrylonitrile (PAN), surfactant-modified cellulose nanocrystals (H-CNC) and polyvinylpyrrolidone (PVP) as the raw materials to prepare a nanofibrous membrane (HCNC/PPAN) with a strong loess-beam-like structure using the electrospinning and sacrificing template strategy. Surfactant adsorption enabled stable dispersion of H-CNC within the polymer matrix. The tensile strength and Young's modulus were 7.46 +/- 0.36 MPa and 150.66 +/- 33.12 MPa, respectively, which represent an increase by 3.15 times and 1.89 times when compared to the corresponding values of the PAN membrane. The H-CNC/PPAN membrane obtained a good pore size distribution after removing PVP by water etching, as a result of the formation of furrows and micro-meso-pores. Moreover, the etching process effectively improved the mechanical properties of the membranes. Based on the presence of hydroxyl and amide groups on the membrane surface, the membrane displayed pre-wetting induced underwater superoleophobicity and underoil superhydrophobicity. Driven by gravity, an ultra-high permeation flux of 7210.51 L & sdot;m � 2 & sdot;h- 1 and a separation efficiency of over 98.93% were achieved. Thanks to its excellent oil repellency and good resistance to acid, alkali and salt, the HCNC/PAN membrane is highly sustainable and has broad potential applications in the field of oil/water separation.

In order to attenuate the pollution problem caused by low fertilizer utilization, a biodegradable urea slow-release capsule was prepared in this study using gelatin as the main material. Glycerol was added to the gelatin solution as a plasticizer, and the mechanical properties and water resistance of the gelatin film were enhanced by crosslinking with glutaraldehyde. The addition of nano-SiO2 (nSiO2) and calcium magnesium phosphate fertilizer power (CaMgP) enhanced the hydrophobicity and tensile strength of the gelatin film. X-ray diffractometer confirmed that the nSiO2 could make the gelatin molecular chains more tightly entangled. Scanning electron microscope indicated that the addition contents of nSiO2 and CaMgP was optimal at 2 wt% and 40 wt%, respectively. The gelatin capsules were loaded with urea particles for slow-release experiments, the results of soil column drenching showed that the release rates of urea from nSiO2-modified and CaMgP-modified cross-linked gelatin capsules were 4.1 % and 5 % after 24 h, respectively, and 78.8 % and 75.2 % after 28 d, respectively.