Direct Observation of Ion Pairing at the Liquid/Solid Interfaces by Surface Enhanced Raman Spectroscopy

Ion-pairing, the association of oppositely charged ionic species in solution and at liquid/solid interfaces has been proposed as a key factor for a wide range of physicochemical phenomena. However, experimental observations of ion pairing at the ligand/solid interfaces are challenging due to difficu...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 31(2015), 33 vom: 25. Aug., Seite 8998-9005
1. Verfasser: Perera, Ganganath S (VerfasserIn)
Weitere Verfasser: Nettles, Charles B 2nd, Zhou, Yadong, Zou, Shengli, Hollis, T Keith, Zhang, Dongmao
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2015
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, U.S. Gov't, Non-P.H.S. Electrolytes Gold 7440-57-5
Beschreibung
Zusammenfassung:Ion-pairing, the association of oppositely charged ionic species in solution and at liquid/solid interfaces has been proposed as a key factor for a wide range of physicochemical phenomena. However, experimental observations of ion pairing at the ligand/solid interfaces are challenging due to difficulties in differentiating ion species in the electrical double layer from that adsorbed on the solid surfaces. Using surface enhanced Raman spectroscopy in combination with electrolyte washing, we presented herein the first direct experimental evidence of ion pairing, the coadsorption of oppositely charged ionic species onto gold nanoparticles (AuNPs). Ion pairing reduces the electrolyte concentration threshold in inducing AuNP aggregation and enhances the competitiveness of electrolyte over neutral molecules for binding to AuNP surfaces. The methodology and insights provided in this work should be important for understanding electrolyte interfacial interactions with nanoparticles
Beschreibung:Date Completed 23.05.2016
Date Revised 25.08.2015
published: Print-Electronic
Citation Status MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.5b01903