PULLMAN, Wash.—If you’re looking for a reason to be nervous about flying, consider that much of your airplane is probably held together by glue.
“Most modern aircraft are glued together,” said Kerry Hipps, a Washington State University professor and chair of chemistry and materials science. “The rivets you see are just to control peeling; the adhesive provides the strength. A very thin interaction between one metal, the adhesive, and the next metal keeps the whole plane in the air.”
Here’s another reason to be nervous: Science isn’t quite sure what those surfaces are doing when their atoms and molecules are, for lack of a more scientific term, shaking hands.
Obviously, things are working pretty well. But Hipps wants to know how they’re working, and he’s going to watch them in unprecedented ways.
“There are a lot of processes that go on at the surface that are important to technology that we’ve never really looked at closely,” he said. “And by closely I mean literally watch the atoms and molecules do their thing. That’s what we want to do.”
Hipps has received a three-year National Science Foundation grant of $483,000 for a molecular-level look at the way liquids and solids interact. The research has implications for a growing number of technologies, from adhesives to chemical sensors, as well as the emerging science of the super-small, nanotechnology.
Hipps’ main tool is a scanning tunneling microscope, a 30-year-old Nobel Prize-winning innovation that can see materials as small as a millionth of a millimeter.
He concentrates on the interface between a surface and a liquid. That’s because one liquid will generally dissolve another, and two solids usually just bump together, sharing just a few layers of atoms.
But the atoms of liquids and solids get on like friendly Rotarians, facilitating natural processes – like a red blood cell’s delivery of oxygen – and technologies – like sensors, sticky notes, catalytic converters and laminates.
The scanning tunneling microscope came into wide use in the mid-1980s and since has helped spawn more than 20,000 research papers. But fewer than 800 looked at the interactions of solids and liquids, Hipps said.
Of those, only a handful of papers involve research above or below room temperature, even though temperature dramatically affects the rate and mechanics of a reaction – and whether it occurs at all.
If we can understand how fast reactions occur and at what temperatures, we can begin to design new types of materials that use both features in making new surfaces and products, said Hipps.
For now, he said, scientists and engineers approach these technologies by trial and error, which can involve hundreds of experiments. But a deeper understanding of molecular interactions and processes can markedly reduce the number of experiments needed to get a desired result, Hipps said.
Such an understanding will lead to technologies that use less energy, create less pollution and use materials more efficiently.
“Energy is expensive and we’re trying to minimize the energy,” Hipps said. “We’re trying to do things in a green way.”