Press Esc to close

Ultra-thin carbon nanotubes can desalinate seawater

Press Trust of India, Washington, Aug 30 2017, 17:23 IST
An artist's depiction of the promise of carbon nanotube porins for desalination. The image depicts a stylized carbon nanotube pipe that delivers clean desalinated water from the ocean to a kitchen tap. Image by Ryan Chen/LLNL

An artist's depiction of the promise of carbon nanotube porins for desalination. The image depicts a stylized carbon nanotube pipe that delivers clean desalinated water from the ocean to a kitchen tap. Image by Ryan Chen/LLNL

Scientists have developed carbon nanotubes over 50,000 times thinner than a human hair which can quickly and effectively separate salt from seawater, an advance that may help solve the global water crisis.

Increasing demands for fresh water pose a global threat to sustainable development, resulting in water scarcity for four billion people, researchers said.

Current water purification technologies can benefit from the development of membranes with specialised pores that mimic highly efficient and water selective biological proteins.

Scientists, including those from Northeastern University in the US, developed carbon nanotube pores that can exclude salt from seawater.

The team found that water permeability in carbon nanotubes (CNTs) with diameters of 0.8 nanometre significantly exceeds that of wider carbon nanotubes.

The nanotubes, hollow structures made of carbon atoms in a unique arrangement, are more than 50,000 times thinner than a human hair.

The super smooth inner surface of the nanotube is responsible for their remarkably high water permeability, while the tiny pore size blocks larger salt ions.

"We found that carbon nanotubes with diameters smaller than a nanometre bear a key structural feature that enables enhanced transport," said Ramya Tunuguntla, a postdoctoral researcher at Lawrence Livermore National Laboratory (LLNL) in the US.

"The narrow hydrophobic channel forces water to translocate in a single-file arrangement, a phenomenon similar to that found in the most efficient biological water transporters," said Tunuguntla.

Computer simulations and experimental studies of water transport through CNTs with diameters larger than one nanometre showed enhanced water flow, but did not match the transport efficiency of biological proteins and did not separate salt efficiently, especially at higher salinities.

The key breakthrough achieved by the LLNL team was to use smaller-diameter nanotubes that delivered the required boost in performance.

"Carbon nanotubes are a unique platform for studying molecular transport and nanofluidics," said Alex Noy principal investigator at LLNL.

"Their sub-nanometre size, atomically smooth surfaces and similarity to cellular water transport channels make them exceptionally suited for this purpose, and it is very exciting to make a synthetic water channel that performs better than nature's own," said Noy.

The research was published in the journal Science.

Go to Top

More from this section
Photo Gallery
Rebel AAP MLA Kapil Misra and BJP MLA Manjinder Singh Sirsa after putting anti-pollution masks on...

Rebel AAP MLA Kapil Misra and BJP MLA Manjinder Singh Sirsa after putting anti-pollution masks on...

IAF planes display an air show during presentation of standards to the 117 Helicopter Unit and 223..

IAF planes display an air show during presentation of standards to the 117 Helicopter Unit and 223..

Forest employees and locals capture a leopard in a cage after it strayed in a village of Udhampur..

Forest employees and locals capture a leopard in a cage after it strayed in a village of Udhampur..

Activists of the Kisan Mukti Sansad hanging dummy bodies of farmers from a flyover during a...

Activists of the Kisan Mukti Sansad hanging dummy bodies of farmers from a flyover during a...

Indian Air Force personnel perform during presentation of standards to the 117 Helicopter Unit...

Indian Air Force personnel perform during presentation of standards to the 117 Helicopter Unit...

A snow cutter machine clears the road after heavy snowfall at Peer Ki Gali in Poonch...

A snow cutter machine clears the road after heavy snowfall at Peer Ki Gali in Poonch...

Students having a view of robots displayed at a stall at

Students having a view of robots displayed at a stall at "20th Bangalore Tech Summit" in Bengaluru..

Russian artists perform a play in Gurugram on Thursday.

Russian artists perform a play in Gurugram on Thursday.

Foreign athletes pose for a group photo during a press conference ahead of the Delhi Half Marathon.

Foreign athletes pose for a group photo during a press conference ahead of the Delhi Half Marathon.

Bollywood actress Vidya Balan during a promotional event in Mumbai on Thursday.

Bollywood actress Vidya Balan during a promotional event in Mumbai on Thursday.

Like us on Facebook

Copyright 2017, The Printers (Mysore) Private Ltd., 75, M.G Road, Post Box 5331, Bengaluru - 560001
Tel: +91 (80) 25880000 Fax No. +91 (80) 25880523
Powered by Yodasoft Technologies Pvt. Ltd.