Filter metal plate coated with multifunctional nano-coating

Abstract

The present invention relates to a functional nanocoating, in particular a filter metal plate treated with metal oxide nanoparticles combined with at least one of fluoroalkylsilanes, one or more organosilanes, and one or more polymers functionalized with fluoroalkylsilanes and / or organosilanes, or a filter metal plate coated with metal oxide nanoparticles combined with a polymer matrix functionalized with fluorinated molecules or groups. The present invention also relates to the use of the coated plate for filtering water, separating emulsions, etc., and to a kit for obtaining the coating.

Description

[Technical Field]

[0001] The present invention relates to the field of filter plates, in particular to filter metal plates coated with a functionalized nanocoating. [Background technology]

[0002] In the field of filter metal plates, Vee-wire (or V-wire) filter metal plates are known, for example, from Aqseptence Group Srl.

[0003] Vee wire filter screens offer significant advantages in use due to their versatility, ease of manufacture, and mechanical strength.

[0004] However, for certain applications such as filter presses, water filtration in extreme cold environments, and oil-water separation, plates alone are not sufficient.

[0005] In the field of filter presses, the use of steel plates as a replacement for currently used polymeric fabrics offers significant processing advantages in terms of wear resistance and can avoid frequent maintenance of the equipment. However, metal surfaces are the cause of virtually irreversible adhesion of filtrate to the screen, making the filter press process inefficient.

[0006] The problem of ice formation on metal plates used in water intake processes, i.e., the process of drawing water from rivers and canals, and immersed in canals affected by the frazil ice phenomenon, is limited to northern countries, especially the United States and Canada, but involves a significant use of energy to heat the plates.

[0007] Fraxil ice phenomenon and the hazards it poses are well known and documented in the literature. (1, 2) Similarly, processes for obtaining nanostructured anti-icing coatings have been reported in the literature. (3-5) However, solutions that can be applied to filter plates and that function to limit ice adhesion under submerged conditions have not yet been reported.

[0008] The problem of oil-water separation by nonmetric coatings on permeable substrates such as metal screens, sponges, and fabrics has been described in the literature. (6-11) However, most of them report highly complex multistep processes that are difficult to apply and difficult to scale up to large surfaces.

[0009] Therefore, there is a need to solve certain problems related to the use of filter metal plates, especially Vee wire plates, in their primary applications. Summary of the Invention

[0010] Coating the filter metal plates with a properly functionalized nanocoating has been found to have the following advantages: i) It provides significant advantages in filter pressing processes, as it ensures the release of solids from the plate surfaces, i.e., in processes where the solid cake does not completely separate from the filter plates, requiring continuous machine stoppages; ii) Suppression of ice buildup that impedes water passage during water intake operations in cold regions; iii) In waste treatment processes, it becomes possible to separate oil from water and recover water from emulsion mixtures.

[0011] One subject of the present invention is a method for coating metal filter plates. a) metal oxide nanoparticles combined with at least one of one or more fluoroalkylsilanes, one or more organosilanes, and one or more polymers functionalized with fluoroalkylsilanes and / or organosilanes; and / or b) metal oxide nanoparticles bound to a polymer matrix functionalized with fluorinated molecules or groups; The use of.

[0012] The subject of the present invention is also a) metal oxide nanoparticles combined with at least one of one or more fluoroalkylsilanes, one or more organosilanes, and one or more polymers functionalized with fluoroalkylsilanes and / or organosilanes; and b) metal oxide nanoparticles bound to a polymer matrix functionalized with fluorinated molecules or groups; and a filter metal plate coated with at least one of the coatings.

[0013] In a preferred embodiment, the filter metal plates are made of stainless steel.

[0014] In a preferred embodiment, the filter metal plate is a Vee wire plate.

[0015] In a preferred embodiment, the metal oxide is silicon dioxide (SiO2).

[0016] In a preferred embodiment, said nanoparticles a) are metal oxide nanoparticles bound to one or more fluoroalkylsilanes.

[0017] In a preferred embodiment, said nanoparticles a) are metal oxide nanoparticles bound to one or more organosilanes.

[0018] In another preferred embodiment, said nanoparticles a) are metal oxide nanoparticles bound to one or more organosilane polymers.

[0019] In a preferred embodiment, the nanoparticles b) are obtained by precipitation of a suspension of metal oxide nanoparticles in poly(diallyldimethylammonium chloride) (PDDA) and perfluorooctanoic acid, or in poly(diallyldimethylammonium chloride) (PDDA) and at least one anionic fluorosurfactant, followed by dispersion in an alcoholic solvent.

[0020] The plates according to the present invention are coated with nanoparticles of inorganic metal oxides, such as SiO2, combined with fluorinated or organosilane polymers. The synergistic effect of the two components allows for technically attractive functionality, which is important in filter plate applications, namely the removal of dirt and ice and the separation of water and oil.

[0021] The materials can be commercially available, and future applications for expandability are easy.

[0022] In terms of mud removal, the introduction of Vee wire screens with the developed nanometer-level coating allows for complete removal of solids from the surface, paving the way for the use of metal plates instead of conventional polymer fabrics.

[0023] The nano-coated Vee wire plate has shown very promising results, including repeated cycle tests conducted in a pilot filter press plant (Figure 2).

[0024] The advantage of the developed coatings lies not only in the functionality achieved but also in the ease of application: in fact, large surfaces can be provided with the claimed coatings by simply painting or spraying them.

[0025] Easily available and applicable materials are used to prepare nanometer-scale coatings that can limit ice adhesion both in air and when immersed in supercooled water. These conditions simulate the frazil phenomenon common in northern waterways. Vee wire screen samples coated according to the present invention were characterized with respect to wettability, particularly their ability to avoid ice buildup when immersed in supercooled water. Compared to the bare samples, the samples treated according to the present invention showed an optimal ability to avoid ice buildup on their surfaces and, as a result, maintained optimal performance even after several immersion cycles (Figure 3).

[0026] Compared to untreated surfaces, Vee wire screens coated according to the present invention and tested for oil-water separation showed a decreased contact angle with water (more hydrophilic) and an increased contact angle with biodiesel (more oleophobic). Finally, separation tests performed for filtration showed an improved separation effect in a 90 / 10 water / biodiesel mixture (Figure 6), making these screens promising candidates for effective use in treating wastewater from industrial plants.

[0027] Another subject of the invention is the use of a filter metal plate coated as described above for filtering a liquid such as water.

[0028] A preferred application is in filter presses, especially for mud removal.

[0029] Another preferred application is water filtration in extremely cold environments, such as temperatures below 0°C, particularly in water intake processes where water is drawn from cryogenic reservoirs or streams.

[0030] Another preferred application is liquid / liquid separation, in particular the separation of oil / water emulsions consisting of an aqueous phase and an oil phase.

[0031] Another subject of the invention is the use of coated filter metal plates in the treatment of wastewater, such as industrial wastewater.

[0032] Next, embodiments and experiments illustrating the principles of the present invention will be described with reference to the following figures. [Brief explanation of the drawings]

[0033] [Figure 1] Vee wire screen after adhesion test with mining mud heated at 50° C. for 1 hour: sx) untreated sample, dx) sample with coating according to the invention. [Figure 2] Vee wire screen after pilot filter press tests with mining mud: sx) untreated sample, dx) sample with coating according to the invention. [Figure 3] Vee wire screen after ice adhesion test under immersion conditions: a) untreated sample, b) sample with coating based on SiO2 only, c) sample with coating according to the invention. [Figure 4] This is the peeling effect in anti-icing applications. [Figure 5] FIG. 1 is a schematic diagram of oil-water separation via a filtration membrane. [Figure 6] This is a separation test of a mixture of 90ml of water and 10ml of biodiesel. [Figure 7] This is a contact angle measurement using water and n-hexadecane. DETAILED DESCRIPTION OF THE INVENTION

[0034] A filter metal plate is understood to be a plate of any metal of any size that is capable of filtering a liquid such as water.

[0035] For the purposes of the present invention, the term "metal" also includes metal alloys. The metal may be steel, aluminum, titanium, copper, zinc, precious metals and alloys thereof.

[0036] For the purposes of the present invention, a metal plate is understood to mean a plate of various shapes, for example, flat or cylindrical. For the purposes of the present invention, a "screen" is synonymous with a plate. Discontinuous surfaces such as screens and metal grids are also included in the definition of a metal plate according to the present invention.

[0037] In a preferred embodiment, the filter metal plates are made of stainless steel, for example type A ISI 316.

[0038] In a preferred embodiment, the filter metal plate is a Vee wire or V-wire plate. A Vee wire plate is specifically understood to be a plate, also called a screen, that is flat or cylindrical and usually has a series of support rods around which a continuous length of wire is wound. WO2018191611 describes an example of a Vee wire plate. Vee wire plates are sold by Acceptance Co., Ltd.

[0039] Nanoparticles are understood to be particles with a diameter of 1 to 500 nm.

[0040] The nanoparticles used in the present invention are made of metal oxides, which may be oxides of silicon, aluminum, titanium, zinc, zirconium, yttrium, and cerium.

[0041] These nanoparticles can be synthesized by methods known in the art or can be commercially available.

[0042] SiO2 nanoparticles can be synthesized by methods known in the art (see, for example, References 12 and 13), or commercially available products can be used. They can be used in the form of a suspension or powder.

[0043] "Nanoparticles bound to" means that there is a bond or interaction (generally non-covalent) between the nanoparticles and the binding moiety. In particular, the nanoparticles may be dispersed in a polymer matrix containing the binding moiety, optionally suitably functionalized. Alternatively, the coating may consist of a first layer containing metal oxide nanoparticles and a second layer containing the binding moiety, e.g., a polymer, in contact with the first layer.

[0044] The coating may include additional elements, for example, elements that a person skilled in the art would consider suitable for a particular application based on their general knowledge in the art.

[0045] For the purposes of the present invention, a "coating" is understood as a composition intended to completely or partially cover a surface, in particular a metal plate, according to the invention. Coating and nanocoating are used synonymously in the present disclosure.

[0046] In a first embodiment, the coating is composed of nanoparticles of a metal oxide, such as SiO2, combined with one or more fluoroalkylsilanes.

[0047] Fluoroalkylsilanes have the formula (RO-)3Si-R T where R is hydrogen or an alkyl group, for example a C1-C4 alkyl group, and R T is an organic compound that ends with a perfluoroalkyl group. For example, R T is C1-C 12 The alkyl group may be any of the following.

[0048] Examples of fluoroalkylsilanes include 1H,1H,2H,2H-perfluorodecyltriethoxysilane and 1H,1H,2H,2H-perfluorooctyltrimethoxysilane.

[0049] In a preferred embodiment, the fluoroalkylsilane is the commercially available compound SIVO, sold for example by Evonik under the name Dynasylan® SIVO. Various types of SIVO may be used in the present invention, for example Dynasylan® SIVO 160, Dynasylan® SIVO 113, and / or Dynasylan® SIVO 110.

[0050] The coating can be obtained by applying an inorganic nanolayer formed by dispersing a suspension of metal oxide nanoparticles in water, followed by an organic layer based on fluoroalkylsilanes dispersed in, for example, alcohol.

[0051] The suspension of metal oxide nanoparticles, e.g., nano-SiO2, is preferably dispersed in water before application, at a concentration of 1% to 10% by weight, preferably 2% to 6% by weight, more preferably 4% by weight.

[0052] The coating can be applied to the metal plate by dip coating, i.e., immersion and removal at a controlled rate, spraying, or percolation to uniformly contact the surface to be treated, all of which methods are well known in the art.

[0053] The process may include a heat treatment after application of the inorganic phase, for example at 200° C. for 1 hour. The application of the organic phase may also be followed by a heat treatment, for example at 150° C. for 30 minutes.

[0054] As an alternative to heat treatment, the coating can be dried with hot air.

[0055] In a preferred embodiment, before applying the nanocoating, the metal plate is subjected to a sandblasting treatment, which in fact allows for better mud removal results to be achieved. Sandblasting is understood as a mechanical process in which a spray of abrasive particles, such as sand, is directed at a solid surface in order to modify the surface finish or shape or to remove contaminants.

[0056] In a second embodiment, the present invention provides a coating comprising particles made of a metal oxide, such as SiO2, combined with one or more organosilane polymers.

[0057] Organosilanes or organosilane polymers are understood to be polymers consisting of one or more molecules containing silicon attached to a carbon chain.

[0058] Examples of organosilane polymers include polysilanes, polysiloxanes, polysilazanes, polyalkylsilanes, polyarylsilanes, or mixtures thereof. The polymers may be of variable length, for example, 1 to 50 repeating units. The polymers may be appropriately functionalized according to knowledge and methods known in the art.

[0059] In a preferred embodiment, the metal oxide nanoparticles are combined with an organosilane.

[0060] For example, in addition to metal oxide nanoparticles, the coating may contain a commercially available product called Metalcoat (trade name TECNADIS METALCOAT BASE) sold by Chem Spec Srl., which contains ceramic nanoparticles and organosilanes in an alcoholic suspension.

[0061] The coating may also include additional ingredients, for example ingredients that improve the effectiveness of the coating.

[0062] In a preferred embodiment, the coating contains an additional component called an enhancer, which consists of a dilute solution of acetic acid in ethanol and acts as an acid catalyst. An example of an enhancer is known under the trade name TECNADIS METALCOAT ENHANCER, sold by Chem Spec Srl.

[0063] In a preferred embodiment, the coating of the filter metal plate is composed of SiO2 nanoparticles, Metalcoat, and an enhancer.

[0064] The coating can be obtained by first applying an inorganic nanoparticle layer formed by dispersing a suspension of metal oxide nanoparticles, e.g., SiO2, in water, followed by a layer comprising, for example, an organosilane dispersed in alcohol, optionally with an enhancer.

[0065] In some embodiments, the layer comprising the organosilane further comprises metal oxide nanoparticles, such as SiO 2 nanoparticles.

[0066] The suspension of nano-SiO2 is preferably dispersed in water at a concentration of 1% to 10% by weight, preferably 2% to 6% by weight, preferably 4% by weight.

[0067] The coating can be applied to the metal plate by dip coating, ie, immersion and removal at a controlled rate, spraying, or penetration by uniform contact with the surface to be treated.

[0068] After the first layer containing nano-SiO2 is applied, the process may include a heat treatment, for example, at 200°C for 1 hour. Alternatively, after the application of a layer containing organosilane, such as Metalcoat, a heat treatment may be performed, for example, at 170°C for 30 minutes.

[0069] Instead of heat treatment, the coating may be dried with hot air.

[0070] In a third embodiment, the present invention provides a coating consisting of nanoparticles formed of metal oxides, such as SiO2, bound to a polymer matrix functionalized with fluorinated molecules or groups.

[0071] The polymer matrix may be made of a polymer selected from polydiallyldimethylammonium chloride, polydimethylsiloxane, such as Sylgard 184 silicone, methyltrimethoxysilane, methyltriacetoxysilane, perfluoropolyether, and chitosan-polyvinyl alcohol.

[0072] These fluorinated molecules or groups may be, for example, perfluorooctanoic acid, anionic fluorosurfactants, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, or derivatives thereof.

[0073] In one embodiment, the coating is obtained by precipitating a suspension of metal oxide nanoparticles in poly(diallyldimethylammonium chloride) (PDDA) and perfluorooctanoic acid, followed by dispersion in an alcohol solvent.

[0074] In another embodiment, the coating is obtained by precipitating a suspension of metal oxide nanoparticles in poly(diallyldimethylammonium chloride) (PDDA) and an anionic fluorosurfactant, followed by dispersion in an alcohol solvent.

[0075] Poly(diallyldimethylammonium chloride) (PDDA) is composed of repeating units having the chemical formula shown in Diagram 1 below. TIFF2025540197000002.tif45132 Diagram 1: Repeating unit of poly(diallyldimethylammonium chloride)

[0076] The anionic fluorosurfactant preferably has the formula CF3(CF2)5(CH2)2O(PO2)O(CH2)3OH. Suitable anionic fluorosurfactants are commercially available, such as Capstone FS-63, available from DuPont. Other fluorosurfactants in the Capstone series available from DuPont can also be used.

[0077] Perfluorooctanoic acid has the formula CF3(CF2)6COOH.

[0078] In one embodiment, the present invention provides a filter metal plate coated with a composition obtained by precipitating a suspension of SiO2 nanoparticles in poly(diallyldimethylammonium chloride) (PDDA) and perfluorooctanoic acid, followed by dispersion in an alcohol solvent. More specifically, this composition can be obtained as follows: SiO2 nanoparticles are dispersed in diluted PDDA in an aqueous solvent, followed by ultrasonic treatment for 30 minutes, followed by dropwise addition of a perfluorooctanoic acid solution, and the precipitate is separated, washed with water, and then dried. To obtain a powder, the product can be manually ground, for example, using a mortar and pestle, to obtain a fine, easily dispersible solid.

[0079] Upon deposition onto the plate, the precipitate obtained as described above is dispersed in an alcohol solvent, preferably ethanol at a concentration of 1% w / v, and preferably treated with ultrasound.

[0080] In another embodiment, the present invention provides a filter metal plate coated with a composition obtained by precipitating a suspension of SiO2 nanoparticles in poly(diallyldimethylammonium chloride) (PDDA) and an anionic fluorosurfactant, followed by dispersion in an alcohol solvent. More specifically, this composition can be obtained as follows: a powder of anionic fluorosurfactant and SiO2 nanoparticles is added to a diluted suspension of poly(diallyldimethylammonium chloride) (PDDA) in an aqueous solvent. The suspension is treated with ultrasound for 1 hour, and the precipitate is washed and dried. The resulting powder can be manually ground, for example, with a mortar and pestle, to obtain a fine, easily dispersible solid.

[0081] Upon deposition onto the plate, the precipitate obtained as described above is dispersed in an alcohol solvent, preferably ethanol at a concentration of 1% w / v, and preferably treated with ultrasound.

[0082] The coating can be applied to the metal plate by dip coating, ie, immersion and removal at a controlled rate, spraying, or penetration by uniform contact with the surface to be treated.

[0083] Preferably, the coated surface is heat treated, for example at a temperature of 150° C. for 30 minutes, to strengthen the adhesion of the coating.

[0084] After dip coating, it is preferable to wait at least 10 minutes at room temperature to allow the solvent to evaporate slowly, thereby reducing stress and tension on the coating as the bulk of the solvent evaporates upon heating.

[0085] Preferably, the coating may be applied repeatedly, for example two or three times, and indeed multiple applications can result in better and more uniform properties at the surface, leading to improved performance.

[0086] The straightforward synthesis process and use of off-the-shelf raw materials make these coatings simple and easily scalable to large-scale facilities.

[0087] The plates of the present invention are useful for filtering liquids such as water, and particularly for use in solid-liquid separation.

[0088] A preferred embodiment is a filter press, which is understood to reduce the volume of liquid materials, especially mud, that have suspended solids therein.

[0089] The plates can also be used advantageously for filtering water in extremely cold environments, for example at temperatures below 0°C.

[0090] Furthermore, they are useful in the separation of oil / water emulsions consisting of an aqueous phase and an oil phase, and in particular in the treatment of wastewater, for example from industrial plants.

[0091] The present invention also relates to kits for preparing the coatings described in this disclosure.

[0092] The kit may, for example, a) the metal oxide nanoparticles described above, and b) a composition comprising at least one of a fluoroalkylsilane, an organosilane, and one or more polymers functionalized with a fluoroalkylsilane and / or an organosilane, or b') at least one polymer and at least one compound comprising a fluorinated molecule or a fluorinated group; may include:

[0093] Preferably, the polymer of b') is a polymer selected from poly(diallyldimethylammonium chloride), polydimethylsiloxane, such as Sylgard 184 silicone, methyltrimethoxysilane, methyltriacetoxysilane, perfluoropolyether, and chitosan-polyvinyl alcohol, and / or the fluorinated molecule or group is selected from perfluorooctanoic acid, anionic fluorosurfactants, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, or molecules or groups derived therefrom.

[0094] Additionally, the kit may include instructions for obtaining the coating and instructions for applying the coating to the filter metal plate.

[0095] The following examples further illustrate the present invention. Example Example 1 Effect of coatings on mud release from Vee wire screens used in filter presses. Materials and Methods

[0096] a) Preparation of type a coating (SiO2 + fluoroalkylsilane) Vee wire screens made of stainless steel (AISI 316) can have their microstructural texture modified by sandblasting and subsequent coating based on inorganic nanoparticles combined with fluoroalkylsilanes (this is not necessary to achieve good release, but it does improve the condition).

[0097] Inorganic nanoparticles of SiO2 are dispersed in an aqueous solvent (commercially available LUDOX HS 40) at a dilution rate of 4 wt % and applied to a Vee wire screen.

[0098] To compare the effect of microstructural texture, a comparison was made between a non-sandblasted Vee wire plate with a surface roughness of Sa = 0.16 μm, named TQ, a plate sandblasted to a surface roughness of Sa = 0.83 μm, named R1, and a plate sandblasted to a surface roughness of Sa = 1.74 μm, named R3.

[0099] Next, a commercially available polymer phase based on fluoroalkylsilanes (SIVO, Evonik) dispersed in isopropyl alcohol is applied.

[0100] The SiO2 and fluoroalkylsilane are deposited on the Vee wire plate by dip coating (5 seconds in the inorganic suspension, 120 seconds in the polymer, immersion and removal at a controlled speed of 2 mm / s). Application by spraying or dipping is also possible, as uniform contact with the surface is required.

[0101] After application of the inorganic phase, a heat treatment is performed at 200 °C for 1 hour, while for the polymer, it is performed at 150 °C for 30 minutes. In the case of hybrid coatings combining inorganic phase and polymer (SiO2 / fluoroalkylsilane), two applications are performed, followed by both heat treatments. The samples obtained in this way with different roughness levels are called SiO2_SIVO, SiO2_SIVO_R1, and SiO2_SIVO_R3.

[0102] b) Preparation of type b coating (SiO2 + fluoroalkylsilane, without heat treatment) This preparation is carried out on a substrate without sandblasting in the same way as in Example 1a), but after applying SiO2 and SIVO, no heat treatment is carried out and the surface is dried with hot air. The obtained sample is called TQ-SiS-1T-1.

[0103] c) Preparation of Type c Coating (Comparative Polymer) This preparation was carried out in the same manner as in Example 1a), except that only the polymer coating was applied to the screen surface. Various polymers were compared: a fluoroalkylsilane called SIVO (Evonik), a water-based fluorinated acrylic resin called AFW (Dupont), and two methylsilicone resins in isopropyl alcohol called DIS1 and DIS2 (Chem Spec). Thus, the samples made on Vee wire screens without sandblasting are called TQ SIVO, TQ AFW, TQ DIS1, and TQ DIS2.

[0104] d) Preparation of type d coating (SiO2) This preparation is carried out in the same way as in Example 1a) on a non-sandblasted surface, but without the application of fluoroalkylsilane. The sample obtained is called SiO2_Hydrophilic.

[0105] e) Preparation of Type e Coatings (Fluoroalkylsilanes on Surfaces with Different Roughnesses) Non-sandblasted and sandblasted Vee wire screens of different roughness were treated with fluoroalkylsilane (SIVO) according to the method of Example 1a) and the resulting samples were called TQ_SIVO, SIVO_R1 and SIVO_R2.

[0106] f) Preparation of type f coating (Al2O3 + fluoroalkylsilane) Al2O3 nanoparticles were obtained by sol / gel synthesis in isopropyl alcohol according to the procedure described in WO2013190587, then applied to a metal screen and treated with the fluoroalkylsilane polymer SIVO (Evonik) in the same way as in Example 1a).

[0107] g) Preparation of type g coating (TiO2 + fluoroalkylsilane) The TiO2 nanoparticles were contained in a 4 wt% aqueous suspension corresponding to the commercial product PARNASOS PH000026 (Colorobbia Group) and applied to a metal screen in the same manner as in Example 1a) and treated with the fluoroalkylsilane polymer SIVO (Evonik). The resulting sample was called TN_SIVO.

[0108] Table 1 lists the samples prepared for analysis of metal screen delamination. Table 1: Samples prepared as described above TIFF2025540197000003.tif141169

[0109] Physical, chemical, and functional characterization The prepared samples were characterized for their surface roughness and wettability by measuring the contact angle with water and n-hexadecane, and the surface energy. All measurements collected were the average of at least five values ​​taken in different areas of the screen to map the entire surface.

[0110] Functional characterization is so defined because it is performed to evaluate the performance of a material under conditions that simulate its intended use. In particular, two types of functional characterization have been developed, both of which simulate mud contact with the surface to test the effect of the coating on mud detachment during filter pressing.

[0111] Dry exfoliation (tested with red mud): After 24 hours of gentle stirring (rolling) to homogenize the mud, 3 g of mud is deposited on a screen slide and placed in a ventilated oven at 50°C for 1 hour.

[0112] After heating, mud release is assessed by lifting the sample vertically at 90° and shaking it until release occurs. Tests are always performed by comparing the coating with an untreated bare sample. This comparison is performed by video analysis of the release kinetics. Samples are scored and classified according to Table 2 based on the percentage of release area and the number of impacts required for release.

[0113] Table 2: Evaluation table used to determine dry peeling in the presence of mud TIFF2025540197000004.tif87131

[0114] Debonding under pressure (tested with red and Morelos mud): After homogenizing the mud in a turbola (for 20 minutes), 10 g of the mud are properly dried and deposited between two screen slides. They are then pressed in a uniaxial press at approximately 40 bar for 60 minutes to simulate filter press conditions. Debonding is assessed by video analysis of the debonding dynamics, and samples are classified by scoring based on the number of impacts required for slippage and eventual cake debonding.

[0115] Table 3: Evaluation table used to determine peeling under pressure TIFF2025540197000005.tif64131

[0116] Results and Discussion Roughness The surface roughness of samples sandblasted with two different grain sizes (NT_R1, NT_R3) was measured and compared with that of the bare sample without surface treatment.

[0117] The important measurement parameters are: · Sa (surface roughness): The degree of surface roughness Ra. An absolute value is assigned to the difference in height between each point and the center line of the surface. · Sz (surface texture): defined as the sum of the five highest peaks and five deepest valleys within the considered area.

[0118] Table 4: Surface roughness after various sandblasting treatments TIFF2025540197000006.tif38139

[0119] As expected, the results showed an increase in both surface roughness and surface texture values, which was also observed in the surface mapping obtained from the device.

[0120] Wettability Table 5 shows the wettability results of the samples. Table 5: Primary wettability properties measured on prepared samples (drop volume 10 μl) TIFF2025540197000007.tif166147

[0121] In general, the wettability results obtained for the various sample preparations show a significant change in water repellency and oil repellency to n-hexadecane between the bare and treated samples, as evidenced by the increase in contact angle (n-hexadecane was chosen to simulate oil repellency due to its low surface tension). The increase in roughness due to sandblasting treatment caused an increase in the water contact angle, which changed from 61° to 81° from sample TQ to sample TQ_R3. This trend supports the Wenzel model, which has been published in the literature (14). However, the increase in roughness alone does not affect the oil repellency to n-hexadecane, which is very difficult to repel due to its low surface tension. The samples with the highest water contact angles were those containing fluoroalkylsilanes (SIVO), namely SiO2_SIVO, Al2O3_SIVO, and R3_SIVO; among these, SiO2_SIVO and Al2O3_SIVO had lower surface energies, likely due to a more homogeneous surface nanostructure.

[0122] Thermal peeling (red mud dried at 50°C) Thermal release was evaluated by analyzing video of each sample after the mud had dried on the screen. Specifically, each sample was scored according to the evaluation table in Table 2 to obtain a ranking between coatings with high and low release performance. In all cases, each test was performed alongside an untreated sample. Each coating was also tested multiple times to ensure reproducibility of results.

[0123] Table 6 shows the overall results of the test, with scores ranging from 1 (very poor) to 7 (excellent).

[0124] Overall, the results confirmed that untreated samples had a significant tendency for mud to stick, and this was confirmed across multiple successive tests. Increased roughness itself also had a negative effect on performance in the absence of a coating (presumably due to an increase in surface area for gripping mud), but no difference was observed with the hydrophobic coating. No delamination occurred with the hydrophilic coating, confirming the need for water repellency.

[0125] From this test, it was found that the best samples for red mud release were those containing SIVO, namely TQ_SIVO, R1_SIVO, R3_SIVO, Al_SIVO, and Si_SIVO, and indeed, the fluorinated polymer appears to play an important role in the release of solids. Polymers D1 and D2 showed good release properties with excellent scores, although not always reproducibly. However, TiO2-based coatings did not perform well, even when combined with SIVO.

[0126] Figure 1 shows images of two samples (the bare sample on the left and the Si_SIVO-treated sample on the right) after the peel test.

[0127] Table 6: Performance evaluation of red mud thermal stripping TIFF2025540197000008.tif206160

[0128] Stripping under pressure (red mud under 40 bar pressure) Peeling under pressure was evaluated by analyzing the video recorded after opening two screens (10 x 5 cm) placed one above the other and left under pressure (40 bar, 1 h) in the presence of mud (10 g). Again, after observing the peeling kinetics, each sample was scored according to Table 3. The aim was to derive a ranking between coatings in terms of their peeling performance, in this case simulated by applying pressure to the screens. Each coating was tested multiple times to ensure the reproducibility of the results.

[0129] Table 7 shows the overall results of the test, with scores ranging from 0 (very poor) to 4 (excellent).

[0130] Table 7: Performance evaluation of red mud stripping under pressure TIFF2025540197000009.tif166166

[0131] The overall evaluation of the results confirmed the significant adhesion tendency of the compressed mud in the untreated samples, which did not peel off or start to slip even after repeated impacts, confirming the behavior observed in dry peeling.

[0132] Unlike the dry test, improved release was observed with increasing roughness. This is likely due to reduced adhesion due to surface inhomogeneity, despite the larger gripping surface. Polymers D1 and D2, as well as the Al2O3-containing sample (Al_SIVO), did not confirm the good performance observed in the dry test. Good performance was also observed for each Si_SIVO sample coated to various roughnesses, as well as for the sample coated with SIVO alone on a bare surface (TQ_SIVO), as well as for the samples coated with sandblasted surfaces (R1_SIVO, R3_SIVO). Hybrid coatings with SiO2 nanostructures bonded to fluorinated polymers (Si_SIVO, Si_SIVO_R1, Si_SIVO_R3) that were roughened to various roughnesses outperformed SIVO alone (TQ_SIVO, R1_SIVO, R3_SIVO), scoring 4 vs. 3. In assessing the impact required to cause delamination, SIVO alone shows a slight improvement in performance as roughness increases, i.e., from TQ_SIVO to R3_SIVO.

[0133] Debonding under pressure (Morelos mud under 40 bar pressure) The peeling tests under pressure on Morelos mud were carried out using the same procedure as for red mud, but only the most promising coating (Si_SIVO) was tested. Furthermore, in this case, the same set of screens was tested repeatedly to evaluate its durability over different cycles.

[0134] The results are shown in Table 8. The selected coatings exhibited optimal performance and good reusability. The untreated samples were found to have poor release capabilities. When observing the performance of Si_SIVO, it was found that the best results were obtained with the as-is surface finish and R3 (greater roughness). Also, the results obtained with the unheated solidified sample (Si_SIVO_T1) that was reused for multiple cycles appear to be comparable.

[0135] Table 8: Performance evaluation of Morelos mud for separation under pressure TIFF2025540197000010.tif207161

[0136] The Si_SIVO_R3 and Si_SIVO coatings were applied to 50 x 50 cm Vee wire screens for application in a pilot plant of a filter press and also showed optimal mud release results at pilot scale, including repeated successive cycles, which were consistent with the functional properties obtained in the laboratory.

[0137] Figure 2 shows the pilot-scale peel test results, highlighting the difference between an untreated Vee wire screen (left) and a screen treated with Si_SIVO_R3 (right).

[0138] Example 2 Effect of anti-icing coatings on water intake vee wire screens. Materials and Methods a) Preparation of type a coating (SiO2 + polymer) Vee wire screens made of stainless steel (AISI 316) are coated with coatings based on inorganic nanoparticles combined with various polymers. Inorganic nanoparticles of SiO2 (commercially available LUDOX HS 40) dispersed in an aqueous solvent are applied to the Vee wire screen at a dilution rate of 4 wt.%.

[0139] Next, a layer of a commercially available polymer, optionally reinforced with an inorganic phase, is applied. To evaluate the effect of the type of polymer combined with SiO2, various commercially available polymers were applied, including fluoroalkylsilane (SIVO, Evonik), polysilazane (A1220, Chem Spec), silicone elastomer (NUSIL R-2180, Avantor), oxide micro-nanoparticles in propylene glycol methyl ether (NANOMYTE SuperAi, NEI), and an 8 wt% alcoholic suspension of organosilane activated with an acid catalyst (METALCOAT+Enhancer, Chem Spec).

[0140] The SiO2 and polymer are deposited on a Vee wire plate by dip coating (immersion and removal at a controlled rate of 2 mm / s, with a 5 second hold time for the inorganic suspension and a 120 second hold time for the polymer). Application by spraying or dipping is also possible, as uniform contact with the surface is required.

[0141] Once the inorganic phase is deposited, a heat treatment is performed at 200°C for 1 hour. However, for the polymers, the heat treatment is performed under the following conditions: SIVO at 150°C for 30 minutes, A1220 at 180°C for 1 hour, NuSil R-2180 at 75°C for 45 minutes and 150°C for 135 minutes, NANOMYTE SuperAi at 105°C for 15 minutes, and Metalcoat at 170°C for 30 minutes. The enhancer is applied after the same conditions.

[0142] The resulting samples are called LUDOX+SIVO, LUDOX+A1220, LUDOX+NuSil, LUDOX+Nanomyte, and LUDOX+Metalcoat+Enhancer.

[0143] b) Preparation of type d coating (SiO2) The preparation is carried out in the same way as in Example 2a), but without the subsequent application of polymer. The sample obtained is called LUDOX.

[0144] c) Preparation of Type c Coating (Comparative Polymer) The preparation is carried out in the same way as in Example 2a), except that only the polymer coating is applied to the screen surface. Various types of polymers were compared: polysilazane (A1220, Chem Spec), silicone elastomer (NUSIL R-2180, Avantor), oxide micro-nanoparticles in propylene glycol methyl ether (NANOMYTE SuperAi, NEI), and an 8 wt% alcoholic suspension of organosilane activated with an acid catalyst (METALCOAT+Enhancer, Chem Spec).

[0145] Post-application heat treatment for the various polymer phases was carried out according to the method of Example 2a).

[0146] The Vee wire screen samples thus produced are designated A1220, Nanomate, NuSil, and Metalcoat+Enhancer.

[0147] d) Preparation of type d coating (Al2O3 and silicone oil) Al2O3 nanoparticles were prepared by sol / gel synthesis in isopropyl alcohol according to the procedure described in WO2013190587 and then applied to a metal screen treated with the fluoroalkylsilane polymer SIVO (Evonik) according to the method of Example 2a), followed by immersion in silicone oil (Sigma-Aldrich, 100 cSt) for 5 minutes and then infiltration with excess oil for 48 hours at ambient temperature. The sample thus produced on a Vee wire screen is referred to as Al2O3 + SIVO + 100 cSt silicone oil.

[0148] Table 9 summarizes all samples prepared for testing for anti-frazil applications. Table 9: Summary of all coatings prepared and tested TIFF2025540197000011.tif102141

[0149] Physical, chemical, and functional characterization Wettability is a physical property that may be indirectly related to anti-icing performance. Therefore, the static contact angle (CA) for water and n-hexadecane, the drop mobility (hysteresis of contact angle, HCA), and the surface energy of the samples were evaluated. All measurements collected were the average of at least three values ​​obtained in different areas of the screen to map the entire surface.

[0150] Functional characterization aims to evaluate the performance of materials by simulating the conditions of use of the applied material.

[0151] An experimental method was designed to compare the prepared coatings in order to mimic the application in waterways and groundwater bodies, and thus the formation and adhesion of ice and frazil ice to the surfaces and walls of immersed equipment.

[0152] Ice adhesion test The experiment was carried out using a Julabo F 34 cryostat. 3 L of double-distilled water was thermostated at -0.2°C and mechanically stirred at 200 rpm. Slight supercooling was set so that heterogeneous ice nucleation would occur with slight external events.

[0153] The Vee wire screen was placed in a -18°C freezer for 20 minutes to allow for the instantaneous formation of non-uniform ice nuclei on the sample surface upon immersion.

[0154] The test was performed by immersing a screen cooled to -18°C in water supercooled to -0.2°C for 1 minute with agitation. During this time, ice nucleation was observed until an ice-water mixture was obtained. The sample was maintained immersed, removed, and placed in a cryostat (~0°C). The behavior of the ice was evaluated in terms of the percentage of surface coverage (ice adhesion) and its ability to be removed by repeated impacts (ice peeling). The sample was struck (at a rate of 100 impacts per minute), and the number of impacts required for complete peeling was used as a key indicator for ranking the sample's performance.

[0155] The samples were scored and classified according to Tables 10 and 11 based on the ice adhesion rate and the number of impacts required to remove the ice.

[0156] Table 10: Evaluation table used for ice adhesion TIFF2025540197000012.tif97133

[0157] Table 11: Evaluation table used for ice detachment TIFF2025540197000013.tif111134

[0158] The overall evaluation takes into account the average adhesion and peeling values.

[0159] Results and Discussion Wettability and functionality evaluation of anti-icing coatings The wettability of a 5x5 cm Vee wire screen was measured after application of various coatings.

[0160] Table 12 shows the wettability measured after applying only the polymer prepared by the method described in Example 2c) "Preparation of Type c Coating (Comparative Polymer)" to the surface.

[0161] Table 12: Primary wettability measurement results for samples prepared by the method of type 2c) TIFF2025540197000014.tif81169

[0162] The inherent non-uniformity of the Vee wire screen surface is accompanied by a high standard deviation of the measurements.

[0163] In the case of "Not measurable" (ND), the measurement was not possible because the hydrophilicity / oleophilicity was high and the liquid quickly penetrated into the flow channels of the screen.

[0164] With the exception of A1220, each coating showed a slight improvement in hydrophobicity and hysteresis, as measured by the CA and HCA for a water droplet, respectively. Only Metalcoat and Nusil improved hydrophobicity and oleophobicity, showing a significant increase in contact angle and a good reduction in surface energy.

[0165] Table 13 shows the wettability measured after application of coatings prepared by the methods described in the examples, 2a), 2b) and 2d), i.e., containing inorganic nanoparticles (SiO2 or Al2O3) alone or combined with a polymer.

[0166] Table 13: Primary wettability measurements of the prepared samples TIFF2025540197000015.tif144169

[0167] As expected, the product based on LUDOX SiO2 alone exhibited improved hydrophilic behavior, allowing rapid penetration of water droplets and oil. The data obtained show that the presence of the inorganic layer slightly improves performance, but does not significantly change the behavior in terms of hydrophobicity, oleophobicity, and surface energy. While wettability may be independent of the inorganic layer, the presence of inorganic nanoparticles is important for improving functionality and durability in use.

[0168] Functional ice adhesion and detachment test The prepared and characterized coatings were tested according to the procedures given in the functional characterization section above.

[0169] Table 14: Ice adhesion and detachment test TIFF2025540197000016.tif130169

[0170] Table 14 shows the functionality results in terms of the efficacy score of the samples after the first immersion test. The results are shown for samples containing a layer of inorganic nanoparticles bound to a polymer compared to the corresponding polymer-only coated sample. The percentage of the surface covered with ice and the number of impacts required to completely remove the ice contribute to the efficacy score.

[0171] Figure 3 shows the results of adhesion and peel tests on an untreated screen (a) and the best performing sample, that is, the sample coated with Ludox+Metalcoat+Enhancer (c). In general, the typical behavior of an untreated screen or an ineffective coating is complete adhesion of ice (100% of the sample area) visible to the naked eye, with gradual melting of the ice causing it to peel off only after 600 impacts.

[0172] Furthermore, the best-performing samples showed very limited ice adhesion after immersion, requiring only a few impacts to detach the ice crystals (Figure 3).

[0173] Functionality results for samples prepared with polymer only by preparation method 2c) The commercially available polymers A1220 and SIVO are not specifically designed for anti-icing applications, but rather to impart water repellency. In fact, under the test conditions, they only achieved low efficacy scores (effectiveness scores of 1-5) both alone and in combination with nanoparticles.

[0174] Although Nanomate and Nusil are marketed as anti-icing products, when applied alone they exhibited significant ice buildup, likely because the experimental conditions of prolonged immersion in very shallow water were too harsh for this category of product.

[0175] Combining these polymers with inorganic silicon nanoparticles results in a slight improvement in performance, indicating that although the dominant role is played by the outer organic polymer, the presence of an inorganic support layer may improve overall behavior.

[0176] Silicon nanoparticles were chosen as the carrier for the organic polymer due to their low cost and already proven excellent performance in the field of protective coatings.

[0177] Functionality results of samples prepared with SiO2 nanoparticles optionally combined with polymers by preparation methods 2a) and 2b) Table 14 shows that the SiO2-based treatments (LUDOX and LUDOX + enhancer) show promising behavior, with efficacy scores ranging from 8.5 to 9, while the combination with organosilane (LUDOX + Metalcoat + enhancer) performs even better, reaching an efficacy score of 10.

[0178] With LUDOX treatment, the ice peels well and becomes visually clean, but the ice crystallites remain firmly attached to the surface (Figure 3b). This behavior is likely due to hydrophilicity, which causes strong adhesion of the ice crystallites but also causes slippage and peeling of large, heavy pieces of ice.

[0179] Metalcoat, combined with LUDOX silicone using an acid-catalyzed "enhancer," demonstrated superior performance, with functionality results consistent with wettability data and confirmed effectiveness in limiting and preventing ice adhesion to the surface.

[0180] Functionality results of samples prepared by method 2d) injecting Al2O3 nanoparticles with silicone oil Coatings containing silicone oil-infused Al2O3 performed poorly, with efficacy scores of 4.5 and 1, respectively.

[0181] Durability test To evaluate the durability of the coating, the prepared samples were subjected to a second cycle of immersion in supercooled water, after which the ice adhesion was checked and the changes in the coating properties were observed.

[0182] Functionality testing: Changes in ice adhesion Table 15 compares the effectiveness scores after the first and second immersion tests. While the wettability data is not significantly affected by the immersion cycle, the functionality results show a general decrease in coating performance after the second immersion cycle.

[0183] The deleterious effects of the immersion test likely include visible effects revealed by the ice adhesion test, but at the microscopic level the wettability appears to be stable.

[0184] Coating degradation is observed in all best performing samples except for Metalcoat combined with LUDOX.

[0185] Table 15: Comparison of efficacy scores after the first and second soaking cycles TIFF2025540197000017.tif133152

[0186] The most important data from Table 15 are also presented graphically in Figure 4.

[0187] Metalcoat+ Enhancer, a commercially available inorganic coating, is very effective at preventing ice buildup and offers good resistance to subsequent cycles.

[0188] Again, the silicon layer (LUDOX+Metalcoat+Enhancer sample) allows for maximum performance in the second cycle by preventing ice buildup, while the SiO2 layer likely acts as a strong starting point for the coating, synergistically extending durability.

[0189] Figure 3c shows the performance achieved by the best coating, with no fouling observed after either of the two immersion cycles.

[0190] Furthermore, LUDOX silicone degrades rapidly after the first cycle, whether treated alone or with only the acid-catalyzed "enhancer."

[0191] conclusion The most promising solutions were selected by conducting wettability evaluation and functionality tests in supercooled water. The evaluation was repeated after two immersion cycles to examine the durability of the coating in the simulated environment.

[0192] Although the wettability data are not affected by the immersion cycle in supercooled water, the frazil ice simulations are considered to be under severe conditions, especially for repeated cycles.

[0193] The introduction of a silicone layer was found to improve the functional performance of the polymer coating, improving its barrier effect and ability to release ice during immersion tests.

[0194] Generally, under less severe conditions, silicone oil-based samples are suggested in the literature as a suitable technique to prevent ice adhesion, but under simulated frazil ice conditions, this is considered too severe, especially in terms of durability.

[0195] The inorganic-based coating proved to be the best performing and most resistant to repeated immersion cycles, even when compared to several polymers marketed as durable anti-icing coatings.

[0196] Among all the solutions tested, a coating consisting of silicon nanoparticles (LUDOX) combined with an organosilane (Metalcoat), applied with an acid catalyst (Enhancer), was identified as the best solution. Indeed, the product called LUDOX+Metalcoat+Enhancer offers excellent functional performance, enhanced by the presence of the LUDOX-based inorganic layer, and exhibits optimal resistance to immersion cycles.

[0197] Example 3: Coating for separating oil / water emulsions Materials and Methods Metal screen Fine mesh screens made of stainless steel (AISI 316) were selected as substrates to be functionalized with coatings for oil / water separation.

[0198] Preparation of coatings The behavior of hydrophilic / oleophobic coatings was investigated, where only the aqueous phase passed through the sample (Figure 5).

[0199] This configuration allows separation to be performed using gravity, since water, which is denser than the oil phase, naturally tends to pass through the screen, especially in a vertical configuration. Furthermore, the flow of the water phase reduces the fouling and clogging of the filter screen that is typically caused by the flow of the oil phase. In fact, the flow of oil through the filter is prevented or limited by the oleophobic coating, minimizing interaction with the filter mesh and limiting fouling, allowing the filter to be reused for repeated separation cycles.

[0200] In the literature, such coatings are typically produced using a polymer phase functionalized with surfactants, but this functionality can also be enhanced by attaching inorganic nanoparticles to the polymer phase, imparting a hierarchical structure aimed at improving the hydrophilic / oleophobic properties and, consequently, oil / water separation.

[0201] inorganic nanoparticles For the preparation, powdered silicon dioxide nanoparticles (SiO2 nanoparticles), specifically, the commercially available product CAB-O-SIL (fumed silica, manufactured by Cabot Corporation), were used.

[0202] polymer The polymer phase used is poly(diallyldimethylammonium chloride) (PDDA), a cationic polymer with a high charge density.

[0203] The types of coatings prepared are listed below. a) Preparation of Type a Coating (PDDA / FS / SiO2) The synthesis was carried out in aqueous media. Anionic fluorosurfactant (FS) Capstone FS-63 (DuPont) and SiO2 nanoparticle powder (Cabot) were added to a dilute suspension of PDDA (2% w / v). The suspension was treated with ultrasound for 1 h, and the precipitate was washed and dried. The resulting powder was ground and dispersed in ethanol with ultrasound at a concentration of 1% w / v, ready for deposition onto metal substrates.

[0204] The coating was performed by dip coating (immersion / removal at a controlled rate of 2 mm / s, static hold time 120 s), or by other application methods (spray coating, immersion, etc.) that can produce a uniform surface.

[0205] The sample was kept at ambient temperature for 10 min to allow the solvent to slowly evaporate, and then heat-treated at 150 °C for 30 min. The deposition process was carried out twice in succession.

[0206] The resulting sample is called Coating A.

[0207] b) Preparation of type b coating (PDDA / PFOA / SiO2) SiO2 nanoparticles (Cabot) were dispersed in diluted PDDA (0.1% w / v) and treated with ultrasound for 30 minutes, after which a perfluorooctanoic acid solution (PFOA, 0.1 M) was added dropwise. The precipitate was washed and dried. The resulting powder was pulverized and dispersed in ethanol at a concentration of 1% w / v using ultrasound.

[0208] The coating and heat treatment were carried out in the same manner as in Example 3a).

[0209] The resulting sample is called Coating B.

[0210] c) Preparation of type c coating (MTM / HCl) Methyltrimethoxysilane (MTM) was mixed with hydrochloric acid (HCl) and sonicated in an ice bath for 5 min to induce hydrolysis. The product was applied immediately after synthesis to prevent excessive increase in the viscosity of the suspension during the subsequent concentration step.

[0211] The coating and heat treatment were carried out in the same manner as in Example 3a).

[0212] The resulting sample is called Coating C.

[0213] Physical, chemical, and functional characterization Samples were characterized by measuring the static contact angle with water and n-hexadecane. All results are derived from the average of at least three values ​​taken on different areas of the sample to map the entire surface.

[0214] Functional characterization aims to evaluate the performance of materials by simulating the conditions of use of the applied material.

[0215] The purpose of the experimental setup was to simulate, on a small scale, a metal filter used to separate a stream consisting of an oil / water emulsion. The simulation was performed without any force other than gravity. The sample was placed between two sections: an upper cylindrical section and a lower conical section (to facilitate collection of the filtrate in the graduated cylinder). Biodiesel was used as the oil phase and mixed with water to create emulsions with a water / biodiesel volume ratio of 70:30 or 90:10. Prior to use, the mixture was stirred to create a true emulsion (which begins to separate due to density after a short time), and the liquid was poured out and the time until filtration was complete was measured. After filtration was complete, the volume of water and oil that passed through the filter could be measured to determine the separation effectiveness. Parameters of interest are listed in Table 16.

[0216] Table 16: Experimental parameters for the setup for functional characterization TIFF2025540197000018.tif57131 *Filters were washed and oven dried after each test.

[0217] By measuring the time required for filtration, the flow resistance posed by the sample can be estimated. In real-world applications, this should usually be as low as possible. As filtration progresses, the flow slows due to a decrease in hydrostatic pressure. From the standpoint of filtration efficiency, the optimal result is complete water penetration and a predetermined amount of biodiesel retention. This result is expressed as a percentage of oil retained on the filter.

[0218] Results and Discussion Wettability The most significant wettability results are shown in Table 17 and Figure 7 and are expressed in terms of contact angle with water (water CA) and n-hexadecane (oil CA).

[0219] Table 17: Contact angle measurements between water and n-hexadecane TIFF2025540197000019.tif36130 *Flow through the substrate.

[0220] The uncoated sample exhibited excellent hydrophobicity, with a contact angle of 112° with water, while n-hexadecane exhibited high oleophilicity, as it tended to spread and quickly pass through the two samples. Because these properties are the opposite of those desired for the proposed application, we needed to observe how these properties would change with the coatings we prepared. Indeed, for Coatings A and B, we observed an increase in hydrophilicity (a decrease in the contact angle with water) and a significant increase in oleophobicity (a significant increase in the contact angle with n-hexadecane).

[0221] Coating C was found to be somewhat hydrophilic but not oleophobic (contact angle with n-hexadecane is approximately 30°), so application of the polymer phase alone would not be sufficient to achieve the necessary oil / water separation.

[0222] Evaluation of functional properties of coatings for oil-water separation The functional properties of the prepared samples were evaluated by evaluating the separation effect of water-biodiesel emulsion. A stainless steel screen was used as a filter medium to allow water to pass through and prevent the oil phase from passing through.

[0223] Initial tests were performed on uncoated screens to evaluate their behavior and compare the results to functionalized substrates. First, tests were performed to measure the individual water and biodiesel flows, followed by tests to measure their ability to separate the two phases in an emulsion.

[0224] Table 18: Characterization of flow through uncoated screens TIFF2025540197000020.tif31138

[0225] According to Table 18, neither water nor oil was retained. All samples passed through very quickly, but oil required more time due to its high viscosity. This result demonstrates that selective filtration is not possible with uncoated materials.

[0226] Data collected on the filtration of water through the coated samples is shown in Table 19. Obstructions should not be created as they may excessively slow the flow. By keeping the pressure drop low, separation can be achieved using only gravity as the driving force for the process.

[0227] Table 19: Water flow through coated screens TIFF2025540197000021.tif30135

[0228] The time it took for water to pass through the filter was 3-4 seconds, slightly less than the coated screen (5 seconds), confirming that the improved surface properties allowed for better water flow, despite the slight reduction in mesh openings due to the coating thickness.

[0229] To evaluate the performance of the prepared coatings, 100 mL of water / biodiesel emulsions with a volume ratio of 90:10 or 70:30 were used to evaluate the separation effect. The most important results are shown in Table 20 below and Figure 6.

[0230] Table 20: Separation test of a mixture of the following starting composition: 90 mL water and 10 mL biodiesel TIFF2025540197000022.tif43140

[0231] Table 21: Separation test of a mixture of the following starting composition: 70 mL water and 30 mL biodiesel TIFF2025540197000023.tif54169 *Because the 90:10 ratio did not demonstrate retention capacity, more stringent conditions (70:30) were not tested.

[0232] The coating demonstrated improved separation, allowing water to pass through quickly and quantitatively (approximately 99%), while oil was significantly retained, with an average yield of approximately 80% in repeated tests. Water rapidly drained between 10 and 90 seconds, after which the biodiesel slowly dripped out. The test was terminated between 180 and 300 seconds, when the dripping was considered complete.

[0233] This data suggests that repeated application increases the separation effect. A thicker and more uniform coating can improve biodiesel retention by providing stronger oleophobicity. The observed trends are summarized below. Multiple applications result in a more pronounced and uniform surface, leading to improved performance. Excellent results are already achieved with just two applications. Among the synthesized coatings, Coating A appears to be the most promising solution. It must be emphasized that Coating A showed the best results, even when tested under more severe conditions (70:30 water / biodiesel).

[0234] conclusion Three coatings were prepared based on a polymer matrix doped with inorganic nanoparticles and functional surfactants, and these products were applied to metal screens.

[0235] First, the wettability of the coated samples was measured.

[0236] Functional characterization was carried out by evaluating the separation effect of water-biodiesel emulsions.

[0237] Generally, the best performing and most durable coating is Coating A, which is obtained by combining SiO2 nanoparticles with a polymer phase (PDDA) in the presence of a fluorinating agent added to maximize oil repellency.

[0238] The facile synthesis process and use of off-the-shelf raw materials make these coatings simple and easily scalable to large-scale facilities.

[0239] References 1 M. Richard and B. Morse, Cold Reg. Sci. Technol., 2008, 53, 131-149. 2 B. Turcotte, B. Morse, M. Dube and F. Anctil, Cold Reg. Sci.Technol., 2013, 94, 21-36. 3 L. Cao, AK Jones, VK Sikka, J. Wu and D. Gao, Langmuir, 2009,25, 12444-12448. 4 S. Farhadi, M. Farzaneh and SA Kulinich, Appl. Sci., 2011, 257,6264-6269. 5 MJ Kreder, J. Alvarenga, P. Kim and J. Aizenberg, Nat. Rev.Mater., DOI:10.1038 / natrevmats.2015.3. 6 L. Zhang, Z. Zhang and P. Wang, NPG Asia Mater.,DOI:10.1038 / am.2012.14. 7 L. Jiang, Z. Tang, KJ Park-Lee, DW Hess and V. Breedveld, Sep.Purif. Technol., 2017, 184, 394-403. 8 O. Arslan, Z. Aytac and T. Uyar, ACS Appl. Mater. Interfaces, 2016,8, 19747-19754. 9 Y. N. Guo, L.Y. Liang, S.X. Bao, F. P. Du and X. Wen, J. Appl.Polym. Sci., 2020, 137, 1-11. 10 Z. Yin, Y. Li, T. Song, M. Bao, Y. Li, J. Lu and Y. Li, Sep. Purif. Technol.,2020, 236, 116308. 11 Y. Wang and X. Gong, J. Mater. Chem. A, 2017, 5, 3759-3773. 12 H. C. Wang, C. Y. Wu, C. C. Chung, M. H. Lai and T. W. Chung, Ind. Eng.Chem. Res., 2006, 45, 8043-8048. 13 O. K. Park and Y. S. Kang, Colloids Surfaces A Physicochem. Eng. Asp.,2005, 257-258, 261-265. 14 X. Dai, B. B. Stogin, S. Yang and T. S. Wong, ACS Nano, 2015, 9,9260-9267.

Claims

1. Coating a): metal oxide nanoparticles bound to at least one of one or more fluoroalkylsilanes, one or more organosilanes, and one or more polymers functionalized with at least one of fluoroalkylsilanes and organosilanes; and Coating b): Metal oxide nanoparticles bound to a polymer matrix functionalized with fluorinated molecules or groups. At least one of the coated filter metal plates.

2. 2. The filter metal plate according to claim 1, The filter metal plate is made of stainless steel.

3. 3. A filter metal plate according to claim 1 or 2, The filter metal plate is a Vee wire screen type filter metal plate.

4. 4. A filter metal plate according to any one of claims 1 to 3, The metal oxide is silicon dioxide (SiO 2 ) a filter metal plate.

5. 5. A filter metal plate according to any one of claims 1 to 4, 1. A filter metal plate, wherein said coating a) contains metal oxide nanoparticles bound to one or more fluoroalkylsilanes and is obtained by applying an inorganic layer of metal oxide nanoparticles to said filter metal plate followed by an organic layer based on fluoroalkylsilanes.

6. 5. A filter metal plate according to any one of claims 1 to 4, 1. A filter metal plate, wherein the coating a) contains metal oxide nanoparticles bound to one or more organosilanes or organosilane polymers, and is obtained by applying an inorganic layer of metal oxide nanoparticles to the filter metal plate, followed by applying a layer comprising an organosilane, optionally together with an enhancer.

7. 7. The filter metal plate according to claim 6, The filter metal plate, wherein the layer comprising the organosilane also contains additional metal oxide nanoparticles.

8. 5. A filter metal plate according to any one of claims 1 to 4, said coating b) comprising metal oxide nanoparticles bound to a polymer matrix functionalized with fluorinated molecules or groups; the polymer matrix is ​​comprised of a polymer selected from polydiallyldimethylammonium chloride, polydimethylsiloxane, methyltrimethoxysilane, methyltriacetoxysilane, perfluoropolyether, and chitosan-polyvinyl alcohol; The filter metal plate, wherein the fluorinated molecules or groups are selected from perfluorooctanoic acid, anionic fluorosurfactants, and 1H,1H,2H,2H-perfluorooctyltriethoxysilane.

9. 5. A filter metal plate according to any one of claims 1 to 4, The coating b) is obtained by precipitating a suspension of metal oxide nanoparticles in poly(diallyldimethylammonium chloride) (PDDA) and perfluorooctanoic acid followed by dispersion in an alcoholic solvent, or by precipitating a suspension of metal oxide nanoparticles in poly(diallyldimethylammonium chloride) (PDDA) and at least one anionic fluorosurfactant followed by dispersion in an alcoholic solvent.

10. 10. A filter metal plate according to any one of claims 1 to 9, The filter metal plate is sandblasted before applying the coating.

11. Use of a filter metal plate according to any one of claims 1 to 10 for filtering liquids such as water.

12. Use of a filter metal plate according to any one of claims 1 to 10 in a filter press, in particular for removing mud.

13. Use of a filter metal plate according to any one of claims 1 to 10 for filtering water in extreme cold environments.

14. Use of a filter metal plate according to any one of claims 1 to 10 for the separation of oil / water emulsions.

15. Use of a filter metal plate according to any one of claims 1 to 10 for treating wastewater, for example industrial wastewater.

16. a) metal oxide nanoparticles bound to at least one of one or more fluoroalkylsilanes, one or more organosilanes, and one or more polymers functionalized with at least one of fluoroalkylsilanes and organosilanes; and b), metal oxide nanoparticles bound to a polymer matrix functionalized with fluorinated molecules or groups; and (c) using at least one of the above for coating a filter metal plate.

17. 17. The method of claim 16, The metal oxide is silicon dioxide (SiO 2 ) a method.

18. 17. The method of claim 16, The method wherein said metal oxide nanoparticles a) are metal oxide nanoparticles bound to one or more fluoroalkylsilanes.

19. 17. The method of claim 16, The method, wherein said metal oxide nanoparticles a) are metal oxide nanoparticles bound to one or more organosilanes or organosilane polymers.

20. 17. The method of claim 16, The metal oxide nanoparticles b) are obtained by precipitation of a suspension of metal oxide nanoparticles in poly(diallyldimethylammonium chloride) (PDDA) and perfluorooctanoic acid followed by dispersion in an alcoholic solvent, or by precipitation of a suspension of metal oxide nanoparticles in poly(diallyldimethylammonium chloride) (PDDA) and at least one anionic fluorosurfactant followed by dispersion in an alcoholic solvent.

21. a) metal oxide nanoparticles bound to at least one of one or more fluoroalkylsilanes, one or more organosilanes, and one or more polymers functionalized with at least one of fluoroalkylsilanes and organosilanes; and b) metal oxide nanoparticles bound to a polymer matrix functionalized with fluorinated molecules or groups; A kit for preparing at least one of the coatings of the above.

22. 22. The kit of claim 21, a) metal oxide nanoparticles, and b) a composition comprising at least one of a fluoroalkylsilane, an organosilane, and one or more polymers functionalized with at least one of a fluoroalkylsilane and an organosilane, or b') at least one polymer and at least one compound containing a fluorinated molecule or a fluorinated group. A kit comprising:

23. 23. The kit of claim 22, a polymer; and a compound containing a fluorinated molecule or a fluorinated group; the polymer is selected from polydiallyldimethylammonium chloride, polydimethylsiloxane, methyltrimethoxysilane, methyltriacetoxysilane, perfluoropolyether, and chitosan-polyvinyl alcohol; the fluorinated molecule or group is selected from perfluorooctanoic acid, anionic fluorosurfactants, and 1H,1H,2H,2H-perfluorooctyltriethoxysilane.

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