A filter membrane with high strength and separation performance
By designing a multi-layered filter membrane, combining chemical bonding and intermolecular forces, the stability and separation efficiency of the filter membrane under high pressure and corrosive environments are solved, achieving a balance between high strength and high efficiency separation performance and extending service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUNAN ZHONGYIN ENVIRONMENTAL PROTECTION EQUIP MFG CO LTD
- Filing Date
- 2025-08-12
- Publication Date
- 2026-07-14
AI Technical Summary
Existing filter membranes are prone to rupture under high pressure, have poor corrosion resistance, are difficult to achieve efficient separation of complex mixture systems, and have a short service life.
The structure consists of a multilayer structure comprising a support and reinforcement layer, a transition bonding layer, a first functional separation layer, an intermediate buffer layer, a second functional separation layer, and a surface modification layer. The layers are connected by chemical bonding or intermolecular forces. The support and reinforcement layer adopts a three-dimensional woven structure, and the functional separation layer is a composite layer of graphene quantum dot-modified polyethersulfone and metal-organic framework materials with polyvinylidene fluoride, which enhances the interlayer bonding strength and separation performance.
It significantly improves the mechanical properties and separation efficiency of the filter membrane. The support layer can withstand high pressure without breaking, and the functional layer efficiently retains impurities, achieving a target substance retention rate of 99.9%. It also has excellent acid and alkali resistance and extends service life.
Smart Images
Figure CN224485562U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of filtration material technology, and more specifically, to a filter membrane with high strength and separation performance. Background Technology
[0002] Filter membranes, as a highly efficient separation material, are widely used in various fields. However, existing filter membranes often suffer from insufficient strength, limited separation performance, and poor corrosion resistance. Under high-pressure filtration environments, filter membranes are prone to rupture; for complex mixtures, efficient separation is difficult to achieve; and in harsh environments such as acids and alkalis, the lifespan of filter membranes is relatively short.
[0003] To address the aforementioned issues, existing technologies have employed various improvement schemes, such as increasing the thickness of the filter membrane to enhance its strength, which reduces the filtration efficiency of the membrane; or using a single functional coating to improve separation performance, but these methods are difficult to adapt to complex separation requirements.
[0004] Therefore, it is of great significance to provide a composite filter membrane that combines high strength and excellent separation performance. Utility Model Content
[0005] In view of this, the present invention addresses the shortcomings of the prior art by proposing a filter membrane with high strength and separation performance, aiming to solve at least one of the problems mentioned in the background art.
[0006] This utility model provides a filter membrane with high strength and separation performance, comprising, from top to bottom, the following:
[0007] Supporting reinforcement layer, transition bonding layer, first functional separation layer, intermediate buffer layer, second functional separation layer and surface finishing layer;
[0008] The supporting reinforcement layer, transition bonding layer, first functional separation layer, intermediate buffer layer, second functional separation layer, and surface modification layer are connected by chemical bonding or intermolecular forces.
[0009] Preferably, the support reinforcement layer adopts a three-dimensional woven structure with a thickness of 150-200 μm and a porosity of 60%-70%, and is connected to the transition bonding layer by chemical bonding.
[0010] Preferably, the transition bonding layer is a nanoscale titanate coupling agent coating with a thickness of 10-15 nm.
[0011] Preferably, the first functional separation layer is composed of graphene quantum dot modified polyethersulfone, with a thickness of 50-80 μm, an average pore size of 0.1-0.3 μm, and a porosity of 45%-55%.
[0012] Preferably, the intermediate buffer layer is a polyimide porous membrane with a thickness of 30-50 μm and a gradient distribution of pore size, with a pore size of 0.05-0.1 μm near the first functional separation layer and a pore size of 0.02-0.05 μm near the second functional separation layer; the porosity is 50%-60%.
[0013] Preferably, the second functional separation layer is a composite layer of metal-organic framework material and polyvinylidene fluoride, with a thickness of 20-40 μm, an average pore size of 0.01-0.03 μm, and a porosity of 35%-45%.
[0014] Preferably, the surface modification layer is a fluorosilane-modified silica nano-coating with a thickness of 5-10 μm, the silica nanoparticles have a particle size of 20-50 nm, the fluorosilane is tridecafluorooctyltriethoxysilane, the modified surface has a water contact angle ≥150°, and the porosity of the surface modification layer is 30%-40%.
[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0016] Excellent mechanical properties: The support and reinforcement layer adopts a three-dimensional woven structure of basalt fiber and carbon fiber, which can withstand high filtration pressure and effectively prevent the filter membrane from breaking under high pressure. The transition bonding layer, through the chemical bonding of titanate coupling agent, makes the bonding strength between the support and reinforcement layer and the functional layer ≥2.0N / cm, preventing interlayer delamination, significantly improving the overall structural stability of the filter membrane, and extending its service life.
[0017] High separation efficiency: The first functional separation layer can efficiently trap larger impurities such as suspended particles and colloids, achieving preliminary separation; the gradient pore size design of the intermediate buffer layer reduces filtration resistance and increases filtration throughput, while supporting the second functional separation layer; the second functional separation layer, through the composite structure of ZIF-8 and polyvinylidene fluoride, utilizes its high specific surface area and microporous characteristics to trap small molecule organic matter, heavy metal ions, etc., achieving deep purification, with a retention rate of ≥99.9% for target substances;
[0018] Synergistic effect of each layer, balanced overall performance: The multi-layer structure is tightly bound together by chemical bonding or intermolecular forces, taking into account both high strength and high separation efficiency, thus solving the problem of "difficulty in balancing strength and performance" in traditional filter membranes.
[0019] The above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure.
[0020] Other features and aspects of this disclosure will become clearer from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description
[0021] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0022] Figure 1 A front structural cross-sectional view of the filter membrane with high strength and separation performance provided in Embodiment 1 of this utility model;
[0023] Figure 2 A front structural cross-sectional view of the filter membrane with high strength and separation performance provided in Embodiment 2 of this utility model;
[0024] Figure 3 This utility model Figure 2 A magnified view of part A in the image.
[0025] Among them: 1-supporting reinforcement layer, 2-transition bonding layer, 3-first functional separation layer, 4-intermediate buffer layer, 5-second functional separation layer, 6-surface finishing layer, 101-three-dimensional braided structure. Detailed Implementation
[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0027] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.
[0029] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0030] See Figure 1-3 As shown, this utility model provides a filter membrane with high strength and separation performance, comprising, from top to bottom, the following components:
[0031] Supporting and reinforcing layer 1, transition bonding layer 2, first functional separation layer 3, intermediate buffer layer 4, second functional separation layer 5, and surface finishing layer 6;
[0032] The supporting reinforcement layer 1, transition bonding layer 2, first functional separation layer 3, intermediate buffer layer, second functional separation layer and surface modification layer are connected by chemical bonding or intermolecular forces.
[0033] In this invention, the supporting reinforcement layer 1 adopts a three-dimensional braided structure 101 with a thickness of 150-200μm and a porosity of 60%-70%, and is connected to the transition bonding layer by chemical bonding.
[0034] This invention employs a composite three-dimensional braided structure 101 of basalt fiber and carbon fiber, which significantly improves the overall mechanical properties of the filter membrane. The tensile strength can reach 300-400MPa, which can withstand high filtration pressure and prevent the filter membrane from breaking.
[0035] In this invention, the transition bonding layer 2 is a nano-scale titanate coupling agent coating with a thickness of 10-15 nm.
[0036] This invention utilizes the chemical bonding effect of titanate coupling agent to tightly bond the support reinforcement layer 1 and the first functional separation layer 3, with a bonding strength ≥2.0 N / cm, effectively preventing interlayer peeling and improving the stability of the filter membrane.
[0037] Specifically, in this invention, the supporting reinforcement layer 1 adopts a three-dimensional braided structure 101, and the material is a composite fiber of basalt fiber and carbon fiber, wherein the basalt fiber accounts for 60%-70% and the carbon fiber accounts for 30%-40%; the fiber diameter is 8-12μm, and the braiding density is 30-40 fibers / cm; the thickness of the supporting reinforcement layer is 150-200μm, and the porosity is 60%-70%. The transition bonding layer 2 is a nano-scale titanate coupling agent coating, the main component of which is isopropyltris(dioctylpyrophosphate)titanate (mass fraction 90%-95%). One end of the titanate coupling agent molecule can chemically react with hydroxyl groups and other groups on the surface of the supporting reinforcement layer 1 to form a stable chemical bond, and the other end can interact with the material of the first functional separation layer 3, thereby tightly bonding the supporting reinforcement layer 1 and the transition bonding layer 2.
[0038] In this invention, the first functional separation layer 3 is composed of graphene quantum dot modified polyethersulfone, with a thickness of 50-80 μm, an average pore size of 0.1-0.3 μm, and a porosity of 45%-55%.
[0039] Graphene quantum dot-modified polyethersulfone materials have good hydrophilicity and chemical corrosion resistance. The pore size of 0.1-0.3μm can effectively trap larger impurities such as suspended particles and colloids in water, while improving the anti-fouling ability of the filter membrane.
[0040] Specifically, relying on the bridging effect of the titanate coupling agent in the transition bonding layer 2, the end of the coupling agent molecule that is not bonded to the supporting reinforcement layer 1 combines with the polyethersulfone and graphene quantum dots in the first functional separation layer 3 through chemical adsorption or chemical bonding, thereby achieving a stable connection between the two layers.
[0041] In this invention, the intermediate buffer layer 4 is a polyimide porous membrane with a thickness of 30-50 μm and a gradient distribution of pore size. The pore size on the side closer to the first functional separation layer 3 is 0.05-0.1 μm, and the pore size on the side closer to the second functional separation layer 5 is 0.02-0.05 μm; the porosity is 50%-60%.
[0042] The gradient pore size design of the polyimide porous membrane of this invention plays a good buffering role, which can support the second functional separation layer 5, reduce filtration resistance, and improve filtration flux. At the same time, the polyimide material has excellent high temperature resistance and solvent resistance, which expands the application range of the filter membrane.
[0043] Specifically, the first functional separation layer 3 is composed of graphene quantum dot-modified polyethersulfone, and the intermediate buffer layer 4 is a polyimide porous membrane. During the preparation process, the two are combined through intermolecular forces (such as van der Waals forces) and material compatibility. At the same time, the porous structure of the intermediate buffer layer 4 also provides a certain physical anchoring effect for its combination with the first functional separation layer 3.
[0044] In this invention, the second functional separation layer 5 is a composite layer of metal-organic framework material and polyvinylidene fluoride, with a thickness of 20-40 μm and an average pore size of 0.01-0.03 μm. Preferably, the metal-organic framework material is ZIF-8 with a particle size of 50-100 nm and a mass percentage of 15%-20%. The average pore size of the second functional separation layer 5 is 0.01-0.03 μm, and the porosity is 35%-45%.
[0045] The composite layer of ZIF-8 and polyvinylidene fluoride has an ultra-high specific surface area and abundant microporous structure. The pore size of 0.01-0.03μm can retain small molecule organic matter, heavy metal ions, etc., to achieve deep purification. The introduction of MOF materials endows the filter membrane with selective adsorption performance and improves separation efficiency.
[0046] Specifically, the polyimide material of the intermediate buffer layer 4 and the polyvinylidene fluoride in the second functional separation layer 5 are chemically compatible, and the layers are bonded together through intermolecular attraction. Furthermore, the gradient pore size design of the intermediate buffer layer 4 increases its contact area with the second functional separation layer 5, further enhancing the bonding effect.
[0047] In this invention, the surface modification layer 6 is a fluorosilane-modified silica nano-coating with a thickness of 5-10 μm. The silica nanoparticles have a particle size of 20-50 nm, the fluorosilane is tridecafluorooctyltriethoxysilane, the modified surface has a water contact angle ≥150°, and the porosity of the surface modification layer 6 is 30%-40%.
[0048] The superhydrophobic surface modification layer 6 can effectively reduce the adsorption of pollutants on the filter membrane surface, improve the anti-fouling performance and cleaning recovery rate of the filter membrane; at the same time, the fluorosilane-modified silica nano-coating enhances the acid and alkali resistance of the filter membrane, and can work stably in an environment with pH = 1-13.
[0049] In some embodiments, the surface modification layer 6 may be removed as needed. Specifically, under the conditions of simplifying the preparation process, reducing production costs, reducing filtration resistance, and increasing filtration throughput, the surface modification layer 6 may be selectively removed, leaving only the support reinforcement layer 1, the transition bonding layer 2, the first functional separation layer 3, the intermediate buffer layer 4, and the second functional separation layer 5.
[0050] Example 1
[0051] See Figure 1 , Figure 1 In the filter membrane shown, which has high strength and separation performance, a support and reinforcement layer 1 is disposed on the bottom surface of the filter membrane. The filter membrane consists of, in the stacking direction, a support and reinforcement layer 1, a transition bonding layer 2, a first functional separation layer 3, an intermediate buffer layer 4, a second functional separation layer 5, and a surface modification layer.
[0052] The support reinforcement layer 1 is made of a three-dimensional woven composite fiber of basalt fiber (65%) and carbon fiber (35%). The fiber diameter is 10μm, the weaving density is 35 fibers / cm, the thickness is 180μm, and the porosity is 65%. It provides stable structural support, making the filter membrane structurally stable and not easily deformed. Its tensile strength can reach 350MPa, which can withstand high filtration pressure.
[0053] The transition bonding layer 2 is an isopropyl tris(dioctyl pyrophosphoryloxy) titanate coating with a thickness of 12 nm and a titanate coupling agent mass fraction of 92%. Through chemical bonding, the supporting reinforcement layer 1 is tightly connected to the adjacent functional layers (first functional separation layer 3 and second functional separation layer 5), with a bonding strength ≥2.0 N / cm. This effectively avoids the problem of functional layers falling off during use, significantly improves the stability of the filter membrane, and also helps to enhance the overall chemical stability of the filter membrane.
[0054] The first functional separation layer 3 is composed of polyethersulfone modified with graphene quantum dots (particle size 7nm, mass percentage 6%), with a thickness of 65μm, an average pore size of 0.2μm, and a porosity of 50%. It can initially intercept larger impurities in the filtration system. Its good hydrophilicity and chemical corrosion resistance help improve the anti-fouling ability of the filter membrane and ensure the smooth operation of the filtration process.
[0055] The intermediate buffer layer 4 is a polyimide porous membrane with a thickness of 40 μm; the pore size is 0.08 μm on the side near the first functional separation layer 3 and 0.03 μm on the side near the second functional separation layer 5; the porosity is 55%, which plays a good buffering role, supporting the second functional separation layer 5, reducing filtration resistance, and increasing filtration flux. At the same time, its excellent high temperature resistance and solvent resistance expand the application range of the filter membrane.
[0056] The second functional separation layer 5 is a composite layer of ZIF-8 (particle size 70nm, mass percentage 18%) and polyvinylidene fluoride, with a thickness of 30μm, an average pore size of 0.02μm, and a porosity of 40%. It can perform deep purification on the system after preliminary filtration, effectively retaining small molecule organic matter, heavy metal ions, etc. Its ultra-high specific surface area and rich microporous structure improve the separation efficiency.
[0057] Surface modification layer: Tridecafluorooctyltriethoxysilane modified silica nanocoating (particle size 30nm), thickness 8μm, surface water contact angle 155°, porosity 35%.
[0058] Example 2
[0059] The other structures are the same as in Example 1, except that the surface modification layer is removed in this example.
[0060] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.
Claims
1. A filter membrane with high strength and separation performance, characterized in that, Including those distributed from top to bottom: Supporting reinforcement layer, transition bonding layer, first functional separation layer, intermediate buffer layer, second functional separation layer and surface finishing layer; The supporting reinforcement layer, transition bonding layer, first functional separation layer, intermediate buffer layer, second functional separation layer, and surface modification layer are connected by chemical bonding or intermolecular forces.
2. The filter membrane according to claim 1, characterized in that, The supporting reinforcement layer adopts a three-dimensional woven structure with a thickness of 150-200μm and a porosity of 60%-70%, and is connected to the transition bonding layer by chemical bonding.
3. The filter membrane according to claim 1, characterized in that, The transition bonding layer is a nanoscale titanate coupling agent coating with a thickness of 10-15 nm.
4. The filter membrane according to claim 1, characterized in that, The first functional separation layer is composed of graphene quantum dot modified polyethersulfone, with a thickness of 50-80 μm, an average pore size of 0.1-0.3 μm, and a porosity of 45%-55%.
5. The filter membrane according to claim 1, characterized in that, The intermediate buffer layer is a polyimide porous membrane with a thickness of 30-50 μm and a gradient distribution of pore size. The pore size is 0.05-0.1 μm on the side closer to the first functional separation layer and 0.02-0.05 μm on the side closer to the second functional separation layer. The porosity is 50%-60%.
6. The filter membrane according to claim 1, characterized in that, The second functional separation layer is a composite layer of metal-organic framework material and polyvinylidene fluoride, with a thickness of 20-40 μm, an average pore size of 0.01-0.03 μm, and a porosity of 35%-45%.
7. The filter membrane according to claim 1, characterized in that, The surface modification layer is a fluorosilane-modified silica nano-coating with a thickness of 5-10 μm. The silica nanoparticles have a particle size of 20-50 nm, the fluorosilane is tridecafluorooctyltriethoxysilane, the modified surface has a water contact angle ≥150°, and the porosity of the surface modification layer is 30%-40%.