Water inside single-walled carbon nanotubes

Jun 25, 2008
Carbon Nanotubes

Researchers have identified a signature for water inside single-walled carbon nanotubes, helping them understand how water is structured and how it moves within these tiny channels.

This is the first time researchers were able to get a snapshot of the water inside the carbon nanotubes.

Single-walled carbon nanotubes (SWCNTs) offer the potential to act as a unique nanofiltration system. While experiments have demonstrated extremely fast flow in these channels, it is still unclear why, and few studies have experimentally probed the detailed structure and movement of the water within nanotubes.

That's where Lawrence Livermore scientists Jason Holt, Julie Herberg, and University of North Carolina's, Yue Wu and colleagues come in.

As described in an article appearing in the July edition of Nanoletters, they used a technique called Nuclear Magnetic Resonance (NMR) to get a glimpse of the water confined inside one-nanometer diameter SWCNTs.

The nanotubes, special molecules made of carbon atoms in a unique arrangement, are hollow and more than 50,000 times thinner than a human hair. The confined water exhibited very different properties from that of bulk water, and this allowed it to be distinguished in the NMR spectrum.

Carbon nanotubes have long been touted for their superior thermal, mechanical and electrical properties, but recent work suggests they can be used as nanoscale filters.

Earlier Livermore studies have suggested that carbon nanotubes may be used for desalination and demineralization because of their small pore size and enhanced flow properties. Conventional desalination membranes are typically much less permeable and require large pressures, entailing high energy costs. However, these more permeable nanotube membranes could reduce the energy costs of desalination significantly.

While the technology offers great promise, there still are important unanswered scientific questions.

"There have been many predictions about how water behaves within carbon nanotubes," said Holt, the principal investigator of the project, which is funded through LLNL's Laboratory Directed Research and Development (LDRD). "With experiments like these, we can directly probe that water and determine how close those predictions were."


Source: DOE/Lawrence Livermore National Laboratory

Explore further: Researchers make magnetic graphene

add to favorites email to friend print save as pdf

Related Stories

Smart anti-icing system for rotor blades

Dec 01, 2014

In very cold climate zones, the wind can blow with tremendous force. But wind turbines have rarely been built in these regions up to now. The risk of ice formation on the rotor blades is just too high. But ...

Tiny carbon nanotube pores make big impact

Oct 29, 2014

A team led by the Lawrence Livermore scientists has created a new kind of ion channel based on short carbon nanotubes, which can be inserted into synthetic bilayers and live cell membranes to form tiny pores ...

Carbon nanotube sponge shows improved water clean-up

Jan 16, 2014

A carbon nanotube sponge capable of soaking up water contaminants, such as fertilisers, pesticides and pharmaceuticals, more than three times more efficiently than previous efforts has been presented in a ...

Recommended for you

Researchers make magnetic graphene

1 hour ago

Graphene, a one-atom thick sheet of carbon atoms arranged in a hexagonal lattice, has many desirable properties. Magnetism alas is not one of them. Magnetism can be induced in graphene by doping it with magnetic ...

The latest fashion: Graphene edges can be tailor-made

Jan 23, 2015

Theoretical physicists at Rice University are living on the edge as they study the astounding properties of graphene. In a new study, they figure out how researchers can fracture graphene nanoribbons to get ...

Nanotechnology changes behavior of materials

Jan 23, 2015

One of the reasons solar cells are not used more widely is cost—the materials used to make them most efficient are expensive. Engineers are exploring ways to print solar cells from inks, but the devices ...

Gold 'nano-drills'

Jan 22, 2015

Spherical gold particles are able to 'drill' a nano-diameter tunnel in ceramic material when heated. This is an easy and attractive way to equip chips with nanopores for DNA analysis, for example. Nanotechnologists ...

The importance of building small things

Jan 22, 2015

Strong materials, such as concrete, are usually heavy, and lightweight materials, such as rubber (for latex gloves) and paper, are usually weak and susceptible to tearing and damage. Julia R. Greer, professor ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

zevkirsh
not rated yet Jun 25, 2008
how about using them as microtubules in micro machines to transport water as a coolant?
yybb
not rated yet Jul 16, 2008
very good

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.