Porous Micropillar Arrays with Oil Infusion: Fabrication, Characterisation, and Wettability Analysis.

Area of Science:

• Materials Science
• Surface Science
• Nanotechnology

Background:

• Superhydrophobic surfaces mimic the lotus leaf, offering self-cleaning, anti-friction, anti-icing, and anti-corrosion properties.
• Polydimethylsiloxane (PDMS) micropillar arrays are widely studied for these applications.
• Modifying surface structures, like introducing porosity, can tune wettability and performance.

Purpose of the Study:

• To develop a simple method for creating porous PDMS micropillar arrays.
• To evaluate the effect of porosity on surface wettability.
• To investigate the impact of perfluoropolyether (PFPE) oil infusion on the performance of porous surfaces.

Main Methods:

• Fabrication of PDMS micropillar arrays with controlled porosity using salt templating.
• Characterization of surface wettability through apparent contact angle and sliding angle measurements.
• Evaluation of wetting behavior before and after PFPE oil infusion.

Main Results:

• Introducing porosity slightly decreased the apparent contact angle (by ~5°) and increased the sliding angle (by ~3.5°).
• PFPE oil infusion into porous arrays reduced sliding angles while maintaining superhydrophobicity.
• Porous surfaces showed slightly reduced water repellency but regained droplet mobility after oil infusion.

Conclusions:

• Salt templating is an effective method for creating porous PDMS micropillar surfaces.
• Porosity influences surface wettability and droplet mobility.
• PFPE oil infusion can restore droplet mobility to porous superhydrophobic surfaces, enhancing their self-cleaning potential.