Preparation of polymer stabilised cholesteric broadband reflection films based on ZIF-8 assisted bidirectional diffusion method

The polymer-stabilised cholesteric liquid crystal (PSCLC) broadband reflective films are prepared by zeolite imidazole framework-8 (ZIF-8)-assisted bidirectional diffusion combined with light curing, altering the single pitch of cholesteric liquid crystals (CLCs). By changing temperature, chiral compounds and ultraviolet (UV) absorbing dyes adsorbed on porous ZIF-8 are able to diffuse bidirectionally into the CLCs' system and produce concentration gradients, thereby inducing a pitch gradient, and the structure of broad reflection bandwidth can be fixed through UV irradiation. In addition, the effects of various factors, such as UV irradiation intensity, UV irradiation time, mass fraction of polymerisable monomers and curing temperature on the pitch gradient of the films are systematically investigated, and the maximum reflection bandwidth of the prepared films is 1274 nm. There is no doubt that new and modified processes and techniques provide significant possibilities for preparing and applying PSCLC films.

Automated summary

Polymer-stabilised cholesteric liquid crystal (PSCLC) broadband reflective films are prepared by zeolite imidazole framework-8 (ZIF-8)-assisted bidirectional diffusion combined with light curing. The effects of various factors on the pitch gradient of the films are systematically investigated, and the maximum reflection bandwidth achieved is 1274 nm.