超滤法测定表面活性剂临界胶束浓度

对超滤法测定表面活性剂的临界胶束浓度(CMC)的单点式超滤法、超滤曲线法、双点式超滤法进行了研究,比较了理想与真实超滤曲线,对超滤膜用于超滤法测定CMC的适用性及容积效应进行了考察.初步探讨了用双点式超滤法代替作超滤曲线法测定CMC的可行性和准确性,并与单点式超滤法进行了比较.试验结果表明,用双点式超滤法测定CMC具有准确性较高、操作简便、节省时间和节约样品用量等优点.用双点法测得的SDS和SLAS的CMC分别为6.70mmol/L和1.40mmol/L;与超滤曲线法得到的CMC相比,偏差分别为2.9%和3.4%.

Determination of Critical Micelle Concentration by Ultrafiltration

Ideal ultrafiltration curve was compared with real one for determining Critical Micelle Concentration of surfactants. Applicability of ultrafiltration membrane and effect of solution volume on determination of CMC were examined. The applicability and accuracy of determination of CMC by single point ,double point and multi point methods were discussed. The experimental results showed that determination of CMC by the double point method had many advantages such as higher accuracy,easier operation,shorter period and less sample. The CMC of SDS and SLAS determined by double point method were 6.70 mmol/L and 1.40 mmol/L respectively,and the deviations from that of ultrafiltration curves were 2.9% and 3.4% respectively.