A co-type ductile film with high tensile strength and fast self-healing properties for shaped fruit preservation.

Traditional petroleum-based plastics have high energy consumption, require professional equipment, are non-degradable after use, and lack antibacterial properties, making it impossible to achieve long-lasting freshness in fruits and vegetables. Herein, we report a novel co-type film-forming method with low energy consumption and without production equipment, which uses PVA-borax gel as a substrate and adds a certain proportion of CMC and TA to prepare multifunctional CMC/TA@PVA-borax composite hydrogels (CTPB). The dynamic borax ester bonding and hydrogen bonding in the CTPB hydrogel results in an ultra-high tensile strength of more than 5500% and rapid self-healing within 8 s. Interestingly, hydrogels can be arbitrarily shaped and stretched like play dough and thus can be stretched into ductile films by co-type film formation. The antimicrobial properties of the hydrogel film can be attributed to the synergistic effects of TA and borax. The mussel structure of TA allows the hydrogel film to adhere directly to different surfaces for more effective bacterial killing. In addition, the hydrogel film has a high level of biosafety and biodegradability and shows good performance in fruit storage. This study provides a convenient and low-energy method for the preparation of films, which in part reduces the increasing environmental pollution caused by petroleum-based plastics.

[Effects of plant polysaccharides-containing compound agents on yield and matter accumulation and transportation of winter wheat].

A field experiment was conducted to study the effects of foliar spraying of three kinds of compound agents [plant polysaccharides (P1), plant polysaccharides plus 5-aminolevulinic acid (P2), and plant polysaccharides plus 5-aminolevulinic acid and dimethylpiperidinium chloride (P3)] at the initial flowering stage of winter wheat on its yield components, sucrose content, soluble sugar content, the accumulation and translocation of dry matter, nitrogen and phosphorus. The grain number per spike and kilo-grains mass of winter wheat increased with the spray of the compound agents. The grain yield increased by more than 8.5% compared with the control. Within 20 days after spraying the three compound agents, the sucrose content of flag leaf had an obvious increase. Compared with the control, P1 and P3 increased the soluble sugar content by more than 4.5% and 11.0%, respectively. P3 enhanced the accumulations of post-anthesis dry matter, nitrogen and phosphorus by 48.5%, 116.9% and 18. 1%, respectively. Correspondingly, contributions of accumulated post-anthesis dry matter and nutrient to grain yield increased significantly. Whereas, the contribution of translocated pre-anthesis nutrient to grain yield in P3 treatment was smaller than in the other treatments. The high yield of winter wheat was related to the regulation of photosynthetic product supply in vegetative organ, the increased soluble sugar content in grain, and the accumulation of post-anthesis dry matter and nutrient regulated by the plant polysaccharides-containing compound agent.