Antibacterial filter with composite adsorption structure and preparation method thereof

Abstract

The present invention discloses an antibacterial filter with a composite adsorption structure and a preparation method thereof. The antibacterial filter with the composite adsorption structure comprises a filter shell, and is characterized in that: the axis of an air inlet cover and an air outlet cover is detachably provided with a composite adsorption structure, the composite adsorption structure comprises an integrally formed spiral blade and a fixed shaft assembled with the axis of the spiral blade, the integrally formed spiral blade is formed by placing a ball-milled slurry into a mold and drying it. The beneficial effects of the present invention are: the composite adsorption material is designed to be in the shape of a spiral blade, which not only increases the contact area between the adsorption material and the filtered gas, but also the spiral channel can effectively reduce the air resistance to a certain extent, and the convective adsorption zone greatly prolongs the contact time of the filtered gas; it avoids the inactivation of graphene oxide caused by high-temperature reduction methods such as chemical reduction, microwave reduction, and photocatalytic reduction, prevents its agglomeration, and can significantly improve the service life of the composite adsorption material.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and more specifically relates to an antibacterial filter with a composite adsorption structure and a preparation method thereof. Background Art

[0002] With the rapid development of science and technology and the gradual advancement of industrialization and urbanization, air pollution is becoming increasingly serious. According to surveys, the degree of indoor air pollution is much greater than that of outdoor air, especially in densely populated areas with relatively sealed environments. As time goes by, there are many harmful substances and bacteria in the air, which seriously endanger human health. Indoor air pollutants generally include suspended particulate matter, gaseous pollutants, microorganisms, and radioactive substances. Various indoor air pollutants can cause varying degrees of damage to the human body. Therefore, the research on air purification technology is particularly important, which is directly related to people's work, life, health, and the stable development of society. At present, most of the air purification products on the market use photocatalysts and fiber filter materials to effectively remove volatile organic matter, dust ions, etc. in the air, but there are still a large number of pathogenic bacteria and viruses in the air. It is difficult for traditional filter materials to filter and kill bacteria and viruses. In addition, the filter materials in the air purifier are also prone to breed bacteria and viruses after a period of use, which will cause secondary pollution. The existing scheme has a certain killing effect on pathogenic bacteria and viruses in the air with the help of antibacterial agents, but its antibacterial effect is difficult to guarantee for a long time.

[0003] The national invention patent discloses a preparation method and application of a magnetic-nanosilver-graphene nanocomposite material, which uses the Hummers method to prepare graphene oxide; then uses the solvothermal method to load ferroferric oxide on graphene oxide to obtain a magnetic-graphene oxide composite material; and uses the redox method to load nanosilver on the magnetic-graphene oxide composite material to obtain a magnetic-nanosilver-graphene nanocomposite material. The resulting magnetic-nanosilver-graphene nanocomposite material has a bactericidal effect, but the solvothermal method needs to be carried out at a high temperature of 200 degrees, which is bound to lead to a decrease in the activity of graphene oxide, which is due to the irreversible effect of high temperature on the nanostructure. Summary of the invention

[0004] In order to solve the above problems and overcome the shortcomings of the prior art, the present invention provides an antibacterial filter with a composite adsorption structure and a preparation method, which can effectively solve the problem of reduced activity of nanocomposite materials due to high temperature.

[0005] The specific technical solution of the present invention to solve the above technical problems is: an antibacterial filter with a composite adsorption structure comprises a housing of the filter, the housing is configured as a hollow structure, and a detachable air inlet cover and an air outlet cover are respectively provided at the front and rear ends of the housing, and the characteristic is that the composite adsorption structure is detachably provided at the axis of the air inlet cover and the air outlet cover,

[0006] The composite adsorption structure comprises an integrally formed spiral blade and a fixed shaft assembled with the axis of the spiral blade, and an activated carbon filter box detachably connected to the shell is also arranged on the outer side of the air outlet cover.

[0007] Furthermore, a left-hand spiral blade and a right-hand spiral blade are symmetrically arranged on the axial surface of the fixed shaft, and the left-hand spiral blade and the right-hand spiral blade are sealed with the inner wall of the shell to form a spiral channel. The ratio of the number of spiral turns of the left-hand spiral blade and the right-hand spiral blade is 2:1. A convection adsorption area is also arranged between the left-hand spiral blade and the right-hand spiral blade, and an exhaust motor and a preset number of contact contacts are arranged on the axial surface of the fixed shaft located in the convection adsorption area.

[0008] Furthermore, the contact contact comprises a contact column connected to the axial surface of the fixed shaft, and a contact is arranged at the end of the contact column.

[0009] Furthermore, the rotating shaft of the exhaust motor is provided with fan blades for exhausting air, and the power line of the exhaust motor passes through the fixed shaft and extends to the outside of the air outlet cover.

[0010] A method for preparing an antibacterial filter with a composite adsorption structure, preparing the composite adsorption structure, the composite adsorption structure comprising an integrally formed spiral blade and a fixed shaft assembled with the axis of the spiral blade, the integrally formed spiral blade is formed by placing ball-milled slurry in a mold and drying it; the specific steps of preparing the ball-milled slurry include:

[0011] Ⅰ: Preparation of graphene oxide powder, preparation of nanosilver dispersion and preparation of nano-iron oxide powder;

[0012] II: adding the prepared nano-iron tetroxide powder and graphene oxide powder into the nano-silver dispersion, wherein the weight proportions of the solute mass in the nano-silver dispersion: the nano-iron tetroxide powder: the graphene oxide powder are 1 part: 1-10 parts: 10-100 parts;

[0013] III: directly mix to prepare a dispersion, ultrasonicate for 2 to 8 hours, and spray dry at low temperature to obtain graphene oxide / nano-iron oxide / nano-silver powder;

[0014] IV: The binder and graphene oxide / nano-iron oxide / nano-silver powder are fully mixed in a mass ratio of 1:10 to 50, and a polyvinyl alcohol aqueous solution with a mass fraction of 1 to 10% is added dropwise to the mixed powder until it becomes a paste, and the paste mixture is ball-milled at 200 r / min for 1 to 5 hours, and the slurry after ball milling is placed in a grinding tool for drying and forming.

[0015] Further,

[0016] Preparation of the graphene oxide powder: add 50-200 mL of concentrated sulfuric acid to a 250 mL reaction bottle, add a solid mixture of 1-5 g of graphite powder and 0.5-3 g of sodium nitrate under stirring, then add 5-15 g of potassium permanganate in portions, control the reaction temperature at 0-20° C., stir and react for 30-120 min, then heat to 30-50° C., continue stirring for 30-60 min, then slowly add 100-200 mL of deionized water, control the temperature at 60-90° C., continue stirring for 5-20 min, and then add 1-10 mL of hydrogen peroxide to reduce the residual oxidant so that the solution turns bright yellow, filter while hot, and wash with 1-10% HCl solution and deionized water until no sulfate is detected in the filtrate, and finally place the filter cake in a vacuum drying oven at 60° C. to fully dry to obtain graphene oxide powder;

[0017] The preparation of the nano silver dispersion is as follows: adding a reducing agent to a silver nitrate solution with a concentration of 0.1 to 10 mg / mL, stirring the solution for reaction for 30 to 120 minutes, and washing the reaction solution with deionized water to remove impurities to obtain a nano silver dispersion;

[0018] The preparation of the nano-iron tetroxide powder is as follows: 5-50 mg of ferric chloride is dissolved in 20-100 mL of ethylene glycol, and then 10-200 mg of sodium hydroxide is added, and ultrasonic dispersion is uniformly performed, and then the prepared mixture is transferred into a hydrothermal reactor, and hydrothermally treated at 80-200° C., and then the reaction liquid is washed with deionized water, and the ethylene glycol solution and excess sodium hydroxide are removed by a centrifuge, and finally the nano-iron tetroxide powder is dried.

[0019] Furthermore, the binder is polypropylene powder, and the reducing agent is one or a mixture of two or more of sodium citrate, polyethylene glycol, or ascorbic acid.

[0020] The beneficial effects of the present invention are:

[0021] The present invention designs the composite adsorption material into a spiral blade shape, which not only increases the contact area between the adsorption material and the filtered gas, but also effectively reduces the air resistance in the spiral channel to a certain extent. In particular, a convection adsorption area is provided between the left-hand spiral blade and the right-hand spiral blade whose spiral turns ratio is 2:1, and an exhaust motor and a preset number of contact contacts are provided on the axial surface of the fixed axis in the convection adsorption area, which greatly prolongs the contact time of the filtered gas and effectively alleviates the disadvantage of a long action time of the graphene oxide / nano-iron tetroxide / nano-silver composite adsorption material;

[0022] The invention abandons the traditional means of high-temperature step-by-step reaction, avoids the inactivation of graphene oxide caused by high-temperature reduction methods such as chemical reduction, microwave reduction, photocatalytic reduction, etc., and obtains a graphene oxide / ferroferric oxide / nano-silver composite adsorption material. The killing ability of the composite adsorption material on Escherichia coli is 4 times that of nano-silver. The magnetic nano-ferroferric oxide itself is also a high-efficiency catalyst, which can not only promote the decomposition of harmful gases adsorbed by the graphene oxide, but also provide active sites for the active graphene oxide, effectively protect the nano-silver, and further promote the antibacterial effect. In particular, the method can protect the nano-silver / nano-ferroferric oxide by the graphene oxide to prevent the agglomeration of the nano-silver / nano-ferroferric oxide, and can significantly improve the service life of the composite adsorption material. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attached Figure 1 It is a schematic diagram of the internal structure of the filter of the present invention;

[0024] Attached Figure 2 This is a schematic diagram of the antibacterial test of Escherichia coli in Example 1 of the present invention;

[0025] Attached Figure 3 This is a schematic diagram of the antibacterial test of Escherichia coli in Comparative Example 3 of the present invention;

[0026] Attached Figure 4 This is a schematic diagram of the antibacterial test of Escherichia coli in Comparative Example 4 of the present invention;

[0027] Attached Figure 5 This is a schematic diagram of the antibacterial test of Escherichia coli in Comparative Example 5 of the present invention;

[0028] Attached Figure 6 This is a schematic diagram of the antibacterial test of Escherichia coli in Comparative Example 6 of the present invention;

[0029] Attached Figure 7 This is a schematic diagram of the blank group Escherichia coli antibacterial test of the present invention; in the accompanying drawings:

[0030] 1. Air inlet cover, 2. Fixed shaft, 3. Shell, 4. Left-hand spiral blade, 5. Contact column, 6. Contact, 7. Fan blade, 8. Exhaust motor, 9. Right-hand spiral blade, 10. Air outlet cover, 11. Activated carbon filter box. DETAILED DESCRIPTION

[0031] In the description of the present invention, specific details are only for a full understanding of the embodiments of the present invention, but those skilled in the art should know that the implementation of the present invention is not limited to these details. In addition, well-known structures and functions are not described or shown in detail to avoid blurring the key points of the embodiments of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The specific implementation of the present invention: an antibacterial filter with a composite adsorption structure comprises a housing 3 of the filter, the housing 3 is configured as a hollow structure, and a detachable air inlet cover 1 and an air outlet cover 10 are respectively provided at the front and rear ends of the housing 3, characterized in that: the axis of the air inlet cover 1 and the air outlet cover 10 is detachably provided with a composite adsorption structure,

[0033] The composite adsorption structure includes an integrally formed spiral blade and a fixed shaft 2 assembled with the axis of the spiral blade. The outer side of the air outlet cover 10 is also provided with an activated carbon filter box 11 detachably connected to the housing 3 .

[0034] A left-hand spiral blade 4 and a right-hand spiral blade 9 are symmetrically arranged on the axial surface of the fixed shaft 2. The left-hand spiral blade 4 and the right-hand spiral blade 9 are sealed with the inner wall of the shell 3 to form a spiral channel. The ratio of the number of spiral turns of the left-hand spiral blade 4 and the right-hand spiral blade 9 is 2:1. A convection adsorption area is also arranged between the left-hand spiral blade 4 and the right-hand spiral blade 9. An exhaust motor 8 and a preset number of contact contacts are arranged on the axial surface of the fixed shaft 2 located in the convection adsorption area.

[0035] The contactor comprises a contact column 5 connected to the axial surface of the fixed shaft 2 , and a contact 6 is arranged at the end of the contact column 5 .

[0036] The rotating shaft of the exhaust motor 8 is provided with fan blades 7 for exhausting air, and the power line of the exhaust motor 8 passes through the fixed shaft 2 and extends to the outside of the air outlet cover 10.

[0037] A method for preparing an antibacterial filter with a composite adsorption structure, the composite adsorption structure comprising an integrally formed spiral blade and a fixed shaft 2 assembled with the axis of the spiral blade, the integrally formed spiral blade or contact contact is formed by placing ball-milled slurry in a mold and drying it; the specific steps of preparing the ball-milled slurry include:

[0038] Ⅰ: Preparation of graphene oxide powder, preparation of nanosilver dispersion and preparation of nano-iron oxide powder;

[0039] II: adding the prepared nano-iron tetroxide powder and graphene oxide powder into the nano-silver dispersion, wherein the weight proportions of the solute mass in the nano-silver dispersion: the nano-iron tetroxide powder: the graphene oxide powder are 1 part: 1-10 parts: 10-100 parts;

[0040] III: directly mix to prepare a dispersion, ultrasonicate for 2 to 8 hours, and spray dry at low temperature to obtain graphene oxide / nano-iron oxide / nano-silver powder;

[0041] IV: The binder and graphene oxide / nano-iron oxide / nano-silver powder are fully mixed in a mass ratio of 1:10 to 50, and a polyvinyl alcohol aqueous solution with a mass fraction of 1 to 10% is added dropwise to the mixed powder until it becomes a paste, and the paste mixture is ball-milled at 200 r / min for 1 to 5 hours, and the slurry after ball milling is placed in a grinding tool for drying and forming.

[0042] Preparation of the graphene oxide powder: add 50-200 mL of concentrated sulfuric acid to a 250 mL reaction bottle, add a solid mixture of 1-5 g of graphite powder and 0.5-3 g of sodium nitrate under stirring, then add 5-15 g of potassium permanganate in portions, control the reaction temperature at 0-20° C., stir and react for 30-120 min, then heat to 30-50° C., continue stirring for 30-60 min, then slowly add 100-200 mL of deionized water, control the temperature at 60-90° C., continue stirring for 5-20 min, and then add 1-10 mL of hydrogen peroxide to reduce the residual oxidant so that the solution turns bright yellow, filter while hot, and wash with 1-10% HCl solution and deionized water until no sulfate is detected in the filtrate, and finally place the filter cake in a vacuum drying oven at 60° C. to fully dry to obtain graphene oxide powder;

[0043] The preparation of the nano silver dispersion is as follows: adding a reducing agent to a silver nitrate solution with a concentration of 0.1 to 10 mg / mL, stirring the solution for reaction for 30 to 120 minutes, and washing the reaction solution with deionized water to remove impurities to obtain a nano silver dispersion;

[0044] The preparation of the nano-iron tetroxide powder is as follows: 5-50 mg of ferric chloride is dissolved in 20-100 mL of ethylene glycol, and then 10-200 mg of sodium hydroxide is added, and ultrasonic dispersion is uniformly performed, and then the prepared mixture is transferred into a hydrothermal reactor, and hydrothermally treated at 80-200° C., and then the reaction liquid is washed with deionized water, and the ethylene glycol solution and excess sodium hydroxide are removed by a centrifuge, and finally the nano-iron tetroxide powder is dried.

[0045] The binder is polypropylene powder, and the reducing agent is one of sodium citrate, polyethylene glycol, or ascorbic acid, or a mixture of two or more thereof.

[0046] Specifically:

[0047] Embodiment 1:

[0048] 1. The preparation process of the graphene oxide / nanosilver / nanoferric oxide composite adsorption layer is as follows:

[0049] ⑴ Add 90mL of concentrated sulfuric acid to a 250mL reaction bottle, add a solid mixture of 3g of graphite powder and 2g of sodium nitrate under stirring, and then add 12g of potassium permanganate in portions, control the reaction temperature at 0-5℃, stir the reaction for 120min, then heat to 35℃, continue stirring for 30min, then slowly add 180mL of deionized water, control the temperature at 60-80℃, continue stirring for 20min, and add 5mL of hydrogen peroxide to reduce the residual oxidant, so that the solution turns bright yellow. Filter while hot and wash with 5% HCl solution and deionized water until no sulfate is detected in the filtrate. Finally, place the filter cake in a vacuum drying oven at 60℃ to fully dry and store for later use.

[0050] ⑵ Add 2.5 mg / mL AgNO 3 8.8 mg of sodium citrate and 2 mL of polyethylene glycol were added to the solution, and the mixture was stirred for 90 min. The impurities in the reaction solution were washed clean with deionized water to obtain a nanosilver dispersion, which was stored for later use.

[0051] ⑶ Dissolve 20 mg of ferric chloride in 100 mL of ethylene glycol, then add 140 mg of sodium hydroxide, and disperse evenly by ultrasonication. Then transfer the prepared mixture into a hydrothermal reactor and perform hydrothermal treatment at 180°C. Then wash the reaction liquid with deionized water, and use a centrifuge to remove the ethylene glycol solution and excess sodium hydroxide. Finally, dry the mixture to obtain ferroferric oxide powder, which is stored for later use.

[0052] (4) Add the prepared nano-iron tetroxide powder and graphene oxide powder to the nano-silver dispersion, wherein the weight proportions of the solute mass in the nano-silver dispersion: nano-iron tetroxide powder: graphene oxide powder are 1 part: 1 part: 30 parts; ultrasonic for 4 hours, spray drying to obtain graphene oxide / iron tetroxide / nano-silver powder. Fully mix the binder polypropylene powder with the graphene oxide / iron tetroxide / nano-silver powder, the mass ratio of the two is 1:10, add 2% polyvinyl alcohol aqueous solution to the mixed powder until it becomes a paste, and ball mill the paste mixture at 200r / min for 2 hours. Take the ball-milled slurry and put it into a grinding tool for drying and forming to obtain a graphene oxide / iron tetroxide / nano-silver composite adsorption layer.

[0053] 2. Assembly of the purification filter: The outside of the filter is a cylindrical protective shell; both ends are activated carbon adsorption layers; the internal graphene oxide / ferroferric oxide / nanosilver composite adsorption layer is in the shape of spiral blades; and it is fixed by a fixed shaft.

[0054] Embodiment 2:

[0055] A method for preparing an antibacterial filter with a composite adsorption structure, the composite adsorption structure comprising an integrally formed spiral blade and a fixed shaft 2 assembled with the axis of the spiral blade, the integrally formed spiral blade or contact contact is formed by placing ball-milled slurry in a mold and drying it; the specific steps of preparing the ball-milled slurry include:

[0056] Ⅰ: Preparation of graphene oxide powder, preparation of nanosilver dispersion and preparation of nano-iron oxide powder;

[0057] II: adding the prepared nano-iron tetroxide powder and graphene oxide powder into the nano-silver dispersion, wherein the weight ratio of the solute mass in the nano-silver dispersion: the nano-iron tetroxide powder: the graphene oxide powder is 1 part: 1 part: 10 parts;

[0058] III: directly mix to prepare a dispersion, ultrasonicate for 2h, and spray dry at low temperature to obtain graphene oxide / nano-iron oxide / nano-silver powder;

[0059] IV: The binder and graphene oxide / nano-iron oxide / nano-silver powder are fully mixed in a mass ratio of 1:10, and a 1% polyvinyl alcohol aqueous solution is added dropwise to the mixed powder until it becomes a paste. The paste mixture is ball-milled at 200 r / min for 1 h, and the slurry after ball milling is placed in a grinding tool for drying and forming.

[0060] Preparation of the graphene oxide powder: add 50 mL of concentrated sulfuric acid to a 250 mL reaction bottle, add a solid mixture of 1 g of graphite powder and 0.5 g of sodium nitrate under stirring, then add 5 g of potassium permanganate in portions, control the reaction temperature at 0° C., stir and react for 30 minutes, then heat to 30° C., continue stirring for 30 minutes, then slowly add 100 mL of deionized water, control the temperature at 60° C., continue stirring for 5 minutes, and then add 1 mL of hydrogen peroxide to reduce the residual oxidant so that the solution turns bright yellow, filter while hot, and wash with 1% HCl solution and deionized water until no sulfate is detected in the filtrate, and finally place the filter cake in a vacuum drying oven at 60° C. to fully dry to obtain graphene oxide powder;

[0061] The preparation of the nanosilver dispersion is as follows: adding a reducing agent to a silver nitrate solution with a concentration of 0.1 mg / mL, stirring the solution for reaction for 30 minutes, and washing the reaction solution with deionized water to remove impurities to obtain a nanosilver dispersion;

[0062] The preparation of the nano-iron tetroxide powder is as follows: 5 mg of ferric chloride is dissolved in 20 mL of ethylene glycol, and then 10 mg of sodium hydroxide is added, and ultrasonic dispersion is uniformly performed, and then the prepared mixture is transferred into a hydrothermal reactor, and hydrothermally treated at 80° C., and then the reaction liquid is washed with deionized water, and the ethylene glycol solution and excess sodium hydroxide are removed by a centrifuge, and finally the nano-iron tetroxide powder is dried.

[0063] The binder is polypropylene powder, and the reducing agent is one of sodium citrate, polyethylene glycol, or ascorbic acid, or a mixture of two or more thereof.

[0064] Embodiment 3:

[0065] A method for preparing an antibacterial filter with a composite adsorption structure, the composite adsorption structure comprising an integrally formed spiral blade and a fixed shaft 2 assembled with the axis of the spiral blade, the integrally formed spiral blade or contact contact is formed by placing ball-milled slurry in a mold and drying it; the specific steps of preparing the ball-milled slurry include:

[0066] Ⅰ: Preparation of graphene oxide powder, preparation of nanosilver dispersion and preparation of nano-iron oxide powder;

[0067] II: adding the prepared nano-iron tetroxide powder and graphene oxide powder into the nano-silver dispersion, wherein the weight proportions of the solute mass in the nano-silver dispersion: the nano-iron tetroxide powder: the graphene oxide powder are 1 part: 10 parts: 100 parts;

[0068] III: directly mix to prepare a dispersion, ultrasonicate for 8 hours, and spray dry at low temperature to obtain graphene oxide / nano-iron oxide / nano-silver powder;

[0069] IV: The binder and graphene oxide / nano-iron oxide / nano-silver powder are fully mixed at a mass ratio of 1:50, and a 10% polyvinyl alcohol aqueous solution is added dropwise to the mixed powder until it becomes a paste. The paste mixture is ball-milled at 200 r / min for 5 h, and the slurry after ball milling is placed in a grinding tool for drying and forming.

[0070] Preparation of the graphene oxide powder: add 200 mL of concentrated sulfuric acid to a 500 mL reaction bottle, add a solid mixture of 5 g of graphite powder and 3 g of sodium nitrate under stirring, then add 15 g of potassium permanganate in portions, control the reaction temperature at 20° C., stir and react for 120 min, then heat to 50° C., continue stirring for 60 min, then slowly add 200 mL of deionized water, control the temperature at 90° C., continue stirring for 20 min, and then add 10 mL of hydrogen peroxide to reduce the residual oxidant so that the solution turns bright yellow, filter while hot, and wash with 10% HCl solution and deionized water until no sulfate is detected in the filtrate, and finally place the filter cake in a vacuum drying oven at 60° C. to fully dry to obtain graphene oxide powder;

[0071] The preparation of the nanosilver dispersion is as follows: a reducing agent is added to a silver nitrate solution with a concentration of 10 mg / mL, the mixture is stirred for reaction for 120 minutes, and impurities are washed away from the reaction solution with deionized water to obtain a nanosilver dispersion;

[0072] The preparation of the nano-iron tetroxide powder is as follows: 50 mg of ferric chloride is dissolved in 100 mL of ethylene glycol, and then 200 mg of sodium hydroxide is added, and ultrasonic dispersion is uniformly performed, and then the prepared mixture is transferred into a hydrothermal reactor, and hydrothermally treated at 200° C., and then the reaction liquid is washed with deionized water, and the ethylene glycol solution and excess sodium hydroxide are removed by a centrifuge, and finally the nano-iron tetroxide powder is dried.

[0073] The binder is polypropylene powder, and the reducing agent is one of sodium citrate, polyethylene glycol, or ascorbic acid, or a mixture of two or more thereof.

[0074] In order to more intuitively demonstrate the process advantage of the composite adsorption material of the present invention being designed into a spiral blade shape, the composite adsorption material of the present invention using a spiral blade shape is used for comparison with the graphene oxide / nano-iron oxide / nano-silver powder prepared by the preparation method of the composite adsorption structure of the present invention using the same process, and the powders are placed in different molds for drying and forming.

[0075] Comparative Example 1: The composite adsorption material is dried and formed into an annular structure, which is sleeved on the inner wall of the shell 3, and a fixed shaft is passed through the center;

[0076] Comparative Example 2: The composite adsorption material is dried to form spiral blades, and the axial surface of the fixed shaft 2 is assembled with spiral blades in the same spiral direction. A spacer is provided at the center of the fixed shaft 2, and an exhaust motor 8 is provided in the spacer;

[0077] Table 1: Comparative test data of spiral blade composite adsorption material structure

[0078] Composite adsorption material Spacer VOCs removal rate Example 1 Helical blades with positive and negative spirals Convection adsorption area 72％ Comparative Example 1 Hollow ring none 20％ Comparative Example 2 Spiral blades of the same spiral Spacer 45％

[0079] From the data analysis in Table 1, it can be seen that the present invention is compared with comparative examples 1 and 2, and it can be seen that the spiral blades with positive and negative spirals in the convection adsorption zone provided in the present invention have a superior VOCs removal rate.

[0080] This is because the composite adsorption material is designed to be in the shape of spiral blades, which not only increases the contact area between the adsorption material and the filtered gas, but also effectively reduces the air resistance in the spiral channel to a certain extent. In particular, a convection adsorption area is provided between the left-hand spiral blade and the right-hand spiral blade with a spiral turn ratio of 2:1. An exhaust motor and a preset number of contact contacts are provided on the axial surface of the fixed axis in the convection adsorption area, which greatly prolongs the contact time of the filtered gas and effectively alleviates the disadvantage of the long action time of the graphene oxide / nano-ferrous oxide / nano-silver composite adsorption material, greatly improving the VOCs removal effect to a certain extent.

[0081] In order to more intuitively demonstrate the process advantages of the composite adsorption structure preparation method of the present invention, the composite adsorption material is prepared by the present invention;

[0082] Comparative Example 3: A composite material was prepared by a stepwise reaction in accordance with the process disclosed in the national invention patent "A preparation method and application of a magnetic-nanosilver-graphene nanocomposite material" by adopting the cited method; the precipitate was dried in a vacuum drying oven at 60 degrees to obtain a powder, a 1% polyvinyl alcohol aqueous solution was added dropwise to the powder until it became a paste, and the paste mixture was ball-milled at 200r / min for 1h to obtain a ball-milled slurry;

[0083] Comparative Example 4: Graphene oxide / nanosilver powder prepared by the reduction method disclosed in the prior art, 1% polyvinyl alcohol aqueous solution was added dropwise to the mixed powder until it became a paste, and the paste mixture was ball-milled at 200 r / min for 1 h to obtain a ball-milled slurry;

[0084] Comparative Example 5: The graphene oxide powder was added to the nanosilver dispersion using the same process of the present invention, mixed to form a dispersion, ultrasonicated for 2 to 8 hours, and spray-dried at low temperature to obtain graphene oxide / nanosilver powder. A polyvinyl alcohol aqueous solution with a mass fraction of 1% was added dropwise to the above powder until it became a paste. The paste mixture was ball-milled at 200 r / min for 1 hour to obtain a ball-milled slurry;

[0085] Comparative Example 6: The single variable principle is adopted to prepare the nano silver powder by the same preparation method of the present invention, and a 1% polyvinyl alcohol aqueous solution is added dropwise to the nano silver powder until it becomes a paste, and the paste mixture is ball-milled at 200 r / min for 1 h to obtain a ball-milled slurry.

[0086] Preparation of LB medium formula (per liter): 5 g yeast extract, 15 g agar powder, 10 g tryptone, 10 g sodium chloride, adjust pH to 7.0 with NaOH, and sterilize by autoclaving at 121°C for 20 min;

[0087] When in use, the LB medium was heated and melted, and the slurry obtained in the above examples and comparative examples was added at 50-55°C at a volume ratio of 0.1%, and a plate was prepared for standby use; the E. coli culture solution of the same dilution multiple was inoculated into the culture dish by the dilution coating method, and the dish was placed in a constant temperature incubator for culture and observation:

[0088] Table 2: Data analysis of antibacterial effects of composite materials prepared by different processes

[0089] Colony map monomer method Reunion E. coli colony count Example 1 Attached Figure 2 Graphene oxide / nano-iron oxide / nano-silver Dispersion none 11 Comparative Example 3 Attached Figure 3 Graphene oxide / nano-iron oxide / nano-silver High temperature reduction none 21 Comparative Example 4 Attached Figure 4 Graphene oxide / silver nanoparticles High temperature reduction none 99 Comparative Example 5 Attached Figure 5 Graphene oxide / silver nanoparticles Dispersion none 33 Comparative Example 6 Attached Figure 6 Nano Silver Dispersion have 77 blank Attached Figure 7 none none none countless

[0090] According to the attached Figure 2-6 The number of colonies in the antibacterial test shows that:

[0091] According to the comparative analysis of Example 1 and Comparative Example 3, since Comparative Example 3 adopts the traditional high-temperature reduction, the high temperature causes the nano-scale graphene oxide structure to change, the activity is reduced, and the number of Escherichia coli colonies is high;

[0092] Comparative analysis of Example 1 and Comparative Example 5 shows that the graphene oxide / nano-iron tetroxide / nano-silver composite material has a better bactericidal effect than graphene oxide / nano-silver. This is because the magnetic nano-iron tetroxide itself is also a highly efficient catalyst, which can not only promote the decomposition of harmful gases adsorbed by graphene oxide, but also provide active sites for the active graphene oxide, effectively protecting the nano-silver and further promoting the antibacterial effect.

[0093] Comparison between Comparative Example 4 and Comparative Example 5 shows that high temperature does affect the activity of nanomaterials, resulting in a decrease in the antibacterial effect of the overall material.

[0094] In summary:

[0095] The present invention designs the composite adsorption material into a spiral blade shape, which not only increases the contact area between the adsorption material and the filtered gas, but also effectively reduces the air resistance in the spiral channel to a certain extent. In particular, a convection adsorption area is provided between the left-hand spiral blade and the right-hand spiral blade whose spiral turns ratio is 2:1, and an exhaust motor and a preset number of contact contacts are provided on the axial surface of the fixed axis in the convection adsorption area, which greatly prolongs the contact time of the filtered gas and effectively alleviates the disadvantage of a long action time of the graphene oxide / nano-iron tetroxide / nano-silver composite adsorption material;

[0096] The invention abandons the traditional means of high-temperature step-by-step reaction, avoids the inactivation of graphene oxide caused by high-temperature reduction methods such as chemical reduction, microwave reduction, photocatalytic reduction, etc., and obtains a graphene oxide / ferroferric oxide / nano-silver composite adsorption material. The killing ability of the composite adsorption material on Escherichia coli is 4 times that of nano-silver. The magnetic nano-ferroferric oxide itself is also a high-efficiency catalyst, which can not only promote the decomposition of harmful gases adsorbed by the graphene oxide, but also provide active sites for the active graphene oxide, effectively protect the nano-silver, and further promote the antibacterial effect. In particular, the method can protect the nano-silver / nano-ferroferric oxide by the graphene oxide to prevent the agglomeration of the nano-silver / nano-ferroferric oxide, and can significantly improve the service life of the composite adsorption material.

Claims

1. A method for preparing an antibacterial filter having a composite adsorption structure, characterized in that The antibacterial filter comprises a composite adsorption structure, wherein the composite adsorption structure comprises an integrally formed spiral blade and a fixed shaft (2) assembled with the axis of the spiral blade, wherein the integrally formed spiral blade is formed by placing ball-milled slurry in a mold and drying it; the specific steps of preparing the ball-milled slurry include: Ⅰ: Preparation of graphene oxide powder, preparation of nano silver dispersion and preparation of nano ferroferric oxide powder; Preparation of the nano silver dispersion: adding a reducing agent to a silver nitrate solution with a concentration of 0.1 to 10 mg / mL, stirring and reacting for 30 to 120 minutes, washing the reaction solution with deionized water to remove impurities, and obtaining a nano silver dispersion; the reducing agent is one or a mixture of two or more of sodium citrate, polyethylene glycol or ascorbic acid; II: adding the prepared nano-iron tetroxide powder and graphene oxide powder into the nano-silver dispersion, wherein the weight proportions of the solute mass in the nano-silver dispersion: the nano-iron tetroxide powder: the graphene oxide powder are 1 part: 1-10 parts: 10-100 parts; III: directly mix to prepare a dispersion, ultrasonicate for 2 to 8 hours, and spray dry at low temperature to obtain graphene oxide / nano-iron oxide / nano-silver powder; IV: The binder polypropylene powder is fully mixed with the graphene oxide / nano-iron oxide / nano-silver powder in a mass ratio of 1:10 to 50, and a polyvinyl alcohol aqueous solution with a mass fraction of 1 to 10% is added dropwise to the mixed powder until it becomes a paste, and the paste mixture is ball-milled at 200 r / min for 1 to 5 hours, and the slurry after ball milling is placed in a grinding tool for drying and forming.

2. The method for preparing an antibacterial filter having a composite adsorption structure according to claim 1, characterized in that: Preparation of the graphene oxide powder: add 50-200 mL of concentrated sulfuric acid to a 250 mL reaction bottle, add a solid mixture of 1-5 g of graphite powder and 0.5-3 g of sodium nitrate under stirring, then add 5-15 g of potassium permanganate in portions, control the reaction temperature at 0-20° C., stir and react for 30-120 min, then heat to 30-50° C., continue stirring for 30-60 min, then slowly add 100-200 mL of deionized water, control the temperature at 60-90° C., continue stirring for 5-20 min, and then add 1-10 mL of hydrogen peroxide to reduce the residual oxidant so that the solution turns bright yellow, filter while hot, and wash with 1-10% HCl solution and deionized water until no sulfate is detected in the filtrate, and finally place the filter cake in a vacuum drying oven at 60° C. to fully dry to obtain graphene oxide powder; The preparation of the nano-iron tetroxide powder is as follows: 5-50 mg of ferric chloride is dissolved in 20-100 mL of ethylene glycol, and then 10-200 mg of sodium hydroxide is added, and ultrasonic dispersion is uniformly performed, and then the prepared mixture is transferred into a hydrothermal reactor, and hydrothermally treated at 80-200° C., and then the reaction liquid is washed with deionized water, and the ethylene glycol solution and excess sodium hydroxide are removed by a centrifuge, and finally the nano-iron tetroxide powder is dried.

3. The method for preparing an antibacterial filter having a composite adsorption structure according to claim 2, characterized in that The antibacterial filter comprises a filter housing (3), the housing (3) being configured as a hollow structure, and a detachable air inlet cover (1) and an air outlet cover (10) being respectively provided at the front and rear ends of the housing (3), wherein the air inlet cover (1) and the air outlet cover (10) are characterized in that the axis of the air inlet cover (1) and the air outlet cover (10) are detachably provided with a composite adsorption structure, The composite adsorption structure comprises an integrally formed spiral blade and a fixed shaft (2) assembled with the axis of the spiral blade, and an activated carbon filter box (11) detachably connected to the shell (3) is also provided on the outer side of the air outlet cover (10).

4. The method for preparing the antibacterial filter having a composite adsorption structure according to claim 3, characterized in that The axial surface of the fixed shaft (2) is symmetrically equipped with a left-hand spiral blade (4) and a right-hand spiral blade (9). The left-hand spiral blade (4) and the right-hand spiral blade (9) are sealed with the inner wall of the shell (3) to form a spiral channel. The ratio of the number of spiral turns of the left-hand spiral blade (4) and the right-hand spiral blade (9) is 2:

1. A convection adsorption area is also arranged between the left-hand spiral blade (4) and the right-hand spiral blade (9). An exhaust motor (8) and a preset number of contact contacts are arranged on the axial surface of the fixed shaft (2) located in the convection adsorption area.

5. The method for preparing an antibacterial filter having a composite adsorption structure according to claim 4, characterized in that The contacting contact comprises a contacting post (5) connected to the axial surface of the fixed shaft (2), and a contact (6) is arranged at the end of the contacting post (5).

6. The method for preparing an antibacterial filter having a composite adsorption structure according to claim 4, characterized in that The rotating shaft of the exhaust motor (8) is provided with fan blades (7) for exhausting air, and the power line of the exhaust motor (8) passes through the fixed shaft (2) and extends to the outside of the air outlet cover (10).

Images