Experimental study on the thermal conductivity of a water-based ternary hybrid nanofluid incorporating MWCNTs-COOH-Fe3O4-rGO

This study explores the thermal conductivity characteristics of ternary nanofluids composed of water-based Fe3O4-decorated carboxylated multi-walled carbon nanotubes (MWCNT-COOH), reduced graphene oxide (rGO), and Fe3O4-CNT-COOH/rGO nanocomposites. The investigation focuses on the influence of temperature and nanocomposite concentration. Ultrasonic probes were employed to ensure the stability of the nanofluid, and its structural properties were analyzed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). Thermal conductivity measurements were conducted using a KD-2 Pro thermal analyzer across a temperature range of 25-60 °C and a nanocomposite mass fraction range of 0.025-0.1%. Results demonstrated that the thermal conductivity ratio increased with higher solid volume fractions and elevated temperatures. Notably, the impact of temperature became more significant at higher nanocomposite concentrations. The findings also revealed a maximum thermal conductivity enhancement of approximately 50%, achieved at a nanocomposite fraction of 0.1% and a temperature of 60 °C.