Nowadays, photo reversible color switching systems (PCSS) are always limited by some requirements, such as good stability, low toxicity, fast light response, long cycling performance and low production cost, therefore, it is a huge challenge to develop such a system that integrates beneficial features. Herein, a new type of PCSS have been demonstrated, which integrated reducing agent of triethanolamine (TEOA), catalyst of β-FeOOH nanorods and the redox driven color conversion characteristics of redox dyes. The system has the advantages of high switching rate, high reversibility (>10 cycles), wavelength selective response, safety and less light damage, which can be widely used in rewritable paper. As-prepared rewritable paper has high contrast, high resolution, suitable printing time and good reversibility, which is in line with the environmental protection concept of green printing. Rewritable paper is a kind of self-erasable rewritable medium which is highly suitable for printing. Environmental protection film has the advantages of low cost, convenient preparation and recycling. It is expected to replace the traditional writing, printing paper, existing systems and make a big step forward to practical application. Even more surprising, it also can be applied for a data encoding and reading strategy.
An advanced biodegradable packaging film with antimicrobial and fresh-maintaining functions was constructed by incorporating berberine and L-arginine into the starch/polyvinyl alcohol (PVA) film matrix. The film was endowed with a dual antibacterial capacity thanks to the intrinsic antibacterial capability of berberine and cascaded photodynamic sterilization. The aggregated berberine presents an excellent photodynamic activity to generate reactive oxygen species (ROS), which further triggers the NO release from L-arginine. Under the synergetic action of ROS and NO, the as-prepared film not only has an antibacterial efficiency of over 99 % against both S. aureus and E. coli but also delays fruit ripening through antagonistic effects on ethylene to extend the shelf life of food. Meanwhile, the as-prepared film presents UV-shielding properties, thermal stability, and considerable mechanical properties. Specifically, the packaging film exhibits good biocompatibility and is biodegradable, with a degradation rate of 56 % within 16 days, which has great potential for improving food safety and environmental events.
危险品化学品经营许可证（带存储）