Renewable ozone / free radical scavenging membrane, preparation method and application of renewable ozone / free radical scavenging membrane in mask

Abstract

The invention belongs to the field of functional textiles, and particularly relates to a renewable ozone / free radical scavenging membrane, a preparation method and application of the renewable ozone / free radical scavenging membrane in a mask. The preparation method comprises the following steps: firstly, adding MnO2 and nano platinum powder / nano palladium powder into an N, N-dimethylformamide solution of polyacrylonitrile, carrying out electrospinning to obtain PAN nano fibers, and preparing the catalytic carbon fiber membrane by adopting a microwave method. Coating and pressing the catalytic carbon fiber membrane with a SiOfiber interwoven porous membrane to obtain a renewable ozone / free radical scavenging membrane; and finally, inserting the renewable ozone / free radical scavenging membrane between the outer layer and the inner layer of the mask to obtain the ozone and free radical scavenging mask. The mask can remove ozone and free radicals and purify inhaled air for a long time, and the regenerated ozone and free radical removing film can regenerate the function through microwaves.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of functional textiles, in particular to a renewable ozone / free radical scavenging film, a preparation method and its application in masks. BACKGROUND

[0002] Free radicals (such as hydroxyl radicals ·OH, superoxide radicals O2·⁻, etc.) and ozone (O3) in air pollution pose a significant threat to human health, with complex harm mechanisms involving oxidative stress, inflammatory response, DNA damage, and other aspects.

[0003] Free radicals (such as hydroxyl radicals ·OH, superoxide radicals O2·⁻) in air pollution have extremely strong oxidizing properties, can directly attack human cells, trigger oxidative stress, cause cell membrane lipid peroxidation, protein denaturation, and DNA damage. Long-term exposure can exacerbate respiratory diseases (such as asthma, COPD), and may affect cardiovascular function through the blood, and even increase the risk of cancer. For example, environmental persistent free radicals (EPFRs) carried in PM2.5 can exist in the body for a long time, continuously catalyze the generation of reactive oxygen species (ROS), and induce chronic inflammation and tissue damage. In addition, free radicals can also penetrate the blood-brain barrier and be associated with the occurrence of neurodegenerative diseases (such as Alzheimer's disease).

[0004] Ozone is a strong oxidizing gas, and short-term exposure can stimulate the respiratory tract, causing cough, chest tightness, and decreased lung function, with a particularly significant impact on asthma patients. After entering the lungs, O3 reacts with the mucosa to generate secondary free radicals (such as ·OH), activates inflammatory pathways, causes lung tissue damage, and even accelerates pulmonary fibrosis. In addition, ozone can penetrate the alveoli into the blood circulation, causing systemic oxidative stress, and is associated with cardiovascular diseases (such as myocardial infarction) and metabolic abnormalities (such as insulin resistance). Notably, O3 can also react with skin surface oil to form a "human oxidation field", which may interfere with skin barrier function or affect the degradation process of indoor pollutants.

[0005] Free radicals and ozone often act together in air pollution, forming a vicious cycle. For example, free radicals carried by PM2.5 can catalyze the decomposition of ozone, generating more highly active oxidizing substances, further exacerbating lung and systemic damage. In indoor environments, ozone reacts with volatile organic compounds (VOCs) to generate new free radicals, while certain personal care products (such as perfumes) may inhibit this process, but the residual chemical components (such as phenoxyethanol) themselves may pose a toxic risk. This synergistic effect makes the health hazards of combined pollution far exceed those of single pollutants, especially posing a greater threat to children, the elderly, and patients with chronic diseases.

[0006] The concentration and harm degree of free radicals (such as ·OH, O2·⁻) and ozone (O3) in the atmosphere are significantly affected by weather conditions and seasonal changes, mainly regulated by factors such as light, temperature, humidity, wind speed and atmospheric circulation. Free radical and ozone pollution show obvious seasonality and weather dependence, with the greatest harm of O3 and free radicals in summer high temperature and strong light, and PM2.5 and persistent free radicals in winter.

[0007] At present, there is no good protection measure in the outdoor to resist the damage of free radicals and ozone in inhaled air to human health. SUMMARY

[0008] Therefore, the purpose of the present application is to provide a renewable ozone / free radical scavenging film, a preparation method and its application in a mask, which can scavenge ozone and free radicals and be applied in a mask to purify inhaled air for a long time.

[0009] In order to solve the above technical problems, the present application provides the following technical solutions:

[0010] In a first aspect of the present application, a preparation method of a renewable ozone / free radical scavenging film is provided, comprising the following steps:

[0011] S1. Add α-MnO2 powder and nano noble metal catalyst to a N,N-dimethylformamide solution of polyacrylonitrile, fully stir and disperse uniformly, then electrospin PAN nanofiber, and then microwave treatment to obtain a catalytic carbon fiber film;

[0012] S2. Electrospin an ethanol solution containing diatomite and polyvinylpyrrolidone to obtain PVP nanofiber, and then sinter at 1000-1200℃ to obtain a SiO2 fiber interwoven porous film;

[0013] S3. Sandwich the catalytic carbon fiber film between two layers of the SiO2 fiber interwoven porous film, and hot-press the edges to composite to obtain the renewable ozone / free radical scavenging film.

[0014] In some embodiments of the present application, in step S1, the addition amount of the α-MnO2 powder and the nano noble metal catalyst in the N,N-dimethylformamide solution of polyacrylonitrile is 600-1000 mg / L and 60-100 mg / L, respectively.

[0015] In some embodiments of the present application, the particle size of the α-MnO2 powder is 10-20 nm.

[0016] In some embodiments of the present application, in step S1, the nano noble metal catalyst is nano platinum powder or nano palladium powder.

[0017] In some embodiments of the present application, the particle size of the nano noble metal catalyst is 3-20 nm.

[0018] In some embodiments of the present application, in the N,N-dimethylformamide solution of the polyacrylonitrile in step S1, the weight average molecular weight of the polyacrylonitrile is 50-200 thousand, and the concentration is 10-15 wt%.

[0019] In some embodiments of the present application, in step S1, the electrospinning conditions are as follows: a receiving distance of 15-20 cm, a liquid supply speed of 1.6-2 mL / h, a collection roller speed of 200-300 rpm, a voltage of 15-20 kV, a temperature of 30-40℃, and a relative humidity of 10-40%.

[0020] In some embodiments of the present application, in step S1, the microwave treatment process is as follows: a pre-oxidation power of 300-600 W and a treatment time of 30-60 min; and a carbonization power of 800-1200 W and a treatment time of 5-15 min.

[0021] In some embodiments of the present application, in step S2, the total mass concentration of the diatomite and the polyvinylpyrrolidone in the ethanol solution is 8-12 wt%.

[0022] In some embodiments of the present application, the weight average molecular weight of the polyvinylpyrrolidone is 1.3-1.5 million

[0023] In some embodiments of the present application, the mass ratio of the diatomite and the polyvinylpyrrolidone is 1:1. This ratio can obtain the SiO2 fiber interwoven porous membrane with the best mechanical properties, i.e. necessary strength and toughness, and also ensure a certain porosity, which is conducive to higher air permeability.

[0024] In some embodiments of the present application, in step S2, the electrospinning conditions are as follows: a receiving distance of 12-15 cm, a liquid supply speed of 0.8-1.2 mL / h, a collection roller speed of 800-1000 rpm, a voltage of 15-20 kV, a temperature of 23-27℃, and a relative humidity of 10-40%.

[0025] In some embodiments of the present application, the edge hot-pressing compounding is specifically as follows: the edges of the catalytic carbon fiber membrane and the SiO2 fiber interwoven porous membrane are coated with inorganic high-temperature glue, and then hot-pressed and formed.

[0026] In some embodiments of the present application, the inorganic high-temperature glue is one of Aremco 645, Alteco NA-100, and Cotronics 989.

[0027] In some embodiments of the present application, the hot-pressing conditions are as follows: hot-pressing temperature is 400-500 DEG C, pressure is 0.5-2.0 MPa, and pressure maintaining time is 1-2 h.

[0028] The second aspect of the present application also provides a regenerable ozone / free radical scavenging film prepared according to the preparation method described above.

[0029] The third aspect of the present application also provides an application of the regenerable ozone / free radical scavenging film described above in preparing a mask.

[0030] The fourth aspect of the present application also provides a mask comprising a mask outer layer, a mask inner layer, and a regenerable ozone / free radical scavenging film arranged between the mask outer layer and the mask inner layer.

[0031] Compared with the prior art, the present application has the following beneficial effects:

[0032] (1) The present application prepares a regenerable ozone / free radical scavenging film by interweaving a high-temperature-resistant catalytic carbon fiber film and a SiO2 fiber interwoven porous film. In use, the alpha-MnO2 and nano noble metal (Pt / Pd) loaded in the catalytic carbon fiber film can catalyze the oxidation and efficient decomposition of ozone (O3) and free radicals (such as ·OH, O2⁻), the SiO2 fiber interwoven porous film serves as a support layer to provide high air permeability and physical filtration, and at the same time, to protect the structure of the carbon fiber film to be stable.

[0033] (2) The regenerable ozone / free radical scavenging film provided by the present application can quickly remove the pollutants adsorbed on the surface of the carbon fiber film after use through microwave irradiation, restore the catalytic activity, and realize repeated use.

[0034] (3) In the sandwich structure of "SiO2 film / carbon fiber film / SiO2 film" designed by the present application, the outer layer SiO2 film blocks particulate matter, and the inner layer SiO2 film protects the user from contacting the catalyst. In addition, the edge sealing with inorganic high-temperature glue can ensure the interlayer bonding strength and not block the pores. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of a mask;

[0036] Figure 2 It is a column chart of ozone scavenging rate obtained from test example 1;

[0037] Figure 3 It is a column chart of free radical scavenging rate obtained from test example 2;

[0038] Figure 4 It is a column chart of ozone scavenging rate after microwave regeneration obtained from test example 3. DETAILED DESCRIPTION

[0039] For a further understanding of the application, preferred embodiments thereof will be described in conjunction with examples, it being understood, however, that this description is made only by way of further illustration and not as a limitation on the right claims.

[0040] Example 1

[0041] A method for preparing a renewable ozone / free radical scavenging membrane, comprising the following steps:

[0042] 1. First, 80 mg of α-MnO2 powder with a particle size of 15 nm and 8 mg of nano platinum powder with a particle size of 15 nm were added to 100 ml of N,N-dimethylformamide (DMF) solution containing 12 wt% of polyacrylonitrile with a weight average molecular weight of 100,000, and after being fully stirred and dispersed, PAN nanofibers were obtained by electrospinning at a receiving distance of 18 cm, a liquid supply speed of 1.8 mL / h, a collection roller speed of 250 rpm, a voltage of 17 kV, a temperature of 35°C, and a relative humidity of 20%, and then pre-oxidized by microwave treatment at a power of 450 W for 45 min, followed by carbonization at a power of 1000 W for 10 min, to obtain a catalytic carbon fiber membrane.

[0043] 2. Diatomite with a total mass concentration of 10 wt% and polyvinylpyrrolidone (PVP) with a weight average molecular weight of 1.4 million were added to 100 ml of ethanol according to an equal mass ratio, and after being fully stirred, PVP nanofibers were obtained by electrospinning at a receiving distance of 13 cm, a liquid supply speed of 1.0 mL / h, a collection roller speed of 900 rpm, a voltage of 17 kV, a temperature of 25°C, and a relative humidity of 20%, and then sintered at 1100°C to obtain a SiO2 fiber interwoven porous membrane.

[0044] 3. The catalytic carbon fiber membrane cut according to the size of the mask was clamped between two layers of SiO2 fiber interwoven porous membranes, and the edges were coated with Aremco 645 inorganic high-temperature glue, and then hot-pressed at 450°C, a pressure of 1.0 MPa, and a pressure holding time of 1.5 h to form a renewable ozone / free radical scavenging membrane.

[0045] Example 2

[0046] A method for preparing a renewable ozone / free radical scavenging membrane, comprising the following steps:

[0047] 1、Firstly, 60 mg of α-MnO2 powder with a particle size of 10 nm and 6 mg of nano-palladium powder with a particle size of 3 nm were added to 100 ml of N,N-dimethylformamide (DMF) solution containing 10 wt% of polyacrylonitrile with a weight average molecular weight of 50,000, and after being fully stirred and uniformly dispersed, PAN nanofibers were obtained by electrospinning at a receiving distance of 15 cm, a liquid supply speed of 1.6 mL / h, a collection roller speed of 200 rpm, a voltage of 15 kV, a temperature of 30°C, and a relative humidity of 10%, and then pre-oxidation was performed at a power of 300 W for 60 min, followed by carbonization microwave treatment at a power of 800 W for 15 min, to obtain a catalytic carbon fiber membrane.

[0048] 2、Diatomite with a total mass concentration of 8 wt% and polyvinylpyrrolidone (PVP) with a weight average molecular weight of 1.3 million were added to 100 ml of ethanol according to an equal mass ratio, and after being fully stirred, PVP nanofibers were obtained by electrospinning at a receiving distance of 12 cm, a liquid supply speed of 0.8 mL / h, a collection roller speed of 800 rpm, a voltage of 15 kV, a temperature of 23°C, and a relative humidity of 10%, and then sintering was performed at 1000°C to obtain a SiO2 fiber interwoven porous membrane.

[0049] 3、The catalytic carbon fiber membrane cut according to the size of the mask was clamped between two layers of SiO2 fiber interwoven porous membranes, the edges were coated with Alteco NA-100 inorganic high-temperature glue, and hot pressing was performed at 400°C, a pressure of 0.5 MPa, and a pressure holding time of 2 h to form a regenerable ozone / free radical removal membrane.

[0050] Example 3

[0051] A method for preparing a regenerable ozone / free radical removal membrane, comprising the following steps:

[0052] 1、Firstly, 100 mg of α-MnO2 powder with a particle size of 20 nm and 10 mg of nano-platinum powder with a particle size of 20 nm were added to 100 ml of N,N-dimethylformamide (DMF) solution containing 15 wt% of polyacrylonitrile with a weight average molecular weight of 200,000, and after being fully stirred and uniformly dispersed, PAN nanofibers were obtained by electrospinning at a receiving distance of 20 cm, a liquid supply speed of 2 mL / h, a collection roller speed of 300 rpm, a voltage of 20 kV, a temperature of 40°C, and a relative humidity of 40%, and then pre-oxidation was performed at a power of 600 W for 30 min, followed by carbonization microwave treatment at a power of 1200 W for 5 min, to obtain a catalytic carbon fiber membrane.

[0053] 2、Diatomite with total mass concentration of 12wt% and polyvinylpyrrolidone (PVP) with weight average molecular weight of 1.5 million were added into 100ml ethanol according to equal mass ratio, PVP nanofibers were obtained by electrospinning with receiving distance of 15cm, liquid supply speed of 1.2mL / h, collection roller speed of 1000r / min, voltage of 20kV, temperature of 27℃ and relative humidity of 40%, and then SiO2 fiber interwoven porous membrane was obtained by sintering at 1200℃.

[0054] 3、Catalytic carbon fiber membrane cut according to the size of the mask was clamped between two layers of SiO2 fiber interwoven porous membrane, and the edges were coated with Cotronics 989 inorganic high temperature glue, and the regenerable ozone / free radical removal membrane was obtained by hot pressing at 500℃ and pressure of 2.0MPa for 1h.

[0055] Comparative Example 1 (without catalytic carbon fiber membrane)

[0056] A method for preparing a SiO2 fiber interwoven porous membrane, comprising the following steps:

[0057] 1、Diatomite with total mass concentration of 10wt% and polyvinylpyrrolidone (PVP) with weight average molecular weight of 1.4 million were added into 100ml ethanol according to equal mass ratio, PVP nanofibers were obtained by electrospinning with receiving distance of 13cm, liquid supply speed of 1.0mL / h, collection roller speed of 900r / min, voltage of 17kV, temperature of 25℃ and relative humidity of 20%, and then SiO2 fiber interwoven porous membrane was obtained by sintering at 1100℃.

[0058] 2、Two layers of SiO2 fiber interwoven porous membrane cut according to the size of the mask were coated with Aremco 645 inorganic high temperature glue at the edges, and the SiO2 fiber interwoven porous membrane was obtained by hot pressing at 450℃ and pressure of 1.0MPa for 1.5h.

[0059] Comparative Example 2 (without SiO2 fiber interwoven porous membrane)

[0060] A method for preparing a catalytic carbon fiber membrane, comprising the following steps:

[0061] 1. First, 80 mg of α-MnO2 powder with a particle size of 15 nm and 8 mg of platinum nanopowder with a particle size of 15 nm were added to 100 ml of N,N-dimethylformamide (DMF) solution containing 12 wt% of polyacrylonitrile with a weight average molecular weight of 100,000, and after being fully stirred and uniformly dispersed, PAN nanofibers were obtained by electrospinning at a receiving distance of 18 cm, a liquid supply speed of 1.8 mL / h, a collection roller speed of 250 rpm, a voltage of 17 kV, a temperature of 35°C, and a relative humidity of 20%, and then pre-oxidation was performed at a power of 450 W for 45 min, followed by carbonization microwave treatment at a power of 1000 W for 10 min, to obtain a catalytic carbon fiber membrane.

[0062] 2. A mask was sewn with a cotton fabric according to the structure of Figure 1

[0063] Comparative Example 3 (without a sandwich structure)

[0064] A composite membrane preparation method, comprising the following steps:

[0065] 1. First, 80 mg of α-MnO2 powder with a particle size of 15 nm and 8 mg of platinum nanopowder with a particle size of 15 nm were added to 100 ml of N,N-dimethylformamide (DMF) solution containing 12 wt% of polyacrylonitrile with a weight average molecular weight of 100,000, and after being fully stirred and uniformly dispersed, PAN nanofibers were obtained by electrospinning at a receiving distance of 18 cm, a liquid supply speed of 1.8 mL / h, a collection roller speed of 250 rpm, a voltage of 17 kV, a temperature of 35°C, and a relative humidity of 20%, and then pre-oxidation was performed at a power of 450 W for 45 min, followed by carbonization microwave treatment at a power of 1000 W for 10 min, to obtain a catalytic carbon fiber membrane.

[0066] 2. Diatomite with a total mass concentration of 10 wt% and polyvinylpyrrolidone (PVP) with a weight average molecular weight of 1.4 million were added to 100 ml of ethanol according to an equal mass ratio, and after being fully stirred, PVP nanofibers were obtained by electrospinning at a receiving distance of 13 cm, a liquid supply speed of 1.0 mL / h, a collection roller speed of 900 rpm, a voltage of 17 kV, a temperature of 25°C, and a relative humidity of 20%, and then SiO2 fiber interwoven porous membranes were obtained by sintering at 1100°C.

[0067] 3. The catalytic carbon fiber membrane and the SiO2 fiber interwoven porous membrane were edge-coated with Aremco 645 inorganic high-temperature glue, and then hot-pressed at 450°C, a pressure of 1.0 MPa, and a pressure holding time of 1.5 h to obtain a composite membrane.

[0068] ​The outer layer and inner layer of the cotton mask are arranged according to... Figure 1 After the mask structure is sewn together, insert the membranes prepared in Examples 1-3 and Comparative Examples 1-3 between the outer and inner layers of the mask, and seal them with Velcro to obtain the mask.

[0069] Test Example 1: Ozone Removal Efficiency Test

[0070] Methods: Mask samples from Examples 1-3 and Comparative Examples 1-3 were placed in a sealed chamber with a constant ozone concentration (initial ozone concentration 100 ppb, relative humidity 80±5%), and breathing was simulated at a flow rate of 30 L / min. The ozone concentration at the outlet was measured using an ozone analyzer (e.g., Thermo Scientific Model 49i), and the removal rate was calculated. The results are as follows: Figure 2 .

[0071] Depend on Figure 2 It can be seen that the ozone removal rates of the masks in Examples 1-3 all exceeded 90%, which is mainly due to their unique "sandwich" structure design. This structure consists of a catalytic carbon fiber membrane and a double-layer SiO2 fiber interwoven porous membrane. The catalytic carbon fiber membrane is loaded with α-MnO2 and nano-platinum / palladium catalyst, which can efficiently catalyze the decomposition of ozone into oxygen (2O3→3O2). The SiO2 porous membrane not only provides good air permeability, but also plays a moisture-proof role in protecting the catalyst from the influence of humidity. In contrast, Comparative Example 1, lacking a catalytic carbon fiber membrane, relies solely on the physical adsorption of the SiO2 membrane, resulting in a removal rate of less than 10%. Comparative Example 2, although containing a catalytic membrane, lacks the protection of the SiO2 membrane, and its removal rate drops to about 60% in an 80% humidity environment, with poor stability. Comparative Example 3, using a non-sandwich structure, has a removal rate of about 70%, showing the limitations of a single-layer protection structure.

[0072] Test Example 2: Free Radical Scavenging Ability Test

[0073] Methods: A Fenton reaction solution was nebulized and dried to a relative humidity of 80±5%. Simulated breathing was performed at a flow rate of 30 L / min. The concentration of hydroxyl radicals (·OH) before and after passing through the masks of Examples 1-3 and Comparative Examples 1-3 was measured using electron paramagnetic resonance (EPR). The hydroxyl radical scavenging rate was calculated. The results are as follows: Figure 3 .

[0074] Depend on Figure 3As can be seen, Examples 1-3 exhibit excellent free radical scavenging performance, with scavenging rates all exceeding 85%. This superior performance is mainly attributed to two key designs: first, the highly efficient catalytic effect of the nano-platinum / palladium catalyst in the catalytic carbon fiber membrane, which can directly decompose free radicals such as ·OH; and second, the multi-layer synergistic protection of the "sandwich" structure, in which the SiO2 fiber interwoven porous membrane effectively blocks particulate matter and provides a stable working environment for the carbon fiber membrane. In contrast, Comparative Example 1, lacking any catalytic component, had a scavenging rate of less than 20%; Comparative Example 2, although containing catalytic materials, lacked the protection of the SiO2 membrane, resulting in a scavenging rate of less than 50%; and Comparative Example 3, lacking a complete sandwich structure and with loose interlayer bonding, achieved a scavenging effect of only about 50%. These comparative data fully demonstrate the importance of the synergistic effect of the nano-noble metal catalyst and the multi-layer membrane structure in this invention, as well as its significant technical advantages in scavenging various air free radicals.

[0075] Test Example 3: Microwave Regeneration Performance Test

[0076] Method: After 8 hours of use, the regenerated ozone / free radical scavenging membrane of the mask sample was removed, microwaved at 500W for 10 minutes, and then reassembled for reuse. This process was repeated 20, 40, and 60 times to test the ozone removal rate. The results are as follows: Figure 4 As shown.

[0077] like Figure 4 As shown, after 60 regeneration cycles, the ozone removal rate of Examples 1-3 still remained above 90% of the initial performance, demonstrating excellent regeneration stability. This superior performance stems from two key technical features: First, microwave irradiation (500W, 10min) effectively removes pollutants adsorbed on the carbon fiber membrane surface, rapidly restoring catalytic activity; second, the outer SiO2 fiber interwoven porous membrane plays a crucial protective role during the regeneration process, maintaining membrane structural integrity and preventing catalyst sintering deactivation during high-temperature regeneration. There are currently no reports of regeneration activity and function in conventional commercial masks. This experimental result not only verifies the feasibility of the "microwave regeneration technology" of this invention but also highlights its significant advantages in practical applications: functional regeneration can be achieved through simple microwave treatment, avoiding the complex processes of traditional chemical cleaning or high-temperature calcination, extending the product's lifespan to over 480 hours, and greatly improving the product's economic and environmental benefits.

[0078] This invention provides a renewable ozone / free radical scavenging membrane, its preparation method, and its application in face masks. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A method for preparing a renewable ozone / free radical scavenging membrane, characterized in that, Includes the following steps: S1. Add α-MnO2 powder and nano-noble metal catalyst to N,N-dimethylformamide solution of polyacrylonitrile, stir and disperse evenly, then electrospin to obtain PAN nanofibers, and then treat with microwave to obtain catalytic carbon fiber membrane. S2. Electrospinning an ethanol solution containing diatomaceous earth and polyvinylpyrrolidone to obtain PVP nanofibers, and then sintering at 1000-1200℃ to obtain a SiO2 fiber interwoven porous membrane. S3. The catalytic carbon fiber membrane is sandwiched between two layers of SiO2 fiber interwoven porous membrane, and the edges are hot-pressed together to obtain the renewable ozone / free radical scavenging membrane.

2. The preparation method according to claim 1, characterized in that, In step S1, the amounts of α-MnO2 powder and nano-noble metal catalyst added to the N,N-dimethylformamide solution of polyacrylonitrile are 600-1000 mg / L and 60-100 mg / L, respectively.

3. The preparation method according to claim 1, characterized in that, In step S1, the nano-precious metal catalyst is nano-platinum powder or nano-palladium powder.

4. The preparation method according to claim 1, characterized in that, In step S1, the N,N-dimethylformamide solution of polyacrylonitrile has a weight-average molecular weight of 50,000 to 200,000 and a concentration of 10 to 15 wt%.

5. The preparation method according to claim 1, characterized in that, In step S1, the electrospinning conditions are as follows: receiving distance 15-20cm, liquid supply rate 1.6-2mL / h, collecting roller speed 200-300 rpm, voltage 15-20kV, temperature 30-40℃, and relative humidity 10-40%.

6. The preparation method according to claim 1, characterized in that, In step S1, the microwave treatment process is as follows: pre-oxidation power 300-600W, processing time 30-60min; carbonization power 800-1200W, processing time 5-15min.

7. The preparation method according to claim 1, characterized in that, In step S2, the total mass concentration of diatomaceous earth and polyvinylpyrrolidone in the ethanol solution containing diatomaceous earth and polyvinylpyrrolidone is 8-12 wt%.

8. The preparation method according to claim 1, characterized in that, In step S2, the electrospinning conditions are as follows: receiving distance 12-15cm, liquid supply rate 0.8-1.2mL / h, collecting roller speed 800-1000 rpm, voltage 15-20kV, temperature 23-27℃, and relative humidity 10-40%.

9. A renewable ozone / free radical scavenging membrane, characterized in that, The renewable ozone / free radical scavenging membrane It is prepared according to any one of claims 1-8.

10. The application of the renewable ozone / free radical scavenging membrane as described in claim 9 in the preparation of face masks.

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