Stability and thermophysical properties test of carbide-derived carbon thermal fluid; a comparison between functionalized and emulsified suspensions

Abstract

In this study, the stability and thermophysical properties of chemically functionalized and gum-Arabic emulsified carbide-derived carbon (CDC)/ water thermal fluids were investigated. The stability of the thermal fluids were studied through zeta potential measurements and imaging methods. The results indicated that functionalized-CDC has a higher stability than the emulsified-CDC. LAMBDA thermal conductivity analyzer, differential scanning calorimeter, and discovery hybrid rheometer were used to evaluate the thermal conductivity, heat capacity and viscosity of the suspensions, respectively. The results demonstrated that the thermal conductivity enhancement was independent of temperature, decreases with gum-Arabic concentration, and significantly enhanced with CDC loading with a maximum enhancement of 26.1% for 0.3 wt% functionalized CDC. Increasing the CDC loading was found to increase the viscosity and decrease the specific heat of the suspensions. Finally, correlation equations proposed for predicting the thermal conductivity and dynamic viscosity of the CDC-water suspension had R2 values of 0.90 and 0.81, respectively.