caa a22 4500 477139043 CHVBK 20180405111727.0 cr unu---uuuuu 170330e19970901xx s 000 0 eng 10.1007/BF02768264 doi (NATIONALLICENCE)springer-10.1007/BF02768264 Thermodynamics of N , N , N -octylpentyldimethyl-ammonium chloride in water-urea mixtures [Elektronische Daten] [R. De Lisi, B. Marongiu, S. Milioto, B. Pittau, S. Porcedda] Specific conductivities, densities, heat capacities, and enthalpies of dilution at 25‡C were measured forN,N,N-octylpentyldimethylammonium chloride (OPAC) in water-urea mixtures at various urea concentrations mu as functions of the surfactant concentration ms. From conductivity data, the cmc and the degree of the counterion dissociation Β of the OPAC micelles were calculated. The cmc increases linearly with increasingm u while Βvs. mu is a smooth concave curve. From the experimental thermodynamic data, the apparentY Φ and partialY 2 molar properties (volumes, heat capacities, and relative enthalpies) are derived as functions of mu andm s . The effect of urea on the dependences of the different properties on ms are discussed. From data in the premicellar region the standard partial molar volumesV 2 0 and heat capacitiesC p2 0 were evaluated. It was observed thatV 2 0 increases linearly withm u whileC p2 0 decreases. The properties of OPAC in the dispersed and micellized forms at the cmc were obtained and, therefore, the thermodynamic functions of micellization were calculated on the basis of the pseudo-phase transition model. Plenum Publishing Corporation, 1997 N,N,N-octylpentyldimethylammonium chloride nationallicence urea nationallicence conductivities nationallicence densities nationallicence heat capacities nationallicence enthalpies of dilution nationallicence partial molar volumes nationallicence partial molar heat capacities nationallicence partial molar relative enthalpies nationallicence critical micelles concentrations nationallicence degrees of counterion dissociation nationallicence thermodynamics of micellization nationallicence De Lisi R. Dipartimento di Chimica Fisica, Universitá di Palermo, via Archirafi 26, 90123, Palermo, Italy aut Marongiu B. Dipartimento di Scienze Chimiche, Universitá di Cagliari, via Ospedale 72, 09124, Cagliari, Italy aut Milioto S. Dipartimento di Chimica Fisica, Universitá di Palermo, via Archirafi 26, 90123, Palermo, Italy aut Pittau B. Dipartimento di Scienze Chimiche, Universitá di Cagliari, via Ospedale 72, 09124, Cagliari, Italy aut Porcedda S. Dipartimento di Scienze Chimiche, Universitá di Cagliari, via Ospedale 72, 09124, Cagliari, Italy aut Journal of Solution Chemistry Springer US 26/9(1997-09-01), 889-911 0095-9782 26:9<889 1997 26 10953 https://doi.org/10.1007/BF02768264 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02768264 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- De Lisi R. Dipartimento di Chimica Fisica, Universitá di Palermo, via Archirafi 26, 90123, Palermo, Italy aut NATIONALLICENCE 700 1- Marongiu B. Dipartimento di Scienze Chimiche, Universitá di Cagliari, via Ospedale 72, 09124, Cagliari, Italy aut NATIONALLICENCE 700 1- Milioto S. Dipartimento di Chimica Fisica, Universitá di Palermo, via Archirafi 26, 90123, Palermo, Italy aut NATIONALLICENCE 700 1- Pittau B. Dipartimento di Scienze Chimiche, Universitá di Cagliari, via Ospedale 72, 09124, Cagliari, Italy aut NATIONALLICENCE 700 1- Porcedda S. Dipartimento di Scienze Chimiche, Universitá di Cagliari, via Ospedale 72, 09124, Cagliari, Italy aut NATIONALLICENCE 773 0- Journal of Solution Chemistry Springer US 26/9(1997-09-01), 889-911 0095-9782 26:9<889 1997 26 10953 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer