Oil poses a considerable danger to aquatic life.
Oil poses a considerable danger to aquatic life. Researchers at the Universities of Bonn and Aachen and the Heimbach-GmbH have developed a new technology for the removal of such contaminations: Textiles with special surface properties passively skim off the oil and move it into a floating container. The scientists used surfaces from the plant kingdom as a model. The study has now been published in the journal "Philosophical Transactions A".
The video clip is as short as it is impressive: The 18-second sequence shows a pipette from which dark-colored crude oil drips into a glass of water. Then a researcher holds a green leaf against the spot. Within a matter of seconds the leaf sucks the oil from the surface of the water, leaving not even a trace behind.
The star of the movie, the small green leaf, comes from the floating fern Salvinia. The special abilities of its leaves make it highly interesting for scientists, because they are extremely hydrophobic: When submerged, they wrap themselves in an air jacket and remain completely dry. Researchers call this behavior "superhydrophobic", which can be translated as "extremely water repellent".
However, the Salvinia surface loves oil which is, in a way, a flip side of superhydrophobia. "This allows the leaves to transport an oil film on their surface", explains Prof. Dr. Wilhelm Barthlott, emeritus of the University of Bonn and former director of its botanic gardens. "And we have also been able to transfer this property to technically producible surfaces, such as textiles."
Read more at University of Bonn
Image: A drop of crude oil on a water surface is adsorbed within seconds by a leaf of the floating fern Salvinia and pulled from the water.(Credit: (c) W. Barthlott, M. Mail/Uni Bonn)
