Related Experiment Video
Updated: May 2, 2026
19:56
Introduction to Solid Supported Membrane Based Electrophysiology
Published on: May 11, 2013
16.5K
Electrostatic interaction of heterogeneously charged surfaces with semipermeable membranes
Faraday Discussions
|March 12, 2014
Summary
Heterogeneous wall charges significantly reduce electrostatic repulsion between charged surfaces and membranes. This finding in electrostatic interactions could facilitate self-assembly in biological and synthetic systems.
Area of Science:
- Physical Chemistry
- Colloid and Surface Science
- Electrochemistry
Background:
- Understanding electrostatic interactions is crucial for phenomena like membrane transport and self-assembly.
- Heterogeneous surface charges present unique challenges compared to uniformly charged surfaces.
- Semipermeable membranes play vital roles in biological and synthetic systems.
Purpose of the Study:
- To investigate the electrostatic interaction between a heterogeneously charged wall and a neutral semipermeable membrane.
- To quantify the electrostatic disjoining pressure generated by counterion clouds in a thin film.
- To explore the impact of wall charge heterogeneity on electrostatic repulsion.
Main Methods:
- Mean-field theory using linearized Poisson-Boltzmann equation and Fourier analysis.
- Langevin dynamics simulations with explicit ions.
- Comparison of theoretical predictions with simulation results.
Main Results:
- A distance-dependent membrane potential arises from permeating counterions.
- Electrostatic repulsion (disjoining pressure) is caused by overlapping counterion clouds.
- Wall charge heterogeneity significantly reduces electrostatic repulsion, especially at low surface charges and small gaps.
Conclusions:
- Theoretical and simulation approaches show good agreement at low surface charges.
- Nonlinearity at higher charges leads to discrepancies between theory and simulations.
- Reduced electrostatic repulsion due to wall heterogeneity can facilitate self-assembly processes.
More Related Videos
Related Concept Videos
01:30The Electrical Double Layer
241
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...
241
01:24Electrochemical Systems
179
Electrochemical systems provide a fascinating insight into the dynamic interplay of charged species within various phases. One notable example is the interaction between a membrane permeable to K⁺ ions but not to Cl⁻ ions, separating an aqueous KCl solution from pure water. As K⁺ ions diffuse through the membrane, they generate net charges on each phase, leading to a potential difference between them.Similarly, when a piece of Zn is immersed in an aqueous ZnSO₄ solution,...
179
01:15Potentiometry: Membrane Electrodes
2.3K
Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at...
2.3K
01:23Theory of Strong Electrolytes
132
The interionic forces of the strong electrolytes depend on the solvent's dielectric constant, which is the ability of a solvent to store electrical energy, based on its polarizability. and the solution's concentration. In high-dielectric solvents and in dilute solutions, weak electrostatic forces keep ions apart. However, in low-dielectric solvents or concentrated solutions, stronger interionic forces may cause ions to pair up as ionic doublets despite being fully ionized. The theory of strong...
132
03:13Intermolecular Forces
62.9K
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen...
62.9K
01:06Interfacial Electrochemical Methods: Overview
1.0K
Interfacial electrochemical methods focus on the phenomena occurring at the boundary between an electrode and a solution, as opposed to bulk methods that concentrate on the solution's overall properties. These interfacial methods are classified as either static or dynamic based on the presence of a nonzero current in the electrochemical cell and the consistency of analyte concentrations. Static methods, such as potentiometry, measure the cell's potential without any significant current...
1.0K