Photochromic transparent wood (PTW) is a kind of highly desirable, green, energy-saving building material with a practical aesthetic. The application of PTW in smart windows still faces daunting challenges owing to the poor stability of photochromic reversibility and low sensitivity to sunlight. In this work, we develop a kind of prominent switchable PTW based on poplar wood (SPTW-P) that shows high sensitivity to sunlight using a new simple fabrication method. In contrast to commonly reported UV-responsive counterpart, our SPTW-P, obtained by microencapsulating active component and polymer with matched refractive index, exhibits the fastest switchable (∼1.5 s) photochromic response to sunlight, high sensitivity of color changing from colorless to peachy pink, strong mechanical strength (87.3 MPa), good transparency, and ideal cycling stability, as evidenced by the 100% maintenance of its original photochromic effect after cycling 30 times. The SPTW-P material not only shows superb UV-blocking (the highest UV-blocking value is up to 97.7%) for protecting skin, excellent thermal insulation for energy saving, good size maintenance, wonderful shape, and chemical stability (100%), but also exhibits excellent aesthetic properties (e.g., moldable aesthetic patterns). This work could promote the development of aesthetic functional transparent wood as sustainable building materials to substantially reduce carbon emissions and energy consumption.
Frequent outbreaks of respiratory diseases caused by the spread of pathogenic microorganisms poses a great threat to human health. Disposable surgical masks (SM) can limit the transmission to some extent but the inability to self-sterilize leads to a potential source of cross-contamination as well as causing hazardous impacts on the soil and aquatic ecosystems. Herein, a sunlight-triggered photoactive self-sterilization metal–organic framework (MOF) film modified SM is reported. The MOF film can be prepared easily and quickly by the co-assembly of UiO-66 nanoparticles and metal-phenolic networks (MPNs, the complexation of tannic acid and iron ions). Unlike the traditional MPN only assisted assembly, this MOF film exhibited a dramatic synergetic photodynamic and photothermal self-sterilization ability for protective equipment surfaces under simulated-solar irradiation without any extra photosensitizers or photothermal agents. A study of the mechanism revealed that the light absorption region of UiO-66 can be expanded by the MPNs, demonstrating a unique photocatalytic sensitization, and thus the MOF film can utilize the sunlight extensively to achieve a photodynamic property. Moreover, such an MOF film demonstrated excellent cytocompatibility, haemocompatibility and breathability, indicating the security of the skin-touched application. This dual-modal photocatalytic MOF film are promising for the long-term usage of disposable protective equipment and for mitigating the heavy burden on the environment.
危险品化学品经营许可证（带存储）