Tribological Effects of Quaternary Ammonium-Functionalized Montmorillonite as Water-Based Additives

Area of Science:

• Materials Science
• Tribology
• Nanotechnology

Background:

• Lubrication additives are crucial for reducing friction and wear in mechanical systems.
• Developing environmentally friendly and high-performance water-based lubricants is an ongoing challenge.
• Montmorillonite (MMT) is a layered clay mineral with potential for surface modification.

Purpose of the Study:

• To fabricate a water-soluble quaternary ammonium salt (QAS)-functionalized montmorillonite (MMT) for use as a water-based lubrication additive.
• To evaluate the tribological performance of the QAS-MMT in reducing friction and wear.
• To elucidate the lubrication mechanism of the QAS-MMT additives.

Main Methods:

• Mechanochemical fabrication of QAS-functionalized MMT (QAS-MMT).
• Characterization of QAS-MMT, including layer spacing and hydrophilicity.
• Tribological testing of QAS-MMT as a water-based lubricant additive for steel/steel contacts.
• Analysis of the frictional mechanism through adsorption and reaction films.

Main Results:

• QAS intercalation expanded MMT layer spacing while maintaining hydrophilicity.
• Ultrathin QAS-MMT exhibited excellent water-stable dispersion.
• A mere 0.1% addition of QAS-MMT reduced friction coefficient by over 71.4% and wear volume by approximately 58.8% compared to water.
• Demonstrated excellent friction reduction and anti-wear performance.

Conclusions:

• QAS-MMT is a highly effective water-based lubrication additive.
• The combination of physical adsorption and chemical reaction films contributes to the outstanding tribological performance.
• QAS-MMT provides superior lubrication for steel/steel interfaces, preventing surface wear.