Modeling Contact Angles with Chemically Specific Dissipative Particle Dynamics

Area of Science:

• Computational chemistry and materials science
• Soft matter physics and interfacial phenomena

Background:

• Accurately modeling interfacial behavior, such as contact angles, is crucial in diverse fields.
• Existing simulation methods often struggle to precisely control surface properties and their impact on wetting phenomena.

Purpose of the Study:

• To introduce and validate a method for incorporating walls into chemically specific dissipative particle dynamics (DPD) models.
• To enable precise tuning of surface energies to achieve desired contact angles for liquid interfaces.
• To ensure the developed methodology satisfies the Young equation for accurate wetting predictions.

Main Methods:

• Developed a technique to introduce chemically specific walls into DPD simulations.
• Established a procedure for determining wall surface energies (positive or negative) to control contact angles.
• Validated the DPD methodology against direct numerical simulations of oil-in-water droplets.
• Tested the approach using an experimental model of water droplets on a silica surface with a monolayer.

Main Results:

• Successfully implemented a DPD framework capable of defining surface energies for introduced walls.
• Demonstrated that the chosen surface energies automatically satisfy the Young equation, predicting accurate contact angles.
• Validated the simulation results against independent numerical simulations and experimental data for oil/water and water/oil systems.

Conclusions:

• The proposed DPD methodology provides a robust and accurate way to model interfacial phenomena with controlled wetting.
• This approach offers a valuable tool for designing and simulating complex fluid-surface interactions in materials science and nanotechnology.
• The ability to tune surface energies and satisfy the Young equation enhances the predictive power of DPD for interfacial engineering.