Naslov
Thermodynamic Properties of Aqueous Solutions of Perfluorinated Ionic Surfactants

Autori
Tomašić, Vlasta ; Chittofrati, Alba ; Kallay Nikola

Izvornik
Colloids Surfaces A (0927-7765) 104 (1995); 95-99

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Enthalpy; heat capacity change; perfluorinated surfactants; perfluoropolyether surfactants; solubility

Sažetak
The enthalpies of dissolution of perfluorooctanoic acid, a perfluoropolyether carboxylic acid and their sodium salts were measured as a function of temperature. The heat capacity changes (Δ Cp) were obtained from the slope of enthalpy vs. temperature plot. The values of Δ Cp for perfluorooctanoic acid and its sodium salt are higher than those of the corresponding hydrogenated compounds and are accompanied by lower critical micellization concentrations. The finding is explained on the basis of the higher hydrophobicity of perfluorinated compounds. Perfluoropolyether carboxylic acid and its sodium salt showed relatively lower Δ Cp values which may be due to the branching or the presence of oxygen in the chain. Measurements of the heat capacity change serve also for the explanation of the temperature dependency of the solubility of surfactants.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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