Antibacterial water filtration membrane and method of making same

Abstract

The application discloses an antibacterial water filtering membrane and a preparation method thereof. The antibacterial water filtering membrane comprises, from bottom to top, a non-woven fabric layer, a first nanofiber membrane layer and a second nanofiber membrane layer. The thickness of the first nanofiber membrane layer is 2-5 microns. The first nanofiber membrane layer comprises nanofibers. The diameter of the nanofibers is 200-400 nm. The material of the nanofibers comprises a high polymer. The prepared antibacterial water filtering membrane is applied to the treatment and purification of outdoor water sources. In the case of low pressure drop, the prepared nanofiber membrane has good interception capacity for particles with different particle sizes and the like, and high-quality water sources can be obtained at any time and anywhere.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to an antibacterial water filtration membrane and a preparation method thereof. Background Art

[0002] Nanofiltration, one of many membrane treatment technologies, has grown in stature due to the development of the water treatment industry as a whole, and membrane treatment technology in particular. Furthermore, chemical treatment, long used for many years, is now widely considered to be extremely environmentally unfriendly and requires additional processing costs. Physical treatment, due to its convenience, environmental friendliness, and lack of additional treatment requirements, has gradually become the mainstream trend in water purification. At the same time, public awareness of water scarcity has deepened, objectively demanding the efficient use of water resources. Therefore, the expansion of global industries and the increase in population size urgently require better water treatment technologies, and this objective market demand has promoted the comprehensive development of membrane treatment technology. Furthermore, with the progress and development of society, outdoor activities have gradually become a part of people's daily leisure and entertainment activities. However, due to the low pressure drop of outdoor water, it is difficult to purify drinking water conveniently and quickly. Therefore, how to utilize and treat outdoor water has become a pressing issue. Summary of the Invention

[0003] The main purpose of the present invention is to provide an antibacterial water filtration membrane and a preparation method thereof, aiming to solve the problem of outdoor water source treatment and purification and obtain high-quality water sources anytime and anywhere.

[0004] To achieve the above-mentioned purpose, the present invention proposes an antibacterial water filtration membrane, which includes a non-woven fabric layer, a first nanofiber membrane layer and a second nanofiber membrane layer stacked in sequence from bottom to top, the thickness of the first nanofiber membrane layer is 2~5μm, the first nanofiber membrane layer includes nanofibers, the diameter of the nanofibers is 200~400nm, and the material of the nanofibers includes a polymer.

[0005] Optionally, the high molecular polymer includes one of polyvinylidene fluoride, polycaprolactone, polypropylene, and polyvinyl alcohol.

[0006] Optionally, the material of the second nanofiber membrane includes any one of polypropylene and polyvinylidene fluoride.

[0007] Optionally, the material of the non-woven fabric layer includes one of PET non-woven fabric, PVA non-woven fabric, PVDF non-woven fabric, PP non-woven fabric, and release paper.

[0008] The present invention also provides a method for preparing an antibacterial water filtration membrane, comprising the following steps:

[0009] S1, dissolving a high molecular weight polymer in an organic solvent to obtain a mixed solution;

[0010] S2, coating the mixed solution on a non-woven fabric layer to obtain a first nanofiber membrane;

[0011] S3. Compounding a second nanofiber membrane on the first nanofiber membrane to obtain a water filtration membrane.

[0012] Optionally, step S1 includes: dissolving the high molecular weight polymer in an organic solvent, and adding zinc acetate to obtain a mixed solution.

[0013] Optionally, the mass ratio of the zinc acetate to the high molecular polymer is 0.1:1 to 2:1.

[0014] Optionally, in step S1, the organic solvent comprises one of N,N-dimethylformamide, dimethyl sulfoxide and dimethylacetamide; and / or,

[0015] The mass ratio of the high molecular weight polymer to the organic solvent is (10-20): (80-90).

[0016] Optionally, step S2 includes: applying the mixed solution on a non-woven fabric layer using an electrospinning method to obtain a first nanofiber membrane.

[0017] Optionally, the operating temperature of the electrospinning method is 100~300 o C; and / or,

[0018] The rotation speed of the electrospinning method is 1500~3500r / min.

[0019] In the technical solution provided by this invention, the antibacterial water filtration membrane comprises a non-woven fabric layer, a first nanofiber membrane layer, and a second nanofiber membrane layer. The non-woven fabric layer provides support and enhances the strength of the water filtration membrane. The first and second nanofiber membrane layers have excellent interception capabilities for particles of varying sizes, ensuring access to high-quality water anytime, anywhere. The stacked structure created by the two membranes combined achieves an interception capacity of over 99% for PM 0.4. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 Schematic diagram of outdoor use of the antibacterial water filtration membrane provided by the present invention;

[0022] Figure 2 TEM image of zinc oxide seed for the embodiment of the present application;

[0023] Figure 3 Microstructure image of nanofiber membrane obtained in Example 4 of the present application;

[0024] Figure 4 Microstructure image of nanofiber membrane obtained in Example 5 of the present application;

[0025] Figure 5 Microstructure image of nanofiber membrane obtained in Comparative Example 1 of the present application.

[0026] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions suggested by the manufacturers are adopted. If the reagents or instruments used are not specified by the manufacturers, they are all conventional products that can be purchased in the market. In addition, the meaning of "and / or" appearing in the whole text includes three parallel solutions. For example, "A and / or B" includes the solution of A, or the solution of B, or the solution of A and B. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that the technical solutions can be realized by the ordinary skilled in the art. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by the ordinary skilled in the art without making creative efforts are within the protection scope of the present application.

[0028] Physical treatment gradually becomes the mainstream trend in the field of water purification due to its convenience, greenness, and no need for additional treatment. At the same time, the public's awareness of water resource scarcity is further deepened, which objectively requires effective use of water resources. Therefore, the expansion of global industry and the increase in population size urgently need better water treatment technology, which promotes the overall development of membrane treatment technology. At the same time, with the progress and development of society, outdoor sports gradually become one of the ways of people's daily leisure and entertainment. However, it is difficult to conveniently and quickly purify drinking water due to the low pressure drop of outdoor water, so how to treat outdoor water has gradually become one of the problems to be solved.

[0029] In view of this, the present application provides an antibacterial water filtration membrane, which aims to solve the treatment and purification of outdoor water sources and obtain high-quality water sources anytime and anywhere. In the drawings of the present application, Figure 1The outdoor use schematic view of the antibacterial water filtering membrane provided by the application is shown in the figure; Figure 2 The TEM diagram of zinc oxide seeds in the embodiment of the application is shown in the figure; Figure 3 The microstructure diagram of the nanofiber membrane obtained in the embodiment 4 of the application is shown in the figure; Figure 4 The microstructure diagram of the nanofiber membrane obtained in the embodiment 5 of the application is shown in the figure; Figure 5 The microstructure diagram of the nanofiber membrane obtained in the comparative example 1 of the application is shown in the figure.

[0030] The application provides an antibacterial water filtering membrane, which comprises, from bottom to top, a non-woven fabric layer, a first nanofiber membrane layer and a second nanofiber membrane layer, the thickness of the first nanofiber membrane layer is 2-5 μm, the first nanofiber membrane layer comprises nanofibers, the diameter of the nanofibers is 200-400 nm, and the material of the nanofibers comprises a high polymer.

[0031] In the technical scheme provided by the application, the antibacterial water filtering membrane comprises a non-woven fabric layer, a first nanofiber membrane layer and a second nanofiber membrane layer, the non-woven fabric layer provides a supporting effect and simultaneously enhances the strength of the water filtering membrane, the first nanofiber membrane layer and the second nanofiber membrane layer have good interception ability for particles with different particle sizes, and high-quality water sources can be obtained at any time and any place. The accumulation structure generated by the two-side membrane compounding can achieve more than 99% interception ability for PM 0.4.

[0032] Further, in the embodiment, the high polymer comprises one of polyvinylidene fluoride, polycaprolactone, polypropylene and polyvinyl alcohol. The application does not limit the specific type of the high polymer, and common electrospinning solutes include polycaprolactone (PCL), polypropylene (PP), polyvinyl alcohol (PVA) and polyvinylidene fluoride (PVDF). In order to save costs and ensure the filtering effect of the nanofiber membrane, in the embodiment, the application adopts one of the above components, preferably PVDF. PVDF is a soft plastic film, the material itself is highly stable to humidity, temperature and chemicals, has the advantages of high mechanical strength, small distortion, high stability and the like, and is one of the most widely used filter membrane materials in the water purification field.

[0033] In order to make the filtering performance of the water filtering membrane better, a layer of nanofiber membrane is further compounded on the single-layer water filtering membrane. Further, in the embodiment, the material of the second nanofiber membrane comprises any one of polypropylene and polyvinylidene fluoride. Through the filtering performance test on the three-dimensional structure nanofiber membrane, the interception efficiency of the single-layer nanofiber membrane for PM 0.4 can reach more than 70%, and the accumulation structure formed after the compounding of the other membrane materials (such as PP and PVDF) can reach more than 99% in filtering performance.

[0034] Furthermore, in this embodiment, the material of the non-woven fabric layer includes one of PET non-woven fabric, PVA non-woven fabric, PVDF non-woven fabric, PP non-woven fabric, and release paper, and the above non-woven fabric is used as the receiving substrate of the nanofiber membrane.

[0035] The present invention also provides a method for preparing an antibacterial water filtration membrane, comprising the following steps:

[0036] S1, dissolving a high molecular weight polymer in an organic solvent to obtain a mixed solution;

[0037] This step involves dissolving a polymer in an organic solvent and adding zinc acetate to form a mixed solution. Under certain heat treatment conditions, the zinc acetate can generate zinc oxide seeds, which exhibit excellent antibacterial properties and improve the drinking safety of outdoor filtered water. Furthermore, the mass ratio of zinc acetate to the polymer is between 0.1:1 and 2:1. Within this mass ratio range, a good antibacterial effect can be achieved. The organic solvent comprises one of N,N-dimethylformamide, dimethyl sulfoxide, and dimethylacetamide; the mass ratio of the polymer to the organic solvent is between 10 and 20:80 and 90. Within this mass ratio range, the polymer is fully dissolved, forming a uniform mixed solution.

[0038] S2, coating the mixed solution on a non-woven fabric layer to obtain a first nanofiber membrane;

[0039] Currently, the filter membranes used for outdoor water purification are mainly divided into three categories, namely flat membranes, hollow fiber membranes and electrospun fiber membranes. Among them, electrospun fiber membranes have a wider range of applications. Nanofibers prepared by electrospinning have the characteristics of large specific surface area, good permeability, small pore size and good pore connectivity. They are very suitable for forming a three-dimensional network structure as a separation and filtration material. This step adopts the electrospinning method, using non-woven fabric as the receiving substrate, and electrospinning the mixed solution. The operating temperature of the electrospinning method is 100~300 o C; the rotation speed of the electrospinning method is 1500~3500r / min, and the nanofiber membrane with a three-dimensional structure is prepared by adjusting the spinning voltage, spinning spacing, spinning environment temperature and humidity, liquid supply rate, etc. during spinning.

[0040] S3. Compounding a second nanofiber membrane on the first nanofiber membrane to obtain a water filtration membrane.

[0041] The interception efficiency of a single-layer nanofiber membrane for PM0.4 can reach more than 70%. In order to make the filtered drinking water cleaner and safer, the first nanofiber membrane is compounded with the second nanofiber membrane. The stacking structure formed after the compounding can achieve a filtration performance of more than 99%.

[0042] The present invention proposes a method for preparing an antibacterial water filtration membrane for use in the treatment and purification of outdoor water sources. Under low pressure drop conditions, the resulting nanofiber membrane has excellent interception capabilities for particles of varying sizes, enabling access to high-quality water sources anytime and anywhere. The three-dimensional structure produced by this method has excellent interception capabilities for particulate matter. The stacked structure, formed by the composite membranes on both sides, can achieve an interception capacity of over 99% for PM 0.4. Simultaneously, zinc acetate is added. Under certain heat treatment conditions, the zinc acetate can generate zinc oxide seeds, which exhibit excellent antibacterial effects and can conveniently purify and treat outdoor water sources anywhere.

[0043] The technical solutions of the present invention are further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0044] Example 1

[0045] An antibacterial water filtration membrane comprises a PET non-woven fabric layer, a nanofiber membrane layer made of polyvinylidene fluoride and a nanofiber membrane layer made of polyvinylidene fluoride, wherein the thickness of the first nanofiber membrane layer is 2 μm and the diameter of the nanofiber is 200 nm.

[0046] Example 2

[0047] An antibacterial water filtration membrane comprises a PVA non-woven fabric layer, a nanofiber membrane layer made of polycaprolactone and a nanofiber membrane layer made of polypropylene, wherein the thickness of the first nanofiber membrane layer is 3 μm and the diameter of the nanofiber is 300 nm.

[0048] Example 3

[0049] An antibacterial water filtration membrane comprises a release paper layer, a nanofiber membrane layer made of polyvinyl alcohol and a nanofiber membrane layer made of polyvinylidene fluoride, wherein the thickness of the first nanofiber membrane layer is 5 μm and the diameter of the nanofiber is 400 nm.

[0050] Example 4

[0051] Weigh 90g of N,N-dimethylformamide in a sample bottle, and then weigh 10g of polyvinylidene fluoride particles, mix and stir at 70 degrees for 1-2h to prepare PVDF solution, add 1g of zinc acetate and blend, use PET non-woven fabric as the receiving substrate, and prepare nanofiber membrane by electrospinning. The spinning conditions are 100 o C, the rotation speed is 1500r / min, and the spinning is completed and placed in the oven for 120 o C heat treatment for 24h, prepare two PVDF nanofiber membrane materials with the same parameters, and compound the two PVDF membranes to obtain the antibacterial water filtration membrane in Example 1. The micromorphology of the nanofiber membrane is as follows Figure 3As shown, it can be seen that the morphology of PVDF nanofibers is smooth cylindrical and the fiber diameter is between 200-400 nm.

[0052] The prepared double-layer nanofiber membrane was tested for liquid filtration efficiency and resistance (pressure drop per millimeter of water column height) at room temperature. Outdoor water was used as the filtration medium, and the nanofiber membrane was tested together with the receiving substrate. The effective area was 100 cm 2 , the liquid flow rate was set to 32±0.2 / min, the sample was measured 3 times, and the average value was taken. The test values ​​of the filtration resistance performance of the PVDF nanofiber membrane are shown in Table 1.

[0053] Table 1 Filtration performance test results of PVDF nanofiber membrane

[0054]

[0055] Example 5

[0056] Weigh 85g of dimethyl sulfoxide into a sample bottle, then weigh 15g of polycaprolactone particles, mix and stir at 70 degrees for 1-2 hours to prepare a polycaprolactone solution, and add 15g of zinc acetate to blend. PVA non-woven fabric is used as the receiving substrate, and the electrospinning method is used. The spinning conditions are 200 o C, the rotation speed is 2000r / min, and the spinning is completed and placed in the oven for 120 o C heat treatment for 24h, a polycaprolactone nanofiber membrane material was prepared, and the polycaprolactone nanofiber membrane was compounded with a polypropylene nanofiber membrane prepared in the same way to obtain the antibacterial water filtration membrane of Example 2. The micromorphology of the nanofiber membrane is as follows Figure 4 As shown, it can be seen that the morphology of polycaprolactone nanofibers is smooth cylindrical, and the fiber diameter is between 200-400 nm.

[0057] At room temperature, the prepared nanofiber membrane was tested for liquid filtration efficiency and resistance (pressure drop per mmH2O column). Outdoor water was used as the filtration medium, and the nanofiber membrane was tested together with the receiving substrate. The effective area was 100 cm 2 The liquid flow rate was set to 32±0.2 / min, the sample was measured 3 times, and the average value was taken. The test values ​​of the filtration resistance performance of the polycaprolactone nanomembrane are shown in Table 2.

[0058] Table 2 Filtration performance test results of polycaprolactone nanofiber membrane

[0059]

[0060] Example 6

[0061] Weigh 80g of dimethylacetamide and 20g of polyvinyl alcohol particles, mix and stir at 70 degrees for 1-2h to prepare a polyvinyl alcohol solution, add 40g of zinc acetate and blend. Use release paper as the receiving substrate and use electrospinning to prepare a polyvinyl alcohol fiber membrane. The spinning conditions are 300 o C, with a rotation speed of 3500 r / min, the polyvinyl alcohol fiber membrane was composited with the polyvinylidene fluoride nanofiber membrane prepared by the same method to obtain the antibacterial water filtration membrane of Example 3, and the filtration performance thereof was tested.

[0062] At room temperature, the prepared nanofiber membrane was tested for liquid filtration efficiency and resistance (pressure drop per millimeter of water column) using a particle filtration efficiency tester produced by Nord Robotics. Outdoor water was used as the filtration medium, and the nanofiber membrane was tested together with the receiving substrate. The effective area was 100 cm 2 , the liquid flow rate was set to 32±0.2 / min, the sample was measured 3 times, and the average value was taken. The test values ​​are shown in Table 3.

[0063] Table 3 Filtration performance test results of polyvinyl alcohol nanofiber membrane

[0064]

[0065] Comparative Example 1

[0066] Weigh 90g of N,N-dimethylformamide into a sample bottle, then weigh 10g of polyvinylidene fluoride particles, mix and stir at 70 degrees for 1-2h to prepare PVDF solution, add 1g of zinc acetate and blend. Use electrospinning method, adjust electrospinning parameters, use PP non-woven fabric as the receiving substrate, and place in an oven at 120 o C heat treatment for 24h, the polyvinylidene fluoride nanofiber membrane material with antibacterial effect was prepared, and the micromorphology of the nanofiber membrane was as follows Figure 5 As shown, it can be seen that the morphology of PVDF nanofibers is smooth cylindrical and the fiber diameter is between 200-400 nm.

[0067] At room temperature, the prepared single-layer nanofiber membrane was tested for liquid filtration efficiency and resistance (pressure drop per mmH2O column). Outdoor water was used as the filtration medium, and the nanofiber membrane was tested together with the receiving substrate. The effective area was 100 cm 2 The liquid flow rate was set to 32±0.2 / min, the sample was measured 3 times, and the average value was taken. The test values ​​of the filtration resistance performance of the PVDF nanomembrane are shown in Table 1.

[0068]

[0069] From the above results, it can be seen that the antibacterial water filtration membrane prepared by the present invention has high filtration efficiency and low water flow resistance. Compared with the comparative document 1, which has a lower filtration efficiency for impurities of 0.3μm and 0.5μm, both below 80%, the antibacterial water filtration membrane prepared by the present invention has a filtration efficiency of more than 95% for impurities of 0.3~5μm.

[0070] In summary, the antibacterial water filtration membrane proposed in the present invention has good water treatment and purification effects, and can solve the existing problem of inconvenient purification of drinking water at low pressure drop.

[0071] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of the present invention.

Claims

1. An antibacterial water filtration membrane, characterized in that: The invention comprises a non-woven fabric layer, a first nanofiber membrane layer, and a second nanofiber membrane layer stacked sequentially from bottom to top, wherein the thickness of the first nanofiber membrane layer is 2-5 μm, the first nanofiber membrane layer comprises nanofibers, the diameter of the nanofibers is 200-400 nm, and the material of the nanofibers comprises a polymer; The method for preparing the antibacterial water filtration membrane comprises the following steps: S1, dissolving a high molecular weight polymer in an organic solvent, and adding zinc acetate to obtain a mixed solution; S2, coating the mixed solution on a non-woven fabric layer to obtain a first nanofiber membrane; S3, compounding a second nanofiber membrane on the first nanofiber membrane to obtain a water filtration membrane; The mass ratio of the zinc acetate to the high molecular polymer is 0.1:1 to 2:1; Step S2 includes: applying the mixed solution on a non-woven fabric layer using an electrospinning method to obtain a first nanofiber membrane; The operating temperature of the electrospinning method is 100~300 o C.

2. The antibacterial water filtration membrane according to claim 1, wherein The high molecular polymer includes one of polyvinylidene fluoride, polycaprolactone, polypropylene and polyvinyl alcohol.

3. The antibacterial water filtration membrane according to claim 1, wherein The material of the second nanofiber membrane includes any one of polypropylene and polyvinylidene fluoride.

4. The antibacterial water filtration membrane according to claim 1, wherein The material of the non-woven fabric layer includes one of PET non-woven fabric, PVA non-woven fabric, PVDF non-woven fabric, PP non-woven fabric, and release paper.

5. The antibacterial water filtration membrane according to claim 1, wherein In step S1, the organic solvent includes one of N,N-dimethylformamide, dimethyl sulfoxide and dimethylacetamide; and / or, The mass ratio of the high molecular weight polymer to the organic solvent is (10-20): (80-90).

6. The antibacterial water filtration membrane according to claim 1, wherein The rotation speed of the electrospinning method is 1500~3500r / min.

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