| Magnetic particle dispersions were prepared in order to observe the effect of particle surface properties, concentration and functional group of binder, milling time, and solvent on dispersion properties. Rheology and transverse susceptibility measurements were used to characterize the dispersion quality of the magnetic paints macroscopically and microscopically, respectively. In this study, by applying the acid-base concept, methods to optimize magnetic dispersions were established. Initially, interaction between acid-base sites on particles and binder was investigated by poisoning the sites with chemicals, then quantifying each type of adsorption (hydrogen and chemical adsorption) using thermogravimetric analysis. With this fundamental information, effects of typical dispersion parameters were investigated. The acid base interaction between binder solution and particles was related to the magnetic and rheological properties of magnetic inks. The results have significant implications for high density particulate media where dispersion will become increasingly important. |
