Indulgent yet responsible fabrics

“We see it (nanotechnology) as having virtually unlimited potential to transform the way we produce, deliver, and use energy, not to mention its likely effect on medical technology and national security.”
— U.S. Energy Secretary Spencer Abraham

Recently, I have been noticing various products claiming to have some kind of nanotechnology-based credential.  Turns out that’s because the nanotech tsunami is just gaining steam – one tally says that over 10,000 products using nanotechnology are already on the market.  In the food industry, the FDA says there are no nano-containing foods on the market in the U.S., yet DK Matai, Chairman of the Asymmetric Threats Contingency Alliance, says that the USA is the world leader in nano foods, followed by Japan, Europe and China[1].   The Environmental Working Group has done it’s own count of lotions, creams, sprays, washes, cosmetics and nutritional supplements on the market in the U.S. and has found close to 10,000 that contain nanoparticles.  And there’s an app for that:  The Project on Emerging Nanotechnologies has an iPhone app called findNano, which urges users to photograph and submit information on a possible nanotech product for inclusion in its inventory.

Eric Drexler,  in his 1986 book, Engines of Creation, pictured a world in which nanomachines no bigger than molecules run amok, consuming the planet’s resources and leaving nothing but grey goo. Other than reading about that apocalyptic event, I didn’t give nanotechnology much thought, since it didn’t seem to have much application to my own life.  Wrong again!

Turns out that there are many who think the next Industrial Revolution is right around the corner –  because of nanotechnology.  They think that nanotechnology  will radically transform the world, and the people, of the early 21st century.  It has the capacity to change the nature of almost every human-made object.  Whether that transformation will be peaceful and beneficial or horrendously destructive is unknown.   So naturally it’s become very controversial.   More about that later.

Nanotechnology as we now know it began about twenty years ago, when  research managers in the U.S. and other countries observed that physicists, biologists, chemists, electrical engineers, optical engineers, and materials scientists were working on interlocking issues at the nanoscale.  Realizing that these researchers could benefit from each other’s insights, they set up a coordinated program called the U.S. National Nanotechnology Initiative (NNI).  The National Nanotechnology Initiative  hopes to promote a future in which the ability to understand and control matter at the nanoscale  will lead to a revolution in technology  that benefits society.  The Initiative coordinates the funding for nanotechnology research and development among twenty-five federal departments and agencies.

I’ll try to give some kind of overview of the questions being asked about nanotechnology so we can begin to grasp the concept before I talk about nanotechnology in textiles (next week) where it is widely used in antimicrobial finishes, soil and water repellant finishes – and as a replacement for dyestuffs.

First, it seems the better term is really nanoscience.  Nanoscience is the study of things that are really really small: A nanometer is one billionth of a meter (10-9 m). This is roughly ten times the size of an individual atom. For comparison, 10 NM is 1000 times smaller than the diameter of a human hair.  How small is that?   “If a centimeter is represented by a football field, a nanometer would be the width of a human hair lying on the field,” offers  William Hofmeister of the University of Tennessee Space Institute’s Center for Laser Applications. 

Nanoparticles are bits of a material in which all three dimensions of the particle are within the nanoscale:  nanotubes have a diameter that’s nanosize, but can be several hundred nanometers (nm) long or even longer.  Nanofilms or nanoplates have a thickness that’s nanosize, but their other two dimensions can be quite large.  These nanoparticles can be designed into structures of a specific size, shape, chemical composition and surface design to create whatever is needed to do the job at hand. They can be suspended in liquid, ground into a powder, embedded into a composite or even added to a gas.

When particles are purposefully manufactured with nanoscale dimensions, we call them engineered nanoparticles. There are two other ways nanoparticles are formed:  as a byproduct of combustion, industrial manufacturing, and other human activities (known as incidental nanoparticles) and through natural processes, such as sea spray and erosion.

Many important functions of living organisms take place at the nanoscale. The human body uses natural nanoscale materials, such as proteins and other molecules, to control the body’s many systems and processes. A typical protein such as hemoglobin, which carries oxygen through the bloodstream, is 5 nms in diameter.  Based on the definition of nanotech given above, biotech can be thought of as a subset of nanotech – “nature’s nanotechnology.”

Manipulating something so mind-bogglingly small is where the “technology” part comes in – it’s  about trying to make technologies, such as computers and medical devices, out of these nanoscale structures.  Nanotechnology is different from older technologies because unusual physical, chemical, and biological properties can emerge in materials at the nanoscale. Nano particles have different physical properties from their macro or life-size scale counterparts.  For example, copper is an opaque mineral, but at the nano scale it is transparent.  Some particles, like aluminum, are stable at macro scale but become combustible when reduced to nano-particles;  a gold nanowire is twenty times stronger than a large bar of gold.

Nanotechnology was first brought to public attention by Richard Feynman, in a talk given in 1959 at the meeting of the American Physical Society: “There’s Plenty of Room at the Bottom” .  During that talk, he explained:

“When we get to the very, very small world—say circuits of seven atoms—we have a lot of new things that would happen that represent completely new opportunities for design. Atoms on a small scale behave like nothing on a large scale, for they satisfy the laws of quantum mechanics. So, as we go down and fiddle around with the atoms down there, we are working with different laws, and we can expect to do different things… If we go down far enough, all of our devices can be mass produced so that they are absolutely perfect copies of one another. We cannot build two large machines so that the dimensions are exactly the same. But if your machine is only 100 atoms high, you …have to get it correct.”

I found this explanation of nanotechnology on the Foresight Institute website:

“The quality of all human-made goods depends on the arrangement of their atoms. The cost of our products depends on how difficult it is for us to get the atoms and molecules to connect up the way we want them. The amount of energy used – and pollution created – depends on the methods we use to place and connect the molecules into a given product. The goal of nanotechnology is to improve our control over how we build things, so that our products can be of the highest quality and while causing the lowest environmental impact.  Nanotech is even expected to help us heal the damage our past cruder and dirtier technologies have caused to the biosphere.  Traditional manufacturing builds in a “top down” fashion, taking a chunk of material and removing chunks of it – for example, by grinding, or by dissolving with acids – until the final product part is achieved. The goal of nanotechnology is to instead build in a “bottom-up” fashion, starting with individual molecules and bringing them together to form product parts in which every atom is in a precise, designed location. In comparison with the top-down approach, this method could potentially have much less material left over, greatly reducing pollution.”

Molecular manufacturing is the name given to a specific type of “bottom-up” construction technology. As its name implies, molecular manufacturing will be achieved when we are able to build things from the molecule up, and we will be able to rearrange matter with atomic precision.

As I mentioned earlier, something so little understood is controversial, with many different points of view. These differences start with the very definition of nanotechnology, and moves on to what nanotechnology can achieve.  Then there is the ethical challenge – what is the moral imperative  about making technology that might help increase our lifespans available to all, for example?

Finally, the concern about possible health and environmental implications is perhaps the most controversial.  The problem is that some properties of these tiny particles are unknown, and potentially harmful, and scientists are still trying to determine whether their size affects their toxicity. Scientists worry that the small particles used in nanotechnology could penetrate biological barriers designed to keep out larger particles; also we don’t have guidelines about how much we can safely ingest without harm.  For more on possible harm to human health, click here.

For governments and other authorities that view commercialization of nanotechnology as a way to develop innovative environmental products and create new industries, the concerns present huge challenges.   Is there sufficient understanding or regulation of nanotech based materials to minimize possible harm to us or our environment?  The possible environmental benefits are tantalizing:  for example, water filters with nanometer-scale pores can remove 100% of the bacteria and viruses, another method will remove salt and heavy metals – meaning water from any source can be recycled and made drinkable while also eliminating downstream pollution.  This possibility alone staggers the imagination.

Nanomaterials are perceived as being untested and not well researched.  Environmental groups like Friends of the Earth Europe acknowledge that nanotechnology has the potential to deliver environmental benefits.  Even so, they have called for a moratorium on the release of so-called nanomaterials until new laws are in place to protect the public.

A study done by the Project on Emerging Nanotechnologies found that:  “a lack of information—about nanotechnology-based products, about their possible health and environmental implications, and about the oversight processes designed to manage risks—breeds public mistrust and suspicion….In the absence of balanced information, people are left to speculate about the possible impacts of nanotechnology, and  often draw on analogies to past technologies, many of which may be misleading, such as asbestos, dioxin, Agent Orange, or nuclear power.”

Mike Treder, Executive Director of The Center for Responsible Nanotechnology, said:  “Approached with pessimism, nanotechnology appears far too hazardous to be allowed to progress to anywhere near its full potential. It’s tempting to just say no, to urge that we shut Pandora’s Box and halt further development. It is a challenge of the highest order. The Center for Responsible Nanotechnology (CRN) … has studied these issues in depth for years now, and the clearest thing we can say is that there is no simple solution.  The disruptive and destabilizing implications of advanced nanotechnology must not be underestimated. At the same time, the near miraculous benefits cannot be forfeited. To save our way of life and usher in an even brighter tomorrow, it will be necessary to develop and implement comprehensive, balanced plans for responsible management of this transformative technology.”

Despite all the concerns, the market for nanomaterials has managed to gain an appreciable commercial presence:  actual size is also in dispute because nobody can decide what should be included (i.e., Nano-enabled, nanointermediates, or nanomaterials) but everybody agrees it’s big, with the US as the largest market.

[1] http://www.mi2g.com/cgi/mi2g/frameset.php?pageid=http%3A//www.mi2g.com/cgi/mi2g/press/170110.php

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