Observation of Electrostatically Driven Surface Adsorption in Mixed Surfactant Systems.

ABSTRACT: We employed heterodyne-detected vibrational sum-frequency generation (HD-VSFG) spectroscopy to obtain a molecular-level understanding of the interaction between the anionic surfactant sodium dodecyl ammonium sulfate (SDS) and the cationic surfactant dodecyltrimethylammonium bromide (DTAB). We observed that these surfactants show a strong cooperative effect on their adsorption to the water-air interface. Even at bulk concentrations 1000 times lower than the critical micelle concentrations of SDS and DTAB, a nearly complete surface surfactant layer is observed when both surfactants are present. This strong enhancement of the surface concentrations of DS^- and DTA⁺ can be quantitatively explained from the favorable Coulomb interaction of the oppositely charged headgroups

SUBMITTER: Vilangottunjalil A 

PROVIDER: S-EPMC10875667 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature