Some are calling it a revolution in manufacturing technology. But, will nanotechnology be a "green" industry? It’s a question that some scientists are saying needs to be answered now, before nano-tech goes big-time. This ScienCentral News video has more.
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Nanotechnology is the ability to manufacture and manipulate particles smaller than 100 nanometers. A nanometer is one billionth of a meter. If you lined up 400 of the largest nanoparticles in a row, they would barely span the width of a human hair. Nanoparticles are like an incredibly fine dust—but not just any dust. Scientists can now create specific shapes of particles, coat them with chemicals or medicines, and leverage the inherent properties of the material (gold, carbon, silver, iron, etc.) to perform novel engineering functions.
"We can design materials that have properties that that have never been available before, never been discovered before," says nanotechnology researcher James Hutchison of the University of Oregon. "So our job really is like molecular architects."
The technology monitoring firm Lux Research estimates that by the year 2015, the global output of goods using nanotechnology will be $4 trillion. But purifying nanoparticles sometimes requires toxic organic solvents, and some nanoparticles themselves are potentially hazards to factory workers and consumers. What is being done to move this budding industry towards greener practices?
The Price of Gold
Hutchison points to gold nanoparticles, just a few nanometers in diameter, seen under an electron microscope.
In Hutchison's lab, researchers are spinning gold—gold and copper nanoparticles so small, billions would fit on the head of a pin. Someday they may become a better way to target tumor cells in cancer patients. The particles could be coated with chemicals that stick to tumor cells, at which point they would release a chemotherapy drug or else be targeted with tumor-destroying infrared light or x-rays. But making the new nanoparticles required a lot of organic solvents. Organic solvents like hexane and chloroform are chemicals that are hazardous to people and the environment.
"We were using 15,000 times more solvent than—in terms of mass of solvent—than actual material we were purifying," Hutchison says. "As we start to scale up, the hazards of those materials become much more important. The waste generated just multiplies."
To reduce that amount, and the impact on the environment, they switched to a technique normally used in biotechnology called diafiltration. It uses water (instead of toxic solvents) and an ultrafine filter to remove contaminant particles of certain sizes. The same technology is used to filter blood in kidney dialysis machines. As they wrote in the American Chemical Society journal Nano, that allowed them to purify their product with just a small amount of water.
Scaling Up Nano
He says these kinds of innovations are needed now, as nanotechnolgy is moving out of the lab and into the factory. Nanoparticles are already being incorporated into hundreds of products, from computer chips and house paint to cosmetics and odor-fighting socks.
"To commercialize these materials, we have to find solutions that make the processes more convenient, much more efficient, and safer," says Hutchison. "We have for the first time in a new technology the opportunity to try to get these things right the first time rather than proceeding with inefficient and unsafe methods, and then having to clean up the mess afterward."
The policy group Project on Emerging Nanotechnologies maintains a list of consumer products that manufacturers say incorporate nanotechnology.
The research was published in the American Chemical Society journal Nano, March 2008, and was funded by W. M. Keck Foundation, Air Force Research Laboratory, and the State of Oregon.