The Future of the Very Small
Within the past year, I have read several things that take this discussion to the next level. Before going there, however, let’s refresh ourselves with the opportunities that exist in our field and why we should be concerned or at least pay attention. A quick frame of reference is also in order. A nanometer is one billionth of a meter. That’s equivalent to the size of a marble compared to Earth!
In a 2009 work, “Nanotechnology for Chemical and Biological Defense,” Margaret E. Kosal, a professor at Georgia Institute of Technology, said, “Nanomaterials have shown a number of novel chemical and physical properties and functions that are different from those of bulk substances.” The next several paragraphs of her book list the ways that nanoscale materials are different in the following properties: mechanical; electrical; optical and photonic; magnetic; chemical; and thermodynamic.
A practical example of work in this area is the incorporation of nanoparticles in metalcasting. It has been shown that the strength of lightweight alloys like magnesium and aluminum can be greatly increased. Heretofore, nanotechnology efforts in metals have relied on powder metal and sintering. Ongoing work at the University of Wisconsin-Madison utilizes ultrasonic waves to keep the nanoparticles apart and uniformly dispersed throughout the metal during solidification. They expect that production of this technology might be three to five years away.
Researchers have found that increases in strength between 100 and 120% have occurred using a 2% volume fraction of nanoparticles in metal-matrix composites. Applications for this material in the aerospace, military and commercial automotive industries are obvious. One of the things that might happen as production becomes viable is the elimination of the need for heat treatment of some lightweight materials. If the strength improvement associated with age hardening is available by an addition to the melt of an aluminum alloy, the time and energy savings are apparent.
Something that might challenge the future of this technology is the potential toxicity of nanoparticles. With this in mind, the EPA plans to regulate nanotechnology through the Toxic Substances Control Act. Their proposals for testing and reporting were due before the end of 2010. The main health concerns involve skin absorption and inhalation. Nanosilver is one of the nanoscale materials receiving significant scrutiny. The safety concerns extend to manufacturers, such as 3M Co. and BASF, that use nanomaterials in various products.
John DiLorento, publisher of the NanoReg Report, says that the hodgepodge of federal, state and international nanotechnology regulations is one of the biggest challenges manufacturers of nanomaterials face. He compares it to the Whack-A-Mole arcade game because once one regulation is proposed, another pops up from a different legislative authority. Efforts are under way to unite industry groups to establish a common voice for addressing nanotechnology regulatory issues.
Acknowledging the risks associated with particles of this size, Kosal’s work discusses the potential threats of nanotechnology as a weapon similar to biological weapons. Nanotechnology may also help in the fight against chemical and biological (CB) threats. Kosal indicates that the CB-threat fight involves four areas: physical protection for people and equipment; detection and diagnosing the threat; decontamination of equipment and infrastructure; and medical countermeasures for affected personnel.
Whether nanomaterials promise to solution-harden lightweight materials without heat treatment or provide a tool for fighting CB weapons, it’s clear the future is bright. It’s also clear that there is much to learn about these super-small materials. We hope that the regulating bodies (such as the EPA) approach this new technology in a way that protects people while not discouraging the research necessary to understand how these “new” materials might be able to make life better for everyone. We could be standing on the threshold of something big, but the potential exists for regulation based on ignorance rather than sound science. May saner minds prevail. IH