Nanotech fibers from ethanol

Mar 19, 2004 9:41 AM, by Wayne Wenzel

Corn farmers could supply the building blocks of the future.

Technology gurus, and even politicians such as Newt Gingrich, are pointing to nanotechnology as a force that will change our world. But to become reality, this science of the small will require an affordable, ready source of its primary raw material, carbon. Petroleum is the obvious choice, but as its price goes up, corn-based ethanol could turn out to be the preferred source of raw materials for our nano future.

A commonly cited estimate is that a nanotechnology-based industry will be worth more than $1 trillion by 2015. Experts forecast that nanomaterials could soon give us tires that never go flat, drill bits that never get dull and thousands of other useful products that will benefit from super-strong, yet affordable materials. The basic building blocks of nanotechnology, called carbon nanotubes, can yield ultrastrong fibers that are 5,000 times smaller than a human hair.

Scientists at the University of Cambridge in England recently detailed in the journal Nature Science how they made tiny twisted ropes by winding freshly made carbon nanotubes onto spinning rods as they came out of a furnace. The team mixed ethanol — the carbon source — with a catalyst called ferrocene and another chemical called thiophene that helps the threads to assemble. The mixture was squirted into a hot furnace in a jet of hydrogen gas. Nanotubes formed into a tangled, cotton candy-like mass and were then wound onto a spindle to form strands.

The scientists report that, so far, the fibers aren't any stronger than typical textile fibers. But they think that there’s still plenty of room for improving the process to make stronger fibers by finding ways to make the nanotubes line up better. In Kevlar, for example, it’s the good alignment of molecules that generates the high strength. The scientists say they should be able to boost their nano fiber’s strength so that it rivals that of standard carbon fibers. And they say the process is relatively cheap, because it uses an ethanol feedstock that can be made from renewable resources.

Who knows? Someday the indestructible tires on your tractor, or an elevator to space, could be made from corn-based ethanol.

For more information about nanotechnology, visit www.smalltimes.com; www.nanobusiness.org; or http://nanodot.org.