Space Industry and Business News  
NANO TECH
Microwaved nanotubes come up clean
by Staff Writers
Houston TX (SPX) Jan 26, 2016


Treatment with a microwave oven and chlorine removes stubborn iron catalyst residues from carbon nanotubes, according to researchers at Rice University and Swansea University. The two-step process may make them more suitable for sensitive applications. Image courtesy Virginia Gomez Jimenez/Swansea University. For a larger version of this image please go here.

Amid all the fancy equipment found in a typical nanomaterials lab, one of the most useful may turn out to be the humble microwave oven. A standard kitchen microwave proved effective as part of a two-step process invented at Rice and Swansea universities to clean carbon nanotubes.

Basic nanotubes are good for many things, like forming into microelectronic components or electrically conductive fibers and composites; for more sensitive uses like drug delivery and solar panels, they need to be as pristine as possible.

Nanotubes form from metal catalysts in the presence of heated gas, but residues of those catalysts (usually iron) sometimes remain stuck on and inside the tubes. The catalyst remnants can be difficult to remove by physical or chemical means because the same carbon-laden gas used to make the tubes lets carbon atoms form encapsulating layers around the remaining iron, reducing the ability to remove it during purification.

In the new process, treating the tubes in open air in a microwave burns off the amorphous carbon. The nanotubes can then be treated with high-temperature chlorine to eliminate almost all of the extraneous particles.

The process was revealed in the Royal Society of Chemistry journal RSC Advances.

The labs of chemists Robert Hauge, Andrew Barron and Charles Dunnill led the study. Barron is a professor at Rice in Houston and at Swansea University in the United Kingdom. Rice's Hauge is a pioneer in nanotube growth techniques. Dunnill is a senior lecturer at the Energy Safety Research Institute at Swansea.

There are many ways to purify nanotubes, but at a cost, Barron said. "The chlorine method developed by Hauge has the advantage of not damaging the nanotubes, unlike other methods," he said. "Unfortunately, many of the residual catalyst particles are surrounded by a carbon layer that stops the chlorine from reacting, and this is a problem for making high-purity carbon nanotubes."

The researchers gathered microscope images and spectroscopy data on batches of single-walled and multiwalled nanotubes before and after microwaving them in a 1,000-watt oven, and again after bathing them in an oxidizing bath of chlorine gas under high heat and pressure. They found that once the iron particles were exposed to the microwave, it was much easier to get them to react with chlorine. The resulting volatile iron chloride was then removed.

Eliminating iron particles lodged inside large multiwalled nanotubes proved to be harder, but transmission electron microscope images showed their numbers, especially in single-walled tubes, to be greatly diminished.

"We would like to remove all the iron, but for many applications, residue within these tubes is less of an issue than if it were on the surface," Barron said. "The presence of residual catalyst on the surface of carbon nanotubes can limit their use in biological or medical applications."

Co-authors of the study are Virginia Gomez, postdoctoral research assistant at Swansea; Silvia Irusta, a professor at the University of Zaragoza, Spain; and Wade Adams, a senior faculty fellow in materials science and nanoengineering at Rice.

Hauge is a distinguished faculty fellow in chemistry and in materials science and nanoengineering at Rice. Barron is the Charles W. Duncan Jr.-Welch Professor of Chemistry and a professor of materials science and nanoengineering at Rice and the Ser Cymru Chair of Low Carbon Energy and Environment at Swansea.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Rice University
Nano Technology News From SpaceMart.com
Computer Chip Architecture, Technology and Manufacture






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
NANO TECH
FAU researchers show how mother-of-pearl is formed from nanoparticles
Erlangen, Germany (SPX) Jan 20, 2016
Materials scientists at FAU have shown for the first time that the mother-of-pearl in clam shells does not form in a crystallisation process but is a result of the aggregation of nanoparticles within an organic matrix. This could lead to a better understanding of the structure of biomaterials which may be useful in the development of new high-performance ceramics. The findings of the research gr ... read more


NANO TECH
CSU imaging tool maps cells' composition in 3-D

Gloop from the deep sea

High-performance material polyimide for the first time with angular shape

Copper deposition to fabricate tiny 3-D objects

NANO TECH
General Dynamics MUOS-Manpack radio supports government testing of MUOS network

Raytheon to produce, test Navy Multiband Terminals

ADS to build one of two satellites for future COMSAT NG system

Thales and Airbus to supply French military satellite communications

NANO TECH
EpicNG satellite installed on Ariane 5 for launch

Building a robust commercial market in low earth orbit

NASA awards ISS cargo transport contracts

SpaceX will try to land its reusable rocket on an ocean dock

NANO TECH
Trimble to provide GPS survey systems for U.S. Marines

SMC releases RFP for GPS III Space Vehicles

GPS vultures swoop down on illegal dumps in Peru

Northrop Grumman to support U.S. Air Force GPS modernization

NANO TECH
Iran to buy 114 Airbuses to revamp ageing fleet

NASA-Funded Balloon Launches to Study Sun

Rockwell Collins to support Pakistani C-130 fleet

World View To Launch From Spaceport Tucson

NANO TECH
Quantum computing is coming - are you prepared for it?

Physicists develop a cooling system for the processors of the future

Dutch hi-tech group ASML posts 'record' year in 2015

Uncovering oxygen's role in enhancing red LEDs

NANO TECH
SpaceX launches US-French oceans satellite

Flooding along the Mississippi seen from space

Fires burning in Africa and Asia cause high ozone in tropical Pacific

Satellites find sustainable energy in cities

NANO TECH
Most Chinese cities fail air quality standards in 2015: Greenpeace

Students design 'plant backpack' to combat air pollution

India's smog-choked capital ends car ban trial

Brazilian police charge companies in mine waste spill









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.