Forces between carboxylic acid surfaces in divalent electrolyte solutions
2000 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 229, no 1, 123-128 p.Article in journal (Refereed) Published
The behavior of self-assembled monolayers of thiohexadecanoic acid adsorbed onto gold interacting in asymmetric 2:1 electrolytes has been studied with direct force measurements. The effects of two divalent cations (Mg2+ and Ca2+) were studied at concentrations ranging from 1 mu M to 10 mM. As compared to interactions in the presence of Na+, the divalent ions adsorb strongly to the surfaces, with the effect of lowering the surface potential and decreasing the double-layer repulsion. At concentrations above 10 mu M, the Ca2+ ions were found to adsorb stronger than Mg2+. Ca2+ ions cause charge reversal at high concentrations, and the net interactions at 10 mM were attractive over the measurable range.
Place, publisher, year, edition, pages
2000. Vol. 229, no 1, 123-128 p.
self-assembled monolayers, surface forces, divalent ions, ion adsorption, charge reversal, carboxylic acids, colloidal stability, self-assembled monolayers, salt-solutions, mica surfaces, films, gold, phosphatidylcholine, microscopy, systems, model
IdentifiersURN: urn:nbn:se:kth:diva-19987ISI: 000088930300014OAI: oai:DiVA.org:kth-19987DiVA: diva2:338680
QC 201005252010-08-102010-08-10Bibliographically approved