Identifying Differences and Similarities in Static and Dynamic Contact Angles between Nanoscale and Microscale...

Area of Science:

• Surface science
• Nanotechnology
• Computational physics

Background:

• Surface texture significantly influences wetting properties.
• Understanding nanoscale effects is crucial for advanced materials design.

Purpose of the Study:

• Quantify effects of nanoscale surface texture on wetting phenomena.
• Investigate dynamic contact angle hysteresis behavior at the nanoscale.
• Compare simulation results with existing theories and experimental data.

Main Methods:

• Molecular dynamics simulations of a moving Lennard-Jones droplet.
• Analysis of static and dynamic contact angles and hysteresis.
• Application and validation of molecular-kinetic theory.

Main Results:

• Static contact angles are consistent with theoretical expectations.
• Nanoscale textures (5-10x particle size) alter advancing/receding angles but not hysteresis.
• Molecular-kinetic theory accurately predicts behavior, indicating molecular fluctuations dominate over pinning at the nanoscale.

Conclusions:

• Nanoscale surface texture's impact on wetting differs from microscale.
• Molecular fluctuations are key to wetting dynamics at the nanoscale.
• Findings inform the design of hierarchical structures with tailored wetting properties.