Researchers have found that when small, smooth carbon spheres are added to motor oil, they can reduce friction and wear typically found in engines by as much as 25%. Researchers say this may suggest a similar enhancement in fuel economy.

The research team found a way potentially to mass produce the spheres, by using ultrasound to produce bubbles in a fluid containing a chemical compound called resorcinol and formaldehyde. The bubbles expand and collapse, generating heat that drives chemical reactions to produce polymer particles. These particles are then heated to about 900 degree Celsius (C), yielding the spheres.

"People have been making these spheres for about the last 10 years, but what we discovered was that instead of taking the 24 hours of synthesis normally needed, we can make them in five minutes," says Vilas Pol, an associate professor of chemical engineering at Purdue University.

The spheres are 100 to 500 nanometers (nm) in diameter, a range that is consistent with the "surface roughness" of moving engine components. “The spheres are able to help fill in these areas and reduce friction,” says mechanical engineering doctoral student, Abdullah Alazemi.

These findings were published in a research paper in American Chemical Society journal (ACS) Applied Materials and Interfaces.