Thermal physical and magnetic properties of water-based yolk-shell Fe3O4@C nanofluids

Fe3O4@C yolk-shell nanoparticles were synthesized by a one-pot solvothermal method using ferrocene as raw material and dispersed in deionized water to configure four different concentrations of water-based Fe3O4@C nanofluids. The morphology of Fe3O4@C nanoparticles was characterized. The results showed that the average particle size of Fe3O4@C nanoparticles was in the range of 82–84 nm with stable yolk-shell structure and large specific surface area. The stability of Fe3O4@C nanofluid was investigated. The results showed that Fe3O4@C nanofluid has good stability with maximum zeta potential values at pH 8–9. The thermal properties of Fe3O4@C nanofluids were investigated, and for the prepared nanofluids, the thermal conductivity increased with temperature and nanoparticle concentration, possessing excellent thermal stability. The magnetic responsiveness of Fe3O4@C nanofluid was characterized, and the results showed that the magnetic properties of Fe3O4@C nanofluid increased with increasing concentration.