不同价态阳离子对ZrO_2纳米晶涂层修饰微滤膜的相互作用研究

THE INTERACTION OF CERAMIC MICROFILTRATION MEMBRANES MODIFIED BY NANO-CRYSTALLINE ZrO_2 COATING WITH DIFFERENT VALENCE CATIONS

分别在CaCl2和KCl稀溶液中,用AFM研究了四方相ZrO2纳米涂层的表面排斥力随作用距离的变化关系。Ca2+在ZrO2纳米涂层表面具有特征吸附,而K+表现出惰性电解质的特征。随着CaCl2浓度的升高,ZrO2纳米晶涂层表面的双电层受到压缩,其排斥力的作用范围缩小,排斥力的强度呈下降趋势。随着CaCl2浓度的增大,渗透通量呈明显下降的趋势。随着KCl浓度的增大,渗透通量呈稍有增大的趋势。所产生的短程非DLVO作用力可能来源于Ca2+的特征吸附。

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 Ca2＋ on the surface of nano-crystalline ZrO2 coating, while K＋ exhibited an inert electrolyte behavior. The electric double layer of Nano-crystalline ZrO2 coating 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 Ca2＋ possibly.