Tag Archives: DTU

What do you do with a problem like regulating nanotechnology risks?

You get points for recognizing the “Sound of Music’ reference. Of course, the points aren’t useful for anything, which leads me in a roundabout way to Michael Berger’s fascinating May 28, 2013 Nanowerk Spotlight article, Does the EU’s chemical regulation sufficiently address nanotechnology risks? It’s a digest of a discussion, published in Nature Nanotechnology’s May 2013 issue, about nanotechnology regulations in light of the European Commission’s (EC; a unit in the European Union structure) Second Regulatory Review on Nanomaterials.

Berger summarizes Steffen Foss Hansen’s The European Union’s chemical legislation needs revision (article is behind a paywall) and Antonio Tajani’s response to Hansen, Substance identification of nanomaterials not key to ensuring their safe use (article is behind a paywall; Note: Links have been removed from the following excerpt),

The European Union’s chemical legislation known as REACH needs revision argues Steffen Foss Hansen, Associate Professor at DTU Environment, Technical University of Denmark. In a correspondence to the Editor of Nature Nanotechnology (“The European Union’s chemical legislation needs revision”), Hansen argues that REACH needs to be revised in three major areas.

First of all, a distinction needs to be made in the legal text of REACH between the bulk and the nano form of a given material and Hansen argues that the European Commission should acknowledge that nanomaterials cannot be identified solely by chemical composition. Additional main identifiers (such as primary particle size distribution, shape – including aspect ratio – specific surface area and surface treatment) are needed as this is the only manner in which it can be made clear that the properties and behavior of nanomaterials differ fundamentally from each other and from the bulk material.

In a response to Hansen’s Correspondence, Antonio Tajani, Vice-President of the European Commission and Commissioner for Industry and Entrepreneurship, writes that substance identification of nanomaterials is not key to ensuring their safe use (“Substance identification of nanomaterials not key to ensuring their safe use”).

Tajani argues that substance identification is only one element and that trying to identify unambiguous rules for substance identification is probably elusive and might result in ever more complex rules on what is considered as the same substance as opposed to different substances, without necessarily resulting in more safety of nanomaterials. Instead, Tajani and the European Commission wish to focus on clarifying what is needed to demonstrate the safe use while also noting that the implementation of regulatory changes would take several years and hence is not desirable.

As per my Oct. 25, 2011 posting (Nanoparticle size doesn’t matter), my thinking on environmental, health, and safety issues regarding engineered nanomaterials has been in the process of change and I note that focusing on the size, shape, and other factors would make regulation next to impossible. So, I’m inclined to agree with Tajani’s arguments that trying to develop “unambiguous rules for substance identification” is not a worthwhile approach to dealing with any EHS issues that nanomaterials may present and will likely prove futile in the same way as gaining points for recognizing my attempted ‘Sound of Music’ reference.

I assume that Tajani and Hansen are referring to engineered nanomaterials as opposed to naturally occurring nanomaterials. (I too forget to specify but unless otherwise noted I’m usually referring to engineered nanomaterials.)

For me, two of the most compelling issues that Hansen presents revolve around a lack of data and standardized testing (from Hansen’s article in Nature),

… there are few measured exposure data and that few environmental fate and behaviour studies are available. …

… there are currently no standardized (eco)toxicity test guidelines in use …

I do wonder how many the word ‘few’ represents as I’m reminded of the plethora of studies on silver nanoparticles and on long, multi-walled carbon nanotubes. Certainly, they are attempting to address the situation regarding consistent testing protocols in the US as per my May 8, 2013 post about the NanoGo Consortium. Perhaps the EC folks could consider using these protocols as a model for a European version?  I assume that Hansen is commenting on a broader, European-inflected picture rather than the piecemeal, ‘globalish’ picture I have formed from my meanderings in the nanosphere.

Hansen also points this out in his Nature article (Note: Footnotes have been removed),

Another disturbing aspect of the Second Regulatory Review on Nanomaterials is that it focuses only on first-generation nanomaterials (that is, passive nanostructures such as nanoparticles). The Staff Working Paper acknowledges that second- and third-generation nanomaterials (for example, targeted drug-delivery systems and novel robotic devices) are entering early stages of market development, …

I’m beginning to find the discussion about definitions and resultant regulations wearing and am coming to the conclusion that the focus should be on bringing the information already gathered together, standardizing tests, determining what is  known and not known, and establishing some forward momentum.

“Control my chirality, please,” said the carbon nanotube to the researchers

A combined Finnish, Russian, and Danish team have found a way to control the chirality of single-walled carbon nanotubes according to an Apr. 30, 2013 news item on Azonano,

An ultimate goal in the field of carbon nanotube research is to synthesise single-walled carbon nanotubes (SWNTs) with controlled chiralities. Twenty years after the discovery of SWNTs, scientists from Aalto University in Finland, A.M. Prokhorov General Physics Institute RAS in Russia and the Center for Electron Nanoscopy of Technical University of Denmark (DTU) have managed to control chirality in carbon nanotubes during their chemical vapor deposition synthesis.

The Aalto University Apr. 29, 2013 news release, which originated the news item, goes on to explain,

 Over the years, substantial progress has been made to develop various structure-controlled synthesis methods. However, precise control over the chiral structure of SWNTs has been largely hindered by a lack of practical means to direct the formation of the metal nanoparticle catalysts and their catalytic dynamics during tube growth.

– We achieved an epitaxial formation of Co nanoparticles by reducing a well-developed solid solution in CO, reveals Maoshuai He, a postdoctoral researcher at Aalto University School of Chemical Technology.

– For the first time, the new catalyst was employed for selective growth of SWNTs, adds senior staff scientist Hua Jiang from Aalto University School of Science.

By introducing the new catalysts into a conventional CVD reactor, the research team demonstrated preferential growth of semiconducting SWNTs (~90%) with an exceptionally high population of (6,5) tubes (53%) at 500 °C. Furthermore, they also showed a shift of the chiral preference from (6,5) tubes at 500 °C  to (7, 6) and (9, 4) nanotubes at 400 °C.

– These findings open new perspectives both for structural control of SWNTs and for elucidating their growth mechanisms, thus are important for the fundamental understanding of science behind nanotube growth, comments Professor Juha Lehtonen from Aalto University.

For anyone like me who needs a description of chirality, there’s this from Wikipedia,

Chirality (pron.: /kaɪˈrælɪtiː/) is a property of asymmetry important in several branches of science. The word chirality is derived from the Greek, χειρ (kheir), “hand”, a familiar chiral object.

An object or a system is chiral if it is not identical to its mirror image, that is, it cannot be superposed onto it. A chiral object and its mirror image are called enantiomorphs (Greek opposite forms) or, when referring to molecules, enantiomers. A non-chiral object is called achiral (sometimes also amphichiral) and can be superposed on its mirror image.

Human hands are perhaps the most universally recognized example of chirality: The left hand is a non-superimposable mirror image of the right hand; no matter how the two hands are oriented, it is impossible for all the major features of both hands to coincide.[2] This difference in symmetry becomes obvious if someone attempts to shake the right hand of a person using his left hand, or if a left-handed glove is placed on a right hand. In mathematics chirality is the property of a figure that is not identical to its mirror image.

One of the researchers notes why they, or anyone else, would want to control the chirality of carbon nanotubes, from the news release,

– Chirality defines the optical and electronic properties of carbon nanotubes, so controlling it is a key to exploiting their practical applications, says Professor Esko I. Kauppinen, the leader of the Nanomaterials Group in Aalto University School of Science.

ETA Apr. 30, 2013 at 4:20 pm PDT: Here’s a link to and a citation for the team’s published paper,

Chiral-Selective Growth of Single-Walled Carbon Nanotubes on Lattice-Mismatched Epitaxial Cobalt Nanoparticles by Maoshuai He, Hua Jiang, Bilu Liu, Pavel V. Fedotov, Alexander I. Chernov, Elena D. Obraztsova, Filippo Cavalca, Jakob B. Wagner, Thomas W. Hansen, Ilya V. Anoshkin, Ekaterina A. Obraztsova, Alexey V. Belkin, Emma Sairanen, Albert G. Nasibulin,  Juha Lehtonen, & Esko I. Kauppinen. Scientific Reports 3, Article number 1460  doi:10.1038/srep01460 Published15 March 2013

This article is open access.

Danish nanotechnology-enabled product database

It’s called the Nanodatabase according to the Nov. 30, 2012 news item on Nanowerk (Note: I have removed a link),

The Danish Consumer Council and the Danish Ecological Council has in cooperation with DTU Environment developed a database, which help consumers identify more than 1,200 products that may contain nanomaterials. The Nanodatabase gives consumers a choice. [emphasis mine]

”Most consumers have no idea if there are nanomaterials or not in the goods they’re buying. And they have no way of finding out, so that they can avoid the products if they are worried about the potentially harmful effects” says Claus Jørgensen, Senior Advisor at the Danish Consumer Council.

This is why the Danish Ecological Council and the Danish Consumer Council in cooperation with experts from DTU [Technical University of Denmark] Environment has decided to launch the Nanodatabase. Now consumers can search the database to see if a certain product contains nanomaterials or is marketed as ‘nano’. This way the consumers can choose if they want the nanomaterials or not.

The database contains more than 1,200 products which contain nanomaterials or are marketed using the nano-claim. [emphasis mine]

“Until we know for sure that the use of nanotechnology is safe and the legislation is in place, we need a label that can help consumers make informed choices”, says Lone Mikkelsen [chemical expert from the Danish Ecological Council].

The two organisations hope that the English version of the database will help consumers in other countries. The hope is that consumers will report products that contain ‘nano’ or claim to be a nano product to the database.

This project reminds me of the Project on Emerging Nanotechnologies (PEN) and their consumer products inventory. I don’t believe they’re adding to that inventory any moreas the March 10, 2011 news release announcing over 1300 nanotechnology-enabled products (as claimed by manufacturers) in the inventory appears to have been PEN’s last. I think they, like the Danish Consumer Council and the Danish Ecological Council, were hoping to raise awareness.