Synthesis, characterization and optical properties of graphene oxide-polystyrene nanocomposites

The synthesis of graphene oxide (GO)-polystyrene (PS) Pickering emulsions, as environment-friendly nanostructures suitable for novel applications, has received significant attention in recent years. In this work, the synthesis and characterization of GO-PS nanocomposites through seeded emulsion polymerization and the selective light reflection properties of dry films have been reported. Amphiphilic molecule sulfonated 3-pentadecyl phenol was used as a co-surfactant to stabilize GO dispersions during the emulsion polymerization process. The particle size of the dispersions as measured by dynamic light scattering decreases from 540nm, for PS without any GO, to 88nm with 1wt% GO content. Scanning electron microscopy studies show a uniform size distribution of the composite particles prepared with GO. The dried films show a structural color that varies with the GO content. The self-assembly behavior of the dried film was further studied using reflectance spectroscopy, which shows a red shift of the reflectance maximum from 440 to 538nm as the GO loading was increased from 0.2 to 0.5wt%, respectively, indicating a different microstructure. X-ray diffraction, transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used to study the morphology and structure of the composite particles on drying. The AFM study confirms the non-spherical shape of the particles. Thermogravimetric analysis shows improved thermal decomposition characteristics of the nanocomposite films. Copyright (c) 2015 John Wiley & Sons, Ltd.