Colourful cholesteric liquid crystal polymer network gratings prepared through nanoimprinting

Both the colourful cholesteric liquid crystal polymer network (CLCN) patterns and the gratings have attracted much attention for their applications as optical materials. Herein, the photochromic cholesteric liquid crystal (CLC) mixtures were prepared using a photoisomerizable chiral dopant. The structural colour of the CLC mixtures was tunable by changing the chiral dopant concentration and the intensity of the 365-nm irradiation light. The CLCN gratings with a structural colour were prepared using the UV nanoimprinting lithography method. The structural colours of the CLCN gratings originate from both the cholesteric and the grating structures. Moreover, a patterned CLCN grating was prepared using a photochromic CLC mixture, which could be applied for decoration and anti-counterfeiting.