Cholesteric liquid crystal paints: in situ photopolymerization of helicoidally stacked multilayer nanostructures for flexible broadband mirrors

Utilizing sequential layer-by-layer (LBL) coating and subsequent photopolymerization, we developed circular-polarizing and free-standing mirrors with a broad reflection bandwidth. Photopolymerizable cholesteric liquid crystal (CLC) paints were first prepared by considering the intrinsic chirality and the coating viscoelasticity. The polymer-stabilized nanostructures had finely tuned helical pitches that selectively reflected light over the entire visible wavelength range. The CLC films exhibited excellent thermomechanical properties and chemical stabilities, which enabled the preparation of patterned optical objects at macroscopic dimensions. The LBL coating and photopolymerization of the CLC paints demonstrated here can provide a simple solution for manufacturing flexible photonic devices with large areas at low cost.