Nanoparticle-Induced Charge Redistribution of the Air-Water Interface

• The airwater interface is believed to carry a negative electrostatic potential that is nontrivial to invert through pH, electrolyte, or electrolyte strength. Here, through a combined experimental and theoretical study, we show that the close approach of a negatively charged nanoparticle induces a charge redistribution of the airwater interface. Using different electrolytes to control the interfacial potential of the nanoparticles, X-ray photoelectron spectroscopy (XPS) results establish that nanoparticles with a more negative zeta potential adsorb closer to the airwater interface than do the same particles with a less negative zeta potential. The short-ranged attractive force between two (nominally) negative surfaces is caused by charge redistribution under the strong electric field of the nanoparticle that locally inverts the charge density of the airwater interface from negative to positive. The nature of the nanoparticles counterions modulates the attractive interaction, which thus could be used to control reactivity, stability, and nanoparticle self-assembly at airwater interfaces.

Ämnesord

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Nyckelord

RAY PHOTOELECTRON-SPECTROSCOPY

IN-SITU

SILICA NANOPARTICLES

AQUEOUS-SOLUTIONS

SPATIAL-DISTRIBUTION

AIR/WATER INTERFACE

MOLECULAR-DYNAMICS

SURFACE-TENSION

POTENTIALS

PARTICLES

Chemistry

Physical

Nanoscience & Nanotechnology

Materials Science

Multidisciplinary

ATES OF AMERICA

V109

P18679

Publikations- och innehållstyp

ref (ämneskategori)

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