DEVICE AND METHOD FOR COLLECTING OIL FROM A WATER SURFACE

Description

[0001] The invention relates to the field of removing oil from water surfaces, in particular to an apparatus and a method for removing oil from water surfaces.

[0002] Energy production, which is largely based on the combustion of oil and fuel, and the transport of crude or mineral oil required for this, often results in the environment being polluted by oil. Bodies of water are particularly affected, for example through tanker accidents or damaged pipelines. This oil must be removed as quickly as possible. Various processes are already available for absorbing oil films on the water surface. Oil absorbents, usually powdered substances, absorb or bind the oil and then either remain on the water surface, from where they must be removed again, or sink to the bottom of the water. In the event of major accidents, oil absorption booms are still used to contain and suck up the oil on the water. However, these cannot be used near shore, and their prophylactic use is not advisable.In cases of acute oil pollution, oil binding mats are also used to absorb the oil, or so-called skimmers are used to actively suck the oil from the surface.

[0003] WO 00 / 00702 A1 describes an oil removal and transport device and a method using the same for removing and transporting oil. The oil is absorbed into a bulk material, the bulk material having an inlet and an outlet, and the oil is passed through a membrane into the inlet of the bulk material. The oil is removed from the outlet of the bulk material. The membrane has an average pore size of no more than 100 micrometers, so that the oil is continuously transported through the membrane into the inlet of the bulk material and continuously discharged from the outlet of the bulk material into a reservoir. For example, a pressure difference can be created across the membrane using a vacuum, or the oil can be pumped into the container via a pump.WO 00 / 00701 A1 describes a component for liquid transport, which has at least one bulk region and a wall region which completely surrounds the bulk region and which comprises a membrane opening region and an open port region.

[0004] C. Zeiger et al. reveal in Bioinspiration & Biomimetics 2016, 11, 056003, microstructures on superhydrophobic plant leaves such as those of the floating ferns of the genus Salvinia as inspiration for oil-absorbing materials. These floating ferns have hydrophobic, water-repellent, or water-resistant, hairs on their surface with hydrophilic, i.e., water-attracting, areas at the tips that bind water to the hair structures and can maintain a film of air underwater on their surface. This phenomenon is known as the Salvinia effect. Floating ferns can absorb oil from water on their leaf surfaces. However, no application of this effect is described.

[0005] US 4 126 556 A discloses a device according to the preamble of claim 1.

[0006] The object of the present invention was to provide a device usable for collecting oil from a water surface. This object is achieved by a device for collecting oil from a water surface according to independent claim 1, comprising a container for receiving the oil and an oil-transporting device, wherein a region of the oil-transporting device can be brought into fluid communication with the water surface and another region of the oil-transporting device is located in the container, wherein the oil can be transported into the container via the oil-transporting device.The oil-transporting device is formed from a hydrophobic, preferably superhydrophobic, sheet-like structure whose surface has filament-like structures which are designed in such a way that they hold a layer of air on the surface of the hydrophobic, preferably superhydrophobic, sheet-like structure under water.

[0007] According to the invention, a device for absorbing oil from a water surface based on air-retaining surfaces is provided. An air-retaining surface is understood to be a surface capable of retaining a layer of air in a submerged state permanently or at least for the duration of the application. In the following, therefore, the term "air-retaining" surfaces is used. The water surface can be any body of water or aqueous substance that may be contaminated with oil or an oil-containing substance, in particular the surface of bodies of water such as seas, lakes, rivers, or canals.

[0008] The use of air-retaining surfaces for oil removal allows the oil to replace the air layer and be transported into a vessel via the air-retaining surface. The device essentially comprises an underwater air-retaining fabric, in particular a textile, and a connected collecting container. The hydrophobic, preferably superhydrophobic, fabric has surface structures that, when submerged underwater, stably hold an air layer on the surface, so that the fabric does not become wet despite contact with water. If the hydrophobic, preferably superhydrophobic, fabric comes into contact with oil or an oily substance, it is adsorbed and replaces the air layer present underwater.

[0009] The sheet material is hydrophobic, preferably superhydrophobic. "Hydrophobic" in the context of the present application means that the contact angle between water and the sheet material is greater than 90°. A particularly high contact angle is referred to as "superhydrophobic." In the context of the present application, the term "superhydrophobic" surface means that the contact angle of the surface with water is greater than 150°. The contact angle can be determined, for example, by drop shape analysis (DSA) using a contact angle measuring device. The contact angle with water is preferably greater than 100°, preferably greater than 140°, and particularly preferably greater than 150°.

[0010] The hydrophobic, preferably superhydrophobic, sheet material is preferably oleophilic, especially at least partially oleophilic. The term "oleophilic" is understood here to mean that the sheet material has an affinity for oil or oil-containing substances or other nonpolar substances, and the surface is easily wetted by them. Lipophilic materials are typically characterized by an oil contact angle of 0° or a low contact angle, for example, measured using a contact angle goniometer.

[0011] The hydrophobic, preferably superhydrophobic, surface structure can be completely oleophilic. A coating with fluorocarbon-containing compounds or silicones, for example, can provide a simultaneously hydrophobic and oleophilic surface.

[0012] The term "oil" in the context of the present invention refers to crude oil or mineral oil, as well as oily or oil-containing substances. The oil is merely adsorbed on the surface of the sheet material. However, the oil is not absorbed. This allows it to be transported across the sheet material and released into the container. The sheet material can partially rest on the water surface, with at least one end submerged in the water, so that it is in fluid contact with the water surface at one end. This allows capillary forces to build up across the sheet material. The sheet material has contact with the water surface at at least one point, so that it can come into contact with the oil and absorb it. A meniscus towards the sheet material, such as can form at the contact point on the water surface, is helpful but not absolutely necessary.The sheet material can be partially submerged in water, for example at one end, so that the sheet material is in contact with the water except for the area of ​​the gas or air layer. The sheet material is preferably not completely submerged. With a completely submerged sheet material, contact with the surface and thus with the oil would only occur if the air-retaining sheet material were brought into contact with the oil from below, so that it comes into contact with the oil at the oil-water interface.

[0013] Part of the sheet is located below the water surface to transport the oil and is in fluid contact with the water. The other end of the sheet is located in the container. Part of the sheet is located below the water surface in the container. This allows the oil to displace the air layer and flow into the container. Without being committed to a specific theory, it is assumed that transport occurs via physisorption and / or van der Waals forces.

[0014] Once the air is displaced and the sheet is wetted with oil, the driving force for transporting the oil or oily substance into the container results from the height difference between the sheet on the outside of the water surface and the inside of the container's bottom. As long as the end of the hydrophobic, preferably superhydrophobic, sheet located in the collection container remains below the water surface and / or the oil film, the oil is transported along the surface of the sheet until its entire surface is covered, and then flows into the collection container.

[0015] As oil enters the container, the oil level inside rises and its weight increases. This causes the container to sink deeper into the water. As long as the oil level inside the container remains below the water surface, oil will be collected from the water surface and flow into the container. As soon as the oil level inside the collection container is equal to the water level, the transport stops.

[0016] By adding additional weights and / or floats, the container's weight can be tared so that it floats, but the bottom of the container is always below the water surface when empty. Since oil has a lower density than water, the buoyancy can be adjusted using external weights and / or floats so that the container does not sink even when filled.

[0017] A particular advantage of the described operating principle of the device is that it neither requires actively oil-sucking pumps nor consumes material that absorbs the oil and then has to be disposed of. The device provides a passive, noiseless solution. No fuel is consumed to operate an actively operating machine, and thus no additional emissions are generated. No additional environmental pollution is caused by the removal of the oil. This allows the device to be used even in nature reserves. The oil is collected and transferred to a collection container. The sheet material can even be cleaned and reused if necessary. Thus, no additional waste is generated besides the collected oil. In particular, the device can also be used prophylactically.The arrangement of the collecting vessel and the oil-adsorbing surface structure is preferably compact and can be adapted to the environment.

[0018] The filled container can be emptied, in embodiments in which a lid is provided, for example by opening the lid.

[0019] The sheet can be fixed inside the container, for example, at the bottom or on the side wall. Preferably, the sheet is removably fixed. The sheet is then replaceable or can be cleaned and reused using physical processes such as washing and / or centrifugation.

[0020] According to the invention, the oil-transporting device is formed from a hydrophobic, preferably superhydrophobic, sheet material. The sheet material is preferably a textile. The sheet material can also be a film. It is essential that a surface of the sheet material has structures that can hold an air layer on the surface underwater. These can be filament-like and / or lattice-like structures.

[0021] A "filament" or "filament-like structure" within the meaning of this application is any elongated structure, regardless of material, that exhibits the required properties. In the textile field, a distinction is made between protruding hairs, protruding fibers, and filaments that are extremely long. However, within the meaning of this application, the term "filament" is used for any type of structure that has ends and is synonymous with the terms "fiber" or "hair" used in the textile field. A filament within the meaning of this application is also a longer structure that is bonded to a surface with two or more points. The area between two contact points then defines the length of the filament for the purposes of this application. These structures can be structures in the range of nanometers to millimeters. The filaments have a greater length than diameter.The diameter-to-length ratio (diameter:length) for the filaments is preferably between 1:2 and 1:40. Suitable filament lengths range from ≥ 1 µm to ≤ 6000 µm, preferably from ≥ 2 µm to ≤ 3000 µm. The diameters of filaments can be measured, for example, using scanning electron microscopy. If the fibers have different diameters along their length, the diameter in the center of the filament (50% of the length) is used as the basis. Preferably, filaments in the range of ≥ 1 to ≤ 1×10 6 are bonded per mm 2 < surface area. The density of the filaments is preferably in the range of ≥ 5 to ≤ 5000, preferably in the range ≥ 20 to ≤ 1000 filaments per mm 2< surface.

[0022] The elasticity, determined as the Young's modulus, of the filaments is preferably in the range from ≥ 10 4 < N / m 2 < to ≤ 10 12 < N / m 2 < , more preferably in the range from ≥ 10 4 < N / m 2 < to ≤ 10 10 < N / m 2 < . The elasticity allows a deflection of the filaments. The elasticity makes it possible to maintain the gas or air layer on the surface even in the event of currents and pressure changes. In particular, the surface of the filaments is hydrophobic, preferably superhydrophobic, and preferably at least partially or completely lipophilic. The filaments are able to maintain an air layer on the surface of the sheet-like structure underwater, permanently or at least for the duration of the application. This air layer can be displaced by the oil, thereby providing a use for absorbing it from a water surface.

[0023] The shape of the filament-like structures or filaments can be arbitrary. For example, the filaments can have tapered, rounded, or flattened ends. In particular, the filaments can be structurally and / or chemically anisotropic. Preferably, the filaments can be structurally anisotropic, i.e., there are regions in which the filaments are cut, in particular in which they form undercuts, preferably closed undercuts. Such structurally anisotropic structures can be similar to, for example, Salvinia molestaHere, a rigid, arbitrarily long stem allows deformation to occur only in the area of ​​the stem with closed undercuts, known as "baskets." The deformation can be measured as described above. Advantageously, rigid, long stems can provide a larger volume of the gas layer, particularly a very high air volume. Increasing the gas volume increases the oil absorption capacity.

[0024] The filaments may also have regions that are chemically anisotropic, particularly where the surface properties result in parts of the filaments being amphiphobic, in particular hydrophobic, while others are amphiphilic, in particular hydrophilic. Amphiphilic means that the contact angle in these regions between the surface and the liquid is < 90°, and hydrophilic means that the contact angle with water is < 90°. Preferably, the tip of the filaments, i.e., the region of the filaments that comes into contact with the water, is hydrophilic. As a result, the tips do not lose contact with the water even when pressure fluctuates. In a particularly preferred embodiment, the filaments have both chemically anisotropic regions and structurally anisotropic regions.

[0025] The fabric is designed as a spacer textile. In this context, a "spacer textile" refers to spacer textiles, in particular warp-knitted spacer fabrics, with two spaced-apart cover layers and spacer threads connecting the cover layers. Spacer textiles with spaced-apart upper and lower cover layers and spacer threads running between them are characterized by good, uniform compression-elastic properties, while maintaining an overall lightweight structure. This promotes the formation of a stable air layer. Spacer textiles can be designed as warp-knitted, woven, or knitted fabrics. The spacer threads are firmly arranged in the upper and lower cover layers. The spacer threads thus correspond to the filament-like structures of the fabric. Suitable thread materials for the spacer threads include, for example, technical polyamide yarns, polyester, or polyethylene. The thread material can be a polyfilament yarn.This can be made of polyester and, for example, have a filament diameter of up to 0.5 mm, preferably 0.2 mm. Monofilaments, for example, made of polyamide, polyester, polypropylene, or polyethylene, are preferably used as spacer threads. These have high flexural rigidity and are characterized by high elasticity.

[0026] The filament-shaped structures form spacer threads that connect two spaced layers of the fabric, and the fabric is designed as a 3D spacer textile.

[0027] The shape of the hydrophobic sheet can vary. Both individual strips and continuous adsorbent surfaces, particularly textiles, can be used. In some embodiments, the sheet is designed as a plurality of strip-shaped surfaces. In further embodiments, the sheet is designed as a continuous surface arranged around the container. The sheet can also be designed as a combination of strip-shaped surfaces and larger continuous surfaces.

[0028] The container can be of any shape. For example, it can be cylindrical or spherical, or have the shape of a cube, cuboid, or cone. The dimensions of the container are also flexible. Small constructions, such as laboratory vials a few centimeters in height and diameter, can be used, as can large collection containers, which can be the size of a barrel or drum, for example. With regard to the container, it is essential that part of the surface structure in the container is below the water surface, because the oil can only flow into the container as long as the end of the hydrophobic, preferably superhydrophobic, surface located in the collection container is below the water surface or the oil film.

[0029] In some embodiments, the device may be designed as a floating device. In other embodiments, the container may be completely submerged.

[0030] In embodiments of the device, the container can be designed to float in the water or be secured to the water surface, with the bottom of the container being below the water surface when empty. Such an embodiment is also referred to below as an "oil float."

[0031] In embodiments, the sheet material can be guided into the container via the side wall of the container or through slit-shaped openings in the side wall. Since the oil film on the sheet material is thin, it can be transported into the container via the surface even if the sheet material is guided into the container via the side wall of the container above the water level. The edge of the container can protrude up to 10 cm or even 20 cm above the water surface. The sheet material can also be guided into the interior of the container through narrow, slit-shaped openings in the side wall of the container. The opening can be located both above and below the water surface. Preferably, the opening is sufficiently wide to allow the oil to be transported across the surface. The height of the opening is preferably low to prevent water from entering.This is supported by the fact that the surface structure is hydrophobic and thus water-repellent both in the oil-unwetted, air-holding state and in the oil-wetted state.

[0032] In some embodiments, the container is provided with a lid. This has the advantage that splash water or rainwater cannot penetrate the container. The lid can be attached to the outside of the container with spacers. The spacers can be guided through a previously attached sheet material and thus penetrate it. In other embodiments, the lid can be attached to the container with an internal, preferably central, screw. The lid preferably has a valve for pressure equalization. Preferably, a valve permeable to the outside is attached to the top.

[0033] Emptying the container or removing the oil can be done, for example, by pumping it out. Alternatively, the oil can be removed by simply pouring it out of the container. Advantageous embodiments are those in which the oil initially flows from the sheet material onto an edge area, which may have a drainage channel, and from there into the collecting container. Alternatively, the entire device can be removed from the water. Small containers can be equipped with a valve at the bottom so that the device can be briefly lifted out of the water and the oil can drain through the valve. Furthermore, a replaceable inner container can be provided.

[0034] In further embodiments of the device, the container can be a closed vessel, which has a pressure equalization device. A closed vessel can be placed below the water surface. Such an embodiment is also referred to below as an "oil diver." The operation corresponds to that of the floating device. If the collecting vessel is completely submerged, this has the advantage of permanently ensuring that the ends of the sheet are below the water surface. A pressure equalization device within the closed collecting vessel is necessary because it is initially filled with air and, without the possibility of venting, no oil can enter the closed vessel. The device can comprise a level indicator, which can be provided with a plug.

[0035] The driving force for oil transport results from the difference in height between the point at which the oil is absorbed, which usually corresponds to the water surface, and the point at which it is released again. In this design, this can be a hollow sphere. The advantage is that this difference can be made greater in the oil diver designs than in the oil float designs. This allows for faster transport using the same materials. In addition, transport is directed exclusively downwards, in contrast to the oil float, where the oil must initially move against the force of gravity through unwetted textile. The hollow sphere can have multiple openings through which the oil is transported into the interior. This can further increase efficiency.

[0036] A further aspect of the invention relates to a method according to independent claim 7 for absorbing oil from a water surface by means of a container for absorbing the oil and an oil-transporting device, wherein a region of the oil-transporting device is brought into liquid connection with the water surface and a further region of the oil-transporting device is located in the container, wherein the oil-transporting device is formed from a hydrophobic, preferably superhydrophobic sheet material, the surface of which has filament-shaped structures which are designed such that they hold a layer of air on the surface under water, wherein the oil is transported into the container via the hydrophobic, preferably superhydrophobic sheet material.

[0037] For the description of the container for holding the oil and the oil-transporting device, reference is made to the above statements regarding the device. If the device is placed in water, on or below a water surface, and a portion of the sheet is below the water surface so that one end is in fluid communication with the water surface, and the portion of the sheet located in the container is below the water surface, the oil can displace the air layer and flow into the container.

[0038] In embodiments of the "oil diver," in which the container floats in the water or is secured to the water surface, with the bottom of the container located below the water surface when empty, this can be achieved by using weights on the container and / or free ends of the sheet. In embodiments of a closed container that is placed below the water surface, it can also be held below the surface by anchoring it to the bottom of the water surface. Such an "oil diver" can, for example, be located approximately 30 cm below the surface. Down to a depth of 30 cm, an air layer held on the surface of the sheet can be replaced by oil, and the oil can drain into the container.

[0039] A further aspect of the invention relates to the use of a device according to the invention comprising a container for receiving the oil and an oil-transporting device, wherein a region of the oil-transporting device can be brought into fluid communication with the water surface and a further region of the oil-transporting device is located in the container, wherein the oil can be transported into the container via the oil-transporting device, wherein the oil-transporting device is formed from a hydrophobic, preferably superhydrophobic, sheet-like structure whose surface has filament-shaped structures which are designed in such a way that they hold a layer of air on the surface under water, for

[0040] Collecting oil from a water surface. For a description of the device, please refer to the above explanations regarding the device.

[0041] Examples and figures illustrating the present invention are given below.

[0042] The figures show: Figure 1 is a schematic representation of the absorption of oil from a water surface by means of a device according to a first embodiment of the invention in Fig. 1A, 1B , 1C, and Fig. 1D Figure 2 shows a schematic representation of a device for collecting oil from a water surface according to a first embodiment of the invention. Figure 3 shows a schematic representation of a device for collecting oil from a water surface according to a second embodiment of the invention.

[0043] Figure 1 shows in the Figures 1A, 1B , 1C and Fig. 1D a schematic representation of the absorption of oil 10 from a water surface 8 by means of a floating device. In Figure 1 A1 shows a floating device for collecting oil 10 from a water surface 8. The device comprises a container 2 for collecting the oil and an oil-transporting device formed from a superhydrophobic sheet material 4. The container 2 floats on the water, with the bottom of the container 2 lying deeper in the water than the superhydrophobic sheet material 4. The edge of the collecting container 2 protrudes above the water surface 8. One end of the sheet material 4 is fixed to the bottom of the container 2, as a result of which a part of the sheet material 4 located in the container 2 is below the level of the water surface 8. The sheet material 4 is placed over the edge of the container 2. The surface floats on the water surface 8, with the end facing away from the container 2 being held below the water surface 8, for example by a small weight.Thus, a portion of the sheet 4 is located below the water surface 8 and is in fluid contact with the water. The superhydrophobic sheet 4 has filament-like structures on its surface that are designed to hold an air layer 6 on the surface underwater.

[0044] Figure 1B shows a further illustration of the Figure 1A shown device. An oil film 10 has spread over the water surface 8. In Figure 1Cthe oil 10 on the water surface 8 comes into contact with the sheet material 4. The oil 10 is adsorbed by the filament-like structures of the sheet material 4. The air layer 6 is thereby replaced by the oil 10. The sheet material 4, for example a flock textile, is preferably not only superhydrophobic but also oleophilic. Being wetted with water underwater represents an energetically very unfavorable state, so air is drawn underwater and held on the surface as an air layer 6. Although this is also an energetically very unfavorable state, since the air must be held against the buoyancy, it is more favorable than if the superhydrophobic, oleophilic sheet material 4 were wetted with water. If the oil 10 comes into contact with the sheet material 4, the oleophilic surface is wetted with oil 10.An energetically more favorable state is achieved when the air layer 6 is replaced and the textile fabric 4 is wetted with oil 10, allowing the air held on the surface to rise. The oil 10 is transported downwards, and the energy stored by the energetically unfavorable process of holding air is released in the process. Transport also takes place above water, whereby the oil 10 can flow into the container 2. The oil 10 is thereby transported in the filament-like structures of the fabric 4 along the surface into the container 2. As long as the edge of the container 2 is not too high above the water surface 8, the oil 10 can flow over the edge into the container 2. As long as the end of the superhydrophobic fabric 4, which is located in the collecting container 2, is below the water surface 8 and / or the oil film 10, the oil 10 is released again.When the end in the collecting container 2 is above the water surface 8 and / or the oil film 10, the transport stops at the time when the flock is completely wetted.

[0045] As the oil 10 enters the container 2, the oil level inside the container 2 rises and its weight increases. As a result, the container 2 sinks deeper into the water. As long as the level of the oil 10 inside the container 2 is below the water surface 8, the oil 10 is collected from the water surface 8 and flows into the container 2. Figure 1D there is no more oil 10 on the water surface 8.

[0046] Figure 2schematically shows an embodiment of a device 1 for collecting oil 10 from a water surface 8, which is designed as a floating device 1, a so-called "oil float." The device 1 comprises a container 2 for collecting the oil and an oil-transporting device formed from a superhydrophobic sheet 4. This sheet has filament-like structures on its surface, which are designed to hold a layer 6 of gas on the surface underwater. The sheet 4 has the form of a continuous surface arranged around the container 2. The sheet 4 is guided into the container 2 through slot-shaped openings 18 in the side wall. The container 2 is provided with a lid 12.

[0047] Figure 3schematically shows an embodiment of a device 1 for collecting oil 10 from a water surface 8, which is designed as a submersible device, a so-called "oil diver." The container for collecting the oil 10 is a closed container 14 in the shape of a hollow sphere. This is held below the water surface 8 by means of an anchor 20. The closed container 14 has two inlet openings 26 through which the superhydrophobic sheet 4 is introduced into the closed container 14. The driving force for the oil transport results from the height difference between the water surface 8, where the oil 10 is collected, and the lower container 14 into which the oil 10 is transported. In the submersible embodiment, the transport is directed exclusively downwards. The device 1 has a device for venting and pressure equalization 16 within the container 14.The venting and pressure equalization device is protected against rain and splash water by a cover 24. Example 1 Oil absorption using a floating device

[0048] To fabricate an oil-absorbing device, a laboratory glass container measuring 5 cm in height and 2 cm in diameter (rolled-edge snap-cap jar 45x22 mm, Scherf Präzision Europa GmbH) was anchored to a Petri dish with washers as anchorage, ensuring stability and sufficient weight. A flock textile with a fiber length of 1.2 mm and a density of 13 fibers per mm² (SwissFlock AG) was cut into strips 15 cm long and 1 cm wide. The surface of the flock textile was hydrophobized with Tegotop 210 (Evonik Industries). One end of the flock textile strip was glued to the inside of the glass container so that the end rested on the bottom of the container.

[0049] The device was placed in an aquarium. The aquarium was filled with water, with the rim of the collecting container protruding approximately 5 mm above the water surface. The flocked textile floated on the water surface. A small weight held the end resting on the water below the water surface, retaining a layer of air. Due to the superhydrophobic properties of the flocked textile, a meniscus formed between the water surface and the textile.

[0050] Then, 10 ml of an oil (isopropyl myristate, Sigma Aldrich) stained with Sudan Black (Sigma Aldrich) was added to the water surface. As the oil spread across the water surface, it eventually reached the flocked textile. Due to the oleophilic properties of the textile and supported by the water's meniscus, the oil was adsorbed onto the surface of the flocked textile. The displacement of the air layer underwater by the oil took only a few seconds. Transport into the glass vessel took somewhat longer. However, as soon as the flocked textile was completely wetted, the oil was redeposited within the glass vessel. Example 2: Oil absorption using a submersible device

[0051] For the oil diver, a plastic Petri dish was glued to a plastic hemisphere with epoxy resin, creating a closed volume. The bonded joints were additionally sealed with hot glue (UHU). Weights were attached to the underside of the sphere to keep the air-filled volume underwater. Two holes were drilled into the top, formed by the Petri dish. Two cut strips of a flock textile (fiber length 1.2 mm, density 13 fibers per mm², SwissFlock AG) with a length of 12 cm and a width of 1 cm were hydrophobized with Tegotop 210 (Evonik Industries). The two strips were placed on top of each other with the fiber side and secured at one end with heat shrink tubing. This end was fed through one of the holes into the interior of the oil diver. The sealing was again done with hot glue.A 4 mm diameter PVC hose was inserted into the remaining opening of the oil diver, allowing pressure equalization between the internal volume of the exchanger and the environment. The entire device was placed in a water-filled aquarium. The diver was positioned below the water surface. The two loose ends of the two flocked textiles rested on the water surface. The PVC hose protruded above the water surface. The seals withstood the water, and the interior of the diver remained dry.

[0052] Subsequently, 10 ml of an oil (isopropyl myristate, Sigma Aldrich) dyed with Sudan black (Sigma Aldrich) was added to the water surface. This was adsorbed onto the surfaces of the flock textiles and completely covered them after just a few seconds. The flock textiles were then transported into the oil diver. The oil dripped down from the fixed ends, which were fixed to the lid within the volume. It was observed that a roughly equal amount of water also penetrated the flock textile into the interior of the oil diver via the flock textile. It is suspected that the reason for this was an excessively large gap between the flock textiles pressed together. Accordingly, it is assumed that improved fixation through pressure, for example, using a clamp, should remedy the problem. Overall, the principle of oil collection underwater using a submersible device was thus demonstrated. List of reference symbols device 1 container 2 superhydrophobic sheet 4 Gas layer 6 water surface 8 Öl 10 Lid 12 Closed container 14 Pressure equalization device 16 Openings 18 anchoring 20 Lid 24 Entrance openings 26

Claims

1. Device for taking up oil (10) from a water surface (8), comprising a container (2) for receiving the oil (10) and an oil-transporting means, wherein a portion of the oil-transporting means can be brought in fluid communication with the water surface (8) and another portion of the oil-transporting means is disposed within the container (2), wherein the oil (10) can be transported into the container via the oil-transporting means, characterized in that the oil-transporting means is formed of a hydrophobic fabric (4), the surface of which comprises filament-shaped structures, which are designed such that they retain an air layer (6) on the surface of the hydrophobic fabric (4) under water, wherein for the transport of the oil (10) a portion of the fabric (4) is located below the water surface (8) and is in fluid communication with the water and another end of the fabric (4) is located in the container (2), wherein a portion of the fabric (4) in the container (2) is located below the level of the water surface (8), whereby the oil (10) can displace the air layer (6) and flow into the container (2), and wherein the fabric structure (4) is designed as a three-dimensional spacer textile which spacer textile comprises two outer layers spaced-apart from one another and spacer threads connecting the outer layers to one another, wherein the spacer threads correspond to the filament-shaped structures of the fabric.

2. Device according to claim 1, characterized in that the fabric (4) is designed in the form of a plurality of strip-shaped surfaces, or in the form of a continuous surface arranged around the container (2).

3. Device according to claim 1 or 2, characterized in that the container (2) floats in the water or is locked on the water surface (8), wherein the bottom of the container (2) in the unfilled state is disposed below the water surface.

4. Device according to any one of the preceding claims, characterized in that the fabric (4) is guided into the container (2) over the side wall of the container (2) or through slotshaped openings in the side wall.

5. Device according to any one of the preceding claims, characterized in that the container (2) comprises a lid (12), wherein the lid (12) preferably comprises a valve for pressure compensation.

6. Device according to any one of the preceding claims, characterized in that the container (2) is a closed container (14), wherein the closed container (14) comprises a means for pressure compensation (16).

7. Method for taking up oil (10) from a water surface (8) by means of a container for receiving the oil (10) and an oil-transporting means, wherein a portion of the oil-transporting means can be brought into fluid communication with the water surface (8) and another portion of the oil-transporting means is disposed within the container (2), wherein the oil-transporting means is formed from a hydrophobic fabric (4) the surface of which comprises filament-shaped structures which are designed such that they retain an air layer (6) on the surface under water, wherein the oil (10) is transported into the container (2) via the hydrophobic surface structure (4), wherein for the transport of the oil (10) a portion of the fabric (4) is located below the water surface (8) and is in fluid communication with the water and another end of the fabric (4) is located in the container (2), wherein a portion of the fabric (4) in the container (2) is located below the level of the water surface (8), whereby the oil (10) displaces the air layer (6) and flows into the container (2), and wherein the fabric structure (4) is designed as a three-dimensional spacer textile which spacer textile comprises two outer layers spaced-apart from one another and spacer threads connecting the outer layers to one another, wherein the spacer threads correspond to the filament-shaped structures of the fabric.

8. Use of a device (1) according to any one of claims 1 to 6 for taking up oil (10) from a water surface (8).