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Self-consistent description of electrokinetic phenomena in particle-based simulations
Juan P Hernández-Ortiz1, Juan J de Pablo2
1Departamento de Materiales y Minerales, Universidad Nacional de Colombia, Sede Medellín, Medellín, Colombia.
The Journal of Chemical Physics
|July 10, 2015
Summary
A novel computational method models charged particle suspensions with fluctuating hydrodynamic and electrostatic interactions. This approach reveals how ionic clouds are altered by flow, leading to cooperative effects in electrokinetics.
Area of Science:
- Computational physics
- Physical chemistry
- Colloid science
Background:
- Studying charged particle suspensions requires accounting for complex hydrodynamic and electrostatic interactions.
- Existing models may not adequately capture fluctuating interactions or arbitrary boundary conditions.
Purpose of the Study:
- To present a new computational method for simulating charged particle suspensions.
- To incorporate fluctuating hydrodynamic and electrostatic interactions within a unified framework.
- To provide a versatile method applicable to various particle types and geometries.
Main Methods:
- A self-consistent Langevin description for particles.
- Green's function formalism for hydrodynamic and electrostatic interactions.
- Ewald-like split for arbitrary boundary conditions.
- Simultaneous solution of convection-diffusion and Nernst-Planck equations for ions.
Main Results:
- The method is applicable to polymers, proteins, and porous particles in electrolytes.
- It handles systems at equilibrium and far from equilibrium.
- Demonstrated severe alteration of ionic clouds by flow and concentration in electrokinetic motion.
- Revealed intriguing cooperative effects arising from altered ionic clouds.
Conclusions:
- The developed computational method offers a robust framework for studying complex particle suspensions.
- It accurately captures the interplay between particle dynamics and continuum electrolyte behavior.
- The findings highlight the significant impact of flow and concentration on ionic cloud structure and cooperative phenomena.
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