Abstract
Sodium p-n-dodecylbenzenesulfonate solutions have been studied by means of small angle neutron scattering measurements at 65°C as a function of the surfactant concentration, as a function of the contrast of the solvent, and as a function of the concentration of added electrolyte. In addition micelles of the isomeric branched chain surfactant sodium p-1-(pentylheptyl)benzenesulfonate have been studied at the same temperature as a function of the contrast of the solvent and as a function of the concentration of added electrolyte to compare the structure and the micellar growth of the two surfactants. Good fits to the experimental results have been obtained by calculating the structure factor by means of the mean spherical approximation using a screened coulombic potential plus hard-core repulsions. Several different models have been used to calculate the particle form factor. For some of the models, the measured geometry and the charge of the aggregates are, within the experimental uncertainties, independent of the contrast between the micelles and the solvent. The thickness of the shell which surrounds the hydrocarbon core implies a rough micellar surface for both surfactants; thus we propose that the planar phenyl group functions as a sort of supplementary head group, leading to a thicker polar shell.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
