Magnetic Particles Study and Their Applications

Magnetic fluids have been developed for decades and show lots of advantages in different areas of applications. This project was focusing mainly on two popular magnetic fluids: 1) the Ferrofluid (FF) which can be used in vacuum sealing and medical purpose, etc. 2) the Magnetorheological (MR) fluid which has the capability of changing material properties by applying an external magnetic field, which can be used to replace hydraulic oil in traditional shock absorber with a more advanced absorber or seismic damper.
During this project, I had successfully fabricated the magnetic nano particles, the Ferrofluid and the MR fluid. In order to study the reasons causing the change of yield stress and the reaction conditions effect on the final particle products and also the factors effect on particle settling speed in the MR fluid, we designed and carried out several experiments by using crashed glass, lithium grease as additives, changing particle ratio, controlling different reaction conditions and other methods to achieve the goals. The measurements included Scanning Electron Microscope, Energy Dispersive X-ray analysis, Vibrating Sample Magnetometer, yield stress tests and particle settling tests had carried out to study the properties of magnetic fluids. The results of the experiments showed additives like crashed glass cannot have the same effect as carbonyl iron powder does in the MR fluid, and the concentration of reagents and reaction temperature will significantly affect the produce of magnetic nano particles. Also the 3D graph of a self-designed MR fluid based car shock absorber had been plotted by Autodesk software.