Testing the Gouy-Chapman theory by means of surface tension measurements for SDS-NaCl-H2O mixtures
2003 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 267, no 1, 151-154 p.Article in journal (Refereed) Published
Surface tension isotherms were measured for sodium dodecyl sulfate (SDS) at different concentrations of added salt (NaCl). The free energy of the surfactant monolayer was assessed by invoking the Gouy-Chapman theory for the charged head groups, the hydrophobic (Tanford) free energy of transfer of the hydrocarbon chain, and the hydrocarbon chain configurational free energy according to Gruen's calculations and finally macroscopic contact terms. In particular, the effect of an increased salt concentration in bulk was examined. Theoretical predictions compare well with the experimental findings, and good agreement was found with respect to both the variation of free energy of the monolayer and the surface pressure behavior. Thus, at least for a liquid-expanded monolayer of SDS, the Gouy-Chapman model yields a satisfactory account of the electrostatic contribution to the thermodynamic properties at different salt concentrations of NaCl.
Place, publisher, year, edition, pages
2003. Vol. 267, no 1, 151-154 p.
surface tension, surface pressured, ionic surfactant, SDS, Gouy-Chapman, air-water-interface, monolayers
IdentifiersURN: urn:nbn:se:kth:diva-22891DOI: 10.1016/s0021-9797(03)00761-6ISI: 000185991800020OAI: oai:DiVA.org:kth-22891DiVA: diva2:341589
QC 201005252010-08-102010-08-10Bibliographically approved