Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Simulations help explain fast water transport in nanotubes

Photo by L. Brian Stauffer

Narayana R. Aluru, professor of mechanical science and engineering, left, and doctoral student Sony Joseph have discovered the physical mechanism behind the rapid transport of water in carbon nanotubes. Image in background shows the trajectory of water molecules in a carbon nanotube moving in the direction of their orientations due to rotation-translation coupling.
Photo by L. Brian Stauffer

Narayana R. Aluru, professor of mechanical science and engineering, left, and doctoral student Sony Joseph have discovered the physical mechanism behind the rapid transport of water in carbon nanotubes. Image in background shows the trajectory of water molecules in a carbon nanotube moving in the direction of their orientations due to rotation-translation coupling.

Abstract:
By discovering the physical mechanism behind the rapid transport of water in carbon nanotubes, scientists at the University of Illinois have moved a step closer to ultra-efficient, next-generation nanofluidic devices for drug delivery, water purification and nano-manufacturing.

Simulations help explain fast water transport in nanotubes

CHAMPAIGN, IL | Posted on September 16th, 2008

"Extraordinarily fast transport of water in carbon nanotubes has generally been attributed to the smoothness of the nanotube walls and their hydrophobic, or water-hating surfaces," said Narayana R. Aluru, a Willett Faculty Scholar and a professor of mechanical science and engineering at the U. of I.

"We can now show that the fast transport can be enhanced by orienting water molecules in a nanotube," Aluru said. "Orientation can give rise to a coupling between the water molecules' rotational and translational motions, resulting in a helical, screw-type motion through the nanotube," Aluru said.

Using molecular dynamics simulations, Aluru and graduate student Sony Joseph examined the physical mechanism behind orientation-driven rapid transport. For the simulations, the system consisted of water molecules in a 9.83 nanometer long nanotube, connected to a bath at each end. Nanotubes of two diameters (0.78 nanometers and 1.25 nanometers) were used. Aluru and Joseph reported their findings in the journal Physical Review Letters.

For very small nanotubes, water molecules fill the nanotube in single-file fashion, and orient in one direction as a result of confinement effects. This orientation produces water transport in one direction. However, the water molecules can flip their orientations collectively at intervals, reversing the flow and resulting in no net transport.

In bigger nanotubes, water molecules are not oriented in any particular direction, again resulting in no transport.

Water is a polar molecule consisting of two hydrogen atoms and one oxygen atom. Although its net charge is zero, the molecule has a positive side (hydrogen) and a negative side (oxygen). This polarity causes the molecule to orient in a particular direction when in the presence of an electric field.

Creating and maintaining that orientation, either by directly applying an electric field or by attaching chemical functional groups at the ends of the nanotubes, produces rapid transport, the researchers report.

"The molecular mechanism governing the relationship between orientation and flow had not been known," Aluru said. "The coupling occurs between the rotation of one molecule and the translation of its neighboring molecules. This coupling moves water through the nanotube in a helical, screw-like fashion."

In addition to explaining recent experimental results obtained by other groups, the researchers' findings also describe a physical mechanism that could be used to pump water through nanotube membranes in next-generation nanofluidic devices.

Funding was provided by the National Science Foundation and the National Institutes of Health.

Aluru is affiliated with the U. of I.'s Beckman Institute, Micro and Nanotechnology Laboratory, and departments of bioengineering and of electrical and computer engineering.

####

For more information, please click here

Contacts:
James E. Kloeppel
Physical Sciences Editor
217-244-1073


Narayana Aluru
217-333-1180

Copyright © University of Illinois at Urbana-Champaign

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

ATTOPSEMI Technology Joins FDXcelerator Program to Deliver Advanced Non-Volatile Memory IP to GLOBALFOUNDRIES 22 FDX Technology Platform: Leading-edge I-fuse brings higher reliability, smaller cell size and ease of programmability for consumer, automotive, and IoT applications March 27th, 2017

Leti and HORIBA Scientific to Host Webinar on Ultrafast Characterization Tool: Plasma Profiling Time-of-Flight Mass Spectrometer Tool Cuts Optimization Time In Layer Deposition and Fabrication of Wide Range of Applications March 27th, 2017

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Microfluidics/Nanofluidics

Particle Works creates range of high performance quantum dots February 23rd, 2017

DNA 'barcoding' allows rapid testing of nanoparticles for therapeutic delivery February 7th, 2017

Zeroing in on the true nature of fluids within nanocapillaries: While exploring the behavior of fluids at the nanoscale, a group of researchers at the French National Center for Scientific Research discovered a peculiar state of fluid mixtures contained in microscopic channels January 11th, 2017

Fabrication of a Miniature Paper-Based Electroosmotic Actuator November 29th, 2016

Nanotubes/Buckyballs/Fullerenes

Intertronics introduce new nanoparticle deagglomeration technology March 15th, 2017

Boron atoms stretch out, gain new powers: Rice University simulations demonstrate 1-D material's stiffness, electrical versatility January 26th, 2017

New stem cell technique shows promise for bone repair January 25th, 2017

Captured on video: DNA nanotubes build a bridge between 2 molecular posts: Research may lead to new lines of direct communication with cells January 9th, 2017

Discoveries

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Researchers make flexible glass for tiny medical devices: Glass can bend over and over again on a nanoscale March 27th, 2017

Announcements

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

ATTOPSEMI Technology Joins FDXcelerator Program to Deliver Advanced Non-Volatile Memory IP to GLOBALFOUNDRIES 22 FDX Technology Platform: Leading-edge I-fuse brings higher reliability, smaller cell size and ease of programmability for consumer, automotive, and IoT applications March 27th, 2017

Leti and HORIBA Scientific to Host Webinar on Ultrafast Characterization Tool: Plasma Profiling Time-of-Flight Mass Spectrometer Tool Cuts Optimization Time In Layer Deposition and Fabrication of Wide Range of Applications March 27th, 2017

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Water

Rare-earths become water-repellent only as they age March 22nd, 2017

Nano-level lubricant tuning improves material for electronic devices and surface coatings February 11th, 2017

Tough aqua material for water purification: Decontamination of water with a robust and sustainable membrane assembled from 2 synergistically working components January 24th, 2017

Scientists have discovered a new state of matter for water January 2nd, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project