Publications associées à Électro-osmose

Contrasting Views of the Electric Double Layer in Electrochemical CO2 Reduction: Continuum Models vs Molecular Dynamics

In the field of electrochemical CO2 reduction, both continuum models and molecular dynamics (MD) models have been used to understand the electric double layer (EDL). MD often focuses on the region within a few nm of the electrode, while continuum models ca ...

Amer Chemical Soc2024

Pathways to enhance electrochemical CO2 reduction identified through direct pore-level modeling

Sophia Haussener, Etienne Boutin, Shuo Liu, Evan Fair Johnson

Electrochemical conversion of CO2 to fuels and valuable products is one pathway to reduce CO2 emissions. Electrolyzers using gas diffusion electrodes (GDEs) show much higher current densities than aqueous phase electrolyzers, yet models for multi-physical ...

2023

Surface Charge Boundary Condition Often Misused in CO2 Reduction Models

Sophia Haussener, Etienne Boutin, Evan Fair Johnson

The Poisson-Nernst-Planck equations have been used to model species transport in electrochemical CO2 reduction, where the surface charge boundary condition accounts for the potential drop across the Stern layer. A direct comparison of the published models ...

AMER CHEMICAL SOC2023

Electrokinetic, electrochemical, and electrostatic surface potentials of the pristine water liquid-vapor interface

Philip Robin Loche

Although conceptually simple, the air-water interface displays rich behavior and is subject to intense experimental and theoretical investigations. Different definitions of the electrostatic surface potential as well as different calculation methods, each ...

AIP Publishing2022

Electrosorption at metal surfaces from first principles

Nicola Marzari

Electrosorption of solvated species at metal electrodes is a most fundamental class of processes in interfacial electrochemistry. Here, we use its sensitive dependence on the electric double layer to assess the performance of ab initio thermodynamics appro ...

NATURE PUBLISHING GROUP2020

Discrete Helmholtz model: a single layer of correlated counter-ions. Metal oxides and silica interfaces, ion-exchange and biological membranes

Hubert Girault, Grégoire Clément Gschwend

The mechanism by which interfaces in solution can be polarised depends on the nature of the charge carriers. In the case of a conductor, the charge carriers are electrons and the polarisation is homogeneous in the plane of the electrode. In the case of an ...

2020

Regulating the anomalous Hall and Nernst effects in Heusler-based trilayers

Jean-Philippe Ansermet, Haiming Yu, Simon Granville, Sa Tu, Junfeng Hu, Song Liu

Anomalous Hall and anomalous Nernst properties of thin MgO/Co-2Fe0.4Mn0.6Si/Pd stacks with perpendicular magnetic anisotropy (PMA) revealed the presence of the magnetic proximity effect (MPE) in the Pd layer. The MPE is evidenced by nanometer range thickne ...

2020

Orthogonal Tip-to-Tip Nanocapillary Alignment Allows for Easy Detection of Fluorescent Emitters in Femtomolar Concentrations

Aleksandra Radenovic, Michael Graf, Po-Ling Chang

Here we present the realization of a novel fluorescence detection method based on the electromigration of fluorescent molecules within a nanocapillary combined with the laser excitation through a platinum (Pt)-coated nanocapillary. By using the Pt nanocapi ...

American Chemical Society (ACS)2018

Variation of the Fermi level and the Electrostatic Force of a Metallic Nanoparticle upon Colliding with an Electrode

Hubert Girault, Pekka Eero Peljo

When a metallic nanoparticle (NP) comes in close contact with an electrode, its Fermi level equilibrates with that of the electrode if their separation is less than the cut-off distance for electron tunnelling. In the absence of chemical reactions in solut ...

Royal Soc Chemistry2017

An Ohmic model for electrokinetic flows of binary asymmetric electrolytes

Alexandre Louis André Persat

The transport of electrolytes in electric fields is a ubiquitous phenomenon commonly harnessed in microfluidics. A classic leaky dielectric model for flow generated by electric fields accurately predicts electrohydrodynamic transport phenomenon but is vali ...

Elsevier Science London2016

Contact potentials, Fermi level equilibration and surface charging

Hubert Girault, Pekka Eero Peljo

This paper focuses on contact electrification from thermodynamic equilibration of the electron electrochemical potentials of two conductors upon contact. The contact potential difference generated in bimetallic macro- and nanosystems, the Fermi level after ...

American Chemical Society2016

Single-layer MoS2 nanopores as nanopower generators

Aleksandra Radenovic, Andras Kis, Dumitru Dumcenco, Michael Graf, Ke Liu, Dmitry Ovchinnikov, Jiandong Feng

Making use of the osmotic pressure difference between fresh water and seawater is an attractive, renewable and clean way to generate power and is known as 'blue energy'(1-3). Another electrokinetic phenomenon, called the streaming potential, occurs when an ...

Nature Publishing Group2016

Macroscopic indicators of fault diagnosis and ageing in electrochemical double layer capacitors

Hubert Girault, Mario Paolone, Véronique Amstutz, Dimitri Torregrossa, Kathryn Ellen Toghill

The ageing behaviour of electric double layer (EDLC) supercapacitors during over-temperature and over-voltage stresses is described. Specific experimental tests were carried out in order to reproduce, under laboratory controlled conditions, the above-menti ...

2015

A durable SWCNT/PET polymer foil based metal free counter electrode for flexible dye-sensitized solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jean-David Décoppet, Thomas Moehl, Fabrizio Giordano, Aswani Yella, Syed Ghufran Hashmi

An ITO free, highly conductive PET foil is fabricated by depositing aqueous single-walled carbon nanotube (SWCNT) ink that exhibits remarkable durability when exposed to severe mechanical stability tests. Excellent adhesion of the SWCNT film on PET was obt ...

Royal Society of Chemistry2014

Stern Layer Formation Induced by Hydrophobic Interactions: A Molecular Level Study

Sylvie Roke, Yixing Chen, Rüdiger Scheu

The molecular ionic surface structure and charge of the electric double layer around a nanodroplet and its structural change induced by hydrophobic effects are measured using vibrational coherent surface scattering spectroscopy, second harmonic scattering, ...

Amer Chemical Soc2013

Colloidal Stability of Self-Assembled Mono layer-Coated Gold Nanoparticles: The Effects of Surface Compositional and Structural Heterogeneity

Francesco Stellacci, Randy Patrick Carney

Surface heterogeneity plays an important role in controlling colloidal phenomena. This study investigated the self-aggregation and bacterial adsorption of self-assembled monolayer coated gold nanoparticles (AuNPs) with different surface compositional and s ...

American Chemical Society2013

Microfabricated All-Around-Electrode AC Electro-osmotic Micropump

Luca Ribetto

This thesis presents the fabrication and characterisation of AC electro-osmotic micropumps with a simple design and velocity generation enhanced by about four times with respect to devices with simpler designs. Electro-osmosis is a convenient and effective ...

EPFL2012

Bubble cell for magnetic bead trapping in capillary electrophoresis

Hubert Girault, Anne-Laure Gassner

A bubble cell capillary classically used to extend the optical path length for UV-vis detection is employed here to trap magnetic beads. With this system, a large amount of beads can be captured without inducing a strong pressure drop, as it is the case wi ...

Springer Verlag2011

Adaptive finite elements with large aspect ratio for electroosmotic and pressure-driven microflows

Martinus Gijs, Marco Picasso, Virabouth Prachittham

A space–time adaptive method is presented for the numerical simulation of mass transport in electroosmotic and pressure-driven microflows in two space dimensions. The method uses finite elements with large aspect ratio, which allows the electroosmotic flow ...

Wiley-Blackwell2010

Microfluidic Protein Preconcentrator Using a Microchannel-Integrated Nafion Strip: Experiment and Modeling

Martinus Gijs, Venkataragavalu Sivagnanam, Meng Shen

We propose a simple microfluidic device for protein preconcentration based on the electrokinetic trapping principle. It comprises a narrow Nafion strip that is simply cut from a commercial membrane and is integrated into a molded poly(dimethylsiloxane) (PD ...

American Chemical Society2010