title: Surfactant self-assembly in the gas phase: bis(2-ethylhexyl)sulfosuccinate-alkaline metal ion aggregates.
abstract: The coating effect of alkali metal salt clusters by the surfactant anion bis(2-ethylhexyl)sulfosuccinate has been investigated by electrospray ionization mass spectrometry (MS) and MS/MS. The analysis of the data emphasized the formation and stability in the gas phase of reverse micelle-like surfactant aggregates carrying in their interior ionic clusters. Two main contributions have been postulated to account for the observed stability: intra-aggregate electrostatic interactions and screening of inter-aggregate attractive interactions due to the exclusion volume effect caused by the surfactant alkyl chains. Moreover, the stability and structural arrangement of these supramolecular aggregates result in strong dependency on the alkali metal salt identity.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Siena, Via Aldo Moro, I-53100 Siena, Italy. gianluca.giorgi@unisi.it
authors.forename: Gianluca
authors.initials: G
authors.lastname: Giorgi
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Ceraulo
authors.forename: Vincenzo Turco
authors.initials: VT
authors.lastname: Liveri
mesh_terms: D005740:Gases / Q000737:chemistry; D008094:Lithium / Q000737:chemistry; D013058:Mass Spectrometry; D008670:Metals / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013386:Succinates / Q000737:chemistry*; D013501:Surface-Active Agents
chemical_list: D005740:Gases; D008670:Metals; D012996:Solutions; D013386:Succinates; D013501:Surface-Active Agents; C511925:bis(2-ethylhexyl)sulfosuccinate; D008094:Lithium; D012964:Sodium