Invisible nanofibres conduct electricity, repel dirt

In a new study, scientists from Ohio State University grew nanofibres of different heights and diameters, and were able to modify the fibres’ molecular structures by exposing them to different chemicals.

The plastic fibres could be the key to some diverse technologies in the future — including self-cleaning surfaces, transparent electronics, and biomedical tools that manipulate strands of DNA.

The patent-pending technology involves a method for growing a bed of fibres of a specific length, and using chemical treatments to tailor the fibres’ properties, explained Arthur J. Epstein, Distinguished University Professor of chemistry and physics and director of the university’s Institute for Magnetic and Electronic Polymers.

In the June issue of the journal Nature Nanotechnology, Ohio State University researchers describe how they created surfaces that, seen with the eye, look as flat and transparent as a sheet of glass.

But seen up close, the surfaces are actually carpeted with tiny fibres.

“One of the good things about working with these polymers is that you’re able to structure them in many different ways,” Epstein said. “Plus, we found that we can coat almost any surface with these fibres.”

Repel oil

They devised one treatment that made the fibres attract water, and another that made the fibres repel water. They found they could also make the surfaces attract or repel oil.

Depending on what polymer they start with, the fibres can also be made to conduct electricity, according to an Ohio State University press release. The ability to tailor the properties of the fibres opens the surface to many different applications, he said. Since dirt, water, and oil don’t stick to the repellent fibres, windows coated with them would stay cleaner longer.

Anti-fog coating

In contrast, the attracting fibres would make a good anti-fog coating, because they pull at water droplets and cause them to spread out flat on the surface. What is more, researchers found that the attracting surface does the same thing to coiled-up strands of DNA.

When they put droplets of water containing DNA on the fibres, the strands uncoiled and hung suspended from the fibres like clotheslines.

Epstein said scientists could use the fibres as a platform to study how DNA interacts with other molecules. They could also use the spread-out DNA to build new nanostructures.