Photochromic nanocellulose composite films with excellent anti-UV capacity

Recently, green and sustainable photochromic devices have attracted considerable attention in the research community. In this work, we report a novel ultraviolet (UV)-responsive nanocellulose film using ammonium molybdate as the photochromic dye. Meanwhile, trirthylene glycol (TEG) was incorporated to accelerate the light-responsive process. Therefore, the photochromic nanocellulose film exhibits a fast response photochromic ability and inherits the high transparency of the nanocellulose film. Moreover, the reversible photochromic of the film can be easily repeated. Importantly, the photochromic and fading processes can be precisely controlled and predicted by adjusting the outside temperature and the film composition. Interestingly, the photochromic cellulose films also have great UV blocking and biodegradability. In summary, this green nanocellulose based photochromic film has a giant potential for flexible light-memory devices.