Theory and simulation of angular hysteresis on planar surfaces

Area of Science:

• Physics
• Materials Science
• Surface Science

Background:

• Contact angle hysteresis is crucial for understanding fluid behavior on solid surfaces.
• Existing models often struggle to accurately capture the dynamic nature of the contact line.

Purpose of the Study:

• To propose a simple yet effective model for simulating contact angle hysteresis.
• To validate the model's performance against experimental data.

Main Methods:

• A friction force model was developed for the triple contact line.
• The model was applied to axisymmetric drops using the Young-Laplace equation.
• A variation was implemented for non-axisymmetric drops using "Surface Evolver" software.

Main Results:

• The model successfully simulates contact angle hysteresis by allowing the contact line to move within a specific angle range.
• The model demonstrates excellent agreement with experimental observations.
• The approach is applicable to both simple (axisymmetric) and complex (non-axisymmetric) drop geometries.

Conclusions:

• The proposed friction-based model provides an accurate and straightforward method for simulating contact angle hysteresis.
• This model enhances the understanding of droplet dynamics on surfaces.
• The findings have implications for various applications involving fluid-surface interactions.