scholarly journals Electric double layer for spherical particles in salt-free concentrated suspensions including ion size effects

2011 ◽  
Vol 13 (9) ◽  
pp. 3960 ◽  
Author(s):  
Rafael Roa ◽  
Félix Carrique ◽  
Emilio Ruiz-Reina
Keyword(s):  
Double Layer ◽  
Size Effects ◽  
Electric Double Layer ◽  
Spherical Particles ◽  
Concentrated Suspensions ◽  
Ion Size

scholarly journals An electric double layer of colloidal particles in salt-free concentrated suspensions including non-uniform size effects and orientational ordering of water dipoles

2016 ◽  
Vol 18 (1) ◽  
pp. 234-243 ◽  
Author(s):  
Jun-Sik Sin ◽  
Hak-Chol Pak ◽  
Kwang-Il Kim ◽  
Kuk-Chol Ri ◽  
Dok-Yong Ju ◽  
...  
Keyword(s):  
Double Layer ◽  
Electric Potential ◽  
Size Effects ◽  
Relative Permittivity ◽  
Electric Double Layer ◽  
Colloidal Particles ◽  
Concentrated Suspensions ◽  
Uniform Size ◽  
Orientational Ordering

Non-uniform size effects and orientational ordering of water dipoles influence the relative permittivity and electric potential in suspension.

A theoretical consideration of ion size effects on the electric double layer and voltammetry of nanometer-sized disk electrodes

2016 ◽  
Vol 193 ◽  
pp. 251-263 ◽  
Author(s):  
Yu Gao ◽  
Yuwen Liu ◽  
Shengli Chen
Keyword(s):  
Size Effect ◽  
Double Layer ◽  
Electric Double Layer ◽  
Finite Size ◽  
Finite Size Effect ◽  
The Poisson Equation ◽  
Electrochemical Interface ◽  
Disk Electrodes ◽  
Ion Size ◽  
Electrochemical Interfaces

Considering that an electric-double-layer (EDL) structure may significantly impact on the mass transport and charge transfer kinetics at the interfaces of nanometer-sized electrodes, while EDL structures could be altered by the finite sizes of electrolyte and redox ions, the possible effects of ion sizes on EDL structures and voltammetric responses of nanometer-sized disk (nanodisk) electrodes are investigated. Modified Boltzmann and Nernst–Planck (NP) equations, which include the influence of the finite ion volumes, are combined with the Poisson equation and modified Butler–Volmer equation to gain knowledge on how the finite sizes of ions and the nanometer sizes of electrodes may couple with each other to affect the structures and reactivities of a nanoscale electrochemical interface. Two typical ion radii, 0.38 nm and 0.68 nm, which could represent the sizes of the commonly used aqueous electrolyte ions (e.g., the solvated K+) and the organic electrolyte ions (e.g., the solvated TEA+) respectively, are considered. The finite size of ions can result in decreased screening of electrode charges, therefore magnifying EDL effects on the ion transport and the electron transfer at electrochemical interfaces. This finite size effect of ions becomes more pronounced for larger ions and at smaller electrodes as the electrode radii is larger than 10 nm. For electrodes with radii smaller than 10 nm, however, the ion size effect may be less pronounced with decreasing the electrode size. This can be explained in terms of the increased edge effect of disk electrodes at nanometer scales, which could relax the ion crowding at/near the outer Helmholtz plane. The conditions and situations under which the ion sizes may have a significant effect on the voltammetry of electrodes are discussed.

THE DISCRETENESS-OF-CHARGE EFFECT IN ELECTRIC DOUBLE LAYER THEORY

1962 ◽  
Vol 40 (3) ◽  
pp. 518-538 ◽  
Author(s):  
S. Levine ◽  
G. M. Bell ◽  
D. Calvert
Keyword(s):  
Adsorption Isotherm ◽  
Double Layer ◽  
Electric Double Layer ◽  
Surface Density ◽  
Aqueous Electrolyte ◽  
Solution Phase ◽  
Charge Effect ◽  
Adsorption Potential ◽  
Simple Method ◽  
Ion Size

The Stern–Grahame–Devanathan theory of the electrical double layer in aqueous systems is modified to include the so-called discreteness-of-charge effect of Esin and Shikov and Ershler. This provides an explanation of a number of phenomena which are at variance with the Stern theory. A simple method of incorporating the above effect into the Stern theory is suggested by the work of Grahame and is equivalent in principle to the discrete-ion approximation employed by the Russian authors. It is shown that the effect can be interpreted in terms of a 'self-atmosphere' potential at the counterions adsorbed in the Stern layer. This provides a new term in the energy of an adsorbed ion, which is very nearly proportional to the surface density of these ions and which had hitherto been included in the specific adsorption potential in the Stern adsorption isotherm. This energy is not small and accounts for the conclusion reached by Grahame that the adsorption potential varies strongly with the surface charge. Grahame found that the potential at the plane separating the compact and diffuse parts of the double layer in the solution phase (i.e. the outer Helmholtz plane) at the mercury –aqueous electrolyte interface displays a maximum as the potential across the interface is varied, and this property is reproduced by the theory. The effect of ion size on the adsorption isotherm is also considered.

Effect of finite ion sizes in electric double layer mediated interaction force between two soft charged plates

RSC Advances ◽  
2015 ◽  
Vol 5 (58) ◽  
pp. 46873-46880 ◽  
Author(s):  
Joseph Andrews ◽  
Siddhartha Das
Keyword(s):  
Osmotic Pressure ◽  
Double Layer ◽  
Electric Double Layer ◽  
Interaction Force ◽  
Ion Size

A new theory quantifies the effect of finite ion size in osmotic pressure (Πosm) between two soft charged plates.

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