Study On The Properties And Preparation Of Aqueous Magentorheological Fluids

Aqueous magnetorheological (MR) fluids are considered as the pivotal material of magnetorheological polishing fuilds used for magnetorheological polishing because of their advantages including higher polishing efficiency and magnetic field-induced yield stress. Therefore, study on the preparation and properties of aqueous MR fluids is an important foundation for magnetorheological polishing. However, the magnetic particles in aqueous MR fluids are prone to settle and agglomerate over a relatively short period of time, and are easy to be oxidized, these problems seriously limit their application. So, improving the dispersion stability and anti-oxidation property are the pivotal technology for preparing a good aqueous MR fluid. In this study, a new method was designed for preparing novel aqueous MR fluids with better dispersion stability, anti-oxidization and magnetorheological effect. First, N-glucose ethylenediamine triacetic acid (GED3A), which has a hydrophilic group and a chelating group, was synthesized, and used to prepare composite magnetic particles (CMPs). Then aqueous MR fluids based on the composite magnetic particles were prepared and characterized.The structure and properties of GED3A and CMPs were characterized by element analysis, FT-IR, SEM, TEM, XRD, VSM, TG-DSC and Zeta potential analysis et al. The results show that GED3A had been successfully synthesized, and possesses the hydrophilic and chelating properties; And CMPs were prepared with GED3A as the shell, CI particles as the core, possessing excellent soft magnetic properties, better anti-oxidization and dispersion stability in water.The dispersion stability, anti-oxidization, zero field viscosity, field-induced shear stress, responsive time and dynamic modulus of the aqueous MR fluids had been investigated by sedimentation experiment, oxidization experiment and magnetorheological effect analysis. The results show that the aqueous MR fluids have better dispersion stability, anti-oxidization property, lower zero field viscosity, higher switch factor and larger dynamic modulus.The experimental investigation results in this study indicate that the CMPs have better anti-oxidization property and dispersion stability in water; the aqueous MR fluids based on the CMPs have better anti-oxidization property, dispersion stability and magnetorheological effect. The method designed for preparing aqueous MR fluids is a promising way for resolving the conflict between stability and magnetorheological effect, and preparing lower zero field viscosity, higher switch factor and better stability aqueous MR fluids.