Windmoeller
Published

Single-Wall Carbon Nanotubes Show No Ecotoxicity

Findings on OCSiAl’s Tuball nanotubes are based on OECD chemical testing guideline 201.

Share

The Tuball single-wall carbon nanotubes produced by Russia’s OCSiAL (U.S. office in Columbus, Ohio) were recently tested for their ecotoxicity potential in accordance with the relevant OECD chemical testing guideline 201, and were shown to have no toxic effects on algae. This in contrast to a set of recent results with muti-wall carbon nanotubes. Among the possible reasons, says OCSiAL, is their unique physical nature, particularly their high flexibility.

The range of applications of carbon nanotubes has continued to increase rapidly and now extends far beyond only high-technology products to include consumer goods. As a result, concerns have been raised about the potential adverse environmental effects of carbon nanotubes.  A single-wall carbon nanotube is a one-atom-thick sheet of graphene that is rolled into a tube. This type of nanotube has been shown to possess a number of important properties, including high flexibility that is far superior to that offered by multi-wall carbon nanotubes or carbon fibers.    

Independent European research laboratory Envigo, which conducted the studies, examined the Tuball single-wall carbon nanotubes by treating algae—recognized as a very sensitive species—with a  saturated solution of the nanotubes for 72 hours, as per the OECD guideline. The measured algal biomass densities and thus the growth rates demonstrated that there were no toxic effects. Said researcher Detlef Schuler in his soon-to-be published article, “There is no indication that dissolved Tuball single-wall carbon nanotubes have any intrinsic ecotoxic properties at all when tested in solution as stipulated by the testing guidelines. Furthermore, unlike multi-wall carbon nanotubes and carbon fibers, single-wall carbon nanotubes are highly flexible and may thus generally have a lower potential to harm the cell walls of algae.”

Fundamentally, distinctive features of single-wall carbon nanotubes, compared with the multi-wall nanotubes and carbon fibers, have historically been underestimated by researchers. A number of recent test results have illuminated various effects of these nanomaterials interacting with the environment. One example is a study led by the Russian Far Eastern Federal University that demonstrated both acute and chronic toxic effects of multi-wall carbon nanotubes on marine algae. The researchers concluded that mechanical damage to the cell walls was the reason for this effect, and that this was due to the rigid nature of this type of nanotube.

Further specific and comprehensive studies on single-wall carbon nanotubes’ potential toxic properties will be conducted in the very near future, including inhalation toxicity studies to be carried out according to the relevant OECD test guidelines. Tests on migration of these nanotubes from a material’s matrix, and case studies in the workplace to measure the exposure to inhaled nanoparticles and the environmental risk for workers are already in the public domain, according to OCSiAL.

It should be noted that the single-wall carbon nanotubes continue to be more expensive than their multi-wall counterparts—although all have come down in price as commercial applications grow. According to OCSiAL, the multi-wall nanotubes are about nine times higher in cost. However, depending on the application, the multi-wall carbon nanotubes require dosage levels between 20 and 100 times higher than their single-wall counterparts—generally making the latter more cost-effective. 

Earlier this year, we reported on how OCSiAl’s Tuball nanotubes were used in the first anti-static blown PE films.

Cranes, Conveyors, Racks, Loaders, Accessories
Orbetron new for 2024 micro twin screw feeder
New Tinius Olsen VectorExtensometer testing
Registration is on Us
Shell Polymers (Real)ationships start here ad
We Love Powders NPE
NPE2024: The Plastics Show
TracerVM Flow Meter features many display options
Plastics Recycling Latam
Go Beyond Blending
Bole Machinery
Trust the experts for fast & efficient changeovers

Related Content

Thermoforming

US Merchants Makes its Mark in Injection Molding

In less than a decade in injection molding, US Merchants has acquired hundreds of machines spread across facilities in California, Texas, Virginia and Arizona, with even more growth coming.

Read More
sustainability

In Sustainable Packaging, the Word is ‘Monomaterial’

In both flexible and rigid packaging, the trend is to replace multimaterial laminates, coextrusions and “composites” with single-material structures, usually based on PE or PP. Nonpackaging applications are following suit.

Read More
Packaging

‘Monomaterial’ Trend in Packaging and Beyond Will Only Thrive

In terms of sustainability measures, monomaterial structures are already making good headway and will evolve even further.

Read More
Film Extrusion

Pregis Performance Flexibles: In the ‘Wow’ Business

Pregis went big and bold with investment in a brand-new, state-of-the-art plant and spent big on expanding an existing facility. High-tech lines, well-known leadership and a commitment to sustainability are bringing the “wow” factor to blown film.

Read More

Read Next

close up on technology

Processor Turns to AI to Help Keep Machines Humming

At captive processor McConkey, a new generation of artificial intelligence models, highlighted by ChatGPT, is helping it wade through the shortage of skilled labor and keep its production lines churning out good parts.

Read More
Extrusion

How Polymer Melts in Single-Screw Extruders

Understanding how polymer melts in a single-screw extruder could help you optimize your screw design to eliminate defect-causing solid polymer fragments.  

Read More
industry 4.0

People 4.0 – How to Get Buy-In from Your Staff for Industry 4.0 Systems

Implementing a production monitoring system as the foundation of a ‘smart factory’ is about integrating people with new technology as much as it is about integrating machines and computers. Here are tips from a company that has gone through the process.

Read More
reduce mold change time injection molding