Adsorption and Dynamics of Sodium Alkylbenzenesulfonates on Alumina
Abstract
Deuterium nuclear magnetic resonance (2H NMR) spectroscopy was used to probe the molecular motion of sodium alkylbenzenesulfonates on γ-alumina in aqueous solutions. Two homologs with a single and a double chain were employed to compare the adsorption characteristics at various coverages. Sodium decylbenzenesulfonate-d4 (SDBS-d4) was chosen as a single-tailed surfactant. Motionally narrowed (single) resonances were observed from this single-chained homolog on the surface and no discrete quadrupolar splitting was found in any of the concentration ranges investigated. The spectra indicated relatively restricted molecular motion at low coverages, but relatively free motion as the adsorption amounts increased. A double-tailed homolog, sodium 4-(1′-heptylnonyl)benzenesulfonate-d4 (SHBS-d4), also showed a single resonance at low coverage on alumina. However, at full coverage, a discrete powder pattern overlapped a single resonance, indicating the formation of a liquid crystal-like molecular environment at the alumina/water interface. In this report, we summarize our recent investigations of the dynamics of the surface-adsorbed surfactants and discuss the differences in the adsorption behavior of the single- and double-chained homologs.
Recommended Citation
K. Nagashima and F. D. Blum, "Adsorption and Dynamics of Sodium Alkylbenzenesulfonates on Alumina," Colloids and Surfaces A, Elsevier, Jan 2001.
The definitive version is available at https://doi.org/10.1016/S0927-7757(00)00611-7
Department(s)
Chemistry
Sponsor(s)
National Science Foundation (U.S.)
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2001 Elsevier, All rights reserved.
Publication Date
01 Jan 2001
