流动电位/胶体滴定法测定聚电解质电荷密度的研究

Determination of Charge Density of Polyelectrolytes by Streaming Potential/Colloid Titration

探讨了应用粒子电荷测定仪的流动电位判定胶体滴定终点的可行性。结果表明流动电位曲线能在样品浓度大于 0 .6× 1 0 - 5mol· L- 1的溶液中准确指示胶体滴定的终点 ,较常用指示剂邻甲胺兰的使用极限浓度低一个数量级。观察到由阳离子聚电质滴定阴离子聚电质能减少盐干扰的现象。

A particle charge detector was used to determine endpoints of colloid titration. The curves of streaming potential could indicate the endpoints of the colloid titration for PDADMAC or PVSK with the concentrations as small as 0.6×10 -5 mol·L -1 . It was observed that the errors of the titration using cationic polyelectrolytes as standard solutions were less than those using anionic polyelectrolytes in the presence of the salts. The titration for cationic starches must be carried out under acidic conditions.