NUS scientist helps create 'super oil absorber'

New material shows promise in sopping up oil and toxic spills
Shobana Kesava, Straits Times 2 Jun 08;

COASTLINES around the world could be spared the devastating effects of oil leaks and toxic spills in five years, thanks to a new material showing promise.

The super-absorbing, paper-like substance - made up of a mesh of fine wires - is being hailed by its creators as a breakthrough in sopping up spills.

Oxides of silicon and manganese go into the wires, which are each a tiny fraction of the width of a human hair.

The material was developed by an international team of scientists, including National University of Singapore (NUS) Assistant Professor Liu Xiao Gang, 34, who won the NUS Young Investigator Award in 2006.

The unique make-up of the strands, known as nanowires, allows them to separate water from oil or other poisonous chemicals containing carbon. Joined into fabric-like layers, they could be floated on the surface of the sea in tanks, where oil could be absorbed, leaving clean water behind.

'We used the same principle as the lotus leaf. Its texture allows water to roll off like marbles, without ever getting wet,' Dr Liu said.

He began research two years ago with Dr Yuan Ji Kang, and Professors Jing Kong and Francesco Stellacci at the Massachusetts Institute of Technology.

The work was inspired by Hurricane Katrina, which devastated the southern United States in 2005. The storm swamped thousands of cars, leaving oil slicks that complicated the natural disaster relief effort.

The new material is expected to cost slightly more than conventional solutions but, being recyclable and more absorbent, it is expected to save money in the long run.

Conventional fabrics used to mop up oil spills are normally not recyclable, Dr Liu said, and a lot more material is needed because water tends to be absorbed along with oil.

The new nanowires absorb up to 20 times the material's weight purely of oil and no water, he said.

On a smaller scale, the new material could also be used to absorb oil leaks in car engines and modified to heal wounds.

The team's research paper on these super-absorbent nanowires was published over the weekend in international scientific journal Nature Nanotechnology.

Nano-design specialist at the Nanyang Technological University, Associate Professor Yeo Kiat Seng, said the team behind the material has made a significant find.

'They will be considered pioneers in this field. This paper shows that the development will benefit mankind. It is better than existing technology, but it has to be demonstrated in real scenarios, not just in the lab,' Dr Yeo said.

Dr Liu said the team plans to do just that.

Already, at least two local defence organisations have expressed interest in finding applications for the technology.

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