Study on the viscosity/drag reduction effect of PEG in aqueous Fe 3 O 4 magnetic fluid

Abstract In order to solve the problem of excessive torque of magnetic fluid in sealing devices, an appropriate amount of drag-reducing agent was added to aqueous magnetic fluid to reduce their viscosity. The rheological properties were investigated by grafting PEG (polyethylene glycol) directly onto the surface of magnetic particles or doping PEG into the aqueous magnetic fluid. The results showed that the viscosity of Fe 3 O 4 -PEG200-sodium dodecylbenzene sulfonate aqueous magnetic fluid synthesized by grafting PEG directly onto the surface of magnetic particles was significantly reduced under the action of a magnetic field at high shear rate. The viscosity of the aqueous magnetic fluid did not decrease significantly when PEG was directly doped in the aqueous magnetic fluid. In addition, the effect of PEG2000 on the viscosity of the magnetic fluid was also investigated in this study. The results show that the drag reduction effect of PEG2000 is not obvious, indicating that the molecular weight is an important influencing factor of the drag reduction effect.