Broadband reflection prepared by loading chiral dopants in white carbon black

Cholesteric liquid crystals with helicoidal molecular architecture are known for their ability to selectively reflect light with the wavelength that is determined by the periodicity of molecular orientations. In this paper, the broadband reflective polymer stabilised cholesteric liquid crystal (PSCLC) films in the near infrared region have been fabricated by introducing the chiral dopant-loaded white carbon black. The non-uniform pitch distribution can be anchored by adjusting the diffusion time of chiral dopants, UV intensity and polymerisation temperature, as well as the concentration of polymerisable monomers. The reflection bandwidth was broadened from 300 nm to 840 nm. The scanning electron microscope (SEM) proved the non-uniform pitch distribution in the composites. In this paper, the investigated results suggested the correlation between diffusion time, polymerisation conditions and reflection bandwidth.