Total Liquid Transfer with Enhanced Contact Line Slippage

Area of Science:

• Surface Science
• Fluid Dynamics
• Materials Science

Background:

• Achieving complete liquid transfer from surfaces is challenging due to factors like contact line pinning and hysteresis.
• Existing surface treatments, including hydrophobic modifications, show limitations in transfer efficiency, especially for small droplets or high speeds.

Purpose of the Study:

• To develop and evaluate a new surface treatment for achieving near-total liquid transfer.
• To investigate the hydrodynamic mechanisms governing liquid droplet transfer from surfaces.

Main Methods:

• High-speed photography and image analysis were used to record and analyze liquid droplet transfer dynamics.
• Comparison of liquid transfer efficiency on pristine, hydrophobic, and lubricant-infused surfaces.

Main Results:

• Viscous and viscoelastic liquids showed improved transfer on pristine surfaces, but slippage was limited.
• Hydrophobic treatments enhanced slippage and receding angles, reaching up to 98% transfer, but surface roughness caused limitations.
• A lubricant-infused surface with PDMS and silicone oil achieved ~99.9% transfer, independent of droplet size and velocity.

Conclusions:

• Lubricant-infused surfaces offer superior liquid transfer performance by providing a smooth, low-hysteresis interface.
• This surface modification method holds significant potential for applications such as gravure printing.