Preparation of Ion Stable Ferrofluid with Water Liquid Carrier and Investigation its Stability, Magnetic Properties and Density

Preparation of ion stable ferrofluid with water liquid carrier is presented in this paper. Iron oxide nanoparticles and tetramethyl ammonium hydroxide (TMAH) were used as solid phase and stable agent respectively. Magnetic properties of nanoparticles and ferrofluid were investigated by VSM. Particle size was calculated by Sherrer formula and magnetic data and compared with the sizes estimated by TEM micrograph. The size of particles were about 10 nm and their saturation magnetization were between 65.5 and 84 emu/g. Saturation magnetization of ferrofluid, its density and the density of suspended particles were calculated using magnetic data and compared with those calculated by direct measurement and a simple method for estimating magnetization of ferrofluid was proposed. Results showed that the extent of stirring the fluid during preparation affect its quality. Also the content of magnetic phase in the fluid directly affects its saturation magnetization and initial susceptibility.