Different Adsorption Behavior of Rare Earth and Metallic Ion Complexes on Langmuir Mono layers Probed by Sum-Frequency Generation Spectroscopy

TitleDifferent Adsorption Behavior of Rare Earth and Metallic Ion Complexes on Langmuir Mono layers Probed by Sum-Frequency Generation Spectroscopy
Publication TypeJournal Article
Year of Publication2013
AuthorsSung W, Vaknin D, Kim D
Journal TitleJournal of the Optical Society of Korea
Volume17
Pages10-15
Date Published02
Type of ArticleArticle
ISBN Number1226-4776
Accession NumberWOS:000315837000003
KeywordsINTERFACES, Interfacial structure, langmuir monolayer, MOLECULAR-ORIENTATION, monolayers, Nonlinear optical, phase-transitions, polarization, spectroscopy, VIBRATIONAL SPECTROSCOPY, water-molecules
Abstract

Adsorption behavior of counterions under a Langmuir monolayer was investigated by sum-frequency generation (SFG) spectroscopy. By comparing SFG spectra of arachidic acid (AA) Langmuir monolayer/water interface with and without added salt, it was found that the simple trivalent cation La3+ adsorbed on AA monolayer only when the carboxylic headgroups are charged (deprotonated), implying that counterion adsorption is induced by Coulomb interaction. On the other hand, metal hydroxide complex Fe(OH)(3) adsorbed even on a charge-neutral AA monolayer, indicating that the adsorption of iron hydroxide is due to chemical interaction such as covalent or hydrogen bonding to the headgroup of the molecules at the monolayer.

URL<Go to ISI>://WOS:000315837000003
DOI10.3807/josk.2013.17.1.010