Imperial College London
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Professor Fernando Bresme

Faculty of Natural Sciences, Department of Chemistry

Professor of Chemical Physics
 
 
 
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Contact

 

+44 (0)20 7594 5886f.bresme Website

 
 
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Assistant

 

Miss Ravinder Dhaliwal +44 (0)20 7594 5717

 
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Location

 

207CMolecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Bresme:2018:10.1039/c8cp04924f,
author = {Bresme, F and Robotham, O and Chio, W-IK and Gonzalez, MA and Kornyshev, A},
doi = {10.1039/c8cp04924f},
journal = {Physical Chemistry Chemical Physics},
pages = {27684--27693},
title = {Debye screening, overscreening and specific adsorption in solutions of organic ions},
url = {http://dx.doi.org/10.1039/c8cp04924f},
volume = {20},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Tetrabutylammonium (TBA) and tetraphenylborate (TPB) ions dissolved in dichloroethane (DCE) are widely used in electrochemistry of liquid–liquid interfaces. Unlike alkali halide solutions in water, TBA–TPB–DCE solutions feature large organic ions and a solvent with a dielectric constant almost one order of magnitude lower than that of water. This is expected to dramatically amplify the impact of ionic correlations in the properties of the solution. Here we report atomistic simulations of TBA–TPB–DCE solutions and analyze ion correlations, clustering, and charge screening effects. We target concentrations in the range of 0.01–0.25 molal (m), hence exploring concentration regimes typical for many experimental investigations. We show that the transition from monotonic to oscillatory decay of the charge density, which signals the onset of strong ion correlations, takes place in this concentration interval, leading to overscreening effects. Furthermore, we investigate the distribution and adsorption of ions at the DCE–air interface. Unlike what is observed for small inorganic ions in water at similar concentrations, we find that TPB and TBA ions accumulate near the DCE surface, resulting in significant interfacial clustering and adsorption at concentrations ∼0.25 m. TPB ions adsorb more strongly leading to free energy wells of ∼1–2 kBT. The adsorption modifies significantly the electrostatic potential of the DCE–air interface, which undergoes a shift of 0.2 V in going from pure DCE to TBA–TPB–DCE solutions at 0.25 m.
AU  - Bresme,F
AU  - Robotham,O
AU  - Chio,W-IK
AU  - Gonzalez,MA
AU  - Kornyshev,A
DO  - 10.1039/c8cp04924f
EP  - 27693
PY  - 2018///
SN  - 1463-9076
SP  - 27684
TI  - Debye screening, overscreening and specific adsorption in solutions of organic ions
T2  - Physical Chemistry Chemical Physics
UR  - http://dx.doi.org/10.1039/c8cp04924f
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000449499100042&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/65623
VL  - 20
ER  -
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