Chemistry in one dimension offers surprising result

Mar 27, 2012

Due to their unique properties single walled carbon nanotubes have been suggested as a promising material for electronics, optics and in other fields of materials science. When scientists from Umea University and Aalto University tried to perform a reaction between hydrogen gas and fullerene molecules encapsulated in nanotubes something very unlikely suddenly appeared possible.

" on the often appears to be different compared to chemistry in the normal scale and carbon nanotubes provide ideal conditions for studies of reactions in nanospace," says Alexandr Talyzin, docent at the Department of Physics, Umeå University.

The standard approch to make chemical recations inside of single walled carbon nanotubes, SWNTs, is to fill the inner space with (e.g. fullerenes, thus forming so called peapods) and make them react with each other.

The nanotube walls will then protect the encapsulated molecules from outer space and make reactions with molecules and atoms outside the tube impossible. Once the SWNTs are filled with C60 molecules there is not enough space for hydrogen molecules to go in. That was the common opinion when the research groups started their experiments a few years ago.

But their experiments leave no doubt, hydrogen does actually penetrate into peapods and react with fullerenes. The evidence is rather direct, when the temperature and pressure of hydrogenation is taken to extreme values the fullerene cage collapses completely and large hydrogen molecules are formed. This was confirmed both by Raman spectroscopy and high resolution TEM.

The study provides one more example that chemical reactions in nanoreactors are not always the same as in “normal” conditions. In three-dimensional structure molecules can react with their neighbours in all possible directions, up, down, right, left etc.

"Inside of carbon nanotubes fullerene molecule have only two neighbours, lets say to the right and to the left. Similarly, the reaction with hydrogen is also limited to one-dimension," says Alexandr Talyzin.

A great advantage is that even single molecules inside of SWNTs can be observed using high resolution electron microscopy, something extremely difficult for bulk powders, he adds. High quality images collected at Aalto University allowed the scientists to observe not only induced collapse of C60, but also hydrogen-driven coalescence of molecules into chain polymers and tubules.

"What we learned is a rather general result for nano-chemistry. Now we have direct evidence that molecules inside of SWNts can be reacted with gases. It opens enormous possibilities for synthesis of novel hybrid materials and chemical modification of encapsulated molecules and materials," says Alexandr Talyzin.

Explore further: Thinnest feasible nano-membrane produced

More information: “Hydrogen driven collapse of C60 inside of SWNTs” is published on line in Angewandte Chemie, onlinelibrary.wiley.com/doi/10.1002/anie.201200946/abstract

Related Stories

Hydrogen opens the road to graphene ... and graphane

May 09, 2011

(PhysOrg.com) -- An international research team has discovered a new method to produce belts of graphene called nanoribbons. By using hydrogen, they have managed to unzip single-walled carbon nanotubes. The ...

Nanochemistry in Action

Mar 06, 2009

(PhysOrg.com) -- Using a single-walled carbon nanotube (SWCNT) as a test tube, scientists can explore chemistry at the nanoscale, which involves some unique effects. Nanotubes provide a confined, one-dimensional ...

Tiny carbon nanotubes show big germ-fighting potential

Sep 03, 2007

In nanoscience’s version of a David-and-Goliath story, scientists in Connecticut are reporting the first direct evidence that carbon nanotubes have powerful antimicrobial activity, a discovery that could help fight the ...

Recommended for you

Thinnest feasible nano-membrane produced

7 hours ago

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The ...

Wiring up carbon-based electronics

10 hours ago

Carbon-based nanostructures such as nanotubes, graphene sheets, and nanoribbons are unique building blocks showing versatile nanomechanical and nanoelectronic properties. These materials which are ordered ...

Making 'bucky-balls' in spin-out's sights

Apr 16, 2014

(Phys.org) —A new Oxford spin-out firm is targeting the difficult challenge of manufacturing fullerenes, known as 'bucky-balls' because of their spherical shape, a type of carbon nanomaterial which, like ...

User comments : 0

More news stories

Thinnest feasible nano-membrane produced

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The ...

Wiring up carbon-based electronics

Carbon-based nanostructures such as nanotubes, graphene sheets, and nanoribbons are unique building blocks showing versatile nanomechanical and nanoelectronic properties. These materials which are ordered ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...