Multi-Layer Biocarbon Carbonized from Cellulose Nanocrystals as a Novel Lubricant Nanoadditive in Rapeseed Oil

Area of Science:

• Materials Science
• Tribology
• Green Chemistry

Background:

• Cellulose nanocrystals (CNCs) are biodegradable but limited as lubricant nanoadditives.
• Converting CNCs to biocarbon presents a promising avenue for enhanced lubrication properties.

Purpose of the Study:

• To develop and evaluate multi-layer biocarbon (MLC) derived from CNCs as a high-performance green lubricant nanoadditive.
• To investigate the tribological performance and lubrication mechanism of MLC in rapeseed oil.

Main Methods:

• Preparation of MLC via ionic liquids-thermal carbonization of CNCs.
• Comprehensive characterization of MLC, including composition and morphology.
• Evaluation of tribological performance using a ball-on-disc tribometer.
• Analysis of worn surfaces and wear residues to elucidate lubrication mechanisms.

Main Results:

• MLC exhibited a high carbon content (77 at%) and a unique multi-layered structure of amorphous carbon nanosheets with embedded carbon dots.
• MLC demonstrated excellent dispersibility and stability in rapeseed oil.
• At 0.04 wt% concentration, MLC reduced the friction coefficient by 12.4% and wear volume by 50.7%, surpassing CNCs.

Conclusions:

• MLC is a highly effective green lubricant nanoadditive derived from CNCs.
• The superior lubrication performance is attributed to MLC's interfacial deposition and fragmenting behaviors.
• This study presents a novel biocarbon preparation method with significant potential for lubrication applications.