Inorganic silicate zeolite material and virus filtering application thereof

Abstract

The invention discloses an inorganic silicate zeolite material and a virus filtering application thereof. By adding the specific dispersing additive and carrying out ultrasonic treatment, aluminum atoms of the hydrogen type zeolite are uniformly distributed in a zeolite structure. Meanwhile, the pore size, the silica-alumina ratio and the particle size of the hydrogen-type zeolite are controlled by controlling the synthesis conditions of the hydrogen-type zeolite, so that the ion exchange capacity and the acid density of a zeolite framework are greatly improved. The regulated zeolite is high in hydrogen ion content after being subjected to ion exchange, so that the obtained hydrogen type zeolite has extremely strong surface acidity and can generate strong chemical action on viruses. The acidic site of the hydrogen zeolite and the basic group of the virus surface protein form a stable hydrogen bond, so that the virus can be rapidly anchored and rapidly inactivated, and the effect of inactivating the virus is achieved. The invention aims to solve the problems of low inactivation efficiency and poor biocompatibility of the existing antiviral material, particularly has an efficient inactivation effect on airborne viruses and the like, and has excellent biological safety.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of solid air adsorbent compositions and the preparation of air virus filtration, and particularly relates to an inorganic silicate zeolite material and its application in virus filtration. It aims to solve the problems of poor biocompatibility and low inactivation efficiency of existing antiviral materials, and has an efficient inactivation effect on airborne viruses, such as the novel coronavirus (SARS-CoV-2), etc., and has excellent biosafety. Background Art

[0002] Viral infections pose a major threat to human health and social development. Effective preventive measures are crucial for controlling the spread of viruses. Viruses can be transmitted through various routes, including airborne transmission (droplet transmission, aerosol transmission) and contact transmission, etc. Among them, airborne transmission is the most important route of virus transmission. Especially in closed or poorly ventilated environments, virus particles in the air can exist and spread for a long time through suspended aerosols. Therefore, controlling airborne transmission is of great significance for preventing viral infections.

[0003] Controlling airborne transmission can be achieved from the perspective of air filtration and purification. By adopting an efficient air filtration system, virus particles and other fine particles in the air can be effectively removed, thereby reducing the risk of virus transmission in the air. These filtration systems usually use HEPA filters (high-efficiency particulate air filters), which can capture particulate matter with a diameter less than 0.3 micrometers, including some virus particles. This physical filtration method can block the transmission of some viruses. However, it cannot inactivate the viruses, and the viruses trapped on the material can survive for up to 7 days, and are very likely to become a source of cross-infection, resulting in secondary virus transmission. Therefore, effectively inactivating viruses is a pain point problem in epidemic prevention.

[0004] Zeolite molecular sieve is an inorganic silicon-aluminate with a regular framework. Its chemical composition general formula is: (M) 2 / n O·xAl2O3·ySiO2·pH2O, where M represents a cation (such as H + 、K + 、Na + 、Ca 2+ 、Ba 2+etc.), n represents the valence of metal ions, x represents the number of moles of Al2O3, y represents the number of moles of SiO2, and p represents the number of moles of H2O. The zeolite mentioned above can be ZSM-5 zeolite, X-type zeolite, Y-type zeolite, A-type zeolite, chabazite, mordenite, L-type zeolite, P-type zeolite, gmelinite. The extra-framework balancing charge cations of the zeolite can be partially or completely replaced by other cations through ion exchange. Zeolite has a uniform microporous structure, and these micropores are close to the diameter of gas molecules, so it can physically adsorb relevant gas molecules. At the same time, physical adsorption can also occur between its large specific surface area and small solid particles. In the past, people used this physical effect to achieve the adsorption and purification of toxic gases and dust in the air. For example, Chinese Patent CN 102133521 A reported that after activating natural zeolite, it can be used to prepare various indoor purification products, which can adsorb air pollutants such as NH3, hydrogen sulfide, formaldehyde, benzene, and dust in the air. This method can only adsorb inorganic small molecules and dust particles, and cannot achieve the capture and killing of viruses, because it only uses a simple physical effect, and only when a chemical effect occurs between the material and the virus can the virus be killed.

[0005] People discovered the virus-killing effects of metal elements such as copper and silver very early and applied them to medical activities and daily life. Exchanging metals such as copper and silver into the zeolite structure, metal-based zeolite materials such as copper-based and silver-based can also kill viruses. These materials mainly utilize the chemical interaction between copper / silver and viruses. However, there are two major defects of metal elements such as copper and silver that limit their applications: one is the cytotoxicity problem: copper and silver ions have certain cytotoxicity. Cytotoxicity refers to the destruction of cell structure by chemical substances outside the cell, ultimately leading to apoptosis or necrosis of the cell. For example, Chinese Patent CN 111227345 A discloses an antibacterial and antiviral mask and its preparation method, and the core layer is an antibacterial and antiviral non-woven fabric obtained by blending silver-copper nano-zeolite and fibers. The mask prepared by this invention has a high antiviral activity rate against SARS, H1N1, H7N9, and H3N2, and a high antibacterial property against Escherichia coli and Staphylococcus aureus. The specification mentions that "copper ions are good at attacking the proteins / amino acids of the cell wall so that silver ions can easily invade the cell, and then jointly attack inside the cell", which shows that copper and silver ions will inevitably damage the cell structure during the antibacterial and antiviral process and have strong cytotoxicity; materials with high cytotoxicity will cause harm to the human body and are not suitable for application in real life. The other is the price problem. The prices of copper and silver are relatively high, which makes the cost of large-scale application of copper-based and silver-based zeolite materials unacceptable. In addition, the high material cost will also increase the production cost of the final product, reducing the market competitiveness of these products.

[0006] In Chinese Patent CN 111941953 B, the inventor developed a medical material with sufficiently low cytotoxicity and sufficiently high antibacterial and antiviral properties by laminating a copper-based zeolite fiber layer with a specific structure and a specific layer in a specific order, controlling the relative pore size of the outermost copper-based zeolite fiber layer and the first intermediate layer, and controlling the mass of the copper-based zeolite to be distributed in a gradient from the outside to the inside along the radial interface. The main active ingredient of this multi-layer copper-based zeolite fiber material is still copper element, and the source of its low cytotoxicity is to control the distribution of copper element on the fiber, so as to keep it away from the human skin. When the copper-based zeolite accidentally comes into contact with the human skin, toxicity may still occur. Therefore, this method cannot fundamentally solve the problem of the cytotoxicity of the copper-based zeolite.

[0007] Based on the above technology, the inventor's subsequent research proposed a new safe and feasible hydrogen-type zeolite-based virus protection material with a different technical idea, using hydrogen ions, a cation different from traditional metals such as copper and silver, as the main active ingredient. The antiviral performance of the hydrogen-type zeolite itself is weak and cannot meet the requirements of practical applications. In the present invention, by controlling the distribution state of aluminum atoms in the zeolite framework through synthesis, a hydrogen-type zeolite with uniform distribution of aluminum atoms is obtained. Since the pure silicon framework of the zeolite is electrically neutral, introducing aluminum atoms generates negative charges, thus requiring hydrogen ions for neutralization. When the aluminum atoms are uniformly distributed, it will guide the counter hydrogen ions to be uniformly distributed in the zeolite framework, thereby greatly enhancing the ion exchange capacity of the zeolite framework. This zeolite can be completely exchanged after ion exchange, with a high hydrogen ion content, so the surface acid density is very strong. Subsequently, by regulating the pore size, silicon-aluminum ratio, and particle size of the hydrogen-type zeolite, the surface acid density of the hydrogen-type zeolite is further increased. The obtained hydrogen-type zeolite has extremely strong surface acidity and can have a strong chemical effect on viruses. The specific principle is that the acidic sites of the hydrogen-type zeolite will form hydrogen bond interactions with the basic groups (Lys356 and Glu340) of the viral surface protein, thereby enabling the viral surface protein to quickly lose its physiological activity and unable to continue invading human cells, thus achieving the effect of inactivating the virus. And hydrogen element, as a non-metallic element, has no cytotoxicity at all and has high biocompatibility with the human body, and is very safe in practical applications. After the hydrogen-type zeolite is compounded with gauze, the obtained hydrogen-type zeolite gauze can also exhibit high antiviral performance, especially with a high killing rate against the novel coronavirus (SARS-Cov-2). The hydrogen-type zeolite gauze composite material can be used in the air purification of viruses, efficiently killing virus aerosols and virus droplets in the air, and preventing the spread of viruses through the air. Summary of the Invention

[0008] The object of the present invention is to solve the problem of poor biocompatibility of existing antiviral materials and air purification materials, and provide an inorganic silicate zeolite material and its virus filtration application for killing viruses in the air.

[0009] In a first aspect, the present invention provides an inorganic silicate zeolite material, which is a modified hydrogen-type zeolite; the modified hydrogen-type zeolite uses hydrogen ions as the cations of the zeolite framework, and its preparation includes: mixing a silicon source, an aluminum source and an organic template agent for aging, then adding a dispersion additive for secondary aging, and performing a hydrothermal reaction after ultrasonic treatment; calcining the hydrothermal reaction product.

[0010] Furthermore, the modified hydrogen-type zeolite utilizes the interaction between the dispersion additive and aluminum atoms to maintain the non-aggregation of aluminum in the synthesis system, so that after the zeolite crystallizes, no aluminum-oxygen-aluminum bonds are formed in the zeolite framework, achieving uniform distribution of aluminum atoms in the framework, thereby increasing the density of acid sites in the zeolite.

[0011] Furthermore, the molar ratio of the silicon source, the aluminum source and the organic template agent is 1-100:1:1-30; the molar ratio of the dispersion additive and the aluminum source is 1-10:1; the aging temperature of the silicon source, the aluminum source and the organic template agent is 60°C-100°C, and the aging time is 3h-24h; the temperature for adding the dispersion additive for secondary aging is 60°C-100°C, and the aging time is 3h-24h; the ultrasonic treatment time is 10min-120min; the temperature of the hydrothermal reaction is 120°C-200°C, and the time is 12h-72h. The calcination temperature is 350°C-750°C, and the calcination time is 3h-10h.

[0012] Furthermore, the dispersion additive is one or more of polyethylene glycol, polypropylene glycol, polyglycerol, and polybutylene glycol, and the viscosity-average molecular weight is 150-2000; the silicon source is one or more of tetraethyl orthosilicate, silica sol, and silicon dioxide, the aluminum source is one or more of sodium aluminate, aluminum nitrate, and alumina, and the organic template agent is one or more of tetrapropylammonium hydroxide, tetraethylammonium hydroxide, and diethylamine.

[0013] Furthermore, the silicon-aluminum ratio of the modified hydrogen-type zeolite is 1-10:1, and the particle size is 0.1-20μm.

[0014] Furthermore, the surface acid sites of the hydrogen-type zeolite form stable hydrogen bonds with the basic groups of the viral surface proteins, confining the viral surface proteins on the zeolite surface, thereby achieving the effect of inactivating the virus.

[0015] In a second aspect, the present invention provides an antiviral gauze, which includes an antiviral layer, and the antiviral layer uses the inorganic silicate zeolite material.

[0016] Further, the antiviral gauze further includes a flexible gauze substrate, wherein the weight concentration of the modified hydrogen-type zeolite in the antiviral layer gradually decreases from the outer layer to the inner layer along the thickness direction of the gauze, and the modified hydrogen-type zeolite accounts for 5%-30% of the total weight of the antiviral gauze.

[0017] In a third aspect, the present invention provides an antiviral mask comprising the antiviral gauze.

[0018] In a fourth aspect, the present invention provides an antiviral air purification filter net comprising the antiviral gauze. It may also be an antiviral air filter paper comprising an inorganic silicate zeolite material.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. By controlling the synthesis conditions of the modified hydrogen-type zeolite, adding a dispersion additive and performing ultrasonic treatment, the present invention controls the pore size, silicon-aluminum ratio, and particle size of the zeolite while controlling the uniform distribution of aluminum atoms in the zeolite structure, thereby greatly enhancing the ion exchange capacity and acid density of the zeolite framework. After ion exchange, the regulated zeolite can be completely exchanged and has a high hydrogen ion content. Therefore, the obtained modified hydrogen-type zeolite has extremely strong surface acidity and can thus have a strong chemical effect on viruses. Specifically, the acidic sites of the modified hydrogen-type zeolite will form stable hydrogen bonds with the basic groups of the viral surface proteins, thereby quickly anchoring the viruses and inactivating them rapidly, achieving the effect of inactivating viruses.

[0021] 2. As a non-metallic element, hydrogen is completely non-cytotoxic. Therefore, the modified hydrogen-type zeolite proposed by the present invention has high biocompatibility with the human body and is very safe in practical applications.

[0022] 3. The modified hydrogen-type zeolite antiviral material proposed by the present invention has two major technical advantages: no cytotoxicity and high antiviral performance. There is no need to consider the problem of cytotoxicity like metal-based zeolites to ensure high virus-killing performance. The technology of the present invention has an efficient effect of killing viruses (especially the novel coronavirus) with strong viability and fast mutation and sufficient biosafety. It is expected to reshape the industry standards of antiviral air purifiers and antiviral masks, break the traditional academic mindset, and break through the technical defects of traditional medical protection in practice, and has high theoretical and industrial practice value. Description of the Drawings

[0023] Figure 1 It is the distribution map of silicon and aluminum elements of the hydrogen-type zeolite in Example 1 (a is the silicon element, b is the aluminum element).

[0024] Figure 2 It is the nuclear magnetic resonance map of aluminum element of the hydrogen-type zeolite in Example 1, proving that there is no Al-O-Al bond in its chemical environment.

[0025] Figure 3 It is the X-ray diffraction pattern of the two kinds of hydrogen-type zeolite composite antiviral gauzes in Example 4.

[0026] Figure 4 It is the scanning electron microscope image of the two kinds of hydrogen-type zeolite composite antiviral gauzes in Example 4.

[0027] Figure 5 It is the cytotoxicity result of the two kinds of hydrogen-type zeolite composite antiviral gauzes in Example 4.

[0028] Figure 6 It is the antiviral performance result of the two kinds of hydrogen-type zeolite composite antiviral gauzes in Example 4.

[0029] Figure 7 It is the air purification virus performance result of the two kinds of hydrogen-type zeolite composite antiviral gauzes in Example 4. Detailed implementation manners

[0030] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] An inorganic silicate zeolite material, comprising an antiviral active substance; the antiviral active substance is a modified hydrogen-type zeolite; the modified hydrogen-type zeolite is Y-type zeolite, ZSM-5 zeolite or Beta zeolite.

[0033] The modified hydrogen-type zeolite uses hydrogen ions as the cations of the zeolite framework, and its preparation includes: mixing a silicon source, an aluminum source and an organic template agent and then aging, subsequently adding a dispersion additive for secondary aging, and finally performing a hydrothermal reaction after ultrasonic treatment.

[0034] The present invention obtains a modified hydrogen-type zeolite with uniformly distributed aluminum atoms, having a suitable pore size (0.3 nm - 2.0 nm, preferably 0.5 - 0.8 nm), a low silicon-aluminum ratio (the atomic number ratio of the two is 1 - 10:1, preferably 1 - 1.5:1), a small particle size (0.1 - 20 μm, preferably 0.1 - 0.5 μm) and a high hydrogen ion exchange capacity (5 - 99%) by strictly controlling the zeolite synthesis conditions (such as the precursor silicon-aluminum ratio, the content of the dispersion additive, the hydrothermal temperature, the hydrothermal time, the ultrasonic time).

[0035] The hydrogen ions that balance the charge outside the framework of the modified hydrogen-type zeolite are used as cations to balance the charge from [SiO4] 0and [AlO4] - The anionic framework structure of zeolite composed of tetrahedrons.

[0036] The specific preparation steps are as follows:

[0037] Step S1: At 60°C - 100°C, mix an aluminum source, a silicon source, and an organic templating agent, and then stir for 3 - 24 hours to obtain a mixed solution;

[0038] As an example, the silicon source is selected from one or more of tetraethyl orthosilicate, silica sol, and silicon dioxide, preferably tetraethyl orthosilicate;

[0039] As an example, the aluminum source is selected from one or more of sodium aluminate, aluminum nitrate, and alumina, preferably aluminum nitrate;

[0040] As an example, the organic templating agent is one or more of tetrapropylammonium hydroxide, tetraethylammonium hydroxide, and diethylamine.

[0041] As an example, the molar ratio of the active ingredient SiO2 in the silicon source to the solvent in the mixed solution is 1:20 - 50; preferably, the solvent in the mixed solution is H2O.

[0042] As an example, the molar ratio of the silicon source, aluminum source, and organic templating agent is 1 - 100:1:1 - 30. Typically and non - restrictively, it can be 1:1:1, 3:1:1, etc.

[0043] As an example, the molar ratio of the dispersion additive and the aluminum source is 1 - 10:1. Typically and non - restrictively, it can be 1:1, 10:1.

[0044] Step S2: Add a dispersion additive to the mixed solution in Step S1 and ensure that the viscosity reaches 20 - 50 cP, and stir for 3 - 24 hours to form a gel system.

[0045] As an example, the dispersion additive is one or more of polyethylene glycol, polypropylene glycol, polyglycerol, and polybutylene glycol, and the viscosity - average molecular weight is 150 - 2000. Preferably, it is polyethylene glycol.

[0046] The dispersion additive is a polymer containing repeating and adjacent ether bonds (R - O - R). The repeating ether bonds can form coordination interactions with aluminum atoms in the zeolite precursor, thus maintaining the non - agglomeration of aluminum in the zeolite synthesis system. After the zeolite crystallizes, no aluminum - oxygen - aluminum bonds are formed in the zeolite framework, proving that the aluminum atoms in the framework are evenly distributed, and thus the density of acid sites in the zeolite is greatly increased.

[0047] After adding the dispersing additive and performing secondary aging, ultrasonic treatment is required. This process step can promote closer coordination between the highly viscous dispersing additive and aluminum atoms, thereby further improving the uniformity of the distribution of aluminum atoms in the zeolite framework.

[0048] Step S3: Hydrothermally react the gel system obtained in Step S2.

[0049] As an example, the hydrothermal reaction conditions are hydrothermal treatment at 120 - 200 °C for 12 - 72 hours.

[0050] Step S4: Calcinate the hydrothermal reaction product obtained in Step S3.

[0051] As an example, the calcination temperature is 350 °C - 750 °C, and the calcination time is 3 h - 10 h.

[0052] The present invention also provides an antiviral gauze, which includes an antiviral layer, and the antiviral layer uses the above-mentioned antiviral material.

[0053] In one implementation, the antiviral gauze further includes a flexible gauze substrate. Among them, the weight concentration of the modified hydrogen-type zeolite in the antiviral layer gradually decreases from the outer layer to the inner layer along the thickness direction of the gauze, and the modified hydrogen-type zeolite accounts for 5% - 30% of the total weight of the antiviral gauze.

[0054] As an example, the flexible gauze substrate layer is selected from cotton gauze, absorbent cotton gauze, polyester gauze, polyester fiber gauze, and various fiber blended gauzes.

[0055] In one implementation, the antiviral material further includes an adhesive layer, and the weight of the adhesive layer accounts for 0.4% - 1.2% of the total weight of the antiviral gauze, preferably 0.5% - 1.0%. The material of the adhesive layer is an aqueous polymer latex, and its glass transition temperature Tg ≤ 25 °C, preferably Tg ≤ 0 °C, more preferably Tg ≤ -15 °C.

[0056] As an example, the polymer latex includes one or a combination of chloroprene rubber, styrene-butadiene rubber, carboxylated styrene-butadiene rubber, polyurethane, pure acrylic rubber, styrene-acrylic rubber, polyacrylate rubber, polyethylene oxide. The diameter of the polymer latex particles is 50 - 500 nanometers, preferably 100 - 300 nanometers.

[0057] As an example, the antiviral layer is formed on the surface of the flexible gauze substrate layer by a coating method, a spraying method, or an in-situ growth method.

[0058] As an example, the virus is the novel coronavirus SARS-CoV-2.

[0059] The present invention also provides a method for preparing the above antiviral gauze, such as the coating method, which may include the following steps:

[0060] Step 1: By controlling the synthesis conditions of zeolite, a modified hydrogen-type zeolite material with appropriate pore size, low silica-alumina ratio, small particle size, uniform distribution of aluminum, and high hydrogen ion exchange capacity is obtained. The modified hydrogen-type zeolite material is used to prepare the antiviral material.

[0061] Step 2: Prepare a mixed slurry of the antiviral material and the binder.

[0062] Step 3: Uniformly coat the mixed slurry obtained in Step 2 on the gauze, and the coating method, spraying method or other suitable composite methods can be used. Preferably, adhesive-assisted compounding can be used.

[0063] Step 4: Dry the antiviral material gauze coated with the mixed slurry at 70-120 °C to obtain the finished product of hydrogen-type zeolite composite antiviral gauze.

[0064] The zeolite in the flexible zeolite gauze described in Step 1 can be one or more of zeolite crystal materials such as Y-type zeolite, ZSM-5 zeolite or Beta zeolite. Further preferably, the type of zeolite can be ZSM-5 type zeolite.

[0065] As an example, the weight of the modified hydrogen-type zeolite accounts for 5%-30% of the total weight of the antiviral gauze material, preferably 10%-20%. Too low a concentration affects the antiviral effect, and too high a concentration affects the flexibility and air permeability of the material.

[0066] As an example, the flexible gauze substrate can be various substances in the form of flexible fabrics, including cotton cloth, absorbent cotton gauze, absorbent cotton non-woven fabric, polyvinyl alcohol gauze, polyurethane non-woven fabric, and fabrics blended with various fibers, etc.

[0067] Specifically, Step 2 is to dilute the binder with water to a binder dilution solution with a solid content of 0.20 wt%-0.80 wt%; add the antiviral material to the binder dilution solution, adjust the pH to between 7.0 and 10.0, and vigorously stir to obtain a stably dispersed mixed slurry;

[0068] In the mixed slurry of the hydrogen-type zeolite and the binder of the antiviral material, a suspending agent can also be added to increase the stability of the slurry. The suspending agent uses xanthan gum, locust bean gum, konjac gum, carrageenan, alginic acid, agar, and their compound mixtures, etc. The mass concentration of the suspending agent in the mixed slurry is 0.02%-0.08%.

[0069] As an example, the binder uses an aqueous polymer latex dilution solution, which is composed of polymer latex particles and water as a dispersant. The polymer latex particles are negatively charged or non-ionic, preferably negatively charged.

[0070] As an example, the weight content of the modified hydrogen-type zeolite in the slurry mixture is 0.50%-5.0%.

[0071] The present invention also provides an antiviral mask. The antiviral mask comprises a four-layer structure, successively including an outer layer, a first intermediate layer, a second intermediate layer and an inner layer; the outer layer and the second intermediate layer are antiviral gauzes, the first intermediate layer is a hydrophobic fiber layer, and the inner layer is a hydrophilic fiber layer. The innermost layer of the medical material refers to the side that adheres to the wearer's body. The outermost layer of the medical material refers to the side that is farthest from the wearer's body. Since the modified hydrogen-type zeolite has no cytotoxicity, it is very suitable for application on the antiviral mask that is in direct contact with the human body, does not produce toxicity or irritation to the human skin, and has obvious biocompatibility advantages.

[0072] In one embodiment, a melt-blown non-woven fabric layer can be added between the first intermediate layer and the second intermediate layer.

[0073] As an example, the composition of the melt-blown non-woven fabric comprises any one or more of polyethylene, polypropylene, polyester, modified polyethylene, modified polypropylene, and modified polyester.

[0074] As an example, the hydrophilic fiber layer is composed of hydrophilic fibers; the hydrophilic fibers refer to fibers having a certain number of strongly polar groups (such as -OH, -NH2, -C=O, etc.) on the macromolecular chain, including any one or more of cotton fibers, viscose fibers, linen fibers, polyacrylonitrile fibers, and hydrophilic modified fibers.

[0075] The hydrophobic fiber layer is composed of fibers with low density and strong hydrophobicity or water resistance; the hydrophobic fibers are selected from any one or more of polyethylene, polypropylene, polyester, modified polyethylene, modified polypropylene, and modified polyester. Typically, a low-density dot-bonded non-woven fabric layer containing polyethylene terephthalate fibers and polyethylene and processed by pressure point bonding can be used.

[0076] The present invention also provides an antiviral air purification filter screen, which comprises an antiviral material.

[0077] In one embodiment, the antiviral air purification filter screen further comprises an electret melt-blown non-woven fabric; the antiviral material and the electret melt-blown non-woven fabric are formed by superposition.

[0078] The main body of the filter net is a double-layer composite structure. One layer is antiviral gauze, and the second layer is electret meltblown non-woven fabric. Among them, the electret meltblown non-woven fabric can be a meltblown non-woven fabric with a filtration level above F7. Further preferably, it is a meltblown non-woven fabric of H11 grade. This can ensure a relatively low air resistance while effectively filtering particulate matter in the air. Subsequently, the antiviral material can effectively capture viruses in the flowing air. On the basis of blocking the airborne transmission of viruses, the viruses are killed to prevent secondary infection. The antiviral material and the electret meltblown non-woven fabric form the main material of the air purification filter net by superposition.

[0079] The above materials can also be verified for virus IC50 concentration, inhibition rate of RBD-ACE2, and virus inactivation by the following detection methods.

[0080] Cytotoxicity test (refer to the national standard "Biological evaluation of medical devices - Part 5: In vitro cytotoxicity test" GB / T 16886.5-2017 / ISO 10993-5:2009): Immerse the medical material in MEM culture medium at a ratio of 0.1 g / mL for 24 h to obtain an extract of the medical material. Place Vero cell medium (1×10 5 ) in a CO2 incubator and culture for 22 - 26 h. Remove the culture medium, add the extract of the medical material, and place it in a CO2 incubator for 24 h. Observe the morphological changes of Vero cells under a microscope. Remove the culture medium, add 50 μL of MTT solution, place it in a CO2 incubator for 2 h, remove the MTT solution, add 100 μL of isopropanol to each well, shake the microtiter plate, and measure the absorbance at 570 nm. According to the measured absorbance, convert it into the corresponding survival rate of the cells.

[0081] Determination of the inhibition rate of RBD-ACE2 by competitive enzyme-linked immunosorbent assay (ELISA): Dilute HRP-SARS-CoV-2 Spike RBD (WT) to 1 μg / mL, take out 50 μL and add it to 4 mg of zeolite powder sample. After shaking and standing for 1 minute, add 200 μL of dilution buffer and centrifuge for 15 s. Aspirate 100 μL of the supernatant and add it to a 96-well plate pre-coated with ACE2. After incubating at 37 °C for 1 h, aspirate the solution in the wells and wash 3 times with washing buffer. Add TMB substrate, incubate for 20 min, then add the terminator, and measure the absorbance at 450 nm. Use the RBD not incubated with zeolite as a positive control, set as 100%. Subtract the blank value (the well without RBD) from the reading, and calculate the inhibition rate with reference to the absorbance of the blank well.

[0082] Testing method for inactivating SARS-CoV-2: Place the antiviral material in a 6-well plate in the shape of a bowl with a concave middle. Slowly drop 0.5 mL of the virus solution onto the medical material (30 s) to ensure that the virus solution is absorbed by the mask and does not drip. Incubate for a certain period of time (15 min). Add 2 mL of culture medium to each well, soak thoroughly for 2 min, discard the mask, and add 1 mL of Vero cell culture medium (5×10 5 ), mix well, and place in a CO2 incubator for 72 h. Observe the cytopathic effect and detect the viral nucleic acid (q-RT PCR). Pipette 200 μL of the cell culture supernatant, extract the viral nucleic acid using a magnetic bead-based nucleic acid extraction kit (MVR01) and a fully automatic nucleic acid extractor, and the final elution volume is 50 μL. Take 5 μL of the nucleic acid extract, use a one-step novel coronavirus nucleic acid detection kit to detect the viral nucleic acid level, and calculate the inhibition rate of the material against the virus according to the Ct value.

[0083] The technical solutions of the present invention will be clearly and completely described below in conjunction with the best embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0084] Example 1

[0085] Prepare a zeolite precursor solution. Using tetraethyl orthosilicate (TEOS) as the silicon source, aluminum nitrate as the aluminum source, tetrapropylammonium hydroxide as the organic template agent, and polyethylene glycol as the dispersion additive, start the materials according to the following molar ratio: 4Na2O:Al2O3:3SiO2:160H2O:20 polyethylene glycol to synthesize the zeolite precursor solution, and then ultrasonically treat for 1 hour. After hydrothermal treatment at 160 °C for 2 days, centrifuge, wash, and dry. Immerse in 1 molar ammonium sulfate solution 3 times, each time for 3 h, rinse with deionized water multiple times, and then calcine at 550 °C for 5 hours to form modified hydrogen-type zeolite.

[0086] Example 2

[0087] Prepare a zeolite precursor solution. Using tetraethyl orthosilicate (TEOS) as the silicon source, aluminum nitrate as the aluminum source, tetrapropylammonium hydroxide as the organic template agent, and polypropylene glycol as the dispersion additive, start the materials according to the following molar ratio: 4Na2O:Al2O3:3SiO2:160H2O:20 polypropylene glycol to synthesize the zeolite precursor solution, and then ultrasonically treat for 1 hour. After hydrothermal treatment at 160 °C for 2 days, centrifuge, wash, and dry. Immerse in 1 molar ammonium sulfate solution 3 times, each time for 3 h, rinse with deionized water multiple times, and then calcine at 550 °C for 5 hours to form modified hydrogen-type zeolite.

[0088] Comparative Example 1

[0089] Prepare a zeolite precursor solution. Using tetraethyl orthosilicate (TEOS) as the silicon source, aluminum nitrate as the aluminum source, tetrapropylammonium hydroxide as the organic template agent, and polyethylene glycol as the dispersion additive, starting materials are composed according to the following molar ratio: 4Na2O:Al2O3:3SiO2:160H2O:20 polyethylene glycol to synthesize the zeolite precursor solution without ultrasonic treatment. After hydrothermal treatment at 160 °C for 2 days, centrifuge, wash, and dry. Immerse it in 1 molar ammonium sulfate solution 3 times, each time for 3 h, rinse with deionized water multiple times, and then calcine at 550 °C for 5 hours to form hydrogen-type zeolite.

[0090] Comparative Example 2

[0091] Prepare a zeolite precursor solution. Using tetraethyl orthosilicate (TEOS) as the silicon source, aluminum nitrate as the aluminum source, tetrapropylammonium hydroxide as the organic template agent, and no dispersion additive is added. Starting materials are composed according to the following molar ratio: 4Na2O:Al2O3:3SiO2:160H2O to synthesize the zeolite precursor solution, and then perform ultrasonic treatment for 1 hour. After hydrothermal treatment at 160 °C for 2 days, centrifuge, wash, and dry. Immerse it in 1 molar ammonium sulfate solution 3 times, each time for 3 h, rinse with deionized water multiple times, and then calcine at 550 °C for 5 hours to form hydrogen-type zeolite.

[0092] The acidity of the hydrogen-type zeolite synthesized in the above examples was measured by pyridine infrared, and the results are shown in Table 1. It can be observed that the order of the total acid amount is Example 1 > Example 2 > Comparative Example 1 > Comparative Example 2, which proves the important role of the dispersion additive and ultrasonic treatment in enhancing the acidity of the hydrogen-type zeolite. After adding a suitable dispersion additive and performing ultrasonic treatment, both Example 1 and Example 2 obtained can exhibit high acidity. As Figure 1 shown, the distribution of aluminum atoms in the hydrogen-type zeolite obtained in Example 1 is very uniform and no agglomeration occurs. As Figure 2 shown, no Al-O-Al bond was observed in the hydrogen-type zeolite obtained in Example 1. These two results indicate that the dispersion additive and ultrasonic treatment make the aluminum distribution in the hydrogen-type zeolite of Example 1 uniform, thus endowing it with extremely strong surface acidity. In Comparative Example 1, since ultrasonic treatment was not performed, the aluminum atom distribution was not uniform enough, so the acidity was weak. In Comparative Example 2, since no dispersion additive was added, the aluminum atom distribution was not uniform enough, so the acidity was the weakest.

[0093] The inhibitory performance of the synthesized hydrogen-type zeolite in the above examples on the binding of the receptor-binding domain (RBD) of the novel coronavirus to the human receptor angiotensin-converting enzyme 2 (ACE2) was determined using a competitive enzyme-linked immunosorbent assay kit (ELISA); the anti-novel coronavirus performance of the leaching solution of the hydrogen-type zeolite against SARS-CoV-2 was determined using real-time fluorescence quantitative polymerase chain reaction (qRT-PCR). The results are shown in Table 2. Both Example 1 and Example 2 with stronger acidity showed good anti-novel coronavirus performance. In Comparative Example 2, due to the absence of a dispersion additive and weaker acidity, the antiviral performance was poor. In Comparative Example 1, due to the lack of ultrasonic treatment and the weakest acidity, the antiviral performance was the worst.

[0094] Table 1 Surface acidity of hydrogen-type zeolite

[0095]

[0096]

[0097] Table 2 Antiviral performance of hydrogen-type zeolite

[0098]

[0099] Example 3

[0100] The addition amounts of the silicon source and the aluminum source in Example 1 were regulated, and other conditions remained unchanged. By comparing the hydrogen-type zeolites with different silicon-aluminum ratios in Example 1, modified hydrogen-type zeolites with different silicon-aluminum ratios were obtained.

[0101] The silicon-aluminum ratio of the synthesized hydrogen-type zeolite was detected by inductively coupled plasma mass spectrometry (ICP-MS). The inhibitory performance of the synthesized hydrogen-type zeolites with different silicon-aluminum ratios on the binding of RBD to ACE2 was determined using ELISA; the anti-novel coronavirus performance of the leaching solutions of the hydrogen-type zeolites with different silicon-aluminum ratios against SARS-CoV-2 was determined using qRT-PCR. The test results are shown in Table 3. From the results in the table, it can be observed that as the silicon-aluminum ratio of the hydrogen-type zeolite increases, both its inhibition rate on RBD-ACE2 and its inhibition rate on SARS-CoV-2 decrease simultaneously. This is because an increase in the silicon-aluminum ratio reduces the ion exchange capacity in the zeolite framework. Only zeolites with a lower silicon-aluminum ratio can accommodate more hydrogen ions, thus showing stronger antiviral performance.

[0102] Table 3 Antiviral performance of modified hydrogen-type zeolites with different silicon-aluminum ratios

[0103] Hydrogen form zeolite number Silica-alumina ratio of modified hydrogen form zeolite Inhibition rate against RBD-ACE2 Inhibition rate against SARS-Cov-2 HZ-1 1.0 99.9％ 99.9％ HZ-2 2.0 99.3％ 98.8％ HZ-3 5.0 98.1％ 97.5％ HZ-4 10.0 93.2％ 83.8％

[0104] Example 4

[0105] Compare the modified hydrogen-type zeolites with different silica-alumina ratios in Comparative Example 1. Use chloroprene latex as a binder and xanthan gum as a suspending agent to form a uniform slurry with the modified hydrogen-type zeolite synthesized in Example 1, and then coat it on gauze. After drying at 100 °C, the hydrogen-type zeolite antiviral gauze is obtained.

[0106] Synthesize hydrogen-type zeolite antiviral gauzes with different silica-alumina ratios using the above method. Use ELISA to measure the inhibitory performance of the synthesized hydrogen-type zeolite antiviral gauzes with different silica-alumina ratios on the binding of RBD and ACE2; use qRT-PCR to measure the anti-SARS-CoV-2 performance of the leachate of the hydrogen-type zeolite antiviral gauzes with different silica-alumina ratios. The test results are shown in Table 4. It can be observed from the results that after bonding the modified hydrogen-type zeolite to the gauze, its antiviral performance can still be maintained. And as the silica-alumina ratio increases, the inhibition rate of the hydrogen-type zeolite antiviral gauze on RBD-ACE2 and the inhibition rate on SARS-CoV-2 decrease. It also shows that an increase in the silica-alumina ratio will reduce the ion exchange capacity in the zeolite framework. Only zeolites with a lower silica-alumina ratio can accommodate more hydrogen ions, thus showing stronger antiviral performance.

[0107] Table 4 Antiviral performance of hydrogen-type zeolite antiviral gauzes with different silica-alumina ratios

[0108]

[0109] Example 5

[0110] The hydrothermal temperature and hydrothermal time of the zeolite in Example 1 were controlled and adjusted (as shown in Table 5), and other conditions remained unchanged. After being soaked in 1 mol / L ammonium sulfate solution three times, 3 h each time, rinsed with deionized water multiple times, and then calcined at 550 °C for 5 hours, hydrogen-type zeolites with different particle sizes were formed. The particle sizes of the synthesized hydrogen-type zeolites were detected by scanning electron microscopy (SEM). The external specific surface area of the synthesized hydrogen-type zeolites was determined by N2 adsorption equilibrium isotherm. Water, binder, suspending agent and the synthesized hydrogen-type zeolites were formed into a uniform slurry, and then coated on gauze. After drying at 100 °C, hydrogen-type zeolite antiviral gauzes with different particle sizes were obtained. The inhibitory performance of the synthesized hydrogen-type zeolites with different particle sizes on the binding of RBD of the new coronavirus to ACE2 was determined by ELISA; then the half inhibitory concentration IC50 was used to measure the inhibitory effect of hydrogen-type zeolites with different particle sizes on RBD-ACE2. The half inhibitory concentration IC50 generally refers to the concentration of the antibody used when the inhibition rate of the antigen is 50% in a competitive ELISA test. The smaller the value of IC50, the stronger the specific inhibitory effect of the antibody. The anti-SARS-CoV-2 performance of the leachate of hydrogen-type zeolites with different particle sizes was determined by qRT-PCR. The test results are shown in Table 5. It can be observed from the results that as the particle size of the hydrogen-type zeolite increases, its external specific surface area decreases accordingly. And its inhibition rate on RBD-ACE2 and its inhibition rate on SARS-CoV-2 also decrease simultaneously, and its half inhibitory concentration IC50 increases sharply. This result shows that the increase in particle size will greatly weaken the antiviral ability of the hydrogen-type zeolite. This is because the increase in particle size will reduce the external specific surface area of the zeolite, so that the total amount of external surface binding sites is reduced while keeping the concentration of binding sites per unit area unchanged, showing weaker antiviral performance. This result proves from one side that the position where the hydrogen-type zeolite chemically interacts with the virus is the external surface of the zeolite.

[0111] Table 5 Antiviral performance of hydrogen-type zeolite antiviral gauzes with different particle sizes

[0112]

[0113]

[0114] Comparative Example 3

[0115] Different types of zeolites were selected, including the modified hydrogen-type ZSM-5 zeolite synthesized in Example 1 and commercial A-type zeolite, X-type zeolite, Y-type zeolite, chabazite, Beta zeolite, SAPO-34 zeolite, SAPO-5 zeolite, SAPO-18 zeolite and P-type zeolite. After being soaked in 1 mol / L ammonium sulfate solution three times, 3 h each time, rinsed with deionized water multiple times, and then calcined at 550 °C for 5 hours, hydrogen-type zeolites were formed.

[0116] Water, a binder, a suspending agent, and the synthesized hydrogen-type zeolite are formed into a uniform slurry, which is then coated on gauze. After drying at 100 °C, hydrogen-type zeolite antiviral gauze with different pore sizes is obtained. The inhibitory performance of the synthesized hydrogen-type zeolite antiviral gauze with different silica-alumina ratios on the binding of RBD to ACE2 is determined by ELISA; the anti-SARS-Cov-2 performance of the leaching solution of the hydrogen-type zeolite antiviral gauze with different silica-alumina ratios is determined by qRT-PCR. The results are shown in Table 6. It is observed that there are significant differences in the inhibition rates of the hydrogen-type zeolite antiviral gauze with different pore sizes on RBD-ACE2 and on SARS-Cov-2. Among them, ZSM-5 zeolite, Y zeolite, and Beta zeolite show extremely high inhibition rates, while the inhibition rates of the other zeolites are relatively low. This may be because the viral surface protein needs to come into contact with the hydrogen ions in the zeolite pores, and the formed hydrogen bonds can firmly lock the virus on the zeolite surface, while zeolites with inappropriate pore sizes cannot achieve this well.

[0117] As Figure 3 shown, obvious diffraction peaks of ZSM-5 zeolite appear on the XRD diffraction peaks of the two obtained hydrogen-type zeolite composite antiviral gauzes, proving that the zeolite is successfully loaded on the antiviral gauze. Figure 4 It is observed from the scanning electron microscope pictures shown that the zeolite particles are firmly loaded on the fibers of the gauze. As Figure 5 shown, the cell survival rates of the two obtained antiviral gauzes are very high and no obvious cytotoxicity is shown, proving that their biosafety is very high. As Figure 6 shown, both antiviral gauzes show 99.99% antiviral performance against the new coronavirus.

[0118] Table 6 Antiviral performance of hydrogen-type zeolite antiviral gauze with different zeolite pore sizes

[0119]

[0120]

[0121] Example 6: Preparation of a cell-free cytotoxic antiviral mask

[0122] Chloroprene latex is used as a binder, xanthan gum is used as a suspending agent, and the hydrogen-type zeolite synthesized in Example 1 is formed into a uniform slurry, which is then coated on gauze. After drying at 100 °C, hydrogen-type zeolite virus gauze is obtained.

[0123] The outermost layer and the second intermediate layer adopt hydrogen-type zeolite antiviral gauze. The first intermediate layer uses polyester fiber as the hydrophobic fiber layer, and the innermost layer uses natural cotton fiber as the hydrophilic fiber layer. The outermost layer, the first intermediate layer, the second intermediate layer, and the innermost layer are stacked in sequence, and the mask body KZ-1 of the present invention is prepared by heat sealing. The cytotoxicity and antiviral performance of the obtained mask are measured to obtain Table 7. It is observed that the hydrogen-type zeolite mask has excellent biocompatibility, and its cell survival rate reaches nearly 95%. And its antiviral performance is very excellent.

[0124] Table 7 Cytotoxicity and antiviral performance of hydrogen-type zeolite mask materials

[0125]

[0126] Example 7: An air purification filter based on hydrogen-type zeolite antiviral gauze

[0127] The filter screen LX-1 is composed of stacking hydrogen-type zeolite antiviral gauze and electret meltblown non-woven fabric. The filter screen is installed on the air-conditioning purification module, and an air filtration experiment is carried out according to the test method of GB / T 18801-2015. The test results are as Figure 7 shown. It is observed that the antiviral performance of the air purification filter screen composed of hydrogen-type zeolite gauze is very excellent. At a dosage of 128 mg / mL, the virus inhibition efficiency can reach more than 90%, while the filtration efficiency of sodium-type zeolite gauze under the same conditions is only less than 30%. The above results prove that the air purification filter screen based on hydrogen-type zeolite antiviral gauze can effectively reduce the virus load in the air and prevent the spread of viruses through the air.

[0128] The conventional technologies in the above embodiments are the existing technologies well known to those skilled in the art, so they will not be elaborated in detail here. The specific embodiments described herein are only illustrative of the spirit of the present invention. Those skilled in the technical field to which the present invention belongs can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0129] Although the present invention has been described in detail and some specific embodiments have been cited, it is obvious that various changes or modifications can be made by those skilled in the art without departing from the spirit and scope of the present invention.

[0130] While the above specific embodiments have shown, described, and pointed out the novel features applied to various embodiments, it should be understood that various omissions, substitutions, and changes in the form and details of the illustrated apparatus or method may be made without departing from the spirit of the present disclosure. Additionally, the above various features and methods may be used independently of each other or may be combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of the present disclosure. Many of the above embodiments include similar components, and thus, these similar components may be interchangeable in different embodiments. Although the present invention has been disclosed in the context of certain embodiments and examples, those skilled in the art should understand that the present invention may extend beyond the specifically disclosed embodiments to other alternative embodiments and / or applications and their obvious modifications and equivalents. Therefore, the present invention is not intended to be limited by the specific disclosure of the preferred embodiments herein. Matters not covered by the present invention are well-known techniques.

Claims

1. An inorganic silicate zeolite material, which is a modified hydrogen-type zeolite; characterized in that, The modified hydrogen-type zeolite uses hydrogen ions as the cations of the zeolite framework, and its preparation includes: mixing a silicon source, an aluminum source, and an organic template agent, followed by aging, then adding a dispersion additive for secondary aging, and performing a hydrothermal reaction after ultrasonic treatment; roasting the hydrothermal reaction product.

2. An inorganic silicate zeolite material according to claim 1, characterized in that, The modified hydrogen-type zeolite utilizes the interaction between the dispersion additive and aluminum atoms to maintain the non-agglomeration of aluminum in the synthesis system, so that after the zeolite crystallizes, no aluminum-oxygen-aluminum bonds are formed in the zeolite framework, realizing the uniform distribution of aluminum atoms in the framework, thereby increasing the density of acid sites in the zeolite.

3. An inorganic silicate zeolite material according to claim 1, characterized in that, The molar ratio of the silicon source, aluminum source, and organic template agent is 1-100:1:1-30; the molar ratio of the dispersion additive to the aluminum source is 1-10:1; the aging temperature of the silicon source, aluminum source, and organic template agent is 60°C-100°C, and the aging time is 3h-24h; the temperature for adding the dispersion additive for secondary aging is 60°C-100°C, and the aging time is 3h-24h; the ultrasonic treatment time is 10min-120min; the temperature of the hydrothermal reaction is 120°C-200°C, and the time is 12h-72h. The roasting temperature is 350°C-750°C, and the roasting time is 3h-10h.

4. An inorganic silicate zeolite material according to claim 1, wherein, The dispersion additive is one or more of polyethylene glycol, polypropylene glycol, polyglycerol, and polybutylene glycol, with a viscosity-average molecular weight of 150-2000; the silicon source is one or more of tetraethyl orthosilicate, silica sol, and silicon dioxide, the aluminum source is one or more of sodium aluminate, aluminum nitrate, and alumina, and the organic template agent is one or more of tetrapropylammonium hydroxide, tetraethylammonium hydroxide, and diethylamine.

5. An inorganic silicate zeolite material according to claim 1, characterized in that, The silicon-aluminum ratio of the modified hydrogen-type zeolite is 1-10:1, and the particle size is 0.1-20μm.

6. An inorganic silicate zeolite material according to claim 1, characterized in that, The surface acid sites of the hydrogen-type zeolite form stable hydrogen bonds with the basic groups of the virus surface protein, confining the virus surface protein on the zeolite surface, thereby achieving the effect of inactivating the virus.

7. An antiviral gauze, characterized in that, It includes an antiviral layer, and the antiviral layer uses an inorganic silicate zeolite material according to any one of claims 1-7.

8. An antiviral gauze according to claim 7, characterized in that, The antiviral gauze further includes a flexible gauze substrate, wherein the weight concentration of the modified hydrogen-type zeolite in the antiviral layer gradually decreases from the outer layer to the inner layer along the thickness direction of the gauze, and the modified hydrogen-type zeolite accounts for 5%-30% of the total weight of the antiviral gauze.

9. An antiviral mask, characterized in that, It includes an antiviral gauze according to claim 7 or 8.

10. An antiviral air purification filter, characterized in that, It includes an antiviral gauze according to claim 7 or 8.

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