聚合硅酸硫酸铝的动电特性

Electrokinetic Characteristics of Polyaluminum Silicate Sulfate(PASS)

利用微电泳技术对聚合硅酸硫酸铝的动电特性研究表明 :聚合硅酸硫酸铝的等电点和硫酸铝相近 ,约为pH值 5 ,但其所带电荷的绝对值高于硫酸铝 ,且碱化度和硅铝比提高 ,均可不同程度地提高其可测Zeta电位的绝对值 ;水解过程中的搅拌作用可增加聚合硅酸硫酸铝的可测Zeta电位的绝对值 ,但不会改变其等电点 ;水中杂离子使聚合硅酸硫酸铝稀释后的pH值较高 ,所带电荷的绝对值降低 ,但却使其等电点向高pH值方向移动 ;

The electrokinetic characteristics of PASS was examined with microelectrophoreic method. The isoeletric point of PASS was approximately at pH 5 when it was titrated with NaOH. It was similar with that of alum at the same conditions. However, its absolute values of Zeta potential either before or after the isoelectric point were higher than that of alum. The higher the basicity, the higher the absolute values of the Zeta potential of PASS. The Si/Al molar ratio only had negligible effect on the Zeta potential, especially for the positive side before the isoelectric point. The absolute values of Zeta potential also increased with stirring, but the isoelectric pH was hardly changed. The isoelectric point and aqueous solution pH of PASS were higher when it was diluted with tap water instead of deionized water, but the absolutely values both before and after its isoelectric point became smaller. The Zeta potential was hardly changed with in reaction time.