The absorbance deviation method: a spectrophotometric estimation of the critical micelle concentration (CMC) of ethoxylated alkylphenol surfactants

The measurement of spectroscopic absorbance at a proper wavelength can lead to the determination of the CMC of ethoxylated alkylphenol through the so-called absorbance deviation method. This method is based on the slight change in the absorbance-concentration trend, which takes place at the CMC. The accuracy of the spectrophotometric measurement allows calculation of the deviation between the two trends and extrapolation of it to zero deviation in order to estimate the CMC. The CMC estimates are satisfactory; the method may be an alternative technique for alkylphenol nonionic surfactants. (C) 1998 Elsevier Science B.V.