Multiscale Investigation of Liquid Imbibition on an Electrodeposited Rough Surface

Area of Science:

• Materials Science
• Surface Chemistry
• Fluid Dynamics

Background:

• Hydrophilic and superhydrophilic surfaces are crucial for applications like biomedical devices and microelectronics.
• Current methods for fabricating controlled rough surfaces are often expensive and complex.
• Understanding liquid imbibition on rough surfaces is vital but challenging due to multiscale physics.

Purpose of the Study:

• To introduce an alternative, cost-effective method for creating controlled rough surfaces via electrodeposition.
• To investigate the influence of various length scales (micrometers to angstroms) on surface roughness and liquid imbibition.
• To explore the molecular-level physics governing droplet contact line dynamics and flow velocities on these surfaces.

Main Methods:

• Electrodeposition of copper ions on copper electrodes to create controlled microscale roughness by adjusting deposition time.
• Molecular dynamics simulations to analyze droplet contact line dynamics (contact angle, footprint radius).
• Evaluation of directional flow velocities within surface asperities at the molecular level.

Main Results:

• Successfully fabricated controlled rough surfaces using electrodeposition, with roughness influenced by deposition time.
• Molecular analysis revealed qualitative alignment between simulated droplet dynamics and real systems.
• Identified and quantified directional flow velocities (axial and horizontal) during imbibition at the molecular scale.

Conclusions:

• Electrodeposition provides a viable method for creating controlled rough surfaces for studying liquid imbibition.
• Molecular-level insights enhance the fundamental understanding of fluid behavior on textured metallic surfaces.
• The study establishes qualitative agreement between simulations and experiments, validating the approach for analyzing complex imbibition phenomena.