Ubbelohde viscometer measurement of water-based Fe3O4 magnetic fluid prepared by coprecipitation

• Fe3O4 nanoparticles were prepared using co-precipitation and coated by sodium dodecyl benzene sulfonate to obtain water-based magnetic fluid.
• The viscosity of different magnetic fluids was measured using an Ubbelohde viscometer.
• The effects of magnetic particles volume fraction, surfactant mass fraction and temperature on the viscosity of magnetic fluids were studied.

Fe3O4 nanoparticles were prepared by co-precipitation and coated by sodium dodecyl benzene sulfonate (SDBS) to obtain water-based magnetic fluid. The viscosity of the magnetic fluid was measured using an Ubbelohde viscometer. The effects of magnetic particles volume fraction, surfactant mass fraction and temperature on the viscosity were studied. Experimental results showed that the magnetic fluid with low magnetic particle volume fraction behaved as a Newtonian fluid and the viscosity of the magnetic fluid increased with an increase of the suspended magnetic particles volume fraction. The experimental data was compared with the results of a theoretically derived equation. The viscosity of the magnetic fluid also increased with an increase in surfactant mass portion, while it decreased with increasing temperature. Moreover, the viscosity increased with increasing the magnetic field intensity. Increasing the temperature and the surfactant mass fraction weakened the influence of the magnetic field on the viscosity of the magnetic fluid.