CelluForce machinery used to refine cellulose nanocrystals. Photo courtesy CelluForce.
By Joy Beckerman
Nanotechnology is an exponentially large area of science based in exponentially small particles. But the beyond-miniscule nature of nanotechnology should be not be mistaken with impact size. Like a gently forming swell in the middle of the ocean that becomes a colossal tidal wave, nanotechnology has already transformed our lives in sweeping ways and will continue to revolutionize our entire way of life. Neal Lane, former assistant to the president for Science & Technology, stated in 1998, “If I were asked for an area of science and engineering that will most likely produce the breakthroughs of tomorrow, I would point to nanoscale science and engineering.”
His prediction was entirely accurate and the U.S. government has since allocated billions of dollars toward nanotechnology research, scads more than was spent on sequencing the human genome when that project was at its height. Japan and the European Union have spent similar amounts.
There are two definitions of nano. One definition is “a billionth part,” or 10-9, for you mathematicians and garden-variety nerds out there. Quantum mechanics are required to fully understand nano-concepts. This metric system definition defines a nanometer as one-billionth of one meter (the length one’s fingernail grows in the time it takes to lift a nail file off the vanity table); a nanogram is one-billionth of one gram; a nanoliter is one billionth of one liter, and so on. The cross in this “t” comprises nearly 500,000 nanometers.
The U.S. government defines nanotechnology differently, describing it as meaning that the smallest dimension of the material being worked with is between one and 100 nanometers.
Magic (as those of us who are not so scientifically-inclined often refer to it) occurs on the nanoscale because that is the level that essential elements and properties of matter are determined. Substances change in dramatic ways when taken down to the nanoscale. For example, the melting temperature of gold begins to drop dramatically when it is cut down to 10 nanometers. Suspensions of silver or gold nanoparticles change color depending upon their size, and all the colors of the rainbow can be produced just by changing the size of the nanoparticle. This is one effect of nanotechnology or a “nanoeffect.”
Another very simple example is calcium carbonate: stacking these molecules in a brick formation produces the durable, opalescent abalone shell, but arranging those same molecules in a saw-tooth pattern produces a frail, chalk-like material. Nanotechnology is essentially the ability to create materials with optimal properties as a result of the ability to customize the atomic structure of those materials. Think of plastic that can conduct electricity or a T-shirt that is also a computer monitor.
Oregon State University professor John Simonsen describes nanotechnology best as “the creation of useful/functional materials, devices and systems through control of matter on the nanometer-length scale and exploitation of novel phenomena and properties (physical, chemical, biological) at that length scale.”
Simonsen begins the nanotechnology lesson by teaching his Wood Science & Engineering and Industrial Hemp students about the Lotus Effect. He explains how the lotus stays so pristinely clean while simultaneously growing in a muddy pond.
It turns out the lotus leaf is covered with tiny, waxy spikes that repel water. But it’s more interesting than that. You may have noticed while driving during a rainstorm that a drop of water slides down the windshield, as opposed to rolling down. Conversely, when a droplet of water falls on a lotus leaf, it rolls down the leaf, as opposed to sliding. This is a result of the tiny, waxy spikes preventing the droplet from spreading out and wetting the surface, causing the water to remain in droplet form. As the droplet rolls down the surface of the leaf, it actually picks up the dirt particles that are sitting on the waxy spikes and cleans the leaf automatically.
This effect has been duplicated and used commercially in a number of ways, the most familiar one being the stain-resistant shirt. A product called Nano-Tex, for example, duplicates the Lotus Effect by using very tiny, nano-sized glass spheres which are processed in a manner that will form small spikes on the surface of the cloth after they are embedded by basically painting them onto the fabric prior to garment manufacturing. Liquids simply roll off the surface of the shirt, as opposed to soaking into the fabric. Self-cleaning awnings and wood sealers are other similar nanotechnology applications.
Nanotechnology has revolutionized the electronics and telecommunications industries in every manner from cell phones to computers to multi-tasking wrist watches and so much more. There are products on the market today from hockey sticks and watercraft to nail polish and sunscreens that incorporate nanotechnology, though we aren’t generally aware of it as we purchase and use them.
But what does nanotechnology have to do with industrial hemp? As Hiruyoki Yano of Kyoto University accurately declared, “The cellulose sub-elementary fibril in plants is the most abundant nanomaterial on Earth!”
Analyzing the risk for nanoparticles, or any other new technology being developed for market, requires the consideration of a multitude of safety and other factors. And while there are a number of nanocellulose sources and types, cellulose nanocrystals in particular are distinguishing themselves because they continue to test as non-toxic and likely benign.
Cellulose nanocrystals can be extracted from cotton and sisal, but most of the cellulose-based nanomaterials that have been produced to date have been produced from wood because it is the most available, cellulose-abundant source. That will change when industrial hemp is more readily available in the U.S.
Industrial hemp may look like flax, kenaf and other similar fiber crops from the outside, but the long, strong hemp stalk contains an exceptional 77% percent cellulose. And hemp bast fiber is precisely the type from which valuable cellulose nanocrystals can be extracted.
Cellulose nanocrystals have a high surface area and are remarkably stiff and strong. In fact, they’re among the stiffest and strongest organic materials that can be obtained in all of nature; their strength measures much higher than glass, higher than aluminum, and actually measures more comparably to steel. Materials such as graphite whisker and carbon nanotube score the highest in stiffness and strength, but cellulose nanocrystals are a considerably low cost nanoparticle, which makes them enormously attractive and competitive when one looks at the larger picture that includes price, availability, toxicity and sustainability. This ultimate package is the reason so many researchers are studying cellulose nanocrystals at such an accelerated rate.
Cellulose nanocrystals may prove to be an excellent material for plastic composites and reinforcement for building materials, automotive parts and conductive materials. Other biomaterials made from cellulose nanocrystals could include textiles, biodegradable plastic bags, bandages, flexible batteries made from electrically-conductive paper, new drug-delivery technologies, transparent flexible displays for electronic devices, special filters for water purification, new types of sensors, and even computer memory to name a few.
“Cellulose nanomaterials are inherently renewable, sustainable, biodegradable and carbon-neutral like the sources from which they were extracted,” said Robert J. Moon, a researcher from the U.S. Forest Service’s Forest Products Laboratory. “They have the potential to be processed at industrial-scale quantities and at low cost compared to other materials.”
Moon went on to say, “Some of the byproducts of the paper industry now go to making biofuels, so we could just add another process to use the leftover cellulose to make a composite material. The cellulose crystals are more difficult to break down into sugars to make liquid fuel. So let’s make a product out of it, building on the existing infrastructure of the pulp and paper industry.”
Nanocellulose is in the process of being commercialized, but at present, the only country engaged in cellulose nanocrystal commercialization is Canada (where cellulose nanocrystals are called nanocrystalline cellulose, and where hemp cultivation has been legal since 1998). A company called CelluForce built a reportedly $41,000,000 manufacturing facility there that can produce a full ton of cellulose nanocrystals per day. Although it may not have achieved full capacity yet, the manufacturing plant is up and running.
Biorefineries are another development in technology where the concept is to build processing facilities that process biomass into a variety of different products. Hemp biorefineries could process seed oil, bast fiber for textiles, hurd for building materials and cellulose nanocrystals. The Canadian company Blue Goose Biorefineries, Inc. is planning to build an operational facility that offers nanocellulose as one of its products, and the company plans to use hemp as one of its important raw materials. Many more biorefineries are expected in the future and it’s anticipated that we will see nanocellulose as one of the high-value products produced from them.
Industrial hemp and nanotechnology, whodathunk? America didn’t need another reason to reintroduce the versatile, valuable, soil-enriching industrial hemp crop, but here we are presented with yet another exceedingly compelling one. Please contact your representatives now to voice your support of legalizing industrial hemp cultivation throughout the United States.
Joy Beckerman is the president of Hemp Ace International and president of the Washington chapter of the Hemp Industries Association.