Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (05): 1271-1276.doi: 10.3866/PKU.WHXB20100535

• COLLOID AND INTERFACE CHEMISTRY • Previous Articles     Next Articles

Determination of Surfactant cmc Based on the Fiber Refractive Index Sensor Principle

HUANG Zhen-Jian, TAN Chun-Hua, HUANG Xu-Guang   

  1. Laboratory of Photonic Information Technology in Guangdong Universities, South China Normal University, Guangzhou 510006, P. R. China
  • Received:2009-11-11 Revised:2010-01-14 Published:2010-04-29
  • Contact: HUANG Xu-Guang E-mail:huangxg@scnu.edu.cn

Abstract:

Anovelmethod for the determination of surfactant criticalmicelle concentration (cmc), based on the fiber refractive index sensor principle was studied. The cmc of a representative anionic surfactant sodium dodecyl sulfate (SDS) and the cmc of a cationic surfactant cetyltrimethylammonium bromide (CTAB) were found to be 8.05×10-3 and 9.11×10-4 mol·L-1 respectively at 25 ℃ using this method, which are in good agreement with literature values. Further determinations of surfactant cmc under various conditions show that the influence of temperature and the inorganic salt NaCl on the accuracy of the method is slight. Therefore, the applicability of the method is proven. We also tested the repeatability and stability of this method. The relative standard deviation (RSD) for the measurement results was 0.17%, which is consistent with our expectation.

Key words: Surfactant, Critical micelle concentration, Fiber sensor, Refractive index, SDS, CTAB

MSC2000: 

  • O648