Novel graphene oxide derivatives and its effect in broad-band reflectors

n-Octylyamine (CA) was chemically grafted onto carboxylic groups of graphene oxide (GO) via amidation reaction. The resultant modified GO sheets (GO-CA) were easily redispersed in common organic solvents or liquid crystals (LCs), facilitating the structure characterisation and the device fabrication by solution processing. Broadband reflectors could be obtained by doping different contents of GO-CA nanosheets into chiral nematic liquid crystalline (N*-LCs) media to a photo-polymerisation. Experimental results showed that both the bandwidth of the reflection spectra and the location of the reflection band of the GO-CA-doped composite films were better than the N*-LCs sample without GO-CA. Effects of polymerisation temperatures and doped contents of GO-CA on the broadband reflection of N*-LC composite films were investigated.