ADELAIDE, Australia, September 27, 2013 (ENS) - University of Adelaide nanotechnology researchers have developed a process for turning waste plastic bags into a high-tech nano-material with multiple uses.
The innovative technology uses plastic grocery bags to make carbon nanotube membranes. These sophisticated and expensive materials have a variety of potential advanced applications, including filtration, sensing, energy storage and a range of biomedical uses.
"Non-biodegradable plastic bags are a serious menace to natural ecosystems and present a problem in terms of disposal," says Professor Dusan Losic, ARC Future Fellow and Research Professor of Nanotechnology in the university's School of Chemical Engineering.
"Transforming these waste materials through nanotechnological recycling provides a potential solution for minimizing environmental pollution at the same time as producing high-added value products," said Professor Losic.
Carbon nanotubes are tiny cylinders of carbon atoms, each measuring one nanometer in diameter, or about 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 industries including in electronics, sports equipment, long-life batteries, sensing devices and wind turbines.
Professor Losic's Nanotech Research Group has grown the carbon nanotubes onto nanoporous alumina membranes. They used pieces of grocery plastic bags which were vaporized in a furnace to produce carbon layers that line the pores in the membrane to make the tiny cylinders called carbon nanotubes.
The nanotech recycling idea was conceived and carried out by PhD student Tariq Altalhi. "Initially we used ethanol to produce the carbon nanotubes," says Professor Losic. "But my student had the idea that any carbon source should be useable."
The huge potential market for carbon nanotubes hinges on industry's ability to produce large quantities more cheaply and uniformly than today's methods permit. Current synthesis methods usually involve complex processes and equipment, yet produce just grams per day, according to most companies on the market.
"In our laboratory, we've developed a new and simplified method of fabrication with controllable dimensions and shapes, and using a waste product as the carbon source," said Losic. The process is catalyst and solvent free, which means the plastic waste can be used without generating poisonous compounds.
This research has been published online ahead of print in the journal "Carbon."
Losic says nanotechnology has the potential to fundamentally transform industry, manufacturing, electronics, healthcare, agriculture, communications and solve the world's most pressing concerns such as clean energy, clean water, cancer and climate change. "Our group is enthusiastically devoted to take part in this revolutionary concept and perform highly innovative research by applying nanotechnology to address some of these problems," stated Losic.
Photo: The Losic Nano Research group, part of the School of Chemical Engineering, University of Adelaide, Professor Dusan Losic, front and center