ZHOU Jian'er ¹ ,WU Yefan ¹ ,SHI Jijun ¹ ,HE Rujie ¹ ,CHEN Meng ¹ ,WANG Jiaheng ²

(1. University Key Laboratory of Inorganic Membrane in Jiangxi Province, Jingdezhen Ceramic Institute, Jingdezhen 333001;2. Shenzhen University, Shenzhen 518060)

Abstract: The variation in surface repulsive force of tetragonal Nano -crystalline ZrO₂ coating with operation range was investigated by atomic force microscopy (AFM) in the calcium chloride and potassium chloride dilute solutions respectively. A characteristic adsorption was found for Ca^{2 +} on the surface of nano -crystalline ZrO₂coating, while K+ exhibited an inert electrolyte behavior. The electric double layer of Nano-crystalline ZrO₂coating surface was compressed, range of action of repulsive force was narrowed, strength of repulsive force was decreased, and the water flux of ceramic microfiltration membrane decreased obviously with the increase of concentration for calcium chloride. But the water flux increased slightly with the increasing of concentration for potassium chloride. The short -range non-DLVO repulsive force comes from the characteristic adsorption of Ca^{2 +}possibly.

Keywords: ceramic membrane, nano-crystalline, flux, water cluster structure