Measurement Critical Micelle Concentration of Surfactant Using UV-VIS Spectroscopy

• Main Authors: Vin-Cent Wu, 吳文生
• Other Authors: Wei-Li Yuan
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/73951287679723372381

碩士 === 逢甲大學 === 材料與製造工程所 === 93 === UV-VIS spectroscopy applied to the determination of critical micelle concentration (CMC) of surfactant is a convenient method with good reproducibility. Red-shift of a particular peak in the UV-VIS spectrum could be observed when surfactant micelles are formed at CMC. Therefore, the CMC under various conditions of temperature, pH, and solvent could be determined. In addition, the results from UV-VIS data are useful in controlling the micellar reactors and in studying the molecular clustering phenomena. Current ways of measuring CMC include UV-VIS spectroscopy, surface tension change, and electro-conductivity change of the surfactant solutions. Owing to more information such as micelle structural change that could be obtained, the research of finding CMC from UV-VIS spectra was conducted. In this work three commonly used surfactants were tested, namely, the cationic CTAB, anionic SDS, and nonionic Tween 80. Analyzed with UV-VIS spectroscopy and compared with the literature data, the CMC of the three aqueous surfactant solutions were determined at some particular local maximum peaks enclosed by the isotherms from the three dimensional regressed response surfaces. Good consistency was found for all the samples in the CMC values from UV-VIS compared to the literature ones.