Related Experiment Video
Updated: Mar 30, 2026
08:23
Automated Lipid Bilayer Membrane Formation Using a Polydimethylsiloxane Thin Film
Published on: July 10, 2016
19.2K
When do defectless alkanethiol SAMs in ionic liquids become penetrable? A molecular dynamics study.
Sergey A Kislenko1, Victoria A Nikitina2, Renat R Nazmutdinov3
1Joint Institute for High Temperatures of RAS, Izhorskaya 13/2, 125412, Moscow, Russian Federation. kislenko@ihed.ras.ru.
Physical Chemistry Chemical Physics : PCCP
|November 17, 2015
Summary
Molecular dynamics simulations reveal that defectless alkanethiol self-assembled monolayers (SAMs) resist ionic liquid permeation until critical surface charge densities are met. Longer alkanethiols offer superior barrier properties.
Area of Science:
- Surface Science
- Electrochemistry
- Computational Chemistry
Background:
- Alkanethiol self-assembled monolayers (SAMs) on Au(111) are crucial for surface modification.
- Understanding ionic liquid (IL) interactions with SAMs is vital for electrochemical applications.
Purpose of the Study:
- To investigate the permeability of defectless alkanethiol SAMs on charged and uncharged Au(111) surfaces.
- To determine the factors influencing ionic permeation from 1-butyl-3-methylimidazolium ([bmim][BF4]) IL.
Main Methods:
- Molecular dynamics simulations were employed.
- Free energy barriers for ion permeation were calculated.
- Potential of mean force was constructed for redox probes.
Main Results:
- Ionic permeation requires critical surface charge densities, beyond monolayer stability limits.
- Ion desolvation and channel formation contribute equally to the permeation barrier.
- Long-chain alkanethiols (SC16H33) provide better barrier properties than short-chain (SC6H13).
Conclusions:
- Defectless SAMs are likely impermeable to IL components under typical electrochemical conditions.
- Observed interfacial capacitance increases may indicate monolayer defects in real systems.
- Further investigation into solute permeation into SAMs is warranted.
