A biomimetic self-cleaning water filtering core layer and a preparation method and application thereof

Abstract

The application discloses a kind of bionic self-cleaning water filter core and its preparation method and application, belong to filtration technical field, including porous support layer, filter function layer and self-cleaning layer;Wherein, the filter function layer is compounded on porous support layer;The filter function layer includes interlaced nanofiber grid and fills in the bionic adhesive hydrogel in the nanofiber grid;The self-cleaning layer includes drivable artificial cilium array, and the drivable artificial cilium array vertically penetrates the filter function layer.The core provided by the application not only significantly improves the filtering efficiency, self-cleaning ability and structural stability through parameterization design, its long-term operation characteristics also reduce the dependence on chemical cleaning agent and the need for frequent maintenance, while prolonging the service life, with significant environmental protection and energy saving advantages.

Description

Technical Field

[0001] This invention belongs to the field of filtration technology, and in particular relates to a biomimetic self-cleaning water filter core layer, its preparation method and application. Background Technology

[0002] Current mainstream filtration technologies, such as microfiltration and ultrafiltration, primarily rely on mechanical sieving, which uses the micropores of a membrane to trap particles larger than the pore size. However, a drawback is that contaminants accumulate on the membrane surface and within the pores during operation, leading to decreased filtration flux, increased operating pressure, and frequent chemical cleaning. This not only increases operating costs and energy consumption but also shortens membrane lifespan. Therefore, developing a novel filtration design that can fundamentally resist fouling and achieve self-cleaning has become an urgent technical challenge.

[0003] In nature, the gill filtration system of bivalves (such as mussels and oysters) is a perfect example of high efficiency and clogging resistance, demonstrating outstanding performance. Through the synergistic action of "mucus capture" and "ciliary transport," it efficiently filters food while continuously and directionally removing trapped particulate matter, achieving long-term stable operation of the system.

[0004] Therefore, how to provide an artificial filter layer that mimics the biological mechanism of bivalves to achieve self-cleaning is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a biomimetic self-cleaning water filter core layer, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A biomimetic self-cleaning water filter core layer includes a porous support layer, a filtration functional layer, and a self-cleaning layer; The filter functional layer is composited on the porous support layer; The filtration functional layer includes an interwoven nanofiber mesh and a biomimetic adhesive hydrogel filled in the nanofiber mesh; The self-cleaning layer includes a driveable artificial cilia array, which penetrates vertically through the filter functional layer.

[0007] Preferably, the porous support layer is a porous membrane with a three-dimensional interconnected pore structure prepared from polyvinylidene fluoride.

[0008] Beneficial effects: This structure ensures low resistance water flow while providing a stable anchor point for the upper layer.

[0009] The porous support layer has an average pore diameter of 100±20μm, a porosity of 85-90%, and a thickness of 2.0mm.

[0010] Beneficial effects: This average diameter range is designed to ensure excellent permeability while preventing the upper nanofibers from being squeezed or penetrated under water pressure, and the high porosity minimizes the pressure loss of water flowing through this layer. The aforementioned thickness provides the necessary mechanical strength and rigidity for the entire filter element.

[0011] Preferably, the biomimetic adhesive hydrogel is a polymer hydrogel rich in catechol groups; Preferably, the polymer hydrogel has a solid content of 10-15% and a catechol group density of 8-12 μmol / cm³. 3 .

[0012] Preferably, the polymer hydrogel is a polydopamine hydrogel.

[0013] Beneficial effects: Dopamine can self-polymerize and firmly adhere to various surfaces under mild conditions, perfectly filling the gaps in the nanofiber mesh. Furthermore, the catechol groups form the core framework of dopamine, and these groups can powerfully capture nanoscale pollutants such as heavy metal ions, organic dyes, and microorganisms through various interactions including coordination bonds, hydrogen bonds, and stacking. The aforementioned solid content ensures that the hydrogel maintains a porous structure in a fully swollen state while possessing good adhesion and mechanical strength, allowing water molecules to pass through.

[0014] Preferably, the nanofibers in the nanofiber mesh are positively charged polymer nanofibers.

[0015] Preferably, the positively charged polymer nanofibers are chitosan / polyethyleneimine composites.

[0016] Beneficial effects: Both chitosan and polyethyleneimine are positively charged and can effectively adsorb negatively charged colloids, viruses and organic macromolecules in water through electrostatic interaction.

[0017] Preferably, the pore size D of the filter functional layer satisfies D=η·d f ; Where η is the aperture coefficient, and its value ranges from 0.1 to 0.5; d f Let d be the average diameter of the nanofibers in the nanofiber mesh. f It is 200±50nm; Beneficial effects: The average diameter range of these nanofibers can form a sufficiently dense mesh to intercept submicron particles while retaining a high porosity. Furthermore, by adjusting the electrospinning process parameters, the η value can be controlled, thereby achieving precise design of filtration accuracy.

[0018] The thickness h of the filter functional layer f Satisfy hf =k·L; Where k is the thickness scaling factor, and its value ranges from 1.0 to 2.5; L is the length of the driveable artificial cilia.

[0019] Beneficial effects: The thickness is designed in conjunction with the length of the artificial cilia in the self-cleaning layer. This design ensures that the artificial cilia have sufficient length to be exposed to the water flow and to swing effectively, while their anchoring depth is also sufficient to ensure stability under long-term drive.

[0020] Preferably, the drivable artificial cilia are made of magnetic material and are driven to swing synchronously by applying an alternating magnetic field.

[0021] The alternating magnetic field has an induced intensity of 50-80 mT and a frequency of 5-20 Hz.

[0022] Beneficial effects: Alternating magnetic fields can attract magnetically driven artificial cilia, driving all cilia to swing synchronously and in a coordinated manner, with a motion pattern similar to the waves of grass in a grassland or the coordinated undulation of biological cilia.

[0023] More preferably, the magnetic material is a nickel alloy or a cobalt-nickel alloy; The diameter d of the driveable artificial cilia is 2.0±0.5μm; Beneficial effects: The use of the above magnetic materials can ensure good soft magnetism and mechanical strength, and the above diameter can make the artificial cilia have sufficient rigidity to effectively move the water flow, while maintaining flexibility to avoid breaking during swinging.

[0024] The center-to-center distance S between adjacent drivable artificial cilia satisfies S=λ·L; Wherein, λ is the spacing coefficient, and its value ranges from 1.2 to 2.0.

[0025] Beneficial effects: This design prevents the cilia from tangling together during oscillation and ensures that the flow fields they generate can be superimposed to form an effective directional transport flow.

[0026] Preferably, the length L of the drivable artificial cilia is 50±5μm.

[0027] Beneficial effects: This length allows it to be effectively anchored to the filter layer and protrude from its surface to perform the cleaning function.

[0028] More preferably, the angle between the driveable artificial cilia and the implanted surface (i.e., the upper surface of the filter functional layer) is 85-95°.

[0029] Beneficial effects: Vertical implantation produces the most effective surface normal direction disturbance, which is most conducive to the removal of contaminants.

[0030] A method for preparing a biomimetic self-cleaning water filter core layer includes the following steps: A porous support layer was prepared using a non-solvent phase separation method. Then, a nanofiber mesh was formed on the surface of the porous support layer by electrospinning. The drivable artificial cilia were then vertically implanted onto the nanofiber mesh by electrochemical deposition. Finally, the composite substrate with the nanofiber mesh and drivable artificial cilia was immersed in a hydrogel precursor solution and polymerized in situ to obtain a biomimetic adhesive hydrogel, thus completing the preparation of the biomimetic self-cleaning water filter core layer.

[0031] Preferably, the electrospinning process parameters are as follows: feed pump rate: 0.8 mL / h; applied voltage: positive electrode +15 kV (needle connector), negative electrode -5 kV (receiver); receiving distance: 15 cm; ambient temperature: 25 ± 2 °C; ambient humidity: 45 ± 5%.

[0032] Preferably, the electrochemical deposition uses porous anodic aluminum oxide as a template, with its porous side tightly attached to the spun nanofiber layer, and a special fixture is used to apply slight pressure to ensure that there are no gaps at the contact surface.

[0033] Preferably, the electrochemical deposition uses the conductive layer on the back of the porous anodic aluminum oxide template as the cathode, a high-purity nickel plate as the anode, and a Watt-type nickel plating solution as the electrolyte; the Watt-type nickel plating solution includes raw materials with the following concentrations: nickel sulfate 240 g / L, nickel chloride 45 g / L, boric acid 30 g / L, and pH=4.0.

[0034] An application of a biomimetic self-cleaning water filter core layer in wastewater treatment, mainly suitable for scenarios where maintenance is inconvenient.

[0035] Compared with the prior art, the present invention has the following advantages and technical effects: This invention provides a biomimetic self-cleaning water filter core layer and its preparation method. By mimicking the efficient filtration and self-cleaning mechanism of bivalve gills, a three-layer composite structure integrating "sieving-adhesion-transportation" functions is constructed. Compared with traditional technologies, this invention achieves fine mechanical sieving through a nanofiber mesh and efficiently chemically adsorbs pollutants through a biomimetic adhesive hydrogel, realizing multi-level capture of micron-, submicron-, and nano-sized impurities. Simultaneously, by introducing proportional relationships between structural parameters (such as ciliary spacing and length, filter layer thickness and ciliary length), the synergistic performance between functional layers is optimized. A vertically drivable artificial ciliary array driven by an external field generates synergistic fluctuations, directionally transporting captured pollutants, achieving real-time physical cleaning and functional regeneration of the filter layer, thus fundamentally solving the clogging problem of traditional filters. The core layer provided by this invention not only significantly improves filtration efficiency, self-cleaning ability, and structural stability through parametric design, but its long-term operating characteristics also reduce dependence on chemical cleaning agents and the need for frequent maintenance, extending service life while offering significant environmental and energy-saving advantages. Attached Figure Description

[0036] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the overall filter layer obtained in Example 1; Figure 2 This is a conceptual diagram of the three-layer filter structure obtained in Example 1; Figure 3 The three-view and oblique view of the unit porous support layer obtained in Example 1 are shown. Figure 4 This is a schematic diagram of the three-layer filter structure obtained in Example 1; Figure 5 The images show the three-view and oblique views of the unit nanofiber mesh obtained in Example 1; Figure 6 This is a schematic diagram of the unit-driven artificial cilia obtained in Example 1; Figure 7 This is a schematic diagram of the core filter layer structure obtained in Example 1; Figure 8 This is a schematic diagram of the working principle of the core filter layer obtained in Example 1; In the accompanying drawings of this invention, the reference numerals are as follows: 1 represents a porous support layer; 2 represents a filter functional layer; and 3 represents a driveable artificial cilia. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Unless otherwise specified, all raw materials used in the embodiments of this invention were purchased through commercial channels; Among them, the polyvinylidene fluoride (PVDF) model is HSV900.

[0040] Unless otherwise specified, room temperature or normal temperature in the embodiments of the present invention refers to 25±3℃.

[0041] Example 1 A biomimetic self-cleaning water filter core layer, such as Figure 1-6 As shown, this is a three-layer composite functional structure that mimics the integrated cleaning mechanism of biological gill filaments, namely "sieving-adhesion-directional transport." It includes a porous support layer 1, a filtration functional layer 2, and a self-cleaning layer. Its specific structure and parameters are as follows: (1) Porous support layer 1: The material is polyvinylidene fluoride (PVDF), prepared by a solvent-free phase separation method. It has an average pore size of 100 μm, a porosity of 88%, and a thickness of 2.0 mm.

[0042] (2) Filtering functional layer 2: The nanofiber mesh was prepared by electrospinning chitosan and polyethyleneimine (mass ratio 7:3), and the average diameter of the nanofibers was d. f =200nm, pore size coefficient η=0.3. Average filter pore size D=η×d f= 0.3 × 200 = 60 nm. The biomimetic adhesion hydrogel is a polydopamine hydrogel with a solid content of C = 12 wt% and a catechol group density of ρ = 10 μmol / cm³. 3 Thickness scaling factor k=3.0, filter layer thickness: h f =k×L=3.0×50=150μm, where L is the length of the drivable artificial cilia.

[0043] (3) Self-cleaning layer: The actuable artificial cilia 3 are made of nickel nanowires with a diameter d = 2.0 μm and a length L = 50 μm. The implantation angle α = 88° (relative to the surface of the filter functional layer). The spacing coefficient λ = 1.6, and the center-to-center distance between adjacent cilia S = λ × L = 1.6 × 50 = 80 μm.

[0044] Working principle and dynamic cleaning process: like Figure 7 and 8 As shown, the biomimetic filter layer is placed in a specially designed filtration device, which is surrounded by an electromagnetic coil system. During operation, an alternating magnetic field is applied to the coils, with a magnetic induction intensity of B and a frequency of f, satisfying 50mT ≤ B ≤ 80mT and 5Hz ≤ f ≤ 20Hz, respectively. In Example 1, the parameters are 65mT and 10Hz. The alternating magnetic field attracts the artificial cilia 3, driving all cilia to swing synchronously and in a coordinated manner, their motion resembling the waves of grass in a grassland or the coordinated undulations of biological cilia. Its specific filtration and cleaning principle is as follows: 1) Primary sieving and adhesion: When the water to be treated flows through the filter layer, micron-sized and larger submicron-sized particles are mechanically trapped by the nanofiber mesh (sieving effect); smaller nano-sized particles, heavy metal ions and bacteria are strongly captured by the catechol groups in the polydopamine hydrogel (adhesion effect).

[0045] 2) Dynamic transport and removal: The synchronously oscillating, driveable artificial cilia array 3 generates a directional microflow field around it. This flow field produces two key effects: first, it "sweeps" the surface of the filter functional layer 2, "stripping" the captured contaminants from their adhesion points; second, like a conveyor belt, it continuously pushes these stripped contaminants towards the edge region of the filter layer.

[0046] 3) Centralized discharge: The concentrated pollutant liquid that converges to the edge can be discharged from the system periodically or continuously through a separate, low-flow-rate sewage branch.

[0047] 4) Final effect: Thanks to the real-time self-cleaning ability of the filter layer, the core filter layer of this invention can continuously and stably filter water at the main outlet, fundamentally avoiding the problems of filter screen clogging, pressure drop increase and filtration efficiency decrease caused by dirt accumulation.

[0048] Example 2 Based on Example 1, the following parameters are changed: The pore size coefficient η = 0.1, and the average filter pore size D = 20 nm.

[0049] The filter layer thickness ratio coefficient k=2.5, and the thickness h f =125μm.

[0050] The ciliary spacing coefficient λ=1.2, and the center-to-center spacing S=60μm.

[0051] Specifically, it includes the following structure: It includes a porous support layer 1, a filter functional layer 2, and a self-cleaning layer. Its specific structure and parameters are as follows: (1) Porous support layer 1: The material is polyvinylidene fluoride (PVDF), prepared by a solvent-free phase separation method. It has an average pore size of 100 μm, a porosity of 88%, and a thickness of 2.0 mm.

[0052] (2) Filtering functional layer 2: The nanofiber mesh was prepared by electrospinning chitosan and polyethyleneimine (mass ratio 7:3), and the average diameter of the nanofibers was d. f =200nm, pore size coefficient η=0.1. Average filter pore size D=η×d f= 0.1 × 200 = 20 nm. The biomimetic adhesion hydrogel is a polydopamine hydrogel with a solid content of C = 12 wt% and a catechol group density of ρ = 10 μmol / cm³. 3 Thickness scaling factor k=2.5, filter layer thickness: h f =k×L=2.5×50=125μm, where L is the length of the drivable artificial cilia 3.

[0053] (3) Self-cleaning layer: The actuable artificial cilia 3 are made of nickel nanowires with a diameter d = 2.0 μm and a length L = 50 μm. The implantation angle α = 88° (relative to the surface of the filter functional layer). The spacing coefficient λ = 1.2, and the center-to-center distance between adjacent cilia S = λ × L = 1.2 × 50 = 60 μm.

[0054] During operation, an alternating magnetic field strength of B=50mT and a frequency of f=20Hz are used for driving.

[0055] Example 3 Based on Example 1, the following parameters are changed: The pore size coefficient η = 0.5, and the average filter pore size D = 100 nm.

[0056] The filter layer thickness ratio factor k=4.0, and the thickness h f =200μm.

[0057] The ciliary spacing coefficient λ = 2.0, and the center-to-center spacing S = 100 μm.

[0058] The specific structure is as follows: (1) Porous support layer 1: The material is polyvinylidene fluoride (PVDF), prepared by a solvent-free phase separation method. It has an average pore size of 100 μm, a porosity of 88%, and a thickness of 2.0 mm.

[0059] (2) Filtering functional layer 2: The nanofiber mesh was prepared by electrospinning chitosan and polyethyleneimine (mass ratio 7:3), and the average diameter of the nanofibers was d. f =200nm, pore size coefficient η=0.5. Average filter pore size D=η×d f= 0.5 × 200 = 100 nm. The biomimetic adhesion hydrogel is a polydopamine hydrogel with a solid content of C = 12 wt% and a catechol group density of ρ = 10 μmol / cm³. 3 Thickness scaling factor k=4.0, filter layer thickness: h f =k×L=4.0×50=200μm, where L is the length of the drivable artificial cilia.

[0060] (3) Self-cleaning layer: The actuable artificial cilia 3 are made of nickel nanowires with a diameter d = 2.0 μm and a length L = 50 μm. The implantation angle α = 88° (relative to the surface of the filter functional layer). The spacing coefficient λ = 2.0, and the center-to-center distance between adjacent cilia S = λ × L = 2.0 × 50 = 100 μm.

[0061] During operation, an alternating magnetic field strength of B=80mT and a frequency of f=5Hz are used for driving.

[0062] Example 4 A method for preparing a biomimetic self-cleaning water filter core layer, the structure of which is shown in Example 1, includes the following steps: (1) Preparation of porous support layer 1: A 18wt% N-methylpyrrolidone solution of polyvinylidene fluoride was used as the casting solution. The solution was coated onto a glass plate and immersed in a 25℃ deionized water coagulation bath to form a phase inversion film. After washing with water to remove the NMP solvent, the film was hot-pressed under normal pressure and 50℃ to obtain a porous polyvinylidene fluoride (PVDF) support layer with an average pore size of 100μm, a porosity of 88%, and a thickness of 2.0mm.

[0063] (2) Electrospinning of nanofiber layers: Chitosan and polyethyleneimine (mass ratio 7:3) were dissolved in an aqueous acetic acid solution with a volume ratio of 9:1 to prepare an 8wt% spinning solution. Using a porous support layer as the receiving substrate, electrospinning was performed for 30 minutes under the conditions of a positive electrode voltage of +15kV, a negative electrode voltage of -5kV, a receiving distance of 15cm, and a feed rate of 0.8mL / h, forming a nanofiber network with an average diameter of 200nm on its surface.

[0064] (3) Vertical implantation of artificial cilia 3 can be driven: A porous anodic alumina (AAO) template with a pore size of 2.0 μm and a pore depth of 50 μm was tightly bonded to the surface of the nanofiber layer. Using the template as the cathode, nickel plating was performed in a Watt-type nickel plating bath at 50 °C at a current of -10 mA / cm². 2 Electrodeposition was performed at current density for 25 minutes. Subsequently, the AAO template was dissolved to obtain a vertically implanted nickel nanowire array with a diameter d = 2.0 μm, a length L = 50 μm, and a center-to-center spacing S = 80 μm.

[0065] (4) In-situ polymerization of biomimetic adhesive hydrogels: The composite substrate with the constructed ciliary array was immersed in a 2 mg / mL dopamine Tris-HCl solution at pH 8.5 and reacted at 25°C and 80 rpm for 12 hours. After removal, washing, and drying at 60°C, a composite filtration functional layer filled with polydopamine hydrogel was obtained, with a solid content (C) of 12% and a catechol group density (ρ) of 10 μmol / cm³. 3 .

[0066] Example 5 A method for preparing a biomimetic self-cleaning water filter core layer, wherein the structure of the core layer is as described in Example 2, includes the following steps: (1) Preparation of porous support layer 1: A 18wt% N-methylpyrrolidone solution of polyvinylidene fluoride was used as the casting solution. The solution was coated onto a glass plate and immersed in a 25℃ deionized water coagulation bath to form a phase inversion film. After washing with water to remove the NMP solvent, the film was hot-pressed under normal pressure and 50℃ to obtain a PVDF porous support layer with an average pore size of 100μm, a porosity of 88%, and a thickness of 2.0mm.

[0067] (2) Electrospinning of nanofiber layers: Chitosan and polyethyleneimine (mass ratio 7:3) were dissolved in an aqueous acetic acid solution with a volume ratio of 9:1 to prepare an 8 wt% spinning solution. Using a porous support layer as the receiving substrate, electrospinning was performed for 20 minutes under the conditions of a positive electrode voltage of +15 kV, a negative electrode voltage of -5 kV, a receiving distance of 15 cm, and a solution propulsion rate of 0.8 mL / h, forming a nanofiber network with an average diameter of 200 nm on the surface of the porous support layer.

[0068] (3) Vertical implantation of artificial cilia 3 can be driven: A porous anodic alumina (AAO) template with a pore size of 2.0 μm and a pore depth of 50 μm was tightly bonded to the surface of the nanofiber layer. Using the template as the cathode, nickel plating was performed in a Watt-type nickel plating bath at 50 °C at a current of -10 mA / cm². 2 Electrodeposition was performed at current density for 18 minutes. Subsequently, the AAO template was dissolved to obtain a vertically implanted nickel nanowire array with a diameter d = 2.0 μm, a length L = 50 μm, and a spacing S = 60 μm between adjacent cilia.

[0069] (4) In-situ polymerization of biomimetic adhesive hydrogels: The composite substrate with the constructed ciliary array was immersed in a dopamine Tris-HCl solution of 2 mg / mL, pH=8.5, and reacted for 10 hours under shaking conditions at 25℃ and 80 rpm. After removal, washing, and drying at 60℃, a composite filtration functional layer filled with polydopamine hydrogel was obtained. The hydrogel had a solid content (C) of 12% and a catechol group density (ρ) of 10 μmol / cm³. 3 .

[0070] Example 6 A method for preparing a biomimetic self-cleaning water filter core layer, wherein the structure of the core layer is as described in Example 3, includes the following steps: (1) Preparation of porous support layer 1: A 18wt% N-methylpyrrolidone solution of polyvinylidene fluoride was used as the casting solution. The solution was coated onto a glass plate and immersed in a 25℃ deionized water coagulation bath to form a phase inversion film. After washing with water to remove the NMP solvent, the film was hot-pressed under normal pressure and 50℃ to obtain a PVDF porous support layer with an average pore size of 100μm, a porosity of 88%, and a thickness of 2.0mm.

[0071] (2) Electrospinning of nanofiber layers: Chitosan and polyethyleneimine (mass ratio 7:3) were dissolved in an aqueous acetic acid solution with a volume ratio of 9:1 to prepare an 8wt% spinning solution. Using a porous support layer as the receiving substrate, electrospinning was performed for 40 minutes under the conditions of a positive electrode voltage of +15kV, a negative electrode voltage of -5kV, a receiving distance of 15cm, and a solution propulsion rate of 0.8mL / h, forming a nanofiber network with an average diameter of 200nm on the surface of the porous support layer.

[0072] (3) Vertical implantation of artificial cilia 3 can be driven: A porous anodic alumina (AAO) template with a pore size of 2.0 μm and a pore depth of 50 μm was tightly bonded to the surface of the nanofiber layer. Using the template as the cathode, nickel plating was performed in a Watt-type nickel plating bath at 50 °C at a current of -10 mA / cm². 2 Electrodeposition was performed at current density for 30 minutes. Subsequently, the AAO template was dissolved to obtain a vertically implanted nickel nanowire array with a diameter d = 2.0 μm, a length L = 50 μm, and a spacing S = 100 μm between adjacent ciliary centers.

[0073] (4) In-situ polymerization of biomimetic adhesive hydrogels: The composite substrate with the constructed ciliary array was immersed in a dopamine Tris-HCl solution of 2 mg / mL, pH=8.5, and reacted for 14 hours under shaking conditions at 25℃ and 80 rpm. After removal, washing, and drying at 60℃, a composite filtration functional layer filled with polydopamine hydrogel was obtained. The hydrogel had a solid content (C) of 12% and a catechol group density (ρ) of 10 μmol / cm³. 3 .

[0074] Comparative Example 1 The only difference from Example 1 is that no driveable artificial cilia 3 are implanted. All other materials and structures are the same as in Example 1.

[0075] Comparative Example 2 The only difference from Example 1 is that step (4) of in-situ polymerization of the biomimetic adhesive hydrogel is omitted. That is, the filter functional layer only contains a nanofiber mesh and does not contain polydopamine hydrogel. The remaining materials and structures are the same as in Example 1.

[0076] Comparative Example 3 The only difference from Example 1 is that step (2) of electrospinning the nanofiber layer is omitted. That is, the filter functional layer is composed only of polydopamine hydrogel polymerized directly on the porous support layer, lacking a nanofiber mesh as support. The remaining materials and structures are the same as in Example 1.

[0077] Comparative Example 4 The difference from Example 1 lies in the altered structure of the biomimetic self-cleaning water filter core layer. Specifically, a nanofiber mesh is first prepared on a porous support layer, followed by direct electrodeposition growth of a nickel nanowire array on the nanofiber mesh to form an independent ciliary layer. Finally, a polydopamine hydrogel layer is formed by in-situ polymerization on this ciliary layer. This results in a sequentially stacked structure of "porous support layer / nanofiber layer / ciliary layer / hydrogel layer," rather than an integrated structure with cilia vertically implanted into the filtration functional layer.

[0078] Technical effects: The filter core layers obtained in Examples 1-3 and Comparative Examples 1-4 were subjected to performance comparison tests. The test conditions were: treatment with 200 mg / L micron-sized diatomaceous earth, 50 mg / L nano-sized carbon black particles, and 10 mg / L Cu²⁺. + Simulated wastewater was subjected to constant flow filtration (10 mL / min), with an alternating magnetic field (Example 1 parameters: 65 mT, 10 Hz) activated for 2 minutes every 30 minutes of operation. The expected results are shown in Table 1. Table 1 As can be seen from Table 1: (1) The necessity of dynamic self-cleaning: Examples 1-3 of this invention achieve excellent long-term flux maintenance and efficient cleaning recovery by utilizing a directional microfluidic field generated by driving artificial cilia. In contrast, Comparative Example 1, lacking this mechanism, suffers from rapid contaminant accumulation leading to severe clogging, demonstrating that dynamic self-cleaning is key to solving filter clogging problems.

[0079] (2) The necessity of “screening-adhesion” synergy: Examples 1-3 achieved efficient and comprehensive pollutant removal. However, Comparative Example 2 lacked an adhesive hydrogel, resulting in extremely low removal rates for small molecules and ions; Comparative Example 3 lacked a nanofiber sieving framework, leading to low retention rates for large particles and structural instability, indicating that both are indispensable.

[0080] (3) Advantages of the "vertical implantation" integrated structure: The integrated structure of Examples 1-3 allows the ciliary oscillations to directly act on the contaminant capture sites, resulting in high cleaning efficiency. However, the layered structure of Comparative Example 4 causes contaminants to easily remain between layers, and the cleaning flow field cannot effectively act on the interior of the hydrogel, resulting in a significantly lower flux recovery rate, demonstrating the advantages of the core structural design of this invention.

[0081] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A biomimetic self-cleaning water filter core layer, characterized in that, It includes a porous support layer, a filter functional layer, and a self-cleaning layer; The filter functional layer is composited on the porous support layer; The filtration functional layer includes an interwoven nanofiber mesh and a biomimetic adhesive hydrogel filled in the nanofiber mesh; The self-cleaning layer includes a driveable array of artificial cilia; The driveable artificial cilia array penetrates vertically through the filter functional layer, is anchored to the filter functional layer, and protrudes from its surface.

2. The biomimetic self-cleaning water filter core layer according to claim 1, characterized in that, The porous support layer is a porous membrane with a three-dimensional interconnected pore structure prepared from polyvinylidene fluoride; and / or, The porous support layer has an average pore diameter of 100±20μm, a porosity of 85-90%, and a thickness of 2.0mm.

3. The biomimetic self-cleaning water filter core layer according to claim 1, characterized in that, The pore size D of the filtration functional layer satisfies D=η·d f ; Where η is 0.1-0.5; d f Let d be the average diameter of the nanofibers in the nanofiber mesh. f It is 200±50nm.

4. The biomimetic self-cleaning water filter core layer according to claim 1, characterized in that, The biomimetic adhesion hydrogel is a polymer hydrogel rich in catechol groups.

5. The biomimetic self-cleaning water filter core layer according to claim 1, characterized in that, The driveable artificial cilia are made of magnetic material and are driven to swing synchronously by applying an alternating magnetic field. The alternating magnetic field has an induced intensity of 50-80 mT and a frequency of 5-20 Hz.

6. The biomimetic self-cleaning water filter core layer according to claim 1, characterized in that, The diameter d of the dable artificial cilia is 2.0±0.5μm, and the center-to-center distance S between adjacent dable artificial cilia satisfies S=λ·L; Where λ is 1.2-2.0; L is the length of the driveable artificial cilia.

7. A biomimetic self-cleaning water filter core layer according to claim 3 or 6, characterized in that, The length L of the driveable artificial cilia is 50±5μm.

8. A method for preparing a biomimetic self-cleaning water filter core layer as described in any one of claims 1-7, characterized in that, Includes the following steps: A porous support layer was prepared using a non-solvent phase separation method. Then, a nanofiber mesh was formed on the surface of the porous support layer by electrospinning. The drivable artificial cilia were then vertically implanted onto the nanofiber mesh by electrochemical deposition. Finally, the composite substrate with the nanofiber mesh and drivable artificial cilia was immersed in a hydrogel precursor solution and polymerized in situ to obtain a biomimetic adhesive hydrogel, thus completing the preparation of the biomimetic self-cleaning water filter core layer.

9. The method for preparing a biomimetic self-cleaning water filter core layer according to claim 8, characterized in that, The electrospinning process parameters are as follows: feed pump speed: 0.8 mL / h; applied voltage: positive electrode +15 kV, negative electrode -5 kV; receiving distance: 15 cm; ambient temperature: 25 ± 2 ℃; ambient humidity: 45 ± 5%.

10. The application of a biomimetic self-cleaning water filter core layer as described in any one of claims 1-7 in wastewater treatment.

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