Fabrication of Robust Carbon Dots Containing Coatings with UV-Shielding, Light Conversion, and Antifogging Multiple Functions

Although a wide variety of single-function coatings have been successfully developed, the integration of multiple functions onto a single coating has remained an immense challenge in the field. Here, we report a simple room-temperature fabrication of robust coatings with UV-shielding, light conversion, and antifogging functionalities. The addition of glutaraldehyde (GA) molecular cross-linker and carbon dot (CD) nanocross-linker with light conversion function to poly(vinyl alcohol) (PVA) resulted in the formation of robust spatial structures of coatings. The fluorescence intensity tests demonstrated that the coatings had an excellent ability to absorb and convert ultraviolet light into blue-violet light. Both cold-warm and hot-vapor tests showed that the coatings had excellent antifogging performance. To our surprise, no creases were observed after coatings were immersed in water for 1 month, indicating that these are much stronger than those reported so far. The 8H pencil hardness and wear resistance attested to their excellent mechanical properties. The current preparation method can be operated at ambient temperature and is not restricted by the substrate type and shape. Therefore, it may also expand the possibilities for future applications of coatings for glass windows, optical microscopes, eyeglasses, agricultural greenhouses, and so on.