Molecular interactions of ionic liquids with SiO₂ surfaces determined from colloid probe atomic force microscopy

Area of Science:

• Materials Science
• Physical Chemistry
• Computational Chemistry

Background:

• Ionic liquids (ILs) exhibit strong interactions with solid surfaces, crucial for applications in lubrication and energy storage.
• The vast number of potential ILs makes selecting optimal candidates for specific interfaces challenging.
• Accurate theoretical models and force field parameters are essential but difficult to obtain for IL-solid interactions.

Purpose of the Study:

• To develop a new methodology for deriving IL-solid interaction parameters directly from experimental data.
• To validate the reliability of these derived parameters using molecular dynamics simulations and NMR diffusometry.

Main Methods:

• Utilized colloid probe atomic force microscopy (CP-AFM) to measure IL-solid interaction forces.
• Derived IL-solid interaction parameters directly from experimental CP-AFM data.
• Performed molecular dynamics (MD) simulations to calculate translational self-diffusion coefficients.
• Validated derived parameters by comparing MD simulation results with experimental NMR diffusometry data.

Main Results:

• Successfully derived reliable interaction parameters for ILs and solid surfaces from CP-AFM measurements.
• MD simulations using the derived parameters accurately predicted translational self-diffusion coefficients.
• The results demonstrate the effectiveness of the new methodology for parameter determination.

Conclusions:

• The developed method provides a robust approach to obtain accurate IL-solid interaction parameters.
• This facilitates the rational design and application of ionic liquids in various fields.
• The integration of experimental AFM data with computational simulations offers a powerful tool for materials development.