Rheological Study of Dextran-Modified Magnetite Nanoparticle Water Suspension

The aim of this work is to investigate the effect of surface modification of superparamagnetic magnetite nanoparticles (sterically stabilized by sodium oleate) by the dextran biocompatible layer on the rheological behavior of water-based magnetic fluids. The flow curves were measured as a function of the magnetic field strength by means of rheometry. The measured viscosity is generally dependent on both the particle concentration and the geometrical factors such as the particle shape and thickness of the adsorbed layers. The rheological properties of the magnetic fluids studied show the effect of the magnetic field strength and the presence of the surfactant second layer (dextran) on their viscosity.