Effect of graphene oxide nanoparticles on thermal properties of paraffin wax

Abstract

Whereas previous studies analyzed thermal properties of pure paraffin, this paper analyzed thermal properties of paraffin added with Graphene Oxide (GO) nanoparticles experimentally. The tested samples are paraffin wax and GO added at various percentages of weight, 1 wt%, 3 wt%, 5 wt% which typically used for photovoltaic panel cooling. The objective is to explore the effect of various weight percentages of GO nanoparticles addition on the thermal properties of the paraffin. All the thermal properties were measured by using thermographic camera, and Differential Scanning Calorimetry (DSC). DSC showed that melting and solidification temperature for paraffin/5 wt% GO has highest reduction which is at 45.91 ℃ and 41.85 ℃, followed by paraffin/3 wt% GO with 46.15 ℃ and 42.02 ℃, and then paraffin/1 wt% GO with 46.25 ℃ and 42.02 ℃, when compared to 63 ℃ and 59.5 ℃ for pure paraffin. Thermographic camera recorded the melting temperature history of all samples for 600 s. From the measurement, it is revealed that paraffin/5 wt% GO has largest heat transfer rate. This is shown by the bigger average temperature gradient of paraffin/5 wt% GO which is at 2.93 followed by paraffin/3 wt% GO at 2.69, paraffin/1 wt% GO at 2.52 and paraffin at 2.03. DSC also revealed that paraffin/5 wt% GO has highest improvement in latent heat which is 163.99 kJ/kg, followed by paraffin/1 wt% GO, paraffin/3 wt% GO and pure paraffin each at 155.85 kJ/kg, 155.0813 kJ/kg and 102 kJ/kg. Paraffin/5 wt% GO also can be seen to have the largest amount of heat stored with 0.62 kJ, followed by paraffin/3 wt% GO, paraffin/1 wt% GO and lastly pure paraffin with 0.44, 0.4 and 0.33 kJ respectively. The results indicate that the rise of GO nanoparticles percentages weight added results in better thermal properties of paraffin. With better charging and discharging rate, highest latent heat, largest amount of heat can be stored, paraffin/5 wt% GO is the most favorable to be used as a photovoltaic panel coolant.