Patent of the Month of July

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Environmentally friendly elimination of oil in water

News of oil desasters regularly shock the public. Russia is currently struggling with a devastating oil catastrophe in Western Siberia; a state of emergency has been declared. Thus, we would like to draw attention to a new, effective and environmentally friendly method of cleaning oil-contaminated waters. The applied method "Device and method for taking up oil from a water surface" has been filed for patent at the University of Bonn in July 2018, numbered DE102018118139A1 and is our patent of the month! Another asset: with Prof. Gries from ITA, RWTH is also involved in the invention.

The method is based on a simple principle: Textiles with particular surface properties passively skim the oil from the water interface and transport it into a floating container. The development of functional textiles fits into the field of bionics, because here too, nature provides the models. Not by chance is the emeritus Professor Wilhelm Barthlott acting as mastermind of the invention. The scientist is a pioneer of biological interface research. At the beginning of the millennium he made sensation with the lotus effect he discovered. The application of the observed self-cleaning powers of lotus petals to commercially profitable products is a beacon for successful technology transfer.

The technology presented here is founded on the Salvinia Effect, another discovery by Prof. Barthlott. Floating fern plants (Salviniaceae) have the ability to stabilise a permanent layer of air underneath their leaves on a water surface. This is achieved through fine, super-hydrophobic leaf hairs with hydrophilic properties at the tip. When the leaves are placed in oily substances, the oil expels such air from beneath the hydrophobic layer and is thus sucked up by the leaves.

In this patent proposal, the leaves are exchanged by functional textiles that adsorb oily water pollution through their hydrophobic function. The difference in height to the container, together with the capillary forces (by gravity) results in a drainage into the vessel.

Versus standard solutions, this method offers a number of advantages. Unlike pumps and oil suction barriers, it requires no power and can hence operate without emissions. The eco-friendly operation is noiseless and thus also suited for use in nature reserves. Furthermore, it leaves no residues that need to be disposed of, as is the case with powder. The textiles can also be reused several times.

In view of the ongoing oil pollution of waters and seas, the technology has great potential for commercial application. It is currently being offered for licensing by PROvendis GmbH. A worldwide patent application has been filed in 2019 (WO002020021031A1). The oil collecting buoy can be realised in variable sizes and is ideal for practical use from garden ponds to large waters.

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W. Barthlott, M. Moosmann, I. Noll, M. Akdere, J. Wagner, N. Roling, L. Koepchen-Thomä, M.A.K. Azad, K. Klopp, T. Gries & M. Mail (2020): Adsorption and superficial transport of oil on biological and bionic superhydrophobic surfaces: a novel technique for oil-water separation. Philosophical Transactions A., DOI: