Transparent epoxy-ZnO/CdS nanocomposites with tunable UV and blue light-shielding capabilities

摘要

It is known that ultraviolet (UV) radiation is harmful to human health and affects the long-term stability of many organic materials. It has recently been discovered that blue radiation also poses a danger. In this study, epoxy-ZnO/CdS (EP-ZC) nanocomposites capable of shielding both UV and blue radiation were developed. First, ZnO/CdS nanoparticles were synthesized through the growth of CdS on prefabricated ZnO quantum dots (ZnO QDs). In contrast to ZnO QDs, which only absorb a portion of UV light, the ZnO/CdS nanoparticles exhibited strong absorption over the wavelength region extending from UV light to blue light. Further, their absorption-band range could be controlled by adjusting the Zn/Cd molar ratio. In situ polymerization was employed to prepare the EP-ZC nanocomposites, which were highly transparent at wavelength greater than 500 nm. It was found that the EP-ZC nanocomposites exhibited strong UV-shielding capability and could almost completely block UV light between 200-400 nm as well as more than 80% of the blue light between 400-450 nm when they contained 0.3 wt% ZnO/CdS nanoparticles. Finally, their optical transparency to visible light in the region beyond blue light was the same as that of pure epoxy due to the uniform dispersion of nanoparticles.