Basic Information

Abstract Number: 580 - 5
Author Name: Jeanne E Pemberton - University of Arizona
Session Title: SEAC - Charles N Reilley and Young Investigators Awards
Event Type: Awards
Event Title: A New Take on an Old Concept: Electrochemical Interface Studies by the Technique ‘Formerly Known As’ Emersion

Presider Name:Henry WhiteCo-Author:Anoma Mudalige
Affiliation:University of UtahAffiliation:University of Arizona

Date: Monday, March 18, 2013
Start Time: 03:20 PM (Slot #5)
Location: 114

Abstract Content

Emersion was a technique originally implemented by Hansen [1] for study of the electrochemical interface. In this approach, the electrode is carefully withdrawn from the solution, presumably leaving the electrochemical double layer from the outer Helmholtz plane inward, attached to the electrode surface. Once removed, Hansen demonstrated that this interface could then be probed using different techniques without undue influence from the bulk solution. Although Hansen’s work eventually demonstrated that the ionic portion of the interface was removed intact, questions about if and how much solvent was removed was debated in the literature over many years, although never successfully resolved. Recent work in the authors’ laboratory provides a resolution to this debate. Experimental efforts to rationalize the observed thickness and composition of emersed interfaces have now demonstrated that forces other than those considered by Hansen are operative in controlling the portion of fluid that is removed during emersion (now renamed ‘forced dewetting’ to more closely describe the process of creation of these layers.) This presentation will discuss these forces in the framework of DLVO theory that is used to quantitatively rationalize all experimental observations on emersed layers. Examples will be provided that further define the chemical information that can be gleaned about interfacial structure using a variety of spectroscopic approaches including ellipsometry, XPS, Raman spectroscopy and IRRAS.

[1] Hansen, W.N.; Wang, C.L.; Humphreys, T.S., J. Electroanal. Chem. 1978, 90, 137-141.