Details

Autor(en) / Beteiligte

• Rodrı́guez, Julio R.
• González-Pérez, Alfredo
• Del Castillo, José L.
• Czapkiewicz, Jan

Titel

Thermodynamics of Micellization of Alkyldimethylbenzylammonium Chlorides in Aqueous Solutions

Ist Teil von

• Journal of colloid and interface science, 2002-06, Vol.250 (2), p.438-443

Ort / Verlag

San Diego, CA: Elsevier Inc

Erscheinungsjahr

2002

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Specific conductivities of alkyldimethylbenzylammonium chlorides (alkyl=decyl-, dodecyl-, tetradecyl-, and hexadecyl-) in aqueous solutions were measured as a function of molality and temperature. Critical micelle molalities (cmc) and degrees of ionization of the micelles, β, were estimated from the dependence of the specific conductivity on molality. It was found that temperature dependence of cmc is U-shaped with a minimum shifting toward higher temperatures with a decrease in the chain length of the alkyl group. The temperature dependence of ln xcmc (where xcmc is the cmc in mole fraction units) was fitted to the equation of Muller, which we modified by taking into account the temperature dependencies both of β and of change in heat capacity upon micellization. From the fitting parameters, Gibbs free energies, enthalpies, and entropies of micellization as a function of temperature were estimated.