Direct Observation of Confinement-Induced Charge Inversion at a Metal Surface
| Autor: | Jacob Klein, Gilad Silbert, Ran Tivony, Dan Ben Yaakov |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Aqueous solution
Surface Properties Chemistry Static Electricity Surface force Charge (physics) Surfaces and Interfaces Electrostatic induction Condensed Matter Physics Colloid symbols.namesake Metals Computational chemistry Chemical physics Static electricity Electrochemistry symbols General Materials Science Surface charge van der Waals force Spectroscopy |
| Zdroj: | Langmuir. 31:12845-12849 |
| ISSN: | 1520-5827 0743-7463 |
| Popis: | Surface interactions across water are central to areas from nanomedicine to colloidal stability. They are predominantly a combination of attractive but short-ranged dispersive (van der Waals) forces, and long-ranged electrostatic forces between the charged surfaces. Here we show, using a surface force balance, that electrostatic forces between two surfaces across water, one at constant charge while the other (a molecularly smooth metal surface) is at constant potential of the same sign, may revert smoothly from repulsion to attraction on progressive confinement of the aqueous intersurface gap. This remarkable effect, long predicted theoretically in the classic Gouy-Chapman (Poisson-Boltzmann) model but never previously experimentally observed, unambiguously demonstrates surface charge reversal at the metal-water surface. This experimental confirmation emphasizes the implications for interactions of dielectrics with metal surfaces in aqueous media. |
| Databáze: | OpenAIRE |
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