Rapid determination of surfactant critical micelle concentration in aqueous solutions using fiber-optic refractive index sensing |
| |
Authors: | Chun Hua Tan |
| |
Institution: | Laboratory of Photonic Information Technology, School for Information and Optoelectronic Science and Engineering, South China Normal University, 510631 Guangzhou, China |
| |
Abstract: | We describe a simple and rapid method for determining the critical micelle concentration (CMC) of surfactants from fiber-optic measurements of refractive index. The refractive index of an aqueous surfactant solution was monitored as the surfactant concentration was increased using an automated dispensing system. On reaching the surfactant’s CMC value, an abrupt change was observed in the rate of increase of the refractive index with increasing concentration. The measurement system provides rapid semiautomatic data collection and analysis, increasing the precision, sensitivity, and range of applicability of the technique while substantially decreasing the amount of manual intervention required. Measurements of CMC for sodium dodecyl sulfate (8.10 mM), cetyltrimethylammonium chloride (1.58 mM), and Triton X-100 (0.21 mM) were in excellent agreement with values previously reported in the literature. The method is applicable to cationic, anionic, and nonionic surfactants, and it offers a facile, in situ, and sensitive means of detecting micelle formation over a broad range of CMC values larger than 10−1 mM. |
| |
Keywords: | Surfactant Critical micelle concentration Refractive index sensor Fiber optic Fresnel reflection Aqueous solutions |
本文献已被 ScienceDirect 等数据库收录! |
|