title: Thermodynamics of micellization of tetraethylammonium perfluorooctylsulfonate in water.
abstract: Conductivity, density, and sound velocity measurements as functions of temperature were made on tetraethylammonium perfluorooctylsulfonate solutions to determine the Krafft point, the dependence on temperature of the critical micelle concentration, the micellar ionization degree, and several thermodynamic properties: Gibbs free energy, enthalpy and entropy of micellization, apparent molar partial volume, thermal expansion coefficient, and the adiabatic compressibility factor of both micellized and unmicellized surfactants. Important changes occur at about 30 degrees C. Results are interpreted on the basis of dehydration of surfactant on micellization and on temperature increase.
authors.affiliation: Grupo de Biofísica e Interfases, Departamento de Física Aplicada, Facultade de Física, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: José L
authors.initials: JL
authors.lastname: López-Fontán
authors.forename: Alfredo
authors.initials: A
authors.lastname: González-Pérez
authors.forename: Julian
authors.initials: J
authors.lastname: Costa
authors.forename: Juan M
authors.initials: JM
authors.lastname: Ruso
authors.forename: Gerardo
authors.initials: G
authors.lastname: Prieto
authors.forename: Pablo C
authors.initials: PC
authors.lastname: Schulz
authors.forename: Félix
authors.initials: F
authors.lastname: Sarmiento
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry*; D005466:Fluorocarbons / Q000737:chemistry*; D008823:Micelles; D013451:Sulfonic Acids / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D013757:Tetraethylammonium Compounds / Q000737:chemistry*; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D017738:Alkanesulfonic Acids; D005466:Fluorocarbons; D008823:Micelles; D013451:Sulfonic Acids; D013501:Surface-Active Agents; D013757:Tetraethylammonium Compounds; D014867:Water; C076994:perfluorooctane sulfonic acid