New method turns plastic bags into high-tech materials

Scientists have developed a new method for turning waste plastic bags into a high-tech nanomaterial.
The process developed by University of Adelaide uses non-biodegradable plastic grocery bags to make 'carbon nanotube membranes' - highly sophisticated and expensive materials with a variety of advanced applications including filtration, energy storage and biomedical innovations.
"Non-biodegradable plastic bags are a serious menace to natural ecosystems and present a problem in terms of disposal," said Professor Dusan Losic, Research Professor of Nanotechnology in the University's School of Chemical Engineering.
"Transforming these waste materials through 'nanotechnological recycling' provides a potential solution for minimising environmental pollution at the same time as producing high-added value products," Losic said.

Carbon nanotubes are tiny cylinders of carbon atoms, one nanometer in diameter (1/10,000 the diameter of a human hair).
They are the strongest and stiffest materials yet discovered - hundreds of times stronger than steel but six times lighter - and their unique mechanical, electrical, thermal and transport properties present exciting opportunities for research and development.

They are already used in a variety of industries including in electronics, sports equipment, long-lasting batteries, sensing devices and wind turbines.
The University of Adelaide's Nanotech Research Group has 'grown' the carbon nanotubes onto nanoporous alumina membranes.
They used pieces of grocery plastic bags which were vaporised in a furnace to produce carbon layers that line the pores in the membrane to make the tiny cylinders (the carbon nanotubes).

The idea was conceived and carried out by student Tariq Altalhi.
"Initially we used ethanol to produce the carbon nanotubes. But my student had the idea that any carbon source should be useable," said Losic.
The process is catalyst and solvent free, which means the plastic waste can be used without generating poisonous compounds.
The research was published in the journal Carbon.