Stability of zirconia sol in the presence of various inorganic electrolytes

Abstract

The zirconia sol was prepared from a zirconium oxychloride solution by forced hydrolysis at 102 °C. The prepared sol consisted of almost spherical, monoclinic, hydrated zirconia particles of 61 nm in diameter. The stability of zirconia sol in the presence of various inorganic electrolytes (LiCl, NaCl, KCl, CsCl, KBr, KI, KNO 3 and K 2 SO 4 ) was studied by the potentiometric titration method. The dependence of the critical concentration of coagulation (ccc) on the dispersion pH was determined for all studied electrolytes. The critical coagulation concentration values for all investigated electrolytes were lower at higher pH values. These values for all 1:1 electrolytes were the same within the range of experimental error. For a given pH value, the cccs of K 2 SO 4 are 3-4 orders of magnitude lower than the corresponding values for the 1:1 electrolytes.