Drop impact dynamics on oil-infused nanostructured surfaces.

Area of Science:

• Fluid Dynamics
• Surface Science
• Nanotechnology

Background:

• Understanding liquid drop impact on surfaces is crucial for various applications.
• Oil-infused surfaces offer unique properties for controlling liquid interactions.
• Nanostructured surfaces enhance surface properties but require investigation under dynamic conditions.

Purpose of the Study:

• To experimentally investigate the impact dynamics of water drops on oil-infused nanostructured surfaces.
• To analyze the influence of oil properties, specifically viscosity, and impact velocity on fluid dynamics.
• To elucidate the mechanisms behind instabilities and patterns formed during drop impact.

Main Methods:

• High-speed microscopy was employed to capture detailed drop impact events.
• Scalable metal oxide nanostructured surfaces were utilized for experiments.
• Systematic variation of oil viscosity and impact velocity allowed for controlled analysis.

Main Results:

• Oil viscosity did not significantly affect the maximal spreading radius of water drops.
• Oil viscosity moderately influenced the retraction dynamics of the impacting drop.
• Low viscosity oil layers were prone to displacement, leading to residual marks and earlier splashing.
• Liquid-liquid interactions induced instabilities, forming flower-like patterns or elongated filaments.

Conclusions:

• Oil viscosity plays a critical role in the stability of the lubricant layer and retraction behavior during drop impact.
• The findings provide insights into the complex fluid phenomena governing drop impact on oil-infused nanostructured surfaces.
• This research contributes to the rational design of surfaces for applications involving drop impacts.