A Mussel-Inspired Polymer-Network Tribofilms Deliver Oil-Based Macroscale Superlubricity on Engineering Steel

Area of Science:

• Tribology
• Materials Science
• Surface Chemistry

Background:

• Superlubricity (friction coefficient ≤ 0.01) is crucial for reducing energy loss and material wear.
• Developing effective oil-based superlubricity, especially for metals, remains a significant challenge.

Purpose of the Study:

• To create a robust oil-based superlubricity system for metallic surfaces.
• To leverage molecular self-assembly inspired by mussel adhesive chemistry.

Main Methods:

• Incorporating dopamine (DA) into ethylene glycol (EG) lubricant.
• Investigating the self-assembly and tribofilm formation at the sliding interface.
• Conducting durability tests on boronized steel.

Main Results:

• Achieved ultralow friction coefficient (< 0.01) and extremely low wear rate (1.9 × 10⁻¹⁷ m³N⁻¹m⁻¹).
• Demonstrated robust performance over a 6-hour test (216,000 cycles).
• Identified dopamine's dual role in forming and anchoring a carbonaceous tribolayer.

Conclusions:

• The developed tribolayer significantly reduces shear strength and energy dissipation compared to pure EG lubrication.
• This molecular self-assembly strategy provides a broadly applicable solution for high-performance superlubricity.
• Opens new avenues for next-generation lubricant development.