Binding constants and partial molar volumes of primary alcohols in sodium dodecylsulfate micelles

Journal Article · Fri Aug 01 04:00:00 EDT 1986 · J. Solution Chem.; (United States)

DOI:https://doi.org/10.1007/BF00644596· OSTI ID:6762507

DeLisi, R; Lizzio, A; Milioto, S; Liveri, V T

The densities of methanol, ethanol, 1-propanol, 1-butanol and 1-hexanol were measured in aqueous solutions of sodium dodecylsulfate at 25/sup 0/C. The partial molar volumes of the alcohols at infinite dilution in the aqueous surfactants solutions were calculated and discussed using a mass-action model for the alcohol distribution between the aqueous and the micellar phase. The partial molar volumes of the alcohols in the aqueous and in the micellar phases, and the ratios between the binding constant and the aggregation number, were calculated. The partial molar volume for all the alcohols in micellar phase is 10 cm/sup 3/-mol/sup -1/ smaller than that in octane. This can be related to the strong hydrophilic interaction between the head groups of the alcohol and the micellized surfactant. From the extrapolated values of the distribution constant and the partial molar volumes in the aqueous and micellar phases, the standard partial molar volume of heptanol in micellar solutions was found to decrease with increasing surfactant concentration. The standard free energy of transfer of alcohols from water to micelles was rationalized in terms of hydrophilic and hydrophobic contributions. A model is proposed in which the empty space around each solute is assumed to be the same in the gas and liquid phases, and is used to explain the behavior of micelles in the presence of amphiphilic solutes.

• Research Organization: Universit di Palermo, Italy
• OSTI ID: 6762507
• Journal Information: J. Solution Chem.; (United States), Journal Name: J. Solution Chem.; (United States) Vol. 15:8; ISSN JSLCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALCOHOLS
ALKALI METAL COMPOUNDS
APPARENT MOLAL VOLUME
BINDING ENERGY
BUTANOLS
DENSITY
DISPLACEMENT FLUIDS
ENERGY
ETHANOL
FLUIDS
FREE ENERGY
HEXANOLS
HYDROXY COMPOUNDS
MATHEMATICAL MODELS
METHANOL
MICELLAR SYSTEMS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
PARTIAL MOLAL VOLUME
PENTANOLS
PHYSICAL PROPERTIES
PROPANOLS
SODIUM COMPOUNDS
SODIUM SULFATES
SOLUBILITY
SULFATES
SULFUR COMPOUNDS
SURFACTANTS
THERMODYNAMIC PROPERTIES