SAMPE Journal - May/June 2013 - (Page 50)

PersPectives Steven Rodgers SAMPE Past President and Consultant, EmergenTek LLC Steven.R@EmergenTek.com Little Thoughts About Nano Safety “In a perfect world everything would be either black or white, right or wrong, and everyone would know the difference. But this isn’t a perfect world. The problem is people who think it is.” – Neal Shusterman, “Unwind” There it was, the offensive thought boldly stated in a headline. It was a thought I had both anticipated and dreaded for years and here it was, distilled and served to the world. The statement was bold and it came from an “authoritative” source but it carried in it a gross oversimplification that, in the end analysis, was misleading. The headline read: “Mesothelioma Symptoms Linked to Nanotechnology – Carbon Nanotubes” Perhaps I am overly sensitive to this kind of headline. After all, headlines are meant to capture a simple thought in a way that “sells” the article. There is certainly stiff competition today for a reader’s attention with the proliferation and availability of information. But it seemed to me that the emphasis of the headline was Nanotechnology. By the time Carbon Nanotubes were mentioned, all of nanotechnology had been implicated. Yet, even with the addition of the words Carbon Nanotubes to the headline it was deceptively simple and misleading. At this point, perhaps you are wondering if I am one of those “all technology is ultimately beautiful” people who would condemn all attacks as being unjustified, the evil scientist who would sacrifice all of the villagers with their torches and pitchforks rather than allow his beloved creation to be maligned. This is certainly not the case. In the Fall of 2007 I was responsible for initiating a SAMPE Technical Community to explore the Health, Safety and Toxicity (HS&T) issues related to Nanomaterials. In part, I did this because it seemed to me that there was a need to identify potential health hazards and deal with them realistically. The reason I wanted to understand the HS&T issues is because I knew that there would always be people who will want to simplify the issues and to paint all nanotechnology with the same broad-brush stroke. In a world of black and white, there is a risk that all nanomaterials will be considered intrinsically dangerous to the detriment of a new, useful class of materials. And that is the substance of my concern: Nanomaterials represent a diverse class of materials and any attempt to treat them all the same ultimately risks either condemning the innocent or absolving the guilty. What makes the topic so complex is the staggering variety of materials and forms that affect the ultimate issue of Nanotoxicology. Unlike people, all nanomaterials are NOT created equal and there are many subtleties that become imminently important. First we need to understand the significance of working at the nanometer scale. First, let me belabor the obvious and say that a nanometer is a really small measurement. If Earth measured one meter (39.37 in) in diameter, then a nanometer would be 1.28cm (0.4 in) in diameter by comparison. When we speak of nanotechnology we are dealing in a range that is roughly 100nm or less in size and there is a very good reason for that seemingly arbitrary definition. In 1959, Dr. Richard Feynman gave a talk at the American Physical Society titled “There’s Plenty of Room at the Bottom”. In that talk he postulated that if we were capable of working at the nano scale that some interesting phenomena would occur. Physical effects as we understand them would become less effective. Things such as gravity and inertia would begin to diminish while things like van der Waals forces (the weak, short-range electrostatic forces between uncharged molecules) would become more pronounced. In fact it is those van der Waals forces that allow gecko lizards to walk on sheets of glass using tens of thousands of nanoscale features on their footpads. What we are discovering is a new understanding of physics that exists between the macro scale (gravity, inertia, etc.) and physics on the sub-microscopic scale (chemistry). One of the reasons we have not seen more commercialization of nanotechnology after decades of research is that in many ways we are still learning the ramifications of this new area of physics. When it comes to HS&T, relationships between materials are not arbitrary but specific and we cannot take all nanomaterials, or even an entire class of nanomaterials, and treat them as if they are all identical, especially when looking at potential interactions with something as delicately balanced as a living organism. When we talk of carbon nanotubes, as the article does, there are a number of qualifying questions that have gone conspicuously unanswered in the article if we are to understand the importance of the report: What diameter are the carbon nanotubes and is that consistent? What aspect ration (length to diameter, or l:d) do they attain and is that consistent? Is it a single wall carbon nanotube 50 SAMPE Journal, Volume 49, No. 3, May/June 2013

Table of Contents for the Digital Edition of SAMPE Journal - May/June 2013

SAMPE Journal - May/June 2013
Contents
President’s Message
Technical Director’s Corner
Mechanical Properties of Bio-Fibers for Composite Materials
SAMPE Journal Editorial Calender
Corporate Partners
Materials & Products
Welcome SAMPE’s Newest Members
SAMPE Proceedings
Resin Transfer Moulding of Composite Panels with Bio-Based Resins
Europe News & Views
SAMPE Europe’s SETEC 13 Wuppertal, Germany
Innovative and Sustainable Approaches to Enhance Fire Resistance of Cellulosic Fibers for Green Polymer Composites
Class of 2013-SAMPE Fellows
The SAMPE Foundation
SAMPE Tech 2013|Wichita, KS
SAMPE Tech 2014|Call for Papers
Industry News
Perspectives
SAMPE 2013|Long Beach
SAMPE 2013 Exhibitor Listing
SAMPE 2013 Show Floor
SAMPE 2013 Exhibitor Products & Services
Advertiser’s Index
Resource Center
Industry Events Calendar
Chapter Contacts

SAMPE Journal - May/June 2013