Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

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

Chitosan coated, chemotherapy packed nanoparticles may target cancer stem cells June 30th, 2015

BASF and Fraunhofer IPMS-CNT jointly develop electronic materials June 30th, 2015

Researchers from the UCA, key players in a pioneering study that may explain the origin of several digestive diseases June 30th, 2015

Oxford Instrumentsí TritonXL Cryofree dilution refrigerator selected for the Oxford NQIT Quantum Technology Hub project June 30th, 2015

Microfluidics/Nanofluidics

Lehigh University researchers unveil engineering innovations at TechConnect 2015: TechConnect is the world's largest accelerator for industry-vetted emerging-technologies ready for commercialization June 11th, 2015

How to cut a vortex into slices: A group of physicists, lead by Olga Vinogradova, professor at the Lomonosov Moscow State University, came up with a way to stir up a liquid in the microchannel June 3rd, 2015

What makes cancer cells spread? New device offers clues May 19th, 2015

Microchip captures clusters of circulating tumor cells -- NIH study May 18th, 2015

Nanotubes/Buckyballs/Fullerenes

Cellulose from wood can be printed in 3-D June 17th, 2015

Researchers grind nanotubes to get nanoribbons: Rice-led experiments demonstrate solid-state carbon nanotube 'templates' June 15th, 2015

Environmental Issues to Hamper Growth of Global Nanocomposites Market June 4th, 2015

Carbon Nanotubes (CNT) Market Trends, Segments And Forecasts To 2022: Grand View Research, Inc June 1st, 2015

Discoveries

Chitosan coated, chemotherapy packed nanoparticles may target cancer stem cells June 30th, 2015

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

Researchers from the UCA, key players in a pioneering study that may explain the origin of several digestive diseases June 30th, 2015

Visible Light-Sensitive Photocatalysts Used for Purification of Contaminated Water in Iran June 30th, 2015

Announcements

BASF and Fraunhofer IPMS-CNT jointly develop electronic materials June 30th, 2015

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

Researchers from the UCA, key players in a pioneering study that may explain the origin of several digestive diseases June 30th, 2015

Oxford Instrumentsí TritonXL Cryofree dilution refrigerator selected for the Oxford NQIT Quantum Technology Hub project June 30th, 2015

Water

Visible Light-Sensitive Photocatalysts Used for Purification of Contaminated Water in Iran June 30th, 2015

Dais Analytic Unveils New Version of Aqualyte Membrane Technology: Updates to the Basis of the Company's Industry-Changing Nanotechnology Designed to Strengthen Position in Global Air, Energy, and Water Markets June 26th, 2015

Bacteria Cellulose, Natural Polymers with Applications in Various Industries Synthesized in Iran June 22nd, 2015

Ceramic Nanomembrane, New Material for Dehydration of Natural Gas June 7th, 2015

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