Blue-light-blocking CdS-PMMA nanocomposite films with tunable cut-off wavelength and narrow absorbing transitional band

The widespread application of white light-emitting diodes makes us surrounding by plenty of blue-rich light, promoting the development of blue-light-blocking filters because blue light between 415 and 455 nm wavelength can cause light damage to the retina cells. While longer wavelength blue light is also essential to trigger physiological responses, which puts forward higher requirements for the precise blue-light-blocking ability of the filters. In this paper, CdS quantum dot (QD) with strong absorption in the blue region was synthesized and its size was regulated by extended reaction time. Polymerizable molecule was chemically grafted on CdS surface and then copolymerized with methyl methacrylate (MMA) monomer for transparent films with a narrow absorption transition band (wavelength span from 0.05 to 0.8 Tmax) about 20 nm and tunable cut-off wavelength at 0.05 Tmax from 436.9 to 447.8 nm due to quantum size effect of CdS QD. This provides a possibility for more accurate adjustment of the blue-light-blocking performance, minimizing the harmful visual damage of short-wave blue light and preserving the beneficial physiological effects of long-wave blue light.