Researchers turns up the heat to make slippery surfaces adhesive
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Researchers at Osaka University, Japan, have developed a method for rendering some of the slipperiest surfaces in existence adhesive.
Non-stick saucepans are often coated in Teflon, a material based on polytetrafluoethylene (PTFE). This chemical is a man-made fluoropolymer with many applications thanks to its remarkable slipperiness: it can be used to create the lowest-friction surfaces in the world.
Despite its usefulness in the home and in manufacturing, the slipperiness of PTFE makes it very awkward to work with. Forcing it to adhere to other materials – such as when applying a Teflon coating to a saucepan – requires manufacturers to use harsh chemicals.
Hoping to find an alternative way to encourage PTFE to adhere to other objects, researchers at Osaka University began to study the possibility of plasma treatments for PTFE. Plasma treatments are typically used for cleaning, activating or etching surfaces before further processing.
“People have been looking at how plasma treatments affects PTFE for some time, but no one has really examined how the treatments affect adhesion properties,” said Dr Yuji Ohkubo, who led the study at Osaka University.
“With our plasma treatment, we improved the adhesion of the PTFE to some extent, but it was only when we combined this with extra heating of the PTFE that we saw it strongly adhering to rubber.”
By adding a heating element during the plasma treatment of PTFE, the researchers were able to alter the surface structure of the material, hardening it and drastically improving the strength of its adherence to other materials, such as rubber surfaces.
“The real advantages of this work are that it avoids using some nasty chemicals and is relatively simple to implement,” said Dr Kazuya Yamamura, co-author of the Scientific Reports study describing the achievement.
“In industrial processes, adding a heater to a plasma chamber is much easier than trying to adjust the temperature through the plasma power. We hope this new technique allows PTFE to be used in new ways that just weren’t possible or practical before.”