AsianScientist (Jul. 20, 2015) – With the help of over 150,000 computing volunteers, scientists have designed a nanotechnology-based strategy to improve water filtration. Their results have been published in Nature Nanotechnology.
Nearly 800 million people worldwide don’t have access to safe drinking water, and some 2.5 billion people live in precariously unsanitary conditions, according to the Centers for Disease Control and Prevention. Together, unsafe drinking water and the inadequate supply of water for hygiene purposes contribute to almost 90 percent of all deaths from diarrheal diseases, but effective water sanitation interventions are still challenging scientists and engineers.
In the present study, minute vibrations of carbon nanotubes called ‘phonons’ have been proposed to enhance the diffusion of water through sanitation filters. A joint effort of a Tsinghua University-Tel Aviv University (TAU) research team, the project was led by Professor Zheng Quanshui of the Tsinghua Center for Nano and Micro Mechanics and Professor Michael Urbakh of the Tel Aviv University School of Chemistry, both of the TAU-Tsinghua XIN Center.
“We’ve discovered that very small vibrations help materials, whether wet or dry, slide more smoothly past each other,” said Urbakh. “Through phonon oscillations—vibrations of water-carrying nanotubes—water transport can be enhanced, and sanitation and desalination improved.”
“Water filtration systems require a lot of energy due to friction at the nano-level. With these oscillations, however, we witnessed three times the efficiency of water transport, and, of course, a great deal of energy saved.”
The research team managed to demonstrate how, under the right conditions, such vibrations produce a 300 percent improvement in the rate of water diffusion by using computers to simulate the flow of water molecules flowing through nanotubes. The results have important implications for desalination processes and energy conservation, e.g. improving the energy efficiency for desalination using reverse osmosis membranes with pores at the nanoscale level, or energy conservation, e.g. membranes with boron nitride nanotubes.
Interestingly, the research was made possible with the help of crowd computing volunteers.
“Our project won the privilege of using IBM’s World Community Grid, an open platform of users from all around the world, to run our program and obtain precise results,” said Urbakh. “We would have required the equivalent of nearly 40,000 years of processing power on a single computer. Instead we had the benefit of some 150,000 computing volunteers from all around the world, who downloaded and ran the project on their laptops and desktop computers.”
Other partners in this international project include researchers at the London Center for Nanotechnology of University College London; the University of Geneva; the University of Sydney and Monash University in Australia; and the Xi’an Jiaotong University in China. The researchers are currently in discussions with companies interested in harnessing the oscillation knowhow for various commercial projects.
The article can be found at: Ma et al. (2015) Water Transport Inside Carbon Nanotubes Mediated by Phonon-Induced Oscillating Friction.
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Source: American Friends of Tel Aviv University; Photo: Shutterstock.
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