Fe₃O₄ nanoparticles decorated multi-walled carbon nanotubes based magnetic nanofluid for heat transfer application

The synthesis of magnetic multi-walled carbon nanotubes (MWCNTs)-iron oxide (Fe₃O₄) nanocomposite (NC) provides many interesting traits in individual moieties unfolding new opportunities for a wide range of applications. Several preparation techniques have been employed in the recent past to synthesize MWCNTs-Fe₃O₄ NCs. Herein, we report the synthesis of Fe₃O₄ nanoparticles (NPs) decorated MWCNTs NC for heat transfer application. The NC was synthesized via co-precipitation method with a high-quality yield. The magnetic characterization of the as-synthesized NC exhibited saturation magnetization and was found to be 34.86 emu/g. Finally, magnetic nanofluids were prepared by dispersing different amounts of the as-synthesized NC into mineral oil, which is rarely reported. A ~50% enhancement in the thermal conductivity of the magnetic nanofluid was observed with loading of ~0.5 g/L of NC, which is better than the results reported so far for various nanofluids.