Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Making carbon nanotubes as usable as common plastics

16.05.2018

Researchers discover that cresols disperse carbon nanotubes at unprecedentedly high concentrations


Four continuous states of (a) carbon nanotube powders in cresol-based solvent: (b) a dilute dispersion for casting thin films, (c) a thick paste for blading coating, painting, screen printing or composite making, (d) a self-standing gel for 3D printing, and finally (e) a kneadable dough that can be readily transformed into various shapes.

Credit

Jiaxing Huang Group, Northwestern University

Northwestern University's Jiaxing Huang is ready to reignite carbon nanotube research. And he's doing so with a common chemical that was once used in household cleaners.

By using an inexpensive, already mass produced, simple solvent called cresol, Huang has discovered a way to make disperse carbon nanotubes at unprecedentedly high concentrations without the need for additives or harsh chemical reactions to modify the nanotubes.

In a surprising twist, Huang also found that as the nanotubes' concentrations increase, the material transitions from a dilute dispersion to a thick paste, then a free-standing gel and finally a kneadable dough that can be shaped and molded.

The study was published online on May 14 in the Proceedings of the National Academy of Sciences.

"Because of their exceptional mechanical, thermal and electrical properties, carbon nanotubes have attracted a lot of attention for a number of applications," said Huang, professor of materials science and engineering in Northwestern's McCormick School of Engineering. "But after decades of research and development, some of the excitement has faded."

The reason? Carbon nanotubes are notoriously tricky to process -- especially in large quantities. About 10,000 times thinner than a human hair, the wiry, tube-shaped structures are said to be stronger than steel and conduct heat and electricity far better than copper.

But when mass produced -- usually in the form of powders -- the tubes twist and clump together. This complication is a major barrier to the material's widespread applications.

"Aggregated tubes are hard to disperse in solvents," Huang said. "And if you cannot get a good dispersion, then you won't be able to make high-quality nanotube thin films that many applications rely on."

In order to bypass this problem, previous researchers used additives to coat the nanotubes, which chemically altered their surfaces and forced them to separate. Although these methods do work, they leave behind residues or alter the nanotubes' surface structures, which can blunt their desirable properties.

By contrast, Huang's team found that cresol does not deteriorate carbon nanotubes' surface functions. And, after separating the entangled tubes, researchers can simply remove the chemical by washing it off or heating it until it evaporates.

Finding unexpected kneads

After unlocking a new way to make carbon nanotubes in higher and higher concentrations, Huang and his team discovered new forms of the material. As the concentration of carbon nanotubes increases, the material transitions from a dilute dispersion to a spreadable paste to a free-standing gel and finally to a kneadable dough. These various forms can be molded, reshaped or used as conductive ink for 3D printing.

"The dough state of nanotubes is fascinating," said Kevin Chiou, a graduate student in Huang's laboratory and first author of the paper. "It can be readily shaped and molded into arbitrary structures just like playdough."

"Essentially, this solvent system now makes nanotubes behave just like polymers," Huang said. "It is really exciting to see cresol-based solvents make once hard-to-process carbon nanotubes as usable as common plastics."

Amanda Morris | EurekAlert!
Further information:
https://news.northwestern.edu/stories/2018/may/making-carbon-nanotubes-as-usable-as-common-plastics/
http://dx.doi.org/10.1073/pnas.1800298115

More articles from Materials Sciences:

nachricht Scientists' design discovery doubles conductivity of indium oxide transparent coatings
18.09.2019 | University of Liverpool

nachricht Heat shields for economical aircrafts
18.09.2019 | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Happy hour for time-resolved crystallography

Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Hamburg and the European Molecular Biology Laboratory (EMBL) outstation in the city have developed a new method to watch biomolecules at work. This method dramatically simplifies starting enzymatic reactions by mixing a cocktail of small amounts of liquids with protein crystals. Determination of the protein structures at different times after mixing can be assembled into a time-lapse sequence that shows the molecular foundations of biology.

The functions of biomolecules are determined by their motions and structural changes. Yet it is a formidable challenge to understand these dynamic motions.

Im Focus: Modular OLED light strips

At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37.

Almost everyone is familiar with light strips for interior design. LED strips are available by the metre in DIY stores around the corner and are just as often...

Im Focus: Tomorrow´s coolants of choice

Scientists assess the potential of magnetic-cooling materials

Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....

Im Focus: The working of a molecular string phone

Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Potsdam (both in Germany) and the University of Toronto (Canada) have pieced together a detailed time-lapse movie revealing all the major steps during the catalytic cycle of an enzyme. Surprisingly, the communication between the protein units is accomplished via a water-network akin to a string telephone. This communication is aligned with a ‘breathing’ motion, that is the expansion and contraction of the protein.

This time-lapse sequence of structures reveals dynamic motions as a fundamental element in the molecular foundations of biology.

Im Focus: Milestones on the Way to the Nuclear Clock

Two research teams have succeeded simultaneously in measuring the long-sought Thorium nuclear transition, which enables extremely precise nuclear clocks. TU Wien (Vienna) is part of both teams.

If you want to build the most accurate clock in the world, you need something that "ticks" very fast and extremely precise. In an atomic clock, electrons are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Society 5.0: putting humans at the heart of digitalisation

10.09.2019 | Event News

Interspeech 2019 conference: Alexa and Siri in Graz

04.09.2019 | Event News

AI for Laser Technology Conference: optimizing the use of lasers with artificial intelligence

29.08.2019 | Event News

 
Latest News

Stroke patients relearning how to walk with peculiar shoe

18.09.2019 | Innovative Products

Statistical inference to mimic the operating manner of highly-experienced crystallographer

18.09.2019 | Physics and Astronomy

Scientists' design discovery doubles conductivity of indium oxide transparent coatings

18.09.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>