Exploring ionic liquids for greener grease
When Ashlie Martini and her team of researchers at University of California Merced (UCM) applied for a NLGI grant to explore the use of ionic liquids in grease, Nynas’ grease specialist Mehdi Fathi-Najafi was assigned as their liaison.
Mehdi Fathi-Najafi
Chief Specialist at Technical Development and Support, Nynas
“It has been a very exciting project and has opened new avenues for further exploration. The only regret I have is that it didn’t last longer,” says Professor Ashlie Martini.
Chairing the university’s Mechanical Engineering department, she lists her interests as friction, wear, and lubrication, and is, according to Mehdi Fathi-Najafi, a “rising star” in tribology.
“We have access to expertise and equipment for tribological studies that perhaps are not so commonly available elsewhere,” Ashlie Martini states humbly.
Ashlie Martini's UCM colleague and Professor of Chemistry Michael Findlater complemented the tribology and grease team with his expertise in the syntheses of ionic liquids.
“So far, ionic liquids have primarily been used in liquid lubricants. Their use in grease has not been explored enough, although the thickener can act as a carrier. Our idea was to bring more ionic liquids into the world of grease, where they might have more impact,” says Ashlie Martini.
Although any number of different ionic liquids could potentially be used, the team focused on some that are possible to scale up. The environmental credentials were also considered.
“Some of the ionic liquids that we are developing are ‘green’, and that’s important as they are supposed to replace some additives that are not so pleasant. The aim is to make the world a bit better,” says Martini.
The experiments included six newly synthesised ionic liquids previously never used in grease, and one ionic liquid that has been used before. These were blended into a base grease provided by Nynas. Samples were sent back and forth between UCM and Nynas, where some of the rheological studies were conducted.
The resulting seven grease samples were performance tested alongside a commercially available grease.
Professor Ashlie Martini with two of her students, Michelle Padilla and Jose Arturo Morales, in the lab at the University of California Merced (UCM).
“Our samples showed very promising results, matching and in some cases even exceeding the performance of the commercial grease in several of the tribological tests. They definitely warrant further investigation and development,” she says.
The NLGI research grant allowed the group to explore freely and “out of the box”. Ashlie Martini was also pleasantly surprised to find Nynas so genuinely interested and engaged in their research, even though this is still at such an early stage, somewhere between basic and applied research.
“It was a pleasure working with Nynas, and Mehdi Fathi-Najafi was very enthusiastic, offering us a lot of help and guidance in addition to assisting us with samples of base greases,” she says. How the work at UCM will progress next depends on what funding can be secured for further research projects.
“Lubrication is not normally considered sexy science, and I rarely use the word when applying for grants. But I find lubrication and tribology a fascinating and fundamental science with some very cool applications, says Ashlie Martini.”
