TY - JOUR
T1 - Surfactant self-assembling in gas phase: electrospray ionization- and matrix-assisted laser desorption/ionization-mass spectrometry of singly charged AOT clusters
AU - Turco Liveri, Vincenzo
AU - Ceraulo, Leopoldo
AU - Ruggirello, Angela Monia
AU - Bongiorno, David
AU - Basso, null
AU - Seraglia, null
AU - Traldi, null
PY - 2005
Y1 - 2005
N2 - The self-assembling of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) in gas phase has been investigated by electrospray ionization- and matrix-assisted laser desorption/ionization mass spectrometry. Large surfactant clusters with an aggregation number close to that found in apolar media have been observed either as positive or negative ions. Moreover, the marked predominance of singly charged species as well as preliminary theoretical calculations strongly suggest an aggregate structure characterized by an internal hydrophilic core hosting the extra charge surrounded by an apolar shell constituted by the surfactant alkyl chains. This structure is similar to that of the more familiar reversed micelles formed when an appropriate surfactant is solubilized in apolar solvents. Finally, similar trends are observed independently either on the ionization technique or the polarity of the solvent used. This, together with the large dependence of the aggregation number on the flow rates, strongly indicates that self-assembling of the surfactant molecules occurs during the evaporation step
AB - The self-assembling of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) in gas phase has been investigated by electrospray ionization- and matrix-assisted laser desorption/ionization mass spectrometry. Large surfactant clusters with an aggregation number close to that found in apolar media have been observed either as positive or negative ions. Moreover, the marked predominance of singly charged species as well as preliminary theoretical calculations strongly suggest an aggregate structure characterized by an internal hydrophilic core hosting the extra charge surrounded by an apolar shell constituted by the surfactant alkyl chains. This structure is similar to that of the more familiar reversed micelles formed when an appropriate surfactant is solubilized in apolar solvents. Finally, similar trends are observed independently either on the ionization technique or the polarity of the solvent used. This, together with the large dependence of the aggregation number on the flow rates, strongly indicates that self-assembling of the surfactant molecules occurs during the evaporation step
KW - ESI-MS and ESI-MS/MS
KW - MALDI-MS
KW - gas-phase self-assembly
KW - surfactants
KW - ESI-MS and ESI-MS/MS
KW - MALDI-MS
KW - gas-phase self-assembly
KW - surfactants
UR - http://hdl.handle.net/10447/13116
M3 - Article
VL - 40
SP - 1618
EP - 1625
JO - Journal of Mass Spectrometry
JF - Journal of Mass Spectrometry
SN - 1076-5174
ER -