The first thing to understand about carbon nanotubes is how truly small they are. They're human constructions at the atomic level, created by stitching together carbon atoms into a layer only one atom thick. When this "fabric" is curled, its ragged edges can be seamlessly joined, or it can be rolled like parchment. The result is a tube that is theoretically infinitely long but is only 1/50,000th as thick as a human hair.
Incredibly, carbon nanotubes are also among the strongest substances known. In tensile strength and stiffness, they're 312 times stronger than high-carbon steel.
These minute objects have given birth to big expectations. Carbon nanotubes have phenomenal potential for innumerable uses, including many that solve environmental problems.
Seldon Laboratories, of Windsor, sprang from nanotech research conducted by Christopher Cooper, a Ph.D. candidate at the Dartmouth College Physics Department. In 2002, Chris partnered with Alan Cummings and Roger Kennedy to form Seldon Laboratories with the goal, Alan says, "of applying this new technology to the world's most pressing problems."
According to Alan, they settled in Windsor because great industrial spaces were available there and because the town was very forward-thinking and supportive. The firm now occupies 16,000 square feet of the old Cone-Blanchard building, the sprawling, tan brick complex on the Connecticut River, and has 32 employees.
With the tiniest of technologies, they've set out to conquer what is arguably humanity's biggest problem: the lack of water.
Drinkable H20 is one of the absolute essentials, right alongside breathing in Maslow's Hierarchy of Needs. Hundreds of millions of people suffer from water poverty: water's sheer absence, water polluted by human-made chemicals, water poisoned by toxic natural minerals, parasites, microorganisms, or viruses. Water-borne disease germs and parasites are among the world's leading causes of death. And while we do know how to purify water, conventional treatment requires funding, equipment, and know-how that's often unavailable where and when it's needed.
To exploit the nanotube's unusual characteristics, the Seldon team developed what is functionally a paper-making process – making a liquid slurry of nanotube fibers, then compressing and drying it — to create a "nanomesh." Assembled into a cylindrical shape, the nanomesh passes water but catches cysts, parasites, fungi, microorganisms, viruses, and many mineral toxins.
Seldon's market-ready product line is small at present. Mainly, they make two sizes of filter, about the size of fat zucchinis, that can be used in a variety of contexts. Pump dirty water in at one end – not much pressure is needed — and safe, clean water emerges from the other. They're small, convenient, and don't depend on complex supporting technology, not even electricity. Alan says their best use is for disaster relief and for difficult outdoor situations, so their primary buyers are organizations such as FEMA, the Red Cross, and the military.
In an emergency, they can be rapidly deployed where they're needed and can be used by people without high-tech training. They can save lives in refugee camps, drought-stricken areas, communities facing water-borne disease outbreaks, and war zones.
Seldon plans to roll out three new products in 2008. The Water Box cleans up to 1,200 gallons before it clogs with contaminants and its cartridge needs replacing. It has been tested for the last year in Rwanda at the Rumangabo Clinic, run by the gorilla-defense organization founded by the late Dian Fossey. Seldon provided the clinic with the technology as well as an electrical pump that increased the volume of safe water available.
Next is the Water Stick, a hand-carried tube that allows users to sip directly from a source of dirty water, with a lifetime capacity of 80 gallons – enough to keep a family of four alive for a week. Smaller still, the Water Straw is for individuals in outdoor recreational or desperate life-or-death situations, providing one gallon. Their most likely buyers, Alan says, will be international aid organizations, the military, and outdoor enthusiasts.
Though first observed in 1952, carbon nanotubes were not brought fully to the scientific community's attention until 1991, and their commercial potentials are just now starting to be explored. Alan says that Seldon is researching using them for air filtration and for softening highly mineralized groundwater without using salts.
Biodiesel production is another hugely promising application. The process now used to refine biodiesel requires mixing vegetable oil with volatile, toxic ethanol or methanol, to remove glycerin. But passing oil through nanotube filters can also separate out this problematic waxy component, without heat or dangerous chemicals. If such filters can be cost-effectively used for biodiesel production, many more Vermont farmers might choose to raise oilseed crops and refine the fuel quickly, easily, and safely themselves.
Seldon Lab's carbon nanotubes are just one example of a once futuristic-seeming technology that has matured with startling rapidity. What else is on the horizon? We live in exciting times.
Daniel Hecht is a novelist and executive director of Vermont Environmental Consortium. For more information about any Green Grapevine topic, contact firstname.lastname@example.org.
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