A nanospider composite ordered nanofiber air filtration membrane, and a preparation method and application thereof

Abstract

The application discloses a nano spider web composite ordered nanofiber air filtration membrane and a preparation method and application thereof. The filtration membrane comprises a multi-stage pore structure and is stable in structure, and is a composite ordered nanofiber membrane capable of completely filtering particulate matters and pathogenic microorganisms through physical interception. The application adopts a polymer solution as a spinning solution, and adopts an electrospinning technology to prepare an ordered nanofiber membrane, and then adopts an electrostatic spraying technology to composite a layer of nano spider web on the surface of the ordered nanofiber membrane. The application improves the filtration efficiency of the nanofiber membrane while ensuring a low pressure drop, and improves the filtration performance of the air filtration membrane.

Description

Technical Field

[0001] This invention belongs to the field of new materials, and specifically relates to a nano-spider web composite ordered nanofiber air filter membrane, its preparation method, and its application. Background Technology

[0002] Fine particulate matter (PM2.5) with a diameter of 2.5 micrometers or less has a significant impact on visibility and air quality.

[0003] Electrospun nanofiber filter materials have attracted widespread attention from researchers worldwide due to their nanoscale fiber diameter, ultra-high specific surface area and porosity, good permeability, easy surface functionalization, and susceptibility to bonding with submicron particles. However, traditional electrospun nanofiber filter materials have significant structural limitations. Firstly, their narrow diameter distribution leads to a tendency for dense packing and high areal density, resulting in a sharp increase in filtration resistance and hindering airflow during filtration. Secondly, conventional electrospun nanofiber membranes also exhibit structural defects in the vertical direction, leading to fragility, breakage, and easy peeling. Therefore, reconstructing the fiber structure to obtain novel nanofiber materials has become a pressing technical challenge. Summary of the Invention

[0004] This invention proposes a nano-spider web composite ordered nanofiber air filter membrane, its preparation method, and its application, in order to solve the above-mentioned technical problems in the prior art.

[0005] One objective of this invention is to provide a method for preparing a nano-spider web composite ordered nanofiber air filter membrane, comprising the following steps:

[0006] S1. The polymer solution is electrospun into an ordered nanofiber membrane using electrospinning technology combined with a double-disc receiving device. The electrospinning technology described in this invention is performed on a TL-pro type electrospinning equipment from Shenzhen Tongli Micro-Nano Technology Co., Ltd. The electrospinning technology involves drawing the prepared solution into a syringe with a metal needle. The syringe is fixed on a slide table, and the solution is extruded under external force. The droplets leave the syringe needle under the traction of a higher voltage. During flight, the jet undergoes phase separation and solidifies into fibers, which are deposited and cover the double-disc receiving device. The polymer solution is electrospun into an ordered nanofiber membrane. The double-disc receiving device is a device from Tongli Micro-Nano Technology Co., Ltd.

[0007] S2. Select a low-concentration high molecular weight polymer solution and corresponding additives that are the same as or different from those in S1. Use the TL-pro electrospinning equipment of Shenzhen Tongli Micro-Nano Technology Co., Ltd. to directly spin the mixed solution into a web. Then, composite two-dimensional mesh-like ultrafine nanofibers on the surface of the ordered nanofiber membrane prepared in S1 to form a nano-spider web composite ordered nanofiber membrane.

[0008] Furthermore, the polymer solution uses polymers including polyvinylidene fluoride, polyacrylonitrile, polystyrene, polylactic acid, polyacrylic acid, polyvinyl alcohol, polyamide 6, polyamide 66, and polyvinylpyrrolidone.

[0009] Furthermore, the receiving substrate of the ordered nanofiber membrane in S1 includes porous membranes, porous filter paper, metal mesh, nonwoven fabrics, various fabrics, or nanofiber membranes.

[0010] Furthermore, the ordered nanofiber membrane prepared in S1 has a fiber diameter of 150nm~400nm and a pore size distribution of 2μm~10μm.

[0011] Furthermore, the additives mentioned in S2 include sodium chloride, lithium chloride, sodium carbonate, silver nitrate, titanium dioxide, lithium bromide, hexadecyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, tetrabutylammonium bromide, and carbon nanotubes.

[0012] Furthermore, the mass concentration of the additive in the polymer solution in S2 is 0.0001wt%~20wt%.

[0013] Furthermore, the two-dimensional mesh-like ultrafine nanofiber membrane prepared in S2 has a spider web diameter of 20~40nm and a spider web pore size of 20nm~100nm.

[0014] The second objective of this invention is to provide a nano-spider web composite ordered nanofiber air filter membrane, which is prepared according to the above-described method for preparing a nano-spider web composite ordered nanofiber air filter membrane.

[0015] The third objective of this invention is to provide an application of a nano-cobweb composite ordered nanofiber air filter membrane in bacterial filtration materials. The nano-cobweb composite ordered nanofiber air filter membrane prepared by the above-mentioned method is applied to bacterial filtration.

[0016] Furthermore, the bacterial filter material filters out Staphylococcus aureus and Escherichia coli.

[0017] Compared with the prior art, the present invention provides a nano-spider web composite ordered nanofiber air filter membrane, its preparation method and application, which has the following beneficial effects:

[0018] (1) The nano-spider web composite ordered nanofiber air filter membrane prepared by the present invention is a composite ordered nanofiber membrane for air filtration that contains a multi-level porous structure, has a stable structure, and can completely intercept particulate matter and pathogenic microorganisms through physical means.

[0019] (2) The nano-cobweb composite ordered structure nanofiber membrane prepared by the present invention has a dual structure of nano-cobweb and ordered structure. The ordered structure is formed by the orderly stacking of fibers and has a very small diameter of nano-cobweb structure. The very small pore size can effectively intercept particulate matter and pathogenic microorganisms, so that the nano-cobweb composite ordered structure nanofiber membrane has a filtration efficiency of more than 99% for particulate matter and pathogenic microorganisms, and has high stability and safety in use, further expanding the application field of the prepared composite nanofiber membrane. The narrow gaps generated by the ordered structure and the air slip effect generated by the very small pore size of the nano-cobweb are conducive to the passage of gas. The pressure drop of the composite nanofiber membrane does not exceed 120 Pa, showing broad application prospects in the field of air filtration.

[0020] (3) The preparation method provided by the present invention uses a wide variety of polymers, additives and organic solvents, which is beneficial for the composite structure of the present invention to adapt to a variety of application scenarios. Attached Figure Description

[0021] Figure 1 An appearance diagram of a composite ordered nanofiber membrane prepared according to an embodiment of the present invention is shown;

[0022] Figure 2 The image shows a SEM image of an activated carbon substrate nano-spider web composite ordered structure nanofiber membrane prepared according to an embodiment of the present invention.

[0023] Figure 3 The image shows a SEM image of a nonwoven fabric substrate nanospider web composite ordered structure nanofiber membrane prepared according to an embodiment of the present invention.

[0024] Figure 4 The image shows a SEM image of a metal mesh substrate nanospider web composite ordered structure nanofiber membrane prepared according to an embodiment of the present invention.

[0025] Figure 5 The image shows a SEM image of a nanofiber membrane substrate with a nanospider web composite ordered structure prepared according to an embodiment of the present invention.

[0026] Figure 6 The image shows a SEM image of a cellulose filter paper substrate nanospider web composite ordered structure nanofiber membrane prepared according to an embodiment of the present invention.

[0027] Figure 7The image shows a SEM image of an ordered nanofiber membrane on a fabric substrate prepared according to an embodiment of the present invention.

[0028] Figure 8 The image shows a SEM image of an ordered nanofiber membrane on an activated carbon substrate prepared according to an embodiment of the present invention.

[0029] Figure 9 The image shows a SEM image of an activated carbon substrate nanofiber membrane prepared according to an embodiment of the present invention.

[0030] Figure 10 The diagram shows the particulate matter filtration performance of a composite ordered nanofiber membrane prepared according to an embodiment of the present invention after ten consecutive uses.

[0031] Figure 11 The diagram shows a comparison of the filtration performance of a PAN ordered nanofiber membrane, a composite ordered nanofiber membrane prepared according to the present invention, and a disordered nanofiber membrane of the same thickness. Detailed Implementation

[0032] To better understand the present invention, specific embodiments will be given to further illustrate the invention. However, it should be understood that the described embodiments are exemplary embodiments, and the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0033] Unless otherwise specified, the techniques used in the following embodiments are conventional methods well known to those skilled in the art, and the reagents and materials used in this invention are obtained from the market or other public channels. The statistical analyses involved in this invention utilize… t The test was analyzed, and the groups were compared. P A value less than 0.05 is considered to be statistically significant.

[0034] The experimental materials and equipment involved in this invention mainly include, but are not limited to: nitrogen; N-dimethylformamide (DMF), analytical grade, purchased from Sinopharm Chemical Reagent Co., Ltd.; polyacrylonitrile (PAN), analytical grade, molecular weight 150,000, purchased from Ron Reagent Co., Ltd.; formic acid, analytical grade, purchased from Sinopharm Chemical Reagent Co., Ltd.; polyamide 6 (PA6), analytical grade, purchased from Ron Reagent Co., Ltd.; sodium chloride, analytical grade, purchased from Sinopharm Chemical Reagent Co., Ltd.; polyvinylidene fluoride (PVDF), analytical grade, molecular weight 570,000, purchased from Ron Reagent Co., Ltd.; cetyltrimethylammonium bromide (CTAB), analytical grade, purchased from Sinopharm Chemical Reagent Co., Ltd. Polyvinyl alcohol (PVA), analytical grade, molecular weight 300,000, purchased from Ron Reagent Co., Ltd.; titanium dioxide, analytical grade, purchased from Sinopharm Chemical Reagent Co., Ltd.; S-4800FESEM scanning electron microscope purchased from Hitachi, Japan; SX-L1056R1 automatic filter material tester purchased from Suzhou Suxin Instrument Equipment Co., Ltd.; JFY-L1000 mask bacterial filtration efficiency tester purchased from Shanghai Jifa Instrument Equipment Co., Ltd.; YG461E air permeability meter purchased from Wenzhou Jigao Testing Instrument Co., Ltd.; electrospinning equipment purchased from Shenzhen Tongli Micro-Nano Technology Co., Ltd. TL-pro type; dual-disc receiving device purchased from Tongli Micro-Nano Technology Co., Ltd.

[0035] The preparation method of the nano-spider web composite ordered nanofiber air filter membrane of the present invention includes the following steps:

[0036] S1. The polymer solution is electrospun into an ordered nanofiber membrane using electrospinning technology combined with a double-disc receiving device. The electrospinning technology described in this invention is performed on a TL-pro type electrospinning equipment from Shenzhen Tongli Micro-Nano Technology Co., Ltd. The electrospinning technology involves drawing the prepared solution into a syringe with a metal needle. The syringe is fixed on a slide table, and the solution is extruded under external force. The droplets leave the syringe needle under the traction of a higher voltage. During flight, the jet undergoes phase separation and solidifies into fibers, which are deposited and cover the double-disc receiving device. The polymer solution is electrospun into an ordered nanofiber membrane. The double-disc receiving device is a device from Tongli Micro-Nano Technology Co., Ltd.

[0037] S2. Select a low-concentration high molecular weight polymer solution and corresponding additives that are the same as or different from those in S1. Use the TL-pro electrospinning equipment of Shenzhen Tongli Micro-Nano Technology Co., Ltd. to directly spin the mixed solution into a web. Then, composite two-dimensional mesh-like ultrafine nanofibers on the surface of the ordered nanofiber membrane prepared in S1 to form a nano-spider web composite ordered nanofiber membrane.

[0038] The parameters used in the preparation of the ordered nanofiber membrane described in S1 are as follows: ambient humidity 20%~50%, ambient temperature 10℃~50℃, injection rate of the syringe pump 0.05ml / h~0.5ml / h, negative voltage -2kV~-4kV, positive voltage +5kV~+15kV, distance from the needle to the receiving device 10cm~30cm, and spinning time 2~10h. The parameters used in the preparation of the nano-spider web described in S2 are as follows: ambient humidity 20%~50%, ambient temperature 10℃~50℃, injection rate of the syringe pump 0.05ml / h~0.5ml / h, negative voltage -2kV~-4kV, positive voltage +15kV~+35kV, distance from the needle to the receiving device 10cm~30cm, and spinning time 10min~60min.

[0039] See Figure 1 A nano-spider web composite ordered nanofiber air filter membrane was prepared.

[0040] Example 1

[0041] In some embodiments of the present invention, a method for preparing an activated carbon fiber substrate composite ordered nanofiber membrane is provided.

[0042] The preparation process includes:

[0043] 1) Use activated carbon fiber membrane as the substrate.

[0044] 2) Add 3g of PAN to 22ml of DMF solution and heat to dissolve. Stir until completely mixed and let stand at room temperature for 24h to obtain PAN / DMF spinning solution. Electrospin the PAN spinning solution into an ordered nanofiber membrane using an electrospinning device and a double-disc take-up device. The spinning parameters used in the spinning process are: voltage of +8.5kV and -4.5kV, double-disc rotation speed of 20r / min, distance from needle to receiving device of 15cm, injection speed of 0.2ml / h, ambient temperature of 25℃, ambient humidity of 30%-40%, and spinning time of 4h.

[0045] 3) Dissolve 3.6g of polyamide-6 in 13.1ml of formic acid solution and stir until completely mixed. Weigh 0.36g of NaCl and add it to the mixed solution. Stir well and let stand for 12h. Then fix the PAN ordered nanofiber membrane onto the roller receiver and cover it with a layer of PA6 nano-spider web using electrostatic spraying technology. The parameters used in the spinning process are: voltage of +30kV and -2kV, roller rotation speed of 50r / min, distance from needle to receiver of device of 15cm, injection speed of 0.2ml / h, ambient temperature of 25℃, ambient humidity of 30%-40%, and spinning time of 10min.

[0046] Results: See Figure 2 The resulting composite nanofiber membrane has a dual structure of nanospider web and ordered structure. The average diameter of the spider web fibers is 33 nm, the average pore size of the spider web is 230 nm, the average diameter of the ordered fibers is 348 nm, and the average pore size of the ordered fiber membrane is 4.5 μm.

[0047] Example 2

[0048] In some embodiments of the present invention, a method for preparing a nonwoven fabric substrate composite ordered nanofiber membrane is provided.

[0049] The preparation process includes:

[0050] 1) Use a 20g nonwoven fabric as the base.

[0051] 2) Add 3g PVA to 27ml of deionized water and heat to dissolve. Stir until completely mixed and let stand at room temperature for 24h to obtain PVA spinning solution. Electrospin the PVA spinning solution into an ordered nanofiber membrane using an electrospinning device and a double-disc take-up device. The spinning parameters used in the spinning process are: voltage of +8.5kV and -4.5kV, double-disc rotation speed of 20r / min, distance from needle to receiving device of 15cm, injection speed of 0.2ml / h, ambient temperature of 25℃, ambient humidity of 30%-40%, and spinning time of 4h.

[0052] 3) Dissolve 3.6g of PVA in 30ml of deionized water and stir until completely mixed. Then weigh out 0.36g of PVA. After being added to the mixed solution and stirred evenly, the mixture was allowed to stand for 12 hours. Then, the PVA ordered nanofiber membrane was fixed onto the roller receiver, and a layer of PVA nano-spider web was coated on it using electrostatic spraying technology. The parameters used in the spinning process were: voltage +30kV, -2kV, roller rotation speed 50r / min, distance from needle to receiver 15cm, injection speed 0.2ml / h, ambient temperature 25℃, ambient humidity 30%-40%, and spinning time 10min.

[0053] Results: See Figure 3 The resulting composite nanofiber membrane has a dual structure of nanospider web and ordered structure. The average diameter of the spider web fibers is 45 nm, the average pore size of the spider web is 160 nm, the average diameter of the ordered fibers is 261 nm, and the average pore size of the ordered fiber membrane is 5.1 μm.

[0054] Example 3

[0055] In some embodiments of the present invention, a method for preparing a metal mesh substrate composite ordered nanofiber membrane is provided.

[0056] The preparation process includes:

[0057] 1) Use a 20-mesh metal mesh as the substrate.

[0058] 2) Add 3g of PVP to 22ml of DMF solution and heat to dissolve. Stir until completely mixed and allow to stand at room temperature for 24 hours to obtain the PVP / DMF spinning solution. Electrospin the PVP / DMF solution into ordered nanofiber membranes using an electrospinning apparatus and a double-disc take-up device. The spinning parameters used were: voltage +8.5kV, -4.5kV, double-disc rotation speed 20r / min, needle-to-receiver distance 15cm, injection speed 0.2ml / h, ambient temperature 25℃, ambient humidity 30%-40%, and spinning time 4h.

[0059] 3) Dissolve 3.6g of polybutyrolactam (PBL) in 43.1ml of formic acid solution and stir until completely mixed. Then, weigh 0.36g of chitosan and add it to the mixture, stir until homogeneous, and let stand for 12 hours. Next, fix the PVP ordered nanofiber membrane onto the roller receiver and cover it with a layer of PBL nano-web using electrostatic spraying technology. The parameters used during the spinning process were: voltage +30kV, -2kV, roller rotation speed 50r / min, distance from needle to receiver 15cm, injection speed 0.2ml / h, ambient temperature 25℃, ambient humidity 30%-40%, and spinning time 10min.

[0060] Results: See Figure 4 The resulting composite nanofiber membrane has a dual structure of nanospider web and ordered structure. The average diameter of the spider web fibers is 37 nm, the average pore size of the spider web is 258 nm, the average diameter of the ordered fibers is 427 nm, and the average pore size of the ordered fiber membrane is 3.9 μm.

[0061] Example 4

[0062] In some embodiments of the present invention, a method for preparing a nanofiber membrane substrate composite ordered nanofiber membrane is provided.

[0063] 1) A nanofiber membrane with an average pore size of 0.5 μm was used as the substrate.

[0064] 2) Add 3g of PAN to 22ml of DMF solution and heat to dissolve. Stir until completely mixed and allow to stand at room temperature for 24h to obtain the PAN / DMF spinning solution. Electrospin the PAN spinning solution into an ordered nanofiber membrane using an electrospinning device and a double-disc take-up device. The spinning parameters used during the spinning process were: voltage +8.5kV, -4.5kV, double-disc rotation speed 20r / min, distance from needle to receiving device 15cm, injection speed 0.2ml / h, ambient temperature 25℃, ambient humidity 30%-40%, and spinning time 4h.

[0065] 3) Dissolve 3.6g of polyamide-6 in 13.1ml of formic acid solution, stir until completely mixed, and then weigh out 0.36g of... After being added to the mixed solution and stirred evenly, the mixture was allowed to stand for 12 hours. Then, the PAN ordered nanofiber membrane was fixed onto the roller receiver, and a layer of PA6 nanofiber spider web was coated on it using electrostatic spraying technology. The parameters used in the spinning process were: voltage +30kV, -2kV, roller rotation speed 50r / min, distance from needle to receiver 15cm, injection speed 0.2ml / h, ambient temperature 25℃, ambient humidity 30%-40%, and spinning time 10min.

[0066] Results: See Figure 5 The resulting composite nanofiber membrane has a dual structure of nanospider web and ordered structure. The average diameter of the spider web fibers is 49 nm, the average pore size of the spider web is 187 nm, the average diameter of the ordered fibers is 348 nm, and the average pore size of the ordered fiber membrane is 4.5 μm.

[0067] Example 5

[0068] In some embodiments of the present invention, a method for preparing a cellulose filter paper substrate composite ordered nanofiber membrane is provided.

[0069] 1) Use cellulose filter paper with an average pore size of 3μm as the substrate.

[0070] 2) Add 3g of PAN to 22ml of DMF solution and heat to dissolve. Stir until completely mixed and allow to stand at room temperature for 24h to obtain the PAN / DMF spinning solution. Electrospin the PAN spinning solution into an ordered nanofiber membrane using an electrospinning device and a double-disc take-up device. The spinning parameters used during the spinning process were: voltage +8.5kV, -4.5kV, double-disc rotation speed 20r / min, distance from needle to receiving device 15cm, injection speed 0.2ml / h, ambient temperature 25℃, ambient humidity 30%-40%, and spinning time 4h.

[0071] 3) Dissolve 3.6g of polyamide-6 in 13.1ml of formic acid solution and stir until completely mixed. Then, weigh 0.36g of LiCl and add it to the mixture, stir until homogeneous, and let it stand for 12 hours. Next, fix the PAN ordered nanofiber membrane onto the roller receiver and cover it with a layer of PA6 nanofiber spider web using electrostatic spraying technology. The parameters used during the spinning process were: voltage +30kV, -2kV, roller rotation speed 50r / min, distance from needle to receiver 15cm, injection speed 0.2ml / h, ambient temperature 25℃, ambient humidity 30%-40%, and spinning time 10min.

[0072] Results: See Figure 6 The resulting composite nanofiber membrane has a dual structure of nanospider web and ordered structure. The average diameter of the spider web fibers is 51 nm, the average pore size of the spider web is 332 nm, the average diameter of the ordered fibers is 348 nm, and the average pore size of the ordered fiber membrane is 4.5 μm.

[0073] Example 6

[0074] In some embodiments of the present invention, a fabric substrate composite ordered nanofiber membrane is provided for preparation.

[0075] 1) Use a fabric with an average pore size of 10μm as the substrate.

[0076] 2) Add 3g of PAN to 22ml of DMF solution and heat to dissolve. Stir until completely mixed and allow to stand at room temperature for 24h to obtain the PAN / DMF spinning solution. Electrospin the PAN spinning solution into an ordered nanofiber membrane using an electrospinning device and a double-disc take-up device. The spinning parameters used during the spinning process were: voltage +8.5kV, -4.5kV, double-disc rotation speed 20r / min, distance from needle to receiving device 15cm, injection speed 0.2ml / h, ambient temperature 25℃, ambient humidity 30%-40%, and spinning time 4h.

[0077] 3) Dissolve 3.6g of PVDF in 17.35ml of DMF solution, stir until completely mixed, and then weigh out 0.36g of... After being added to the mixed solution and stirred evenly, the mixture was allowed to stand for 12 hours. Then, the PAN ordered nanofiber membrane was fixed onto the roller receiver, and a layer of PVDF nano-spider web was coated on it using electrostatic spraying technology. The parameters used in the spinning process were: voltage +30kV, -2kV, roller rotation speed 50r / min, distance from needle to receiver 15cm, injection speed 0.2ml / h, ambient temperature 25℃, ambient humidity 30%-40%, and spinning time 10min.

[0078] Results: See Figure 7 The resulting composite nanofiber membrane has a dual structure of nanospider web and ordered structure. The average diameter of the spider web fibers is 47 nm, the average pore size of the spider web is 330 nm, the average diameter of the ordered fibers is 348 nm, and the average pore size of the ordered fiber membrane is 4.5 μm.

[0079] Comparative Example 1

[0080] In some embodiments of the present invention, a filter membrane is provided that lacks a second layer of nano-web in an ordered nanofiber membrane on an activated carbon fiber substrate.

[0081] 1) Use activated carbon fiber membrane as substrate.

[0082] 2) Add 3g of PAN to 22ml of DMF solution and heat to dissolve. Stir until completely mixed and allow to stand at room temperature for 24h to obtain the PAN / DMF spinning solution. Electrospin the PAN spinning solution into an ordered nanofiber membrane using an electrospinning device and a double-disc take-up device. The spinning parameters used during the spinning process were: voltage +8.5kV, -4.5kV, double-disc rotation speed 20r / min, distance from needle to receiving device 15cm, injection speed 0.2ml / h, ambient temperature 25℃, ambient humidity 30%-40%, and spinning time 4h.

[0083] Results: See Figure 8 The resulting ordered nanofiber membrane had an average fiber diameter of 348 nm and an average pore size of 4.5 μm.

[0084] Comparative Example 2

[0085] In some embodiments of the present invention, a filter membrane is provided that lacks a first layer of ordered nanofiber membrane in an activated carbon substrate nanofiber membrane.

[0086] 1) Use activated carbon fiber membrane as the substrate.

[0087] 2) Dissolve 3.6g of polyamide-6 in 13.1ml of formic acid solution and stir until completely mixed. Weigh 0.36g of NaCl and add it to the mixed solution. Stir well and let stand for 12h. Then fix the activated carbon fiber membrane onto the roller receiver and cover it with a layer of PA6 nano-spider web using electrostatic spraying technology. The parameters used in the spinning process are: voltage of +30kV and -2kV, roller rotation speed of 50r / min, distance from needle to receiver of device of 15cm, injection speed of 0.2ml / h, ambient temperature of 25℃, ambient humidity of 30%-40%, and spinning time of 10min.

[0088] Results: See Figure 9The average diameter of the obtained spider web fibers was 33 nm, and the average pore size of the spider web was 230 nm.

[0089] Comparative experimental results

[0090] In some embodiments of the present invention, a comparative experiment of filtration performance testing and bacterial filtration performance testing is provided.

[0091] Filtration performance testing: The nanofiber membranes prepared in Examples 1-6 and Comparative Examples 1-2 were subjected to filtration performance testing. The test medium was NaCl aerosol, and the dust emission concentration was 20-200. The concentration was adjusted by atomization pressure. The median particle size (CMD) was 0.185 ± 0.02 μm. The geometric standard deviation of the particle size distribution was < 1.6. The test results are shown in Table 1.

[0092] Table 1

[0093]

[0094] Conclusion: The test results in Table 1 show that the filtration efficiency of individual ordered nanofiber membranes and individual nano-cobweb fiber membranes is relatively low. The filtration efficiency of nano-cobweb composite ordered nanofiber membranes is higher than 99.99%, and the pressure drop is lower than 120 Pa, indicating that the nano-cobweb composite ordered structure has excellent filtration performance.

[0095] Bacterial Filtration Performance Test: The nanofiber membranes prepared in Examples 1-6 and Comparative Examples 1-2 were subjected to bacterial filtration performance tests. The membranes were prepared using Staphylococcus aureus (approximately...). A bacterial suspension (cfu / mL) was used to generate bacterial aerosols using an aerosol generator. The average particle diameter (MPS) of the bacterial aerosols was (3.0±0.3)μm, and the geometric standard deviation of the bacterial aerosol distribution should not exceed 1.5. A dual-path simultaneous comparative sampling method was adopted, that is, the bacterial count in the same aerosol was collected simultaneously in the experimental group and the positive control group. The filtered bacteria were collected using a six-stage Anderson sampler. After incubation and colony counting, the colony count was converted into the number of particles impacting the surface. The bacterial filtration efficiency of the mask was obtained by calculating the ratio of the experimental mask sample to the positive bacteria. The test results are shown in Table 2.

[0096] Table 2

[0097]

[0098] Conclusion: The experimental results in Table 2 show that the nano-spider web composite ordered nanofiber membrane has a filtration efficiency of over 99% for Staphylococcus aureus and Escherichia coli, and can effectively intercept pathogenic microorganisms represented by Staphylococcus aureus and Escherichia coli.

[0099] Filtration performance stability test: To further investigate the stability of the filtration performance of the nanofiber membrane with the ordered structure of the nanospider web composite, the composite nanofiber membrane prepared in Example 1 was subjected to 10 consecutive filtration efficiency tests. The results are shown in [reference needed]. Figure 10 This indicates that the composite nanofiber membrane has excellent stability.

[0100] To further illustrate the superiority of the nano-spider web composite ordered nanofiber membrane, the filtration performance of the composite ordered nanofiber membrane prepared in Example 1, the ordered nanofiber membrane, and the disordered nanofiber membrane of the same thickness were compared. The results are shown in [reference needed]. Figure 11 This indicates that the composite nanofiber membrane has excellent particulate matter filtration performance.

[0101] The above are merely embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of this application.

Claims

1. A method for preparing a nanospider composite ordered nanofibrous air filtration membrane, characterized by, Includes the following steps: S1. By combining electrospinning technology with a double-disc receiving device, the polymer solution is electrospun into an ordered nanofiber membrane. The electrospinning technology involves drawing the prepared polymer solution into a syringe with a metal needle through an electrospinning device. The syringe is fixed on a slide table, and the solution is squeezed out under the action of external force. The droplets leave the syringe needle under the traction of a voltage of +8.5kV and -4.5kV. During the flight, the jet solidifies into fibers through phase separation and deposits on the double-disc receiving device. The polymer solution is electrospun into an ordered nanofiber membrane. S2. A mixed solution is prepared by selecting a low-concentration high molecular weight polymer solution and corresponding additives that are the same as or different from S1. The mixed solution is then directly sprayed into a web using an electrospinning device. Two-dimensional mesh-like ultrafine nanofibers are then composited on the surface of the ordered nanofiber membrane prepared in S1 to form a nano-spider web composite ordered nanofiber air filter membrane. The nano-spider web composite ordered nanofiber air filter membrane has a dual structure of nano-spider web and ordered structure. The ordered structure is achieved through the orderly stacking of fibers. The narrow gaps created by the ordered structure and the air slip effect generated by the small pores of the nano-spider web facilitate the passage of gas. The pressure drop of the nano-spider web composite ordered nanofiber air filter membrane does not exceed 120 Pa. The receiving substrate of the ordered nanofiber membrane in S1 includes porous membranes, porous filter paper, metal mesh, nonwoven fabrics, various fabrics or nanofiber membranes. The ordered nanofiber membrane prepared in S1 has a fiber diameter of 150 nm to 400 nm and a pore size distribution of 2 μm to 10 μm. The additives in S2 include sodium chloride, lithium chloride, sodium carbonate, silver nitrate, titanium dioxide, lithium bromide, hexadecyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, tetrabutylammonium bromide, or carbon nanotubes. The two-dimensional mesh-like ultrafine nanofiber membrane prepared in S2 has a spider web diameter of 20nm~40nm and a spider web pore size of 20nm~100nm.

2. The production method according to claim 1, characterized by, The polymer solution uses polymers including polyvinylidene fluoride, polyacrylonitrile, polystyrene, polylactic acid, polyacrylic acid, polyvinyl alcohol, polyamide 6, polyamide 66, or polyvinylpyrrolidone.

3. The preparation method according to claim 1, characterized in that, The mass concentration of the additive in the polymer solution in S2 is 0.0001wt%~20wt%.

4. A nanospider composite ordered nanofibrous air filtration membrane characterized in that, It is prepared according to any one of claims 1 to 3.

5. Use of a nanospider composite ordered nanofibrous air filtration membrane in a bacterial filtration material, characterized in that, The nano-spider web composite ordered nanofiber air filter membrane prepared by the preparation method according to any one of claims 1 to 3 or the nano-spider web composite ordered nanofiber air filter membrane according to claim 4.

6. Use of the nanospider composite ordered nanofibrous air filtration membrane according to claim 5 in bacterial filtration materials, characterized by, The types of bacteria filtered include Staphylococcus aureus and Escherichia coli.

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