Customizing oil-wettability in air-without affecting extreme water repellency

Area of Science:

• Materials Science
• Surface Chemistry

Background:

• Superhydrophobic surfaces mimic lotus leaves, repelling water but often attracting oil.
• Superamphiphobic surfaces repel both water and oil, requiring different fabrication methods.
• Controlling oil wettability on superhydrophobic surfaces is challenging.

Purpose of the Study:

• To develop a single, scalable method for creating superhydrophobic surfaces with tunable oil wettability.
• To demonstrate control over oil affinity, ranging from superoleophilic to superoleophobic, while maintaining superhydrophobicity.

Main Methods:

• A rapid and scalable spray deposition technique was employed.
• Two small molecules were reacted via 1,4 conjugate addition in a diluted reaction mixture.
• Surface wettability was tuned by adjusting the dilution of the reaction mixture.

Main Results:

• Superhydrophobic surfaces with tunable oil wettability (superoleophilic to superoleophobic) were successfully synthesized.
• The superhydrophobicity was maintained across the range of oil wettabilities.
• The synthesized surfaces demonstrated durability against physical and chemical challenges.
• The interfaces showed potential for oil/water separation, anti-fouling, and self-cleaning applications.

Conclusions:

• A versatile spray deposition method allows for precise control over oil wettability on superhydrophobic surfaces.
• This approach simplifies the fabrication of surfaces with tailored liquid repellency for diverse applications.
• The developed surfaces offer robust performance for practical, outdoor uses.