Effect of Electrolyte Concentration on the Stern Layer Thickness at a Charged Interface. Issue 11 (16th February 2016)

• Record Type: Journal Article
• Authors: Brown, Matthew A.; Goel, Alok; Abbas, Zareen
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 11(2016)
• Page Start: 3790
• Page End: 3794
• Publication Date: 2016-02-16
• Subjects: electrical double layer -- liquid microjets -- potential drop -- solid–liquid interface -- Stern layer capacitance; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201512025
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The chemistry and physics of charged interfaces is regulated by the structure of the electrical double layer (EDL). Herein we quantify the average thickness of the Stern layer at the silica (SiO2 ) nanoparticle/aqueous electrolyte interface as a function of NaCl concentration following direct measurement of the nanoparticles' surface potential by X‐ray photoelectron spectroscopy (XPS). We find the Stern layer compresses (becomes thinner) as the electrolyte concentration is increased. This finding provides a simple and intuitive picture of the EDL that explains the concurrent increase in surface charge density, but decrease in surface and zeta potentials, as the electrolyte concentration is increased. Abstract : The electrical double layer (EDL) is presented in a simple and intuitive picture that explains the concurrent increase in surface charge density, but decrease in surface and zeta potentials, as electrolyte concentration is increased.