Graphene in car engine's oil benefits lubrication and reduces fuel consumption

Engine oil and mpg improved by Graphene balls Graphene in car engine's oil reduces friction and improves mpg
The use of graphene balls in oil could yield significant engine efficiency improvements in coming years.

Despite improvements to lubricates such as engine oil, the average car uses 15% of its fuel consumption overcoming friction within the engine and gearbox. It is a prime area for improvement with nano materials potentially offering significant gain. However, in practice, problems with dispersion means nano-lubricants can create more issues than they solve.

“Every year, millions of tons of fuel are wasted because of friction,” says Jiaxing Huang, an associate Professor of materials science and engineering at Northwestern University near Chicago. “It’s a serious problem.”

Developers of lubricants have long searched for nano-additives that enhance oil performance, with carbon nanoparticles trialled on numerous occasions. The particles, however, tend to clump together, which makes them less effective. The particles may also jam between surfaces causing severe aggregation that actually increases friction and wear.

To overcome the problem, past researchers have modified the particles with extra chemicals, called surfactants, to make them disperse in a more uniform manner. However, this still doesn’t entirely solve the problem.

“Under friction, the surfactant molecules can rub off and decompose,” says fellow researcher Yip-Wah Chung, a professor of materials science and engineering at the university. “When that happens, the particles clump up again.”

Huang and his collaborators decided upon trying crumpled graphene balls – novel ultrafine particles that resemble crumpled balls of paper – to see what affect the material would have on the tribological property of oil.

Graphene balls are made by drying tiny water droplets with graphene based sheets inside. Capillary force generated by the evaporation of water crumples the sheets into miniaturised balls.

In a series of tests, oil modified with crumpled graphene balls outperformed some commercial lubricants by 15%, both in terms of reducing friction and the degree of wear on steel surfaces.

The Eureka moment came at a lunch when Huang showed the principles of graphene balls to a colleague, by screwing up a napkin and throwing it on the table. “When [I saw a paper] ball land on a table, it rolled,” says fellow researcher Yip-Wah Chung, a professor of materials science and engineering at the university. “It reminded me of ball bearings that roll between surfaces to reduce friction.”

The unique shape of crumpled graphene balls mean they self-disperse without needing any surfactants. Their pointy surfaces mean they are unable to make close contact with other graphene balls. Even when they are squeezed together, they easily separate again when disturbed.

Huang and his team also found that the performance of crumpled graphene balls is not sensitive to their concentrations in the oil.

“A few [graphene balls] are sufficient, and if you increase the concentration by 10 times, performance is about the same,” says Huang. “For all other carbon additives, such performance is very sensitive to concentration. You have to find the sweet spot.”

Next, the team plans to explore the additional benefit of using crumpled graphene balls in oil as they can be used as carriers. Because the ball-like particles have high surface area and open spaces, they are good carriers for materials with other functions, such as corrosion inhibition. The research continues.

Author
Justin Cunningham

This material is protected by MA Business copyright
See Terms and Conditions.
One-off usage is permitted but bulk copying is not.
For multiple copies contact the sales team.

 

Supporting Information
Do you have any comments about this article?
how much composition of graphene is mixed with engine oil

Comment nikhil, 28/11/2016
Name
 
Email
 
Comments
 

Your comments/feedback may be edited prior to publishing. Not all entries will be published.
Please view our Terms and Conditions before leaving a comment.

© MA Business Ltd (a Mark Allen Group Company) 2018