Nano-MIL-88A(Fe) Enabled Clear Cellulose Films with Excellent UV-Shielding Performance and Robust Environment Resistance

While tremendous efforts have been dedicated to developing cellulose-based ultraviolet (UV)-blocking films, challenges still remain in simultaneously achieving high transparency, low haze and excellent UV shielding properties via simple and green strategy. Here, we present a facile and eco-friendly route to fabricate flexible, biodegradable and clear UV-shielding nano-MIL-88A(Fe)@carboxymethylated cellulose films (M(Fe)CCFs) via in situ synthesis of nano-MIL-88A(Fe) in carboxymethylated cellulose hydrogel followed by natural drying. The carboxymethylated cellulose film has high transmittance (93.2%) and low haze (1.8%). The introduction of nano-MIL-88A(Fe) endowed M(Fe)CCFs superior UV-shielding ability, while retaining high transmittance (81.5-85.3%) and low haze (2.5-4.9%). Moreover, M(Fe)CCFs showed stable UV blocking performance under UV irradiation, high temperature, acidic or alkaline conditions. Quite encouragingly, the UV-shielding ability of M(Fe)CCFs did not deteriorate, even after 30 days of immersion in aqueous solution, providing films with a long-term use capacity. Thus, M(Fe)CCFs show high potential in the UV protection field. Overall, these UV-blocking films with outstanding performances are a promising candidate to replace conventional film materials made from synthetic polymers in fields such as packaging and flexible electronics.