Investigation of rheological and corrosion properties of graphene-based eutectic salt

Abstract

This work investigates the rheological and corrosion properties of eutectic salt and graphene (GE) dispersed in eutectic salt. The base eutectic salt was prepared by mixing 41% CsNO3, 24.75% Ca(NO3)2, 21.25% KNO3, 7.34% LiNO3 and 5.66% NaNO3 by weight. Later, GE-based eutectic salt was prepared by dispersing 0.01, 0.05 and 0.1 wt% of GE in the eutectic salt. It was observed that doping of GE has significantly enhanced the viscosity of base eutectic salt. This enhancement in GE-dispersed eutectic salt is mainly due to the presence of GE sheet network in the eutectic salt. Moreover, non-Newtonian behavior was observed for GE-dispersed eutectic salts at 70, 80 and 90 °C, whereas at 200 °C it behaves as a Newtonian fluid. Furthermore, corrosion studies were performed to analyze the effects of eutectic salt and GE-dispersed eutectic salt on copper and stainless steel (SS304). Fourier transform infrared spectrometer result shows that the presence of all nitrate bonds in synthesized base salt and GE-dispersed base salt. X-ray diffraction depicts that the doping of GE in eutectic salt does not alter the crystal structure of nitrate salts. Results from EDX show uniform corrosion for SS304 with increasing GE concentration in eutectic base salt, while copper exhibited increase in corrosion rate with increasing GE concentration.