Polytetrafluoroethylene (PTFE), also known as DuPont’s Teflon®, is renowned for keeping things from sticking, and is used as a dry lubricating polymer on machine components, from kitchen tools to space and biomedical applications. Recently, research engineers at the University of Arkansas, Fayetteville, discovered that the polymer could be made even less adhesive. They treated thin films of PTFE with silica nanoparticles and found that the lubricating material significantly reduced wear of the polymer while maintaining a low level of friction.
They say that their discovery will enable machinery to last longer and operate more efficiently. Solid lubricants, such as PTFE, have low maintenance costs, are self-lubricating, produce low friction, and are resistant to high temperatures and chemicals.
Recently though, scientists and engineers have attempted to improve the material by incorporating nanoparticle “fillers” to reduce wear and extend its life. But, high concentrations of nanofillers create a problem: While reducing wear, they also increase friction.
The Arkansas researchers found that by incorporating silica into PTFE in two different concentrations, applying the thin films to a stainless steel substrate, and subjecting the films to abrasive tests, they were able to measure the degree of friction and wear resistance and found that the composite films with higher concentration of silica had much narrower wear tracks after the samples were subjected to rubbing tests.
