Clearing out uncharged molecules may prevent charge buildup
A little vitamin E could zap static cling.
The chemical wipes out static electricity by getting rid of molecules that stabilize charge, researchers report in the Sept. 20 Science. By adding vitamin E or similar chemicals to coatings for electronics, manufacturers could fend off the electrostatic shocks that fry computer chips.
Static electricity may be best known for delivering tiny jolts to people shuffling across carpets. But in electronics, “the situation is very serious,” says physical chemist Fernando Galembeck of the University of Campinas in Brazil, who was not involved with the new work. Beyond messing up motherboards, electrostatic shocks can spark fires and explosions that injure people and damage property. “These things happen all the time,” he says.
Static electricity has kindled scientists’ interest for millennia, ever since Greek philosopher Thales of Miletus purportedly charged up a hunk of amber by rubbing it against wool around 2,600 years ago. Still, how exactly friction causes static electricity remains a mystery, says chemical engineer Daniel Lacks of Case Western Reserve University in Cleveland. “What happens when things charge is totally unknown scientifically.”
In the last few years, Bilge Baytekin, study leader Bartosz Grzybowski and colleagues at Northwestern University in Evanston, Ill., have chipped away at the big unknown. They’ve shown how to charge two pieces of identical polymer just by touching them together. When the two pieces rub against one another, friction breaks chemical bonds on the polymers’ surface. Then new bonds form between the pieces, making them cling to each other like sticky tape, says Baytekin.
When researchers peel the pieces apart, the bonds linking the polymers together rip, leaving different chemical fragments hanging. Some of these fragments carry charge — a key part of static electricity.
But other chemical fragments may be important, too. Tearing polymers apart also creates uncharged molecules called radicals, which have gone mostly overlooked by scientists studying static electricity, Baytekin says. “They said, ‘Oh, radicals are uncharged, we don’t care about them.’”
So she and colleagues charged up plastic and silicone polymers and then used a type of microscopy that can map molecules’ locations. Charges and radicals clustered together, says study coauthor H. Tarik Baytekin. “This is very exciting.”
The radicals might act like a molecular support crew, stabilizing the charges and letting static electricity linger, he says. To test the idea, the team dipped polymers into solutions containing radical scavengers, such as vitamin E. These chemicals mop up radicals, leaving charges alone.
Pieces coated in radical scavengers ditched their charge much faster than uncoated pieces.
“These guys came up with an idea that is totally new — that radicals stabilize charge,” Lacks says. “I’ve never seen anything like it.”
H. Tarik Baytekin thinks radical scavengers could help quench static electricity in many different industries, from electronics to textiles. And Bilge Baytekin thinks a comb dipped in the radical scavenging solution might even smooth out frizzy hair. She hasn’t tried the experiment yet.
H.T. Baytekin et al. Control of surface charges by radicals as a principle of antistatic polymers protecting electronic circuitry. Science. Vol. 341, September 20, 2013, p. 1368. doi:10.1126/science.1241326. [Go to]
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