A floating fern in the wild has inspired scientists to develop a superhydrophobic spacer fabric that can be produced industrially to remove oil spills from water surfaces in an energy-saving, cost-effective way and without the use of toxic substances.
The research and team: A team of researchers from the ITA (at RWTH Aachen University), the University of Bonn and Heimbach GmbH was able to prove that a novel biomimetic the Bionic Oil Adsorber (BOA) technology is surprisingly efficient and sustainable for a self-controlled separation and automatic collection of oil films including their complete removal from the water.
- BOA can be adapted for open water application but also for the use in inland waters. Furthermore, it is promising, that the textile can be used in various related separation processes.
- The product is currently being further developed so that it can be launched in the market in 2–3 years.
- Long-time routine examination of around 20,000 different species showed that there is an almost infinite variety of structures and functionalities. Some species in particular stand out for their excellent oil adsorption properties. It was shown that, e.g., leaves of the floating fern Salvinia molesta adsorb oil, separate it from water surfaces, and transport it on their surfaces.
- The observations inspired them to transfer the effect to technical textiles for separating oil and water. The result is the superhydrophobic spacer fabric that can be produced industrially and is therefore easily scalable.
Bionic Oil Adsorber: The bio-inspired textile can be integrated into a device called the Bionic Oil Adsorber (BOA). The oil is separated from the surrounding water by the surface properties of the textile and transported through the textile driven solely by capillary forces, even against gravity.
- When it reaches the end of the textile in the collection container, the oil desorbs without any further external influence due to gravitational forces.
- With the current scale approximately 4 litres of diesel can be separated from water by one device of the Bionic Oil Adsorber per hour.
How it works: Starting from the contamination in the form of an oil film on the water surface, the separation and collection process works according to the following steps:
- The BOA is introduced into the oil film.
- The oil is adsorbed by the textile and separated from the water at the same time.
- The oil is transported through the textile into the collection container.
- The oil drips from the textile into the collection container.
- The oil is collected until the container is emptied.
The context: Despite the steady expansion of renewable energies, global oil production, oil consumption and the risk of oil pollution have increased steadily over the last two decades. Accidents often occur during the extraction, transportation and use of oil, resulting in serious and sometimes irreversible environmental pollution and harm to humans.
- There are various methods for removing this oil pollution from water surfaces. However, all methods have various shortcomings that make them difficult to use and, in particular, limit the removal of oil from inland waters.
