A preparation method of filter membrane for mask and mask

Abstract

The present application relates to the field of film preparation, and specifically discloses a method for preparing a filter membrane for a mask and a mask; a method for preparing a filter membrane for a mask, comprising the following steps: weighing melamine and urea in a mass ratio of 2.5-3.5:1, grinding and treating to obtain a mixture; calcining the mixture at 540-580°C for 3-5 hours, and cooling to obtain a finished product; a mask comprising an outer layer, a filter layer and an inner layer; the outer layer is made of a non-woven fabric treated with a hydrophobic and translucent liquid; the filter layer is made of a filter membrane loaded on the surface of the non-woven fabric; the inner layer is made of an adsorbent loaded on the surface of the non-woven fabric, the filter membrane is between the non-woven fabrics of the outer layer and the filter layer, and the adsorbent is between the filter layer and the inner layer of the non-woven fabric; the mask has good breathability and sterilization effects, thereby making the mask better in breathability and safer to wear.

Description

Technical Field

[0001] The present application relates to the field of film preparation, and more specifically, to a method for preparing a filter membrane for a mask and a mask. Background Art

[0002] A mask is a sanitary and epidemic prevention product that can block harmful gases, odors, droplets, viruses and other substances. It is generally made of gauze or paper.

[0003] Masks have a certain filtering effect on the air entering the lungs, making them the preferred item for preventing respiratory infectious diseases.

[0004] Existing masks generally have porous filters, which easily cause living bacteria to adhere to the surface of the mask, not only affecting the wearing safety, but also making it easy for living bacteria to be inhaled by the human body as the wearing time increases. For the elderly and children, the probability of viral infection increases, which aggravates the impact on their own health. If the filter layer of the mask is set with multiple layers, although the blocking rate of living bacteria can be improved, the breathability of the mask is affected, which can easily lead to breathing difficulties, especially for the elderly, children and people with poor cardiopulmonary function. Poor breathing can easily cause the body to suffer from hypoxia and shock.

[0005] Therefore, how to prepare a filter membrane for a mask so that it has both good breathability and sterilization effects, so that the mask has good breathability and is safer to wear, thereby ensuring the health of the wearer. Summary of the Invention

[0006] In order to prepare a filter membrane for a mask so that it has both good breathability and sterilization effects, so that the mask has good breathability and is safer to wear to ensure the health of the wearer, the present application provides a method for preparing a filter membrane for a mask and a mask.

[0007] In the first aspect, the present application provides a method for preparing a filter membrane for a mask, which adopts the following technical solution:

[0008] A method for preparing a filter membrane for a mask, comprising the following steps:

[0009] S1. Weigh melamine and urea in a mass ratio of 2.5-3.5:1, grind them, and prepare a mixture;

[0010] S2. The mixture is calcined at 540-580° C. for 3-5 hours with nitrogen as a protective gas during the calcination process, and then cooled to obtain a finished product.

[0011] By adopting the above technical solution, melamine and urea react to form a graphite phase carbon nitride film. When the film is applied to the mask, the electrons in the graphite phase carbon nitride film absorb the energy of photons and are excited from the ground state to the excited state, resulting in the separation of electron-hole pairs; and the graphite phase carbon nitride reacts with water and oxygen to form free radicals or free radical ions, which can further react with 3 O2 reacts to form reactive oxygen species, such as superoxide, hydrogen peroxide and hydroxyl radicals. This reaction mainly occurs on the bacterial cell membrane. Unsaturated phospholipid molecules can be oxidized by reactive oxygen to lipid peroxides, which damages the bacterial cell membrane, increases ion permeability, and interferes with normal cell metabolism, thereby achieving a bactericidal effect. At the same time, due to the electron spin diversity compatible with graphene phase carbon nitride, energy can be directly transferred to 3 O2 and form singlet oxygen ( 1 O2); highly reactive 1 O2 can cause serious oxidative damage to unsaturated lipids, polypeptides, enzymes, and genetic materials. Reactive oxygen can directly attack unsaturated double bonds or amide groups in organic compounds, generate new active groups, and stimulate chain decomposition reactions, thereby making the prepared graphite phase carbon nitride filter membrane have a better photocatalytic bactericidal effect.

[0012] Graphite phase carbon nitride film has the advantages of being lightweight and breathable. By utilizing its good breathability and bactericidal effects, the mask can be made more breathable and safer to wear, thereby ensuring the health of the wearer.

[0013] Preferably, the particle size of melamine and urea after the grinding treatment is 800-2000 mesh.

[0014] By adopting the above technical solution, the grinding particle size is limited, so that melamine and urea are evenly mixed and their rapid reaction is guaranteed, thereby promoting the formation of the filter membrane and improving the photocatalytic sterilization effect.

[0015] In the second aspect, the present application provides a mask, which adopts the following technical solution:

[0016] A mask comprises a mask fabric and two ear hooks, wherein the mask fabric comprises an outer layer, a filter layer and an inner layer; the outer layer is made of a non-woven fabric treated with a hydrophobic and light-transmitting liquid; the filter layer is made of a filter membrane loaded on the surface of the non-woven fabric; the inner layer is made of an adsorbent loaded on the surface of the non-woven fabric, the filter membrane is between the non-woven fabrics of the outer layer and the filter layer, and the adsorbent is between the filter layer and the inner non-woven fabric.

[0017] By adopting the above technical solution, the non-woven fabric is treated with a hydrophobic and translucent liquid, so that the outer layer has a good light transmittance, which facilitates the passage of light while having good hydrophobicity; the filter membrane is arranged between the non-woven fabrics of the outer layer and the filter layer, and the moisture penetration effect of the inner layer of the non-woven fabric is combined with the light transmission effect of the outer layer to facilitate the reaction of moisture and oxygen on the filter membrane on the filter layer, thereby killing the bacteria between the outer layer and the filter layer; and the adsorbent of the inner layer can further adsorb the living bacteria that penetrate the filter layer, and can also adsorb the dead bacteria, so as to avoid the living bacteria and the dead bacteria from passing through the inner layer of the non-woven fabric and being inhaled into the lungs, affecting people's health.

[0018] Preferably, the hydrophobic light-transmitting liquid is composed of hydroxy silicone oil, catalyst, modified PMMA microspheres and natural mica in a mass ratio of 1:0.1-0.2:0.05-0.15:0.05-0.15.

[0019] By adopting the above technical solution, hydroxy silicone oil, catalyst, modified PMMA microspheres and natural mica are combined, and the modified PMMA microspheres and natural mica are used as the supporting skeleton. The hydroxy silicone oil and the catalyst are combined to form a three-dimensional network structure. The hydrophobic effect of the hydroxy silicone oil is utilized to make the network structure hydrophobic, thereby improving the hydrophobicity of the outer non-woven fabric and making the outer layer have a better waterproof effect.

[0020] Hydroxy silicone oil, catalyst, modified PMMA microspheres and natural mica are combined to utilize the good light transmittance of modified PMMA microspheres and natural mica to facilitate light to reach the surface of the filter membrane. Combined with moisture and oxygen, it further promotes the sterilization reaction of the filter membrane, making the mask have a better sterilization effect. After the mask is made, it is guaranteed to have good breathability and good sterilization effect to ensure the health of the wearer.

[0021] Preferably, the modified PMMA microspheres are prepared by modifying PMMA microspheres with a polyvinyl alcohol solution.

[0022] By adopting the above technical solution, after the PMMA microspheres are modified with polyvinyl alcohol, hydroxyl groups are loaded on the surface of the PMMA microspheres. Hydroxyl silicone oil is used in combination with the hydroxyl groups on the surface of the modified PMMA microspheres. This not only improves the dispersion stability of the PMMA microspheres in the hydrophobic and translucent liquid, but also further promotes the formation of a three-dimensional cross-linked network, ensuring the breathability of the outer layer while improving the waterproofness of the outer layer. At the same time, it facilitates light to pass through the outer layer to reach the surface of the filter membrane for a photocatalytic reaction, thereby ensuring that the filter membrane kills bacteria, thereby ensuring that the manufactured mask has high safety. Even if worn for a long time or in an environment with a lot of bacteria, it is not easy to inhale too many bacteria and affect your health.

[0023] Preferably, the adsorbent is prepared by treating bamboo fiber with a chitosan solution.

[0024] By adopting the above technical solution, bamboo fiber and chitosan are combined, and chitosan is loaded on bamboo fiber. When the mask is made, the inner layer contacts the face, and the exhaled water vapor is easily guided by the bamboo fiber and chitosan to pass through the inner layer of non-woven fabric to reach the filter membrane of the filter layer, thereby ensuring the photocatalytic reaction on the filter layer and making the filter layer have a better sterilization effect.

[0025] Bamboo fiber, chitosan and filter layer work together to kill bacteria on the surface of the filter layer through the photocatalytic reaction of the filter layer. The bacteria that pass through the filter layer can be adsorbed and killed by bamboo fiber and chitosan. The bamboo fiber attracts bacteria and the chitosan produces a mucous membrane adsorption effect on bacteria to further kill the living bacteria that pass through the filter layer. At the same time, the dead bacteria that pass through the filter layer can also be adsorbed and treated, so as to avoid the living bacteria and dead bacteria from being inhaled by the human body through the inner layer of non-woven fabric, thereby ensuring human health.

[0026] Preferably, the outer layer and the filter layer are edge-bonded using EVA melt.

[0027] By adopting the above technical solution, the edges of the hot melt adhesive mesh are bonded, so that the mask can maintain breathability and light transmission at the breathing position, and is not easily blocked by the hot melt adhesive. The edge bonding of the hot melt adhesive mesh can also prevent external bacteria from entering the surface of the filter layer, thereby reducing the number of bacteria.

[0028] Preferably, the filter membrane and the non-woven fabric in the filter layer are bonded together using a carboxymethyl chitosan solution, and the non-woven fabric and the adsorbent in the inner layer are bonded together using a carboxymethyl chitosan solution.

[0029] By adopting the above technical solution, the bonding effect of the carboxymethyl chitosan solution is utilized to facilitate bonding the filter membrane to the surface of the non-woven fabric, while ensuring water permeability, so that the filter membrane can undergo a photocatalytic reaction to sterilize; and it is also convenient for the non-woven fabric to be bonded to the adsorbent, utilizing the inhibitory and adsorption effects of carboxymethyl chitosan on bacteria, further preventing bacteria from being inhaled by the human body, thereby ensuring human health.

[0030] Preferably, an adhesive liquid is sprayed between the filter layer and the inner layer to form an adhesion layer, and 20-50 g of the adhesive liquid is sprayed per square meter of the filter layer surface.

[0031] By adopting the above technical solution, the adhesive liquid can bond the filter layer and the inner layer, limit the spraying amount of the adhesive liquid, ensure the penetration of water molecules, and thus ensure the progress of the photocatalytic reaction, so that the mask has better bactericidal and antibacterial effects, and can prevent bacteria from entering the human body and affecting human health as much as possible.

[0032] Preferably, the adhesive solution is composed of sodium alginate solution and chitosan fiber filaments in a mass ratio of 1:0.1-0.4.

[0033] By adopting the above technical solution, sodium alginate solution and chitosan fiber filaments are matched, and the skeleton of chitosan fiber filaments is used to make the adhesive liquid form a water-permeable and breathable network structure to facilitate the penetration and transfer of water.

[0034] Sodium alginate solution, chitosan fiber filaments, and adsorbent are matched with each other, and the bonding effect of sodium alginate solution is utilized to facilitate the adhesion of the filter layer and the inner layer. The carboxyl group in sodium alginate is combined with the hydroxyl group of bamboo fiber and the amino group of chitosan in the adsorbent, as well as the viscosity of sodium alginate solution and the adsorption property of bamboo fiber. The nearby adhesive liquid is further stably attached to the surface of the adsorbent. The water vapor exhaled by the person first reaches the surface of the non-woven fabric, and then is transferred to the network structure formed by the chitosan fiber filaments and the sodium alginate solution under the drainage effect of the adsorbent. Finally, the water reaches the surface of the filter membrane of the filter layer, ensuring the progress of the photocatalytic reaction, thereby ensuring the sterilization effect of the filter membrane on the mask.

[0035] Sodium alginate solution, chitosan fiber filaments and adsorbents are combined to divert moisture while attracting bacteria to attach to the surface of chitosan fiber filaments and adsorbents, so as to prevent dead bacteria and living bacteria from passing through the inner layer into the human body and affecting human health; even when wearing a mask in an environment with a lot of bacteria, it is not easy to inhale bacteria, thus having higher safety.

[0036] In summary, this application has the following beneficial effects:

[0037] 1. Melamine and urea react to form a graphite carbon nitride film. The graphite carbon nitride reacts with water and oxygen under light, causing the bacterial cell membrane to be destroyed, increasing ion permeability, and interfering with normal cell metabolism, thereby achieving a bactericidal effect.

[0038] 2. The outer layer, filter layer and inner layer are coordinated. The outer non-woven fabric is treated with a hydrophobic and translucent liquid, so that the outer layer has good light transmittance and waterproof properties under the condition of breathability, ensuring that light and oxygen can reach the surface of the graphite carbon nitride film on the filter layer, and water is easily guided by the inner non-woven fabric to reach the surface of the graphite carbon nitride film on the filter layer, realizing a photocatalytic reaction and ensuring a sterilization effect. At the same time, the adsorbent in the inner layer can adsorb bacteria and bacterial corpses to avoid bacteria from being inhaled into the human body and affecting human health.

[0039] 3. Hydroxy silicone oil, catalyst, modified PMMA microspheres and natural mica are combined, with modified PMMA microspheres and natural mica as the supporting skeleton, combined with hydroxy silicone oil and catalyst to form a three-dimensional network structure, and the hydrophobic effect of hydroxy silicone oil is utilized to make the network structure hydrophobic, thereby improving the hydrophobicity of the outer layer of non-woven fabric, making the outer layer have better waterproof effect; and it has a better bactericidal effect.

[0040] 4. The outer layer is a layer of non-woven fabric, the filter layer is a non-woven fabric and a filter membrane, and the inner layer is a non-woven fabric and an absorbent material. While ensuring the breathable effect, the mask has a better sterilization effect and improves the safety of the mask.

[0041] 5. The combination of carboxymethyl chitosan and adhesive liquid further promotes the formation of a network structure, thereby facilitating the exhaled water to reach the surface of the filter membrane. At the same time, it also has a certain antibacterial and bactericidal effect, and has higher safety when preparing masks. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 : This is a plate count chart showing that the graphite phase carbon nitride film of the present application kills Escherichia coli;

[0043] Figure 2 : This is the result diagram of the sacrificial agent quenching experiment of this application. DETAILED DESCRIPTION

[0044] The present application is further described in detail below with reference to the embodiments.

[0045] All the following raw materials used are sterile raw materials.

[0046] Preparation example of hydrophobic transparent liquid

[0047] The polyvinyl alcohol in the following raw materials is polyvinyl alcohol PVA1788 produced by Jinan Jinniu Chemical Co., Ltd.; other raw materials and equipment are commonly available on the market.

[0048] Preparation Example 1: A hydrophobic light-transmitting liquid was prepared by the following method:

[0049] Weighing PMMA microspheres, placing them in a polyvinyl alcohol solution, dispersing and stirring them, and mixing them evenly to obtain modified PMMA microspheres; the PMMA microspheres have a particle size of 5 μm; and the polyvinyl alcohol solution is a polyvinyl alcohol aqueous solution with a mass fraction of 5%;

[0050] 1 kg of hydroxy silicone oil, 0.15 kg of catalyst, 0.1 kg of modified PMMA microspheres and 0.1 kg of natural mica were weighed and mixed evenly to prepare a hydrophobic and translucent liquid; the catalyst was an organic tin metal catalyst; and the natural mica was a transparent natural mica sheet with a particle size of 10 μm.

[0051] Preparation Example 2: This preparation example differs from Preparation Example 1 in that:

[0052] 1 kg of hydroxy silicone oil, 0.1 kg of catalyst, 0.05 kg of modified PMMA microspheres and 0.05 kg of natural mica were weighed and mixed and stirred uniformly to prepare a hydrophobic and light-transmitting liquid.

[0053] Preparation Example 3: This preparation example differs from Preparation Example 1 in that:

[0054] 1 kg of hydroxy silicone oil, 0.2 kg of catalyst, 0.15 kg of modified PMMA microspheres and 0.15 kg of natural mica were weighed and mixed and stirred uniformly to prepare a hydrophobic and light-transmitting liquid.

[0055] Preparation example of adsorbent

[0056] Preparation Example 4: The adsorbent is prepared by the following method:

[0057] Weigh chitosan, place it in dilute acetic acid, stir and dissolve it, and prepare a chitosan solution with a mass fraction of 3%; the chitosan deacetylation degree is 85%; the dilute acetic acid is a dilute acetic acid aqueous solution with a mass fraction of 5%;

[0058] 1 kg of bamboo fiber was weighed and placed in 10 kg of chitosan solution, dispersed and stirred for 10 minutes, and then the bamboo fiber was filtered out and dried to obtain an adsorbent; the length of the bamboo fiber was 2 mm.

[0059] Preparation example of adhesive solution

[0060] Preparation Example 5: The adhesive liquid is prepared by the following method:

[0061] Weigh sodium alginate, place it in water, and stir to dissolve it to prepare a 1% sodium alginate aqueous solution;

[0062] 0.3 kg of chitosan fiber filaments were added to 1 kg of sodium alginate aqueous solution, dispersed, and evenly mixed to prepare an adhesive solution; the length of the chitosan fiber filaments was 0.5 mm.

[0063] Preparation Example 6: This preparation example differs from Preparation Example 5 in that:

[0064] 0.1 kg of chitosan fiber was added to 1 kg of sodium alginate aqueous solution, dispersed, and mixed uniformly to prepare a bonding liquid.

[0065] Preparation Example 7: This preparation example differs from Preparation Example 5 in that:

[0066] 0.4 kg of chitosan fiber was added to 1 kg of sodium alginate aqueous solution, dispersed, and mixed uniformly to prepare a bonding liquid.

[0067] Example

[0068] Example 1: A method for preparing a filter membrane for a mask:

[0069] Weigh 75 mg of melamine and 25 mg of urea, mix and stir evenly, and then grind them to a particle size of 1500 mesh to prepare a mixture;

[0070] S2. The mixture was evenly placed in a 100 mL ceramic crucible, and then the cleaned smeared glass was covered on the top of the ceramic crucible. Finally, the entire device was sealed with aluminum foil. Then, it was placed in a tube furnace and calcined at 550 ° C for 4 h. Nitrogen was used as the protective gas during the calcination process. After the calcination was completed, it was naturally cooled to room temperature to obtain a graphite phase carbon nitride film on the glass substrate. 100 mg of the raw material can produce a 96.25 cm 2 Graphitic carbon nitride film.

[0071] Example 2: This example differs from Example 1 in that:

[0072] Weigh 75 mg of melamine and 30 mg of urea, mix and stir evenly, and then grind to a particle size of 800 mesh to prepare a mixture;

[0073] S2. Place the mixture evenly in a 100mL ceramic crucible, then cover the top of the ceramic crucible with cleaned smeared glass, and finally seal the entire device with aluminum foil; then place it in a tube furnace and calcine it at 540℃ for 5h. Nitrogen is used as the protective gas during the calcination process. After calcination, it is naturally cooled to room temperature to obtain a graphite phase carbon nitride film on the glass substrate.

[0074] Example 3: This example differs from Example 1 in that:

[0075] Weigh 84 mg of melamine and 24 mg of urea, mix and stir evenly, and then grind them to a particle size of 2000 mesh to prepare a mixture;

[0076] S2. Place the mixture evenly in a 100mL ceramic crucible, then cover the top of the ceramic crucible with cleaned smeared glass, and finally seal the entire device with aluminum foil; then place it in a tubular furnace and calcine it at 580℃ for 3h. Nitrogen is used as the protective gas during the calcination process. After calcination, it is naturally cooled to room temperature to obtain a graphite phase carbon nitride film on the glass substrate.

[0077] Application Examples

[0078] Application example 1: A mask:

[0079] Contains mask fabric and two ear hooks. The mask fabric includes an outer layer, a filter layer and an inner layer.

[0080] The preparation method is as follows:

[0081] The nonwoven fabric was immersed in the hydrophobic light-transmitting liquid prepared in Preparation Example 1 and stirred for 20 minutes, and then the nonwoven fabric was taken out to drain the surface liquid and dried to obtain the outer layer;

[0082] A carboxymethyl chitosan solution was evenly sprayed on one surface of the non-woven fabric, and then covered with the graphite phase carbon nitride film prepared in Example 1, with 20 g of carboxymethyl chitosan solution per square meter of the non-woven fabric surface. After drying, a filter layer was prepared; the carboxymethyl chitosan solution was a 1% by mass carboxymethyl chitosan aqueous solution;

[0083] The carboxymethyl chitosan solution was evenly sprayed on the surface of the non-woven fabric, 40 g of the carboxymethyl chitosan solution was sprayed on each square meter of the filter layer surface, and then the adsorbent prepared in Preparation Example 4 was evenly sprayed to prepare the inner layer; the carboxymethyl chitosan solution was a 1% by mass carboxymethyl chitosan aqueous solution;

[0084] The outer layer is evenly sprayed with EVA melt near the edge, and then covered with a filter layer. The filter membrane of the filter layer is located between the non-woven fabric of the filter layer and the outer layer. After cooling and solidification, a composite layer is obtained. The EVA melt is obtained by heating EVA particles to 100°C and completely melting them. After the EVA melt is dried, an EVA layer is formed. The EVA layer is 1mm away from the edge of the non-woven fabric on all sides, and the width of the EVA layer is 0.3mm.

[0085] The adhesive liquid prepared in Example 5 was evenly sprayed on one side of the outer layer of the filter layer principle, 40 g of the adhesive liquid was sprayed per square meter of the filter layer surface, and then the inner layer was covered and dried to obtain a mask fabric;

[0086] The mask fabric is heat-pressed at the edge and two ear hooks are heat-pressed at both ends of the mask fabric. After aseptic treatment and packaging, a finished mask is obtained.

[0087] Application Example 2: This application example differs from Application Example 1 in that:

[0088] During the preparation process:

[0089] The nonwoven fabric was immersed in the hydrophobic and light-transmitting liquid prepared in Preparation Example 2 and stirred for 20 minutes, and then the nonwoven fabric was taken out to drain the surface liquid and dried to obtain the outer layer;

[0090] The filter membrane is the graphite phase carbon nitride membrane prepared in Example 2;

[0091] The adhesive liquid prepared in Preparation Example 5 was evenly sprayed on one side of the outer layer of the filter layer principle, 20 g of the adhesive liquid was sprayed per square meter of the filter layer surface, and then the inner layer was covered. After drying, a finished mask was obtained.

[0092] Application Example 3: This application example differs from Application Example 1 in that:

[0093] During the preparation process:

[0094] The nonwoven fabric was immersed in the hydrophobic light-transmitting liquid prepared in Preparation Example 3 and stirred for 20 minutes, and then the nonwoven fabric was taken out to drain the surface liquid and dried to obtain the outer layer;

[0095] The filter membrane is the graphite carbon nitride membrane prepared in Example 3;

[0096] The adhesive liquid prepared in Preparation Example 5 was evenly sprayed on one side of the outer layer of the filter layer principle, 50 g of the adhesive liquid was sprayed per square meter of the filter layer surface, and then the inner layer was covered. After drying, a finished mask was obtained.

[0097] Application Example 4: This application example differs from Application Example 1 in that:

[0098] No modified PMMA microspheres and natural mica were added to the hydrophobic translucent liquid.

[0099] Application Example 5: This application example differs from Application Example 1 in that:

[0100] The modified PMMA microspheres were replaced by PMMA microspheres of equal mass in the hydrophobic transparent liquid.

[0101] Application Example 6: This application example differs from Application Example 1 in that:

[0102] The absorbent material is bamboo fiber.

[0103] Application Example 7: This application example differs from Application Example 1 in that:

[0104] No chitosan fibers were added to the adhesive solution.

[0105] Comparative Example

[0106] Comparative Application Example 1: The difference between this comparative application example and application example 1 is:

[0107] The surface of the filter layer uses activated carbon to replace the graphite phase carbon nitride film, and the activated carbon particle size is 40 mesh.

[0108] Comparative Application Example 2: The difference between this comparative application example and application example 1 is:

[0109] There is no hydrophobic light-transmitting liquid on the surface of the outer non-woven fabric.

[0110] Comparative Application Example 3: The difference between this comparative application example and application example 1 is:

[0111] The adsorbent material on the surface of the inner non-woven fabric is replaced with an equal mass of silica.

[0112] Performance testing

[0113] 1. Sterilization performance test

[0114] The finished graphite carbon nitride filter membranes were prepared by the preparation method of Example 1. The inactivation rate of E. coli was used as the index: E. coli was cultured in liquid culture medium for 20 hours and collected by centrifugation at 8000 rpm (5 min). 4 (CFU)mL -1 ) Add 12cm 2 A g-C3N4 film (graphitic carbon nitride film) was placed in a reactor. A 300W xenon lamp with a 420nm cutoff filter (Celi-HXF300, China Communications Jinyuan Technology Co., Ltd.) was used as the visible light source. A circulating cooling water bath was used to stabilize the system temperature (25°C). Each batch of experiments lasted 4 hours, with samples taken every hour. All collected samples were redispersed in phosphate buffer and then spread onto agar plates using a spreading rod. After incubation at 37°C for 20 hours, the number of viable cells was determined by plate count. All glassware and photocatalysts used in the experiments were autoclaved at 121°C for 30 minutes before use, and all experiments were performed under sterile conditions.

[0115] The photocatalytic disinfection performance of the g-C3N4 film can be visually observed by counting colonies on agar plates. Equal amounts of the reaction solution were taken at 0, 2, and 4 hours of illumination, further diluted, and then spread on nutrient agar plates.

[0116] refer to Figure 1 As shown, the graphite phase carbon nitride filter membrane has good bactericidal performance under the cooperation of visible light; most of the E. coli were inactivated within 2 hours, and almost completely inactivated after 4 hours (the sterilization rate reached 99.99%).

[0117] 2. Sterilization mechanism detection

[0118] The finished graphite carbon nitride filter membranes were prepared by the preparation method of Example 1; different active species were selectively removed by using selective scavengers. Histidine (0.5 mM) was used to remove singlet oxygen ( 1 O2), hydrogen peroxide (H2O2) was eliminated with catalase (200 U / mL), and photogenerated holes (h + ), isopropanol (2.5 mM) was used to eliminate hydroxyl radicals (·OH), and chromium (VI) (2 mM) was used to eliminate photogenerated electrons (e - ), and tetramethylpiperidine (TEMPOL) (1 mM) was used to scavenge superoxide radicals (·O 2 The disinfection performance was tested using a cell density quantification method. The experiment was repeated three times for each condition.

[0119] See also Figure 2It can be seen that the effect of adding histidine on the disinfection effect is negligible. The addition of catalase significantly reduced the efficiency of photocatalytic disinfection, indicating that H2O2 plays an important role in the inactivation of bacteria. The valence band position of g-C3N4 is more negative than the redox potential of ·OH / OH-, so it is difficult for OH- to be oxidized to produce ·OH. Therefore, ·OH plays a very small role in photocatalytic disinfection. ·O 2- and e - It is also the key active substance in the photocatalytic disinfection process. The addition of tetramethylpiperidine significantly reduces the photocatalytic efficiency. 2- ) is an active intermediate in the production of H2O2. 2- The more, the more H2O2 is produced. Based on these results, we can determine that the disinfection mechanism occurs through the production of superoxide and water peroxide.

[0120] 3. Contact angle detection

[0121] Masks were prepared using the preparation methods of Application Examples 1-3 and Comparative Application Example 2 respectively; the contact angle of the outer layer was detected with reference to GB / T30693-2014, and the data was recorded.

[0122] 4. Light transmittance detection

[0123] Masks were prepared using the preparation methods of Application Examples 1-3 and Comparative Application Example 2 respectively; the light transmittance of the outer layer was tested and the data was recorded.

[0124] 5. Water vapor transmission rate test: Masks were prepared using the preparation methods of Application Examples 1-3 and Comparative Application Example 3, and the water vapor transmission rate of the inner layer was tested and the data was recorded.

[0125] 6. Bacteria penetration detection

[0126] Finished masks were prepared using the preparation methods of Application Examples 1-7 and Comparative Application Examples 1-3, respectively. A hole was opened in a sealed glass box and the mask was fitted into the hole. Escherichia coli, Staphylococcus aureus, etc. were added to the glass box. A 300W xenon lamp was placed in the glass box. Water vapor was sprayed on one side of the inner layer of the mask to simulate human exhaled gas. After 4 hours, the number of bacteria on the side of the inner layer away from the outer layer was detected and the data was recorded. Note: Except for the change in the mask sample, the other conditions were the same.

[0127] Table 1: Performance test table

[0128]

[0129]

[0130] From Application Examples 1-3 and Table 1, it can be seen that the mask prepared in the present application is not only waterproof, but also has a certain degree of light transmittance, and the inner layer has good moisture permeability, which can allow light and moisture to reach the graphite phase carbon nitride filter membrane of the filter layer, ensuring the progress of the photocatalytic reaction, thereby ensuring the sterilization effect of the mask; and after wearing the mask for a long time, it is not easy for bacteria to pass through the inner layer of the mask and be inhaled by the human body, so that the mask has the advantage of high safety.

[0131] Combining Application Example 1 and Application Examples 4-7 and Table 1, it can be seen that modified PMMA microspheres and natural mica were not added to the hydrophobic and translucent liquid in Application Example 4, and modified PMMA microspheres of equal mass were used to replace modified PMMA microspheres in the hydrophobic and translucent liquid in Application Example 5. Compared with Application Example 1, the number of bacteria in Application Examples 4 and 5 was higher than that in Application Example 1; this shows that the combination of hydroxyl silicone oil, modified PMMA microspheres and natural mica can block bacteria while ensuring waterproof effect and light transmittance.

[0132] The adsorbent material of Application Example 6 is bamboo fiber. Compared with Application Example 1, the number of bacteria in Application Example 6 is greater than that in Application Example 1; this shows that bamboo fiber and chitosan are combined, and the attraction effect of bamboo fiber and the adsorption and bonding effect of chitosan are used to further bind the bacteria, thus preventing the bacteria from penetrating the inner layer and being inhaled by the human body.

[0133] The adhesive liquid of Application Example 7 did not contain chitosan fibers. Compared with Application Example 1, the number of bacteria in Application Example 7 was greater than that in Application Example 1. This indicates that the combination of sodium alginate solution and chitosan fibers can further prevent living bacteria, bacterial corpses, etc. from penetrating the filter layer and the inner layer, thereby minimizing the inhalation of bacteria by the human body.

[0134] Combining Application Example 1 and Comparative Application Examples 1-3 and Table 1, it can be seen that the surface of the filter layer of Comparative Application Example 1 is loaded with activated carbon instead of the graphite phase carbon nitride film. Compared with Application Example 1, the number of bacteria in Comparative Application Example 1 is greater than that in Application Example 1; this shows that the bactericidal effect and barrier effect of activated carbon with larger particle size on bacteria are worse than those of graphite phase carbon nitride film, that is, graphite phase carbon nitride ink can further improve the killing and barrier effect of bacteria, thereby improving the safety of the mask.

[0135] In comparative application example 2, there is no hydrophobic and translucent liquid on the surface of the outer non-woven fabric. Compared with application example 1, the contact angle of comparative application example 2 is smaller than that of application example 1, the transmittance is slightly higher than that of application example 1, and the number of bacteria is greater than that of application example 1; this indicates that the non-woven fabric without hydrophobic treatment has no network structure on the surface of the non-woven fabric, which is not only unable to repel water, but also unable to block bacteria, thereby affecting the use of the finished mask.

[0136] In comparative application example 3, the adsorbent material is replaced with silica of equal mass on the surface of the inner layer of the non-woven fabric. Compared with application example 1, the water vapor permeability of comparative application example 3 is lower than that of application example 1, and the number of bacteria is greater than that of application example 1; this indicates that silica not only cannot adsorb bacteria, but also easily blocks the flow of water vapor, resulting in affected moisture permeability, thereby affecting the killing and barrier effects of the graphite phase carbon nitride film on bacteria.

[0137] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A mask, characterized in that: It includes mask fabric and two ear hooks. The mask fabric includes an outer layer, a filter layer and an inner layer. The outer layer is made of non-woven fabric treated with a hydrophobic and light-transmitting liquid. The filter layer is made of a filter membrane loaded on the surface of the non-woven fabric. The inner layer is made of an adsorbent loaded on the surface of the non-woven fabric. The filter membrane is between the non-woven fabrics of the outer layer and the filter layer, and the adsorbent is between the filter layer and the inner non-woven fabric. The hydrophobic light-transmitting liquid is composed of hydroxy silicone oil, a catalyst, modified PMMA microspheres and natural mica in a mass ratio of 1:0.1-0.2:0.05-0.15:0.05-0.15; the modified PMMA microspheres are prepared by modifying PMMA microspheres with a polyvinyl alcohol solution; The steps for preparing the filter membrane are as follows: S1. Weigh melamine and urea in a mass ratio of 2.5-3.5:1, grind them, and prepare a mixture; S2. The mixture is calcined at 540-580° C. for 3-5 hours with nitrogen as a protective gas during the calcination process, and then cooled to obtain a finished product.

2. A mask according to claim 1, characterized in that: The particle size of the melamine and urea after the grinding treatment is 800-2000 meshes.

3. A mask according to claim 1, characterized in that, The adsorbent is prepared by treating bamboo fiber with chitosan solution.

4. A mask according to claim 1, characterized in that, The outer layer and the filter layer are bonded at their edges using EVA melt.

5. A mask according to claim 1, characterized in that, The filter membrane and the non-woven fabric in the filter layer are bonded together by using a carboxymethyl chitosan solution, and the non-woven fabric and the adsorbent in the inner layer are bonded together by using a carboxymethyl chitosan solution.

6. A mask according to claim 1, characterized in that, An adhesive liquid is sprayed between the filter layer and the inner layer to form an adhesion layer, and 20-50 g of the adhesive liquid is sprayed per square meter of the filter layer surface.

7. A mask according to claim 6, characterized in that, The bonding liquid consists of a sodium alginate solution and chitosan fiber filaments in a mass ratio of 1:0.1-0.4.

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