Partition coefficient of araphiphilic hemicyanine dyes between the aqueous and the micellar phase of sodium dodecyl sulfate by differential absorbance spectroscopy

摘要

Solubilization in terms of hydrophobic interactions of amphiphilic hemicyanine dyes by micelles of the anionic surfactant sodium dodecyl sulfate was studied. The critical micelle concentration was determined by a specific conductivity method. The water-micelle partition coefficient (K-x) of these dyes was determined using a differential absorbance technique. The standard free energy change of solubilization (Delta G degrees(p)) and free energy change per methylene group of the dyes, Delta G degrees(CH2) at 25 degrees C was also calculated. K-x, Delta G degrees(p), and Delta G degrees(CH2) were also calculated using both conductivity and differential absorbance data. Lengthening of the dialkyl chains of the hemicyanine dyes led to greater hydrophobic interaction and consequently enhanced solubility within micelles of sodium dodecyl sulfate. (C) 1998 Elsevier Science B.V. All rights reserved. [References: 16]