Hematite ($\alpha-Fe_2O_3$) was prepared using Matijevic' method. The range of particle axial ratio was between 1 and 6 and the particle size distribution was monodisperse.
The particle with axial ratio of 3 showed more stable dispersion than the particles of axial ratio 1,6 when the stability was governed by electrostatics. $SO_4^{2-}$ ion had more effects on the depression of electrical double layer than $Cl^-$ ion.
The adsorbed amount of poly (ethylene oxide) (PEO) on Hematite particle increased as the particle axial ratio became largr and PEO molecular weight became higher. The amount near isoelectric point was larger than that above or below this point.
For the particles adsorbed with polymers, the particle having the axial ratio 1 was more stable than that of axial ratio about 3 when $CaCl_2$ or $Na_2SO_4$ was added. The stability was fairly increased when PEO was adsorbed. The Critical flocculation concentration of $CaCl_2$ was higher than that of $Na_2SO_4$ because the power of $SO_4\,^{2-}$ ion that could decrease the solvency of PEO into water was stronger than that of $Cl^-$ ion. The mechanism of polymer adsorption could be influenced by the particle geometric shape and could be a governing factor for the stability of PEO adsorbed particle.
