Photochromic materials are mainly based on hybrid consisting of poly (ethylene oxide)-poly (propyl oxide)-poly (ethylene oxide) (EPE) and tungstate, which were readily prepared in a self-assembly method. The low-cost materials and processing flow are benefit for large area fabrication. The aqueous solution demonstrates that fast response coloration for induced light. Moreover, after evaporated, much enhanced photochromic effect preform in the gel. The mechanism of enhanced coloration has been proposed, which may depend strongly on weak coordination of polymer and tungstate in acid condition, correlated to the oxygen vacancy concentration. The electron-hole pair separation is due to the hybridization of the W_5d-O_2p energy state and folding behavior of EPE molecule when dehydration. The i...[ Read more ]

Photochromic materials are mainly based on hybrid consisting of poly (ethylene oxide)-poly (propyl oxide)-poly (ethylene oxide) (EPE) and tungstate, which were readily prepared in a self-assembly method. The low-cost materials and processing flow are benefit for large area fabrication. The aqueous solution demonstrates that fast response coloration for induced light. Moreover, after evaporated, much enhanced photochromic effect preform in the gel. The mechanism of enhanced coloration has been proposed, which may depend strongly on weak coordination of polymer and tungstate in acid condition, correlated to the oxygen vacancy concentration. The electron-hole pair separation is due to the hybridization of the W_5d-O_2p energy state and folding behavior of EPE molecule when dehydration. The inhibition of recombination of electron-hole pair contributes to the distinguish photochromic efficiency of film.

Furthermore, the photosensitive tungstate-containing film can be easily coated on fibers. The separation of electron and hole undergo to generate oxygen radicals, and the generation of different amounts of ROS can be induced by weak irradiation. Various hybrid materials can perform as “Band-Aid” fibers with reversible and sustainable release of H₂O₂. It is found that these “Band-Aids” are able to successfully induce apoptosis of melanoma cells. Among these materials, the rapid response and outstanding chromic type is based on Brønsted acid sites. This PEO-conjugated tungstate gel has the ability to provide a precise controllable release of H₂O₂, which is related both to tungstate concentration and to irradiation time. In vivo experimental results indicate that these gels have a greater healing effect in the early stages of tumor formation.