Thermodynamics of micellization of C 7 and C 8 lecithins
2002; Taylor & Francis; Volume: 100; Issue: 10 Linguagem: Inglês
10.1080/00268970210127942
ISSN1362-3028
AutoresPablo Martı́nez-Landeira, Lina Besada, Laura Seoane, Juan M. Ruso, Gerardo Prieto, Félix Sarmiento,
Tópico(s)Thermodynamic properties of mixtures
ResumoThe surface tensions of the lecithins diheptanoyl- and dioctanoylphosphatidylcholine in phosphate medium, pH 7.4, have been measured over the temperature range 288.15–313.15K. Critical micelle concentrations, thermodynamic micellization parameters, adsorption parameters, transfer data of micelles to the aqueous surface and surface area minima per molecule were obtained from these measurements. Critical micelle concentrations slightly decrease with temperature. The micellization processes became increasingly exothermic with increase in temperature. The variation of Gibbs energies of transfer indicates that the processes are most favourable at low temperatures. From a study of entropy-enthalpy compensation phenomenon a compensation temperature of 300−1 K−1 was found, and from the intercept an analysis of the hydrophobic-hydrophilic balance was carried out.
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