Investigation on the enhanced dielectric properties of graphene oxide/thiol-ene composites

Abstract The graphene oxide/off-stoichiometric thiol-ene (GO/OSTE) composites were prepared via a “click” chemical reaction. Experimental results from scanning electron microscope (SEM), Raman, and X-ray photoelectron spectroscopy (XPS) analyses demonstrated that GO can be well-incorporated into the OSTE matrix, with covalent crosslinking occurring between the GO surface and the OSTE polymer. Thermogravimetric analysis (TGA) results indicated that the GO/OSTE composites exhibit excellent thermal stability below 350 °C. It is found that the dielectric parameters, as well as the electrical conductivity of the GO/OSTE composites, are strongly dependent on the GO content and frequency. The dielectric constant of the GO/OSTE composites rises as the GO content increases, owing to enhanced interface polarization effects and dipole polarization responses. When the mass fraction of GO is about 0.06 wt%, the measured dielectric constant at 10 3 Hz is about 23.6, approximately six times greater than that of the OSTE matrix. At 10 7 Hz, the electrical conductivity also increases by about ten-fold, likely attributed to the hopping motion of charge carriers under high-frequency electric fields.