Embedding graphene nanoparticles into poly(N,N′-dimethylacrylamine) to prepare transparent nanocomposite films with high refractive index

Abstract

Transparent nanocomposite films of (graphene nanoparticles)-poly(N,N′-dimethylacrylamide) (GNPs–PDMAA) with a high refractive index are prepared via a facile in situ polymerization method. The structure and properties of GNPs and the nanocomposite films were studied by X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, and transmission electron microscopy (TEM), which indicate that GNPs with a diameter of 3–5 nm have been successfully immobilized into the polymer matrix and are homogeneously dispersed in PDMAA. The GNPs–PDMAA nanocomposite films exhibit good transparency in the visible range. The refractive index of the transparent GNPs–PDMAA nanocomposite films is in the range from 1.516 to 1.976 at 632.8 nm, which linearly increases with the content of GNPs from 0 to 50 wt%. It is also found that the transparent nanocomposite films can be prepared using mixed monomers containing N,N′-dimethylacrylamide (DMAA) and styrene (St) at an equal weight ratio following the UV/thermal dual-cure process. The refractive index of the nanocomposite film reached 2.058 with 50 wt% contents of GNPs. Our study provides a facile and feasible route to produce transparent nanocomposite films with tunable refractive indices for potential optical applications.