Antibacterial ionically controlled release fibers, air filtration materials and methods of making the same

Abstract

The application discloses antibacterial ion controllable release fiber, air filtering material and a preparation method thereof, wherein the antibacterial ion controllable release air filtering material comprises a fiber body, dopamine attached to the fiber body, an antibacterial agent deposited on the dopamine surface of the fiber body, and a controllable release layer attached to the antibacterial agent surface; the raw material of the controllable release layer is a substance swelling in a bacterial metabolic environment. The application overcomes the defect that the antibacterial filtering material disclosed in the prior art does not have long-acting property, has a bactericidal ion controllable release bactericidal function, a bactericidal retention rate > 99%, and a storage time > 70 days.

Description

Technical Field

[0001] This invention relates to the field of antibacterial air filter materials, specifically to a fiber with controlled release of antibacterial ions, an air filter material, and a method for preparing the same. Background Technology

[0002] Antibacterial air filter materials are crucial for purifying bioaerosols in enclosed spaces and preventing diseases caused by microorganisms. Filter materials acquire their antibacterial function by loading antibacterial materials (Ag, CuO, ZnO, TiO2, quaternary ammonium salts). Common loading methods include impregnation, aerosol deposition, and electrospinning. However, in the impregnation method, antibacterial substances easily clog the pores of the filter material and are unevenly distributed, resulting in high resistance and energy consumption in the prepared antibacterial air filter material. Antibacterial filter materials prepared by intercepting nano-silver particle aerosols exhibit increased resistance after being loaded onto the filter material surface compared to materials without nano-silver particles, and the nano-silver particles are prone to detachment from the fiber surface. Antibacterial filter materials prepared by electrospinning have poor strength, making it difficult to ensure stable performance during use.

[0003] However, the antibacterial agents in existing antibacterial filter materials are released uncontrollably during use, resulting in the bactericidal function of the filter materials not being long-lasting. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the antibacterial filter materials disclosed in the prior art do not have long-lasting effect, thereby providing an air filter material with controlled release of antibacterial ions that effectively extends the life of antibacterial materials and its preparation method.

[0005] A fiber with controlled release of antibacterial ions includes a fiber body, dopamine attached to the fiber body, an antibacterial agent deposited on the surface of the dopamine on the fiber body, and a controlled release layer attached to the surface of the antibacterial agent.

[0006] The raw materials for the controlled release layer include one or more of chitosan and PAA (polyacrylic acid).

[0007] The loading amount of the controlled-release layer in the fiber with controlled release of antibacterial ions is 0.1 wt% or more, preferably 0.3% or more, and more preferably 0.3-50%. For example, the loading amount of the controlled-release layer in the fiber with controlled release of antibacterial ions is 0.1 wt%, 0.3 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, etc.

[0008] The loading amount of the antibacterial agent in the fiber with controlled release of antibacterial ions is 0.2 wt% or more, preferably 5 wt% to 30 wt%. For example, the loading amount of the antibacterial agent in the fiber with controlled release of antibacterial ions is 0.2 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, etc.

[0009] The antibacterial agent includes one or more of Ag, CuO, ZnO, TiO2, and quaternary ammonium salts.

[0010] When the antibacterial agent includes one or more of Ag, CuO, ZnO, and TiO2, the loading of the antibacterial agent in the fiber with controllable release of antibacterial ions is more than 2 wt%, preferably 5 wt% to 30 wt%.

[0011] The fiber body includes one or more of the following: cellulose fiber, Tencel fiber, glass fiber, PP fiber, PET fiber, and aramid fiber.

[0012] A method for preparing a fiber with controlled release of antibacterial ions, comprising:

[0013] Obtain fibers with dopamine-mediated in-situ surface loading of antibacterial agents;

[0014] Preparation of controlled release layer: Dopamine-mediated in-situ surface-loaded antibacterial agent fiber is mixed with controlled release layer solution, and after cleaning, fiber with controlled release of antibacterial ions is obtained.

[0015] The preparation process of the dopamine-mediated surface-loaded antibacterial agent fiber includes:

[0016] Dopamine adhesion: The uniformly dispersed fiber body is mixed with a dopamine solution and stirred to obtain fibers with polydopamine deposited on the surface.

[0017] Deposition of antibacterial agents: Fibers with surface-deposited polydopamine are mixed with an antibacterial agent raw material solution, and after reaction, dopamine-mediated in-situ surface-loaded antibacterial agents are obtained.

[0018] The concentration of the dopamine solution is 0.5 g / L to 4.0 g / L;

[0019] And / or, the mass ratio of the fiber body to dopamine is (0.2–3.0):(0.5–4.0);

[0020] And / or, in the dopamine attachment step, the stirring reaction time is 12 to 24 hours.

[0021] When the antibacterial agent raw material solution includes a metal ion solution and a reducing agent, the concentration of metal ions in the metal ion solution is 5–40 g / L.

[0022] When the antibacterial agent raw material solution includes a quaternary ammonium salt, the concentration of the antibacterial agent raw material solution is 0.2 wt% or more.

[0023] And / or, the metal ion solution includes a silver ion solution, preferably a silver nitrate solution;

[0024] And / or, the reducing agent includes one or more of sodium borohydride, glucose, sodium citrate, or DMAB (dimethylaminobenzaldehyde);

[0025] And / or, the mass ratio of the surface-deposited polydopamine fiber to the antibacterial agent is 70:30-95:5.

[0026] The concentration of the controlled-release layer solution is 0.1–10 g / L;

[0027] And / or, the mass ratio of the dopamine-mediated surface-loaded antibacterial agent fiber to the controlled-release layer is (0.2–3):(0.01–0.1).

[0028] An air filter material with controlled release of antibacterial ions, comprising a fiber prepared by a wet process; wherein the fiber is the aforementioned antibacterial ion controlled release fiber or an antibacterial ion controlled release fiber prepared by the aforementioned preparation method.

[0029] Preferably, the wet process is a papermaking method.

[0030] The technical solution of this invention has the following advantages:

[0031] 1. The present invention provides a fiber with controlled release of antibacterial ions. The controlled release layer swells in acidic or alkaline environments where bacteria metabolize, increasing the release rate of bactericidal ions in the antibacterial agent and achieving a better bactericidal effect. In an environment without bacteria, the molecular chains of the controlled release layer contract, which can inhibit the release of antibacterial ions in the antibacterial agent, thereby effectively extending the effective life of the antibacterial material. That is, in a neutral environment where there are no bacteria on the surface, the release of antibacterial ions (antibacterial agent) is slow, while in an acidic or alkaline environment where bacteria are present, the release of antibacterial ions (antibacterial agent) is rapid. It has a bactericidal function with controlled release of bactericidal ions, a bactericidal retention rate of >99%, and a storage time of more than 70 days.

[0032] 2. In the method of this invention, antibacterial filter materials prepared by polydopamine-mediated fiber are deposited with antibacterial agents in situ, and an antibacterial metal layer composed of antibacterial agents such as silver and copper is deposited in situ on the surface. Subsequently, a controlled release layer (chitosan, PAA, etc.) is modified on the surface of the antibacterial metal layer. Then, the fibers with in situ deposited antibacterial agents and controlled release layers are prepared into high-efficiency air filter materials by wet processing. The filter materials prepared by this method do not significantly increase the resistance. Compared with antibacterial filter materials prepared by traditional impregnation methods, the filter materials prepared by this method have a filtration efficiency increased by 10% to 30% and a resistance decreased by 10% to 30%. The kill rate of Gram-positive and Gram-negative bacteria is greater than 90%, and can even reach more than 99%.

[0033] 3. The air filter material with controlled release of antibacterial ions in this invention can be used for indoor air purification (residential, commercial buildings, civil defense projects, and enclosed cabins), effectively intercepting and killing bioaerosols. Through in-situ deposition of antibacterial agents on the fiber surface, the antibacterial agent is uniformly loaded onto the surface of the fiber body, avoiding the problem of pore blockage between the fibers; the prepared material has low resistance and low energy consumption. Simultaneously, the controlled release layer of high-molecular-weight material on the surface of the antibacterial agent responds to pH, enabling the effective release of bactericidal ions from the antibacterial agent when bacteria are present on the surface of the air filter material; when there are no bacteria on the surface of the air filter material, the controlled release layer can inhibit the release of bactericidal ions, effectively extending the duration of the kill rate against Gram-positive and Gram-negative bacteria to greater than 99%. Detailed Implementation

[0034] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0035] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0036] Example 1

[0037] A fiber with controlled release of antibacterial ions, the preparation method of which is as follows:

[0038] 1. Dopamine attachment

[0039] A dopamine solution with a concentration of 2.0 g / L was prepared. A certain amount of fiber bulk (using cellulose fibers with a diameter of 15-30 μm and a length of 2-5 mm) was dispersed and placed into the dopamine solution. The mass concentration of the fiber bulk after addition was 1.5 g / L. The mixture was stirred and reacted for 12 hours to obtain fibers with surface-deposited polydopamine. The mass ratio of the fiber bulk to dopamine was 1.5:2.

[0040] 2. Deposition of antibacterial agents

[0041] After rinsing the fibers with surface-deposited polydopamine, they were placed in a metal ion solution (i.e., silver ammonia solution; the silver ammonia solution was obtained by adding 28-30% ammonia water dropwise to a 20g / L silver nitrate solution until it became clear) and dispersed evenly to obtain a fiber solution. A reducing agent (glucose) was added to the evenly dispersed fiber solution, and the glucose content in the metal ion solution was 40g / L after the addition. After the reaction was complete, the fibers were taken out and washed with deionized water to obtain fibers with dopamine-mediated in-situ surface-loaded antibacterial agents. The mass ratio of surface-deposited polydopamine fibers to antibacterial agents was 100:8.

[0042] 3. Preparation of the controlled release layer

[0043] 3g of dopamine-mediated surface-loaded antibacterial agent-coated fiber was immersed in 100mL of a controlled-release layer solution (pH-sensitive polymer solution). The controlled-release layer solution was a chitosan-acetic acid solution with a chitosan concentration of 0.1g / L. After 120min, the fiber was removed and rinsed with deionized water to obtain fiber with controlled release of antibacterial ions. In this embodiment, the mass ratio of the dopamine-mediated surface-loaded antibacterial agent-coated fiber to the controlled-release layer was 3:0.01, meaning the loading of the controlled-release layer in the fiber with controlled release of antibacterial ions was approximately 0.3wt%.

[0044] An air filter material with controlled release of antibacterial ions is prepared by means of the following method: the air filter material is prepared by papermaking using fibers with controlled release of antibacterial ions.

[0045] The papermaking method described herein comprises the conventional papermaking processes of pulp preparation, conveying, forming, dewatering, drying, and finishing. Specifically, fibers with controllable release of antibacterial ions are separately prepared into fiber pulp. The prepared fiber pulp is then transported through pipelines to the forming wire section. The fiber pulp enters the forming wire section and forms a uniform humid air filter material on a high-speed running conveyor belt. The humid air filter material is gradually dewatered through a vacuum suction box, press rollers, and other equipment to form a semi-dry air filter material with a certain strength. The semi-dry air filter material enters the drying section and is heated and dried by multiple sets of drying cylinders until the final moisture content is reduced to about 5%. The dried air filter material is then cut and slit as needed to obtain the final product 1a.

[0046] Comparative Example 1

[0047] The difference from Example 1 is that the air filter material 1b is prepared by replacing the fiber with dopamine-mediated surface in-situ antibacterial agent in Example 1 with the fiber with controlled release of antibacterial ions, or the air filter material 1c is prepared directly by replacing the fiber body in Example 1 with the fiber with controlled release of antibacterial ions. The other processes for preparing the air filter material are exactly the same as those in Example 1.

[0048] Example 2

[0049] A fiber with controlled release of antibacterial ions, the preparation method of which is as follows:

[0050] 1. Dopamine attachment

[0051] A dopamine solution with a concentration of 0.5 g / L was prepared. A certain amount of fiber bulk (using fibrillated Tencel fibers with an average diameter of 2 μm and a length of 1 mm) was dispersed and placed into the dopamine solution. The mass concentration of the fiber bulk after addition was 0.5 g / L. The mixture was stirred and reacted for 24 hours to obtain fibers with polydopamine deposited on the surface. The mass ratio of the fiber bulk to dopamine was 0.5:0.5.

[0052] 2. Deposition of antibacterial agents

[0053] After rinsing the surface-deposited polydopamine fibers, they were placed in a metal ion solution (i.e., silver ammonia solution; the silver ammonia solution was obtained by adding 28-30% ammonia water dropwise to a 25g / L silver nitrate solution until it became clear) and dispersed evenly to obtain a fiber solution. A reducing agent (glucose) was added to the evenly dispersed fiber solution, and the mass concentration of glucose in the metal ion solution after addition was 50g / L. After the reaction was complete, the fibers were taken out and washed with deionized water to obtain dopamine-mediated fibers with in-situ surface-loaded antibacterial agents. The mass ratio of surface-deposited polydopamine fibers to antibacterial agents was 100:30.

[0054] 3. Preparation of the controlled release layer

[0055] 2.5 g of dopamine-mediated surface-loaded antibacterial agent fiber was immersed in 100 mL of a controlled-release layer solution (pH-sensitive polymer solution), which was a chitosan-acetic acid solution with a chitosan concentration of 1 g / L. After 240 min, the fiber was removed and rinsed with deionized water to obtain fiber with controlled release of antibacterial ions. In this embodiment, the mass ratio of dopamine-mediated surface-loaded antibacterial agent fiber to controlled-release layer was 2.5:0.1, that is, the loading of controlled-release layer in fiber with controlled release of antibacterial ions was approximately 4 wt%.

[0056] An air filter material with controlled release of antibacterial ions is prepared by means of the following method: the air filter material is prepared by papermaking using fibers with controlled release of antibacterial ions.

[0057] The papermaking method described herein comprises the conventional papermaking processes of pulp preparation, conveying, forming, dewatering, drying, and finishing. Specifically, fibers with controllable release of antibacterial ions are separately prepared into fiber pulp. The prepared fiber pulp is then transported through pipelines to the forming wire section. The fiber pulp enters the forming wire section and forms a uniform humid air filter material on a high-speed running conveyor belt. The humid air filter material is gradually dewatered through a vacuum suction box, press rollers, and other equipment to form a semi-dry air filter material with a certain strength. The semi-dry air filter material enters the drying section and is heated and dried by multiple sets of drying cylinders until the final moisture content is reduced to approximately 5%. The dried air filter material is then cut and slit as needed to obtain the final product 2a.

[0058] Comparative Example 2

[0059] The difference from Example 2 is that the air filter material 2b is prepared by replacing the fiber with the fiber that releases antibacterial ions in a controlled manner with the dopamine-mediated surface in situ loading of antibacterial agent as in Example 2, or the air filter material 2c is prepared directly by replacing the fiber body with the fiber that releases antibacterial ions as in Example 2. The other processes for preparing the air filter material are exactly the same as in Example 2.

[0060] Example 3

[0061] A fiber with controlled release of antibacterial ions, the preparation method of which is as follows:

[0062] 1. Dopamine attachment

[0063] A dopamine solution with a concentration of 4.0 g / L was prepared. A certain amount of fiber body (glass fiber with an average diameter of 200 nm to 1 μm and a length of 1 to 5 mm) was dispersed and placed into the dopamine solution. The mass concentration of the fiber body after addition was 3.0 g / L. The mixture was stirred and reacted for 18 hours to obtain fibers with surface-deposited polydopamine. The mass ratio of the fiber body to dopamine was 3:4.

[0064] 2. Deposition of antibacterial agents

[0065] After rinsing the fibers with surface-deposited polydopamine, they were placed in a metal ion solution (i.e., silver ammonia solution; the silver ammonia solution was obtained by adding 28-30% ammonia water dropwise to a 40g / L silver nitrate solution until it became clear) and dispersed evenly to obtain a fiber solution. A reducing agent (glucose) was added to the evenly dispersed fiber solution, and the mass concentration of glucose in the metal ion solution after addition was 80g / L. After the reaction was complete, the fibers were taken out and washed with deionized water to obtain fibers with dopamine-mediated in-situ surface-loaded antibacterial agents. The mass ratio of surface-deposited polydopamine fibers to antibacterial agents was 100:8.

[0066] 3. Preparation of the controlled release layer

[0067] 2g of dopamine-mediated surface-loaded antibacterial agent fiber was immersed in 100mL of controlled-release layer solution (pH-sensitive polymer solution). The controlled-release layer solution was a chitosan-glacial acetic acid solution with a concentration of 10g / L. After 180min, the fiber was removed and rinsed with deionized water to obtain fiber with controlled release of antibacterial ions. In this embodiment, the mass ratio of dopamine-mediated surface-loaded antibacterial agent fiber to controlled-release layer was 2:1, that is, the loading of controlled-release layer in fiber with controlled release of antibacterial ions was about 50wt%.

[0068] An air filter material with controlled release of antibacterial ions is prepared by means of the following method: the air filter material is prepared by papermaking using fibers with controlled release of antibacterial ions.

[0069] The papermaking method described herein comprises the conventional papermaking processes of pulp preparation, conveying, forming, dewatering, drying, and finishing. Specifically, fibers with controllable antibacterial ion release are separately prepared into fiber pulp. The prepared fiber pulp is then transported through pipelines to the forming wire section. The fiber pulp enters the forming wire section and forms a uniform humid air filter material on a high-speed running conveyor belt. The humid air filter material is gradually dewatered through equipment such as a vacuum suction box and press rollers, forming a semi-dry air filter material with a certain strength. The semi-dry air filter material enters the drying section and is heated and dried by multiple sets of drying cylinders until the final moisture content is reduced to about 5%. The dried air filter material is then cut and slit as needed to obtain the final product 3a.

[0070] Comparative Example 3

[0071] The difference from Example 3 is that the air filter material 3b is prepared directly by replacing the fiber with the controlled release of antibacterial ions with the dopamine-mediated surface in situ loading antibacterial agent as in Example 3, or the air filter material 3c is prepared directly by replacing the fiber body with the controlled release of antibacterial ions as in Example 3. The other processes for preparing the air filter material are exactly the same as in Example 3.

[0072] Example 4

[0073] A fiber with controlled release of antibacterial ions, the preparation method of which is as follows:

[0074] 1. Dopamine attachment

[0075] A dopamine solution with a concentration of 2 g / L was prepared. A certain amount of fiber body (PP fiber with a diameter of 17 μm and a length of 6 mm) was dispersed and placed into the dopamine solution. The mass concentration of the fiber body after addition was 1.0 g / L. The mixture was stirred and reacted for 18 hours to obtain fibers with surface-deposited polydopamine. The mass ratio of the fiber body to dopamine was 1:2.

[0076] 2. Deposition of antibacterial agents

[0077] After rinsing the fibers with surface-deposited polydopamine, they were placed in a metal ion solution (i.e., silver ammonia solution; the silver ammonia solution was obtained by adding 28-30% ammonia water dropwise to a 40g / L silver nitrate solution until it became clear) and dispersed evenly to obtain a fiber solution. A reducing agent (sodium borohydride) was added to the evenly dispersed fiber solution. After the addition, the mass concentration of sodium borohydride in the metal ion solution was 50g / L. After the reaction was complete, the fibers were taken out and washed with deionized water to obtain fibers with dopamine-mediated in-situ surface-loaded antibacterial agents. The mass ratio of surface-deposited polydopamine fibers to antibacterial agents was 100:25.

[0078] 3. Preparation of the controlled release layer

[0079] 1 g of dopamine-mediated surface-loaded antibacterial agent fiber was immersed in 100 mL of a controlled-release layer solution (pH-sensitive polymer solution). The controlled-release layer solution was a chitosan-acetic acid solution with a chitosan concentration of 0.3 g / L. After 120 min, the fiber was removed and rinsed with deionized water to obtain fiber with controlled release of antibacterial ions. In this embodiment, the mass ratio of dopamine-mediated surface-loaded antibacterial agent fiber to controlled-release layer was 1:0.03, that is, the loading amount of controlled-release layer in fiber with controlled release of antibacterial ions was about 3 wt%.

[0080] An air filter material with controlled release of antibacterial ions is prepared by means of the following method: the air filter material is prepared by papermaking using fibers with controlled release of antibacterial ions.

[0081] The papermaking method described herein comprises the conventional papermaking processes of pulp preparation, conveying, forming, dewatering, drying, and finishing. Specifically, fibers with controllable release of antibacterial ions are separately prepared into fiber pulp. The prepared fiber pulp is then transported through pipelines to the forming wire section. The fiber pulp enters the forming wire section and forms a uniform humid air filter material on a high-speed running conveyor belt. The humid air filter material is gradually dewatered through equipment such as a vacuum suction box and press rollers, forming a semi-dry air filter material with a certain strength. The semi-dry air filter material enters the drying section and is heated and dried by multiple sets of drying cylinders until the final moisture content is reduced to about 5%. The dried air filter material is then cut and slit as needed to obtain the final product 4a.

[0082] Comparative Example 4

[0083] The difference from Example 4 is that the air filter material 4b is prepared by replacing the fiber with the fiber that releases antibacterial ions in a controlled manner with the dopamine-mediated surface in situ loading of antibacterial agent as in Example 4, or the air filter material 4c is prepared directly by replacing the fiber body with the fiber that releases antibacterial ions as in Example 4. The other processes for preparing the air filter material are exactly the same as those in Example 4.

[0084] Example 5

[0085] A fiber with controlled release of antibacterial ions, the preparation method of which is as follows:

[0086] 1. Dopamine attachment

[0087] A dopamine solution with a concentration of 1.0 g / L was prepared. A certain amount of fiber body (using aramid fiber with a diameter of 12 μm and a length of 6 mm) was dispersed and placed into the dopamine solution. The mass concentration of the fiber body after addition was 2.0 g / L. The mixture was stirred and reacted for 12 hours to obtain fiber with surface-deposited polydopamine. The mass ratio of the fiber body to dopamine was 1:2.

[0088] 2. Deposition of antibacterial agents

[0089] After rinsing the fibers with surface-deposited polydopamine, they were placed in a metal ion solution (i.e., silver ammonia solution; the silver ammonia solution was obtained by adding 28-30% ammonia water dropwise to a 20g / L silver nitrate solution until it became clear) and dispersed evenly to obtain a fiber solution. A reducing agent (sodium citrate) was added to the evenly dispersed fiber solution, and the mass concentration of sodium citrate in the metal ion solution after addition was 25g / L. After the reaction was complete, the fibers were taken out and washed with deionized water to obtain fibers with dopamine-mediated in-situ surface-loaded antibacterial agents. The mass ratio of surface-deposited polydopamine fibers to antibacterial agents was 100:6.

[0090] 3. Preparation of the controlled release layer

[0091] 1 g of dopamine-mediated surface-loaded antibacterial agent fiber was immersed in 100 mL of a controlled-release layer solution (pH-sensitive polymer solution). The controlled-release layer solution was a 2 g / L chitosan-glacial acetic acid solution. After 240 min, the fiber was removed and rinsed with deionized water to obtain fiber with controlled release of antibacterial ions. In this embodiment, the mass ratio of dopamine-mediated surface-loaded antibacterial agent fiber to controlled-release layer was 1:0.2, that is, the loading of controlled-release layer in fiber with controlled release of antibacterial ions was about 20 wt%.

[0092] An air filter material with controlled release of antibacterial ions is prepared by means of the following method: the air filter material is prepared by papermaking using fibers with controlled release of antibacterial ions.

[0093] The papermaking method described herein comprises the conventional papermaking processes of pulp preparation, conveying, forming, dewatering, drying, and finishing. Specifically, fibers with controllable release of antibacterial ions are separately prepared into fiber pulp. The prepared fiber pulp is then transported through pipelines to the forming wire section. The fiber pulp enters the forming wire section and forms a uniform humid air filter material on a high-speed running conveyor belt. The humid air filter material is gradually dewatered through a vacuum suction box, press rollers, and other equipment to form a semi-dry air filter material with a certain strength. The semi-dry air filter material enters the drying section and is heated and dried by multiple sets of drying cylinders until the final moisture content is reduced to about 5%. The dried air filter material is then cut and slit as needed to obtain the final product 5a.

[0094] Comparative Example 5

[0095] The difference from Example 5 is that the air filter material 5b is prepared by replacing the fiber with the controlled release of antibacterial ions with the dopamine-mediated surface in situ loading antibacterial agent as in Example 5, or the air filter material 5c is prepared directly by replacing the fiber body with the controlled release of antibacterial ions as in Example 5. The other processes for preparing the air filter material are exactly the same as those in Example 5.

[0096] Example 6

[0097] A fiber with controlled release of antibacterial ions, the preparation method of which is as follows:

[0098] 1. Dopamine attachment

[0099] A dopamine solution with a concentration of 2.0 g / L was prepared. A certain amount of fiber bulk (using cellulose fibers with a diameter of 15-30 μm and a length of 2-4 mm) was dispersed and placed into the dopamine solution. The mass concentration of the fiber bulk after addition was 1.5 g / L. The mixture was stirred and reacted for 12 hours to obtain fibers with surface-deposited polydopamine. The mass ratio of the fiber bulk to dopamine was 1.5:2.

[0100] 2. Deposition of antibacterial agents

[0101] After rinsing the surface-deposited polydopamine fibers, they were placed in a metal ion solution (containing a mixed solution of 50 mM copper chloride, 100 mM boric acid, and 50 mM EDTA, with the pH of the mixed solution adjusted to 7) and dispersed evenly to obtain a fiber solution. A reducing agent (DMAB solution) was added to the evenly dispersed fiber solution. The mass concentration of the added DMAB in the metal ion solution was 100 mM (14.9 g / L). After the reaction was complete, the fibers were removed and washed with deionized water to obtain dopamine-mediated fibers with in-situ surface-loaded antibacterial agents. The mass ratio of surface-deposited polydopamine fibers to antibacterial agents was 100:15.

[0102] 3. Preparation of the controlled release layer

[0103] 1 g of dopamine-mediated surface-loaded antibacterial agent fiber was immersed in 100 mL of a controlled-release layer solution (pH-sensitive polymer solution). The controlled-release layer solution was a PAA solution with a concentration of 2 g / L. After 120 min, the fiber was removed and rinsed with deionized water to obtain fiber with controlled release of antibacterial ions. In this embodiment, the mass ratio of dopamine-mediated surface-loaded antibacterial agent fiber to controlled-release layer was 1:0.2, that is, the loading of controlled-release layer in fiber with controlled release of antibacterial ions was about 20 wt%.

[0104] An air filter material with controlled release of antibacterial ions is prepared by means of the following method: the air filter material is prepared by papermaking using fibers with controlled release of antibacterial ions.

[0105] The papermaking method described herein comprises the conventional papermaking processes of pulp preparation, conveying, forming, dewatering, drying, and finishing. Specifically, fibers with controllable release of antibacterial ions are separately prepared into fiber pulp. The prepared fiber pulp is then transported through pipelines to the forming wire section. The fiber pulp enters the forming wire section and forms a uniform humid air filter material on a high-speed running conveyor belt. The humid air filter material is gradually dewatered through a vacuum suction box, press rollers, and other equipment to form a semi-dry air filter material with a certain strength. The semi-dry air filter material enters the drying section and is heated and dried by multiple sets of drying cylinders until the final moisture content is reduced to about 5%. The dried air filter material is then cut and slit as needed to obtain the final product 6a.

[0106] Example 7

[0107] A fiber with controlled release of antibacterial ions, the preparation method of which is as follows:

[0108] 1. Dopamine attachment

[0109] A dopamine solution with a concentration of 2.0 g / L was prepared. A certain amount of fiber bulk (using fibrillated nanocellulose fibers with a diameter of 200 nm-2 μm and a length of 1-3 mm) was dispersed and placed into the dopamine solution. The mass concentration of the fiber bulk after addition was 1.5 g / L. The mixture was stirred and reacted for 12 hours to obtain fibers with polydopamine deposited on the surface. The mass ratio of the fiber bulk to dopamine was 1.5:2.

[0110] 2. Deposition of antibacterial agents

[0111] After rinsing the fibers with surface-deposited polydopamine, they were placed in an antibacterial agent solution (a 0.1 g / L solution of 2,3-epoxypropyltrimethylammonium chloride) and dispersed evenly to obtain a fiber solution. After the reaction was complete, the fibers were removed and cleaned with deionized water to obtain fibers with dopamine-mediated in-situ surface-loaded antibacterial agent. The mass ratio of the surface-deposited polydopamine fibers to the antibacterial agent 2,3-epoxypropyltrimethylammonium chloride was 400:1.

[0112] 3. Preparation of the controlled release layer

[0113] Five g of dopamine-mediated surface-loaded antibacterial agent-coated fiber was immersed in 100 mL of a controlled-release layer solution (pH-sensitive polymer solution). The controlled-release layer solution was a 3 g / L PAA solution. After 240 min, the fiber was removed and rinsed with deionized water to obtain fiber with controlled release of antibacterial ions. In this embodiment, the mass ratio of dopamine-mediated surface-loaded antibacterial agent-coated fiber to controlled-release layer was 5:0.3, that is, the loading of controlled-release layer in fiber with controlled release of antibacterial ions was approximately 5.7 wt%.

[0114] An air filter material with controlled release of antibacterial ions is prepared by means of the following method: the air filter material is prepared by papermaking using fibers with controlled release of antibacterial ions.

[0115] The papermaking method described herein comprises the conventional papermaking processes of pulp preparation, conveying, forming, dewatering, drying, and finishing. Specifically, fibers with controllable release of antibacterial ions are separately prepared into fiber pulp. The prepared fiber pulp is then transported through pipelines to the forming wire section. The fiber pulp enters the forming wire section and forms a uniform humid air filter material on a high-speed running conveyor belt. The humid air filter material is gradually dewatered through a vacuum suction box, press rollers, and other equipment to form a semi-dry air filter material with a certain strength. The semi-dry air filter material enters the drying section and is heated and dried by multiple sets of drying cylinders until the final moisture content is reduced to about 5%. The dried air filter material is then cut and slit as needed to obtain the final product 7a.

[0116] Comparative Example 6

[0117] The difference from Example 1 is that the air filter material d is prepared directly from the fiber body of Example 1, which is prepared by conventional impregnation method and loaded with antibacterial agent.

[0118] The preparation process of the antibacterial agent-loaded fiber prepared by the conventional impregnation method is as follows:

[0119] The fiber body was directly placed into a metal ion solution (the same antibacterial agent raw material solution as in Example 1) and dispersed evenly to obtain a fiber solution. A reducing agent (40 g / L glucose solution) was added to the evenly dispersed fiber solution. After the reaction was complete, the fiber was taken out and washed with deionized water to obtain fiber loaded with antibacterial agent.

[0120] Experimental Example

[0121] The filtration efficiency (surface velocity 5.3 cm / s), resistance (surface velocity 5.3 cm / s), and shelf life with antibacterial efficiency greater than 99% of the different air filter materials in the examples and comparative examples were tested.

[0122] The testing process for filtration efficiency (surface velocity 5.3 cm / s) and resistance (surface velocity 5.3 cm / s) is as follows:

[0123] According to the test method in standard GB 2626-2019 Respiratory Protective Self-priming Filtering Particulate Respirators, the single-sheet filter material efficiency test bench was used for testing.

[0124] The process for testing antibacterial efficiency is as follows:

[0125] According to standard GB / T 20944.3-200 Evaluation of antibacterial properties of textiles - Part 3: Oscillation method, the bactericidal efficiency of antibacterial filter materials was tested.

[0126] The testing process for determining the shelf life with an antibacterial retention rate greater than 99% is as follows:

[0127] The filter material loaded with the controlled-release bactericidal layer was stored for 180 days. The bactericidal efficiency of the filter material during the storage process was tested according to the antibacterial efficiency test method, and the number of days when the antibacterial retention rate was greater than 99% compared with the first test was obtained.

[0128] The detection results of the above embodiments and comparative examples are shown in Table 1 below.

[0129] Table 1

[0130]

[0131]

[0132] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A fiber with controlled release of antibacterial ions, characterized in that, It includes the fiber body, polydopamine attached to the fiber body, an antibacterial agent deposited on the surface of the polydopamine on the fiber body, and a controlled release layer attached to the surface of the antibacterial agent. The raw material of the controlled-release layer is a substance that swells in the environment of bacterial metabolism; the raw material of the controlled-release layer includes one or more of chitosan and PAA; the loading amount of the controlled-release layer in the fiber with controlled release of antibacterial ions is 0.3 wt%-50 wt%. The loading of the antibacterial agent in the fiber with controlled release of antibacterial ions is 5wt%-30wt%.

2. The fiber according to claim 1, characterized in that, The antibacterial agent includes one or more of Ag, CuO, ZnO, TiO2, and quaternary ammonium salts; The fiber body includes one or more of cellulose fiber, glass fiber, PP fiber, PET fiber, and aramid fiber.

3. The fiber according to claim 1, characterized in that, The fiber body is Tencel fiber.

4. A method for preparing a fiber with controlled release of antibacterial ions, characterized in that, include: Obtain a fiber with a dopamine-mediated surface-in-situ loading of an antimicrobial agent; the fiber with the dopamine-mediated surface-in-situ loading of an antimicrobial agent comprises a fiber body, polydopamine attached to the fiber body, and an antimicrobial agent deposited on the surface of the polydopamine on the fiber body. Preparation of controlled release layer: Dopamine-mediated in-situ surface-loaded antibacterial agent fibers are mixed with controlled release layer solution, and after cleaning, fibers with controlled release of antibacterial ions are obtained; The controlled-release layer solution includes substances that swell in the environment of bacterial metabolism; the raw materials of the controlled-release layer include one or more of chitosan and PAA; the loading amount of the controlled-release layer in the fiber with controlled release of antibacterial ions is 0.3 wt%-50 wt%. The loading of the antibacterial agent in the fiber with controlled release of antibacterial ions is 5wt%-30wt%.

5. The preparation method according to claim 4, characterized in that, The preparation process of the dopamine-mediated surface-loaded antibacterial agent fiber includes: Dopamine adhesion: The uniformly dispersed fiber body is mixed with a dopamine solution and stirred to obtain fibers with polydopamine deposited on the surface. Deposition of antibacterial agents: Fibers with surface-deposited polydopamine are mixed with an antibacterial agent raw material solution, and after reaction, dopamine-mediated in-situ surface-loaded antibacterial agents are obtained.

6. The preparation method according to claim 5, characterized in that, The concentration of the dopamine solution is 0.5 g / L to 4.0 g / L; And / or, the mass ratio of the fiber body to dopamine is (0.2 ~ 3.0): (0.5 ~ 4.0); And / or, in the dopamine attachment step, the stirring reaction time is 12-24 hours; And / or, the antibacterial agent raw material solution includes a metal ion solution and a reducing agent.

7. The preparation method according to claim 6, characterized in that, The concentration of the metal ion solution is 5~40 g / L; And / or, the metal ion solution includes a silver ion solution; And / or, the reducing agent includes one or more of sodium borohydride, glucose, sodium citrate, or DMAB.

8. The preparation method according to claim 7, characterized in that, The metal ion solution is a silver nitrate solution.

9. The preparation method according to any one of claims 4-8, characterized in that, The concentration of the controlled-release layer solution is 0.1~10 g / L; And / or, the mass ratio of the dopamine-mediated surface-loaded antibacterial agent fiber to the controlled-release layer is (0.2~3):(0.01~0.1).

10. A filter material with controlled release of antibacterial ions, prepared by papermaking using fibers; characterized in that, The fiber is the antibacterial ion controlled release fiber according to any one of claims 1-3 or the antibacterial ion controlled release fiber prepared by the preparation method according to any one of claims 4-9.

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