08/22/2011

University of Vienna

Nanotechnology for water filter

Nanotechnology has developed tremendously in the past decade and was able to create many new materials with a vast range of potential applications. Carbon nanotubes are an example of these new materials and consist of cylindrical molecules of carbon with diameters of a few nanometers – one nanometer is one millionth of a millimeter. Carbon nanotubes possess exceptional electronic, mechanical and chemical properties, for example they can be used to clean polluted water. Scientists of the University of Vienna had recently published to this new research field in the well-known journal "Environmental Science & Technology".

Among many potential applications, carbon nanotubes are great candidate materials for cleaning polluted water. Many water pollutants have very high affinity for carbon nanotubes and pollutants could be removed from contaminated water by filters made of this nanomaterial, for example water soluble drugs which can hardly be separated from water by activated carbon. Problems due to filters' saturation could be reduced as carbon nanotubes have a very large surface area (e.g. 500 m2 per gram of nanotube) and consequently a very high capacity to retain pollutants. "Maintenance and wastes related to water depollution could thus be reduced", says Thilo Hofmann, Vice Dean of the Faculty of Earth Sciences, Geography and Astronomy of the University of Vienna.

Assessing carbon nanotubes' environmental sustainability

A lot of research has focussed on carbon nanotubes in the past decade. However, the exceptional properties of carbon nanotubes make them difficult to study. Standard methods give limited results and the behaviour of carbon nanotubes in realistic conditions is still poorly understood. "Innovative technologies always come with benefits and drawbacks for human and environmental quality and a good understanding of the interactions between contaminants and carbon nanotubes as well as how carbon nanotubes behave in the environment is essential before they can be used in filters", explains Mélanie Kah, who does research on this project together with Xiaoran Zhang.

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