Tunable Lyotropic Photonic Liquid Crystal Based on Graphene Oxide

A direct colloidal self-assembly approach was utilized to prepare photonic crystals based on exfoliated graphene oxide (GO) in aqueous solution. The GO sheets form ordered photonic structure spontaneously without the need for multiple processing steps. The wavelength of light reflected by the GO photonic crystal dispersion can be controlled over the entire visible light spectrum simply by varying the GO concentration. The aspect ratio of the GO sheets and mediation of the intersheet forces are found to be the key factors influencing the stability of photonic crystal formation. The usefulness and limitations of the GO photonic crystals prepared in this study are discussed.