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Scaling Behavior of Ionic Conductance Dependent on Surface Charge Inside a Single-Digit Nanopore
Anping Ji1,2, Lang Zhou1, Qiming Xiao1,2
1School of Mechanical Engineering, Chongqing Three Gorges University, Chongqing 404100, China.
Molecules (Basel, Switzerland)
|January 11, 2025
Summary
Ionic conductance in nanopores follows a power-law, influenced by surface charges. This study presents a new method to measure surface charge density in nanopores, accounting for potential leakage effects.
Area of Science:
- Nanotechnology
- Physical Chemistry
- Electrochemistry
Background:
- Ionic conductance in charged nanopores shows power-law behavior (G0∝c0α) driven by surface charges.
- Surface charge dictates zeta potential and ion distribution, impacting ion transport in nanopores, especially with leakage.
- Accurate measurement of surface charge density in single-digit nanopores is challenging.
Purpose of the Study:
- To propose a methodology for analyzing the power-law variation of ionic conductance in nanopores.
- To account for potential leakage effects in nanopore conductance measurements.
- To accurately determine surface charge density and ion mobility in nanopores.
Main Methods:
- Experimental measurement of ionic current using silicon nitride nanopores.
- Application of continuous theory to investigate pore-bound concentration and surface charge relationships.
- Development of a modified conductance model incorporating potential leakage.
Main Results:
- Established a coefficient (α) to analyze factors controlling potential leakage.
- Demonstrated a power-law relationship for concentration influenced by potential leakage.
- Obtained ion mobility within the nanopore by modifying the conductance model.
Conclusions:
- The proposed methodology effectively explores power-law variations in ionic conductance.
- Potential leakage significantly influences concentration and ionic transport in nanopores.
- The study provides a framework for accurate surface charge and ion mobility determination in nanopores.
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