Nanometer type multifunctional negative ion material and preparation method thereof

Abstract

The invention relates to a nano multifunctional negative ion material and a preparation method thereof, and belongs to the technical field of negative ion materials, and the preparation method comprises the following steps: combining nano composite powder with graphene oxide to obtain a composite material; combining the composite material with an anhydride compound to obtain a reinforced material; combining a reinforcing material with the modified quaternized chitosan to obtain a nano multifunctional negative ion material; in the technical scheme of the invention, the nano composite powder is formed by mixing the rare earth mixed material, the nano zinc oxide powder and the nano silicon dioxide powder, has a synergistic effect, and can better improve the negative ion release performance and stability of the negative ion material; the composite material is combined with the anhydride compound and then is combined with the modified quaternized chitosan, so that the dispersity and the stability of the composite material can be further improved, the negative ion release rate, the far infrared radiation performance and the antibacterial property of the negative ion material are improved, and the comprehensive performance of the negative ion material is overall improved.

Description

Technical Field

[0001] This invention belongs to the field of negative ion materials technology, specifically relating to a nano-type multifunctional negative ion material and its preparation method. Background Technology

[0002] In recent years, with the rapid pace of industrialization, air pollution has become increasingly serious, posing a growing threat to human health. Negative ions, hailed as "air vitamins," have garnered widespread attention due to their ability to effectively improve air quality. Studies show that indoor negative ion concentrations are generally low, typically only a few to a few hundred per cubic centimeter, due to factors such as building materials, construction dust, industrial exhaust, and vehicle emissions. Therefore, increasing the concentration of negative ions in indoor air has broad application prospects in improving environmental quality and enhancing human health and quality of life. Negative ion materials not only purify and sterilize the air but also promote human health. Consequently, they have been widely used in textiles, ceramics, and building materials. However, traditional negative ion materials (such as natural tourmaline and ordinary diatomaceous earth), while capable of releasing small amounts of negative ions, still have limitations, such as limited release capacity and poor stability. Therefore, there is an urgent need to develop a high-performance, multifunctional nanomaterial for negative ions, enabling its widespread application across multiple fields.

[0003] In existing technologies, the preparation of nano-type multifunctional negative ion materials typically involves combining multiple negative ion materials. However, due to the high surface energy of nanoparticles, they are prone to aggregation, leading to reduced stability and release efficiency. Furthermore, the negative ion release capacity of current materials is limited, failing to meet the demands for efficient and continuous negative ion release in practical applications, necessitating further improvements in release efficiency. Additionally, most negative ion materials have relatively limited functionality, primarily focusing on negative ion release and lacking other functions such as antibacterial properties and far-infrared radiation, thus restricting their application scope. Summary of the Invention

[0004] The purpose of this invention is to provide a nano-type multifunctional negative ion material and its preparation method. A composite material is obtained by combining nanocomposite powder with graphene oxide. Coating the surface of the nanocomposite powder with graphene oxide not only increases its dispersibility and prevents agglomeration, but the nanocomposite powder, composed of rare earth mixed materials, nano zinc oxide powder, and nano silica powder, also has a synergistic effect, effectively improving the negative ion release performance and stability of the negative ion material. Combining the composite material with an acid anhydride compound yields a reinforcing material. The acid anhydride compound is composed of methacrylic anhydride and maleic anhydride, which synergistically enhance the dispersibility and stability of the negative ion material, and also increase its negative ion release. Combining the reinforcing material with modified quaternized chitosan yields the nano-type multifunctional negative ion material. Modified quaternized chitosan has good antibacterial effects, effectively improving the antibacterial performance and stability of the negative ion material. Finally, the obtained nano-type multifunctional negative ion material exhibits good negative ion release rate, stability, far-infrared radiation performance, and antibacterial properties, expanding the application range of negative ion materials and demonstrating good overall performance.

[0005] The technical problem this invention aims to solve is as follows: In existing technologies, the preparation of nano-type multifunctional negative ion materials typically involves combining multiple negative ion materials. However, due to the high surface energy of nanoparticles, they are prone to aggregation, leading to reduced stability and release efficiency. Furthermore, the negative ion release capacity of existing negative ion materials is limited, failing to meet the demands for efficient and continuous negative ion release in practical applications, necessitating further improvements in release efficiency. Additionally, most negative ion materials have relatively limited functionality, primarily focusing on negative ion release and lacking other functions such as antibacterial properties and far-infrared radiation, thus restricting their application scope.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for preparing a nano-type multifunctional negative ion material includes the following steps: S1: A composite material is obtained by combining nanocomposite powder with graphene oxide; S2: Combining composite materials with acid anhydride compounds yields reinforced materials; S3: By combining reinforcing materials with modified quaternized chitosan, a nano-type multifunctional negative ion material is obtained.

[0007] Furthermore, step S1 specifically includes: A1: Add the nanocomposite powder to anhydrous ethanol and stir for 20-30 min to obtain a suspension. Add the silane coupling agent to a mixed solution of anhydrous ethanol and deionized water and stir until homogeneous to obtain a silane solution. Add the silane solution to the suspension and stir at 45-55℃ for 5.5-6.5 h. After the reaction is complete, filter the solution, wash with anhydrous ethanol and deionized water, and finally vacuum dry at 75-85℃ to obtain silanized nanocomposite powder. A2: Add silanized nanocomposite powder to deionized water and stir until homogeneous to obtain dispersion A. Add graphene oxide to deionized water and sonicate for 1-2 hours to obtain dispersion B. Add dispersion B to dispersion A and stir for 1.5-2.5 hours. After the reaction is complete, filter, wash with deionized water, and finally vacuum dry at 75-85℃ to obtain crude product. Then ball mill and sieve to obtain composite material.

[0008] In the above reaction process, in step A1, the surface of the nanocomposite powder has hydroxyl groups. After the silane coupling agent is hydrolyzed, silanol groups are generated, which can combine with the hydroxyl groups on the surface of the nanocomposite powder to graft the silane coupling agent onto the surface of the nanocomposite powder, thus obtaining silanized nanocomposite powder. In step A2, the surface of the silanized nanocomposite powder is positively charged in the aqueous solution, while the surface of graphene oxide is negatively charged in the aqueous solution. The silanized nanocomposite powder and graphene oxide are combined through electrostatic self-assembly, thereby coating the surface of the silanized nanocomposite powder with graphene oxide, and finally obtaining a composite material.

[0009] Further, in step A1, the mass ratio of the nanocomposite powder to anhydrous ethanol is 0.8-1.2:10-15.

[0010] Further, in step A1, the nanocomposite powder is composed of rare earth mixed materials, nano zinc oxide powder and nano silicon dioxide powder mixed in a mass ratio of 1-1.2:0.7-0.8:0.5-0.6.

[0011] Furthermore, the rare earth composite material is composed of nano-lanthanum oxide and nano-cerium oxide mixed in a mass ratio of 1-2:1.

[0012] Further, in step A1, the mass ratio of the silane coupling agent, anhydrous ethanol, and deionized water mixed solution is 1.8-2.2:45-55.

[0013] Further, in step A1, the silane coupling agent is 3-aminopropyltriethoxysilane or N-[3-(trimethoxysilyl)propyl]ethylenediamine.

[0014] Further, in step A2, the mass ratio of the silanized nanocomposite powder to deionized water is 0.8-1.2:20-30.

[0015] Further, in step A2, the mass ratio of graphene oxide to deionized water is 0.08-0.12:90-110.

[0016] Furthermore, in step A2, the ball milling speed is 600-800 rpm and the ball milling time is 40-60 min.

[0017] Furthermore, step S2 specifically includes: The composite material from step S1 was added to N,N-dimethylformamide and stirred until homogeneous. Then, it was heated to 35-45°C, and an acid anhydride compound was added. The mixture was stirred and reacted at 35-45°C for 1.5-2.5 hours. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and finally dried under vacuum at 65-75°C to obtain the reinforced material.

[0018] In the above reaction process, the surface of the composite material has hydroxyl groups, and the acid anhydride compound has acid anhydride groups. The hydroxyl groups on the surface of the composite material can react and combine with the acid anhydride groups in the acid anhydride compound, thus combining the composite material with the acid anhydride compound to finally obtain the reinforced material.

[0019] Furthermore, the mass ratio of the composite material, N,N-dimethylformamide, and acid anhydride compound is 4.8-5.2:30-40:2.3-2.7.

[0020] Furthermore, the anhydride compound is composed of methacrylic anhydride and maleic anhydride in a mass ratio of 0.8-0.9:0.6-0.7.

[0021] Furthermore, step S3 specifically includes: The reinforcing material from step S2 is added to deionized water and ultrasonically treated for 30-40 minutes to obtain component A. Modified quaternized chitosan is added to acetic acid solution and stirred evenly. It is then degassed with nitrogen for 25-35 minutes to obtain component B. Component A and catalyst are added to component B, and the mixture is reacted for 11-13 hours under nitrogen atmosphere and constant temperature water bath at 55-65℃. The pH of the system is adjusted to 6.8-7.2 with sodium hydroxide solution. The mixture is dialyzed with deionized water, and acetic acid is removed by vacuum distillation. Finally, it is freeze-dried to obtain nano-type multifunctional negative ion material.

[0022] In the above reaction process, the modified quaternized chitosan molecular chain has active hydrogen atoms. In the presence of a catalyst, the active hydrogen atoms on the modified quaternized chitosan molecular chain are attacked to generate free radicals. The generated free radicals can initiate free radical grafting polymerization of carbon-carbon double bonds in the reinforcing material, combining the reinforcing material with the modified quaternized chitosan, and finally obtaining a nano-type multifunctional negative ion material.

[0023] Furthermore, the mass ratio of the reinforcing material to deionized water is 0.8-1.2:30-40.

[0024] Furthermore, the mass ratio of the modified quaternized chitosan to the acetic acid solution is 0.8-1.2:140-160.

[0025] Furthermore, the mass ratio of component A, catalyst, and component B is 3:0.2:1.

[0026] Furthermore, the catalyst is ammonium persulfate.

[0027] Furthermore, the preparation method of the modified quaternized chitosan includes the following steps: Quaternized chitosan was added to an acetic acid solution and stirred evenly at room temperature to obtain a chitosan solution. Phenolic acid was added to ethanol, followed by MES buffer and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and reacted at room temperature for 0.5-1 h. Then N-hydroxysuccinimide was added, and the reaction was carried out in an ice-water bath for 0.5-1 h to obtain an intermediate product. The intermediate product was added to the chitosan solution and stirred at room temperature for 11-13 h. After the reaction was completed, the mixture was dialyzed with deionized water, centrifuged for 25-35 min, and finally freeze-dried to obtain modified quaternized chitosan.

[0028] In the above reaction process, quaternized chitosan has amino groups and phenolic acid has carboxyl groups. The amino groups in quaternized chitosan can react and combine with the carboxyl groups in phenolic acid, thus combining quaternized chitosan and phenolic acid together to finally obtain modified quaternized chitosan.

[0029] Furthermore, the mass ratio of the quaternized chitosan to the acetic acid solution is 1-1.4:25-30.

[0030] Further, the mass ratio of the phenolic acid, ethanol, MES buffer, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide is 1-1.2:5-10:18-22:1.3-1.5:0.8-1.

[0031] Furthermore, the phenolic acid is composed of protocatechuic acid and gallic acid in a mass ratio of 0.7-0.8:0.5-0.6.

[0032] Furthermore, the mass ratio of the intermediate product to the chitosan solution is 1:1.

[0033] Furthermore, the preparation method of the quaternized chitosan includes the following steps: Chitosan and quaternizing reagent were added to deionized water and then stirred and refluxed at 80°C for 36 hours. After the reaction was completed, the mixture was dialyzed with deionized water for 3 days. Unreacted quaternizing reagent was removed by vacuum distillation at 45°C. Finally, the mixture was freeze-dried at -40°C for 24 hours to obtain quaternized chitosan.

[0034] In the above reaction process, chitosan has amino groups and the quaternizing agent has epoxy groups. Some of the amino groups in chitosan can combine with the epoxy groups in the quaternizing agent through a ring-opening reaction, grafting the quaternizing agent onto chitosan, and finally obtaining quaternized chitosan.

[0035] Furthermore, the mass ratio of chitosan, quaternizing agent, and deionized water is 16:7.2:240.

[0036] Furthermore, the quaternizing agent is glycidyltrimethylammonium chloride.

[0037] A nano-type multifunctional negative ion material prepared by the method described above.

[0038] The beneficial effects of this invention are: (1) In the technical solution of this invention, a composite material is obtained by combining nanocomposite powder with graphene oxide; the nanocomposite powder is composed of rare earth mixed material, nano zinc oxide powder and nano silica powder, which have a synergistic effect. The rare earth mixed material is composed of nano lanthanum oxide and nano cerium oxide, which have good negative ion release rate and thermal stability, which can further improve the negative ion release performance of the negative ion material and increase the negative ion concentration. By combining the nanocomposite powder with graphene oxide through electrostatic self-assembly, graphene oxide can be coated on the surface of the nanocomposite powder, which can not only improve the dispersion performance of the nanocomposite powder and prevent its agglomeration, but also further enhance the negative ion release performance of the negative ion material. This process improves both the energy and stability of the composite material, while also enhancing its far-infrared radiation and antibacterial properties. Combining the composite material with anhydride compounds creates a reinforced material. The anhydride compounds are composed of a mixture of methacrylic anhydride and maleic anhydride, which have a synergistic effect, further improving the dispersibility and stability of the composite material, preventing aggregation, enhancing the negative ion release performance of the negative ion material, increasing the negative ion concentration, and also having a positive impact on its far-infrared radiation and antibacterial properties. Combining the composite material with anhydride compounds not only increases the binding force between the two but also provides reaction sites for subsequent reactions, further enhancing the negative ion release performance, stability, far-infrared radiation performance, and antibacterial properties of the negative ion material.

[0039] (2) In the technical solution of this invention, a nano-type multifunctional negative ion material is obtained by combining the reinforcing material with modified quaternized chitosan; the modified quaternized chitosan is prepared by combining phenolic acid with quaternized chitosan; the phenolic acid is composed of protocatechuic acid and gallic acid, which can play a synergistic antibacterial role and effectively improve the antibacterial performance of the negative ion material. Although quaternized chitosan itself also has a certain antibacterial effect, it is mainly effective against Gram-positive bacteria (such as Staphylococcus aureus) and is ineffective against Gram-negative bacteria (such as Escherichia coli). Therefore, the modified quaternized chitosan is prepared by combining the reinforcing material with modified quaternized chitosan. Modified quaternized chitosan, prepared by combining phenolic acid with quaternized chitosan, can effectively improve the antibacterial properties and stability of negative ion materials, and further enhance their negative ion release performance and increase negative ion concentration. Combining reinforcing materials with modified quaternized chitosan strengthens the bond between the two, significantly improving the negative ion release performance, stability, and antibacterial properties of the negative ion materials. It also has a positive impact on the far-infrared radiation performance of the negative ion materials, thus improving their overall performance and extending their service life.

[0040] (3) In the technical solution of the present invention, nanocomposite powder is combined with graphene oxide, then with acid anhydride compounds, and then with modified quaternized chitosan to finally obtain nano-type multifunctional negative ion material; the obtained nano-type multifunctional negative ion material not only has good negative ion release performance and stability, but also effectively improves the far-infrared radiation performance and antibacterial performance of negative ion material, increases the multifunctionality of negative ion material, expands the application range of negative ion material, and its overall comprehensive performance is good. Detailed Implementation

[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] The specific parameters of the raw materials used in this invention are as follows: Lanthanum oxide nanoparticles, with a particle size of 30-50 nm (preferably 30 nm), were provided by Xuancheng Jingrui New Materials Co., Ltd.; cerium oxide nanoparticles, with an average particle size of 20 nm, were provided by Beijing Deco Island Gold Technology Co., Ltd.; zinc oxide nanoparticles, with a particle size of 30 nm and model number PZT-30, were provided by Nanjing Baoket New Materials Co., Ltd.; and silica nanoparticles, with a particle size of 20 nm and a specific surface area of ​​200 m², were provided. 2 / g, provided by Nanjing Baoket New Materials Co., Ltd.; Graphene oxide (monolayer graphene oxide), thickness: 1nm, sheet diameter: 0.2-10µm, provided by Suzhou Kaifa New Materials Technology Co., Ltd.; Methacrylic anhydride, CAS No.: 760-93-0, product number: BD137614, provided by Shanghai Bid Pharmaceutical Technology Co., Ltd.; Maleic anhydride, CAS No.: 108-31-6, product number: M821319, provided by Shanghai Maclean Biochemical Technology Co., Ltd.; Chitosan, C AS No.: 9012-76-4, Product No.: 013631425, provided by Shanghai Titan Technology Co., Ltd.; Protocatechuic acid, CAS No.: 99-50-3, provided by Nantong Runfeng Petrochemical Co., Ltd.; Gallic acid, CAS No.: 149-91-7, Product No.: G823163, provided by Shanghai Maclean Biochemical Technology Co., Ltd.; MES buffer, 0.5M, pH=5.5, Product No.: M885674, provided by Shanghai Maclean Biochemical Technology Co., Ltd.

[0043] The preparation method of quaternized chitosan includes the following steps: Chitosan, glycidyltrimethylammonium chloride, and deionized water were added to deionized water at a mass ratio of 16:7.2:240. The mixture was then stirred and refluxed at 80°C for 36 hours. After the reaction was completed, the mixture was added to a dialysis bag (with a molecular weight cutoff of 14 kDa) and dialyzed with deionized water for 3 days. Unreacted glycidyltrimethylammonium chloride was removed by vacuum distillation at 45°C. Finally, the mixture was freeze-dried at -40°C for 24 hours to obtain quaternized chitosan.

[0044] Example 1 The specific steps for preparing nano-type multifunctional negative ion materials are as follows: S1: Preparation of composite materials, the specific steps are as follows: A1: The nanocomposite powder was added to anhydrous ethanol at a mass ratio of 0.8:10, and stirred at 400 rpm for 30 minutes to obtain a suspension. Then, 3-aminopropyltriethoxysilane was added to a mixed solution of anhydrous ethanol and deionized water at a mass ratio of 1.8:45 (volume ratio of anhydrous ethanol to deionized water 1:1), and stirred until homogeneous to obtain a silane solution. Finally, the silane solution was added to the suspension at a mass ratio of 1:1. Then, the mixture was stirred at 45℃ for 6.5 h. After the reaction was completed, it was filtered and washed three times each with anhydrous ethanol and deionized water (each time the mass of anhydrous ethanol was 10 times the mass of the nanocomposite powder, and each time the mass of deionized water was 12 times the mass of the nanocomposite powder). Finally, it was vacuum dried at 75℃ for 12 h to obtain silanized nanocomposite powder. The nanocomposite powder was composed of rare earth mixed materials, nano zinc oxide powder and nano silica powder in a mass ratio of 1:0.7:0.5; the rare earth mixed materials were composed of nano lanthanum oxide and nano cerium oxide in a mass ratio of 1:1. A2: Following a mass ratio of silanized nanocomposite powder to deionized water of 0.8:20, the silanized nanocomposite powder was added to deionized water and stirred until homogeneous to obtain dispersion A. Following a mass ratio of graphene oxide to deionized water of 0.08:90, graphene oxide was added to deionized water and ultrasonically treated for 1 hour (ultrasonic power 100W, ultrasonic frequency 40kHz) to obtain dispersion B. Following a mass ratio of dispersion A to dispersion B of 1:1, dispersion B was added to dispersion A. The mixture was stirred at 400 rpm for 2.5 hours. After the reaction was completed, it was filtered and washed three times with deionized water (each time the mass of deionized water was 12 times the mass of the silanized nanocomposite powder). Finally, it was vacuum dried at 75°C for 24 hours to obtain a crude product. Then, it was ball-milled at 600 rpm for 60 minutes using zirconia balls as grinding media. The mass of the zirconia balls was 10 times the mass of the crude product (i.e., the ball-to-material ratio was 10:1). The mixture was then passed through a 1000-mesh sieve to obtain the composite material. S2: According to the mass ratio of composite material, N,N-dimethylformamide, and acid anhydride compound of 4.8:30:2.3, the composite material from step S1 was added to N,N-dimethylformamide and stirred evenly. Then, it was heated to 35°C, and then the acid anhydride compound was added. The mixture was stirred and reacted at 35°C for 2.5 hours. After the reaction was completed, it was filtered and washed 5 times with anhydrous ethanol (each time the mass of anhydrous ethanol was 5 times the mass of N,N-dimethylformamide). Finally, it was vacuum dried at 65°C for 24 hours to obtain the reinforcing material. The acid anhydride compound was composed of methacrylic anhydride and maleic anhydride mixed in a mass ratio of 0.8:0.6. S3: According to the mass ratio of reinforcing material to deionized water of 0.8:30, the reinforcing material from step S2 was added to deionized water and ultrasonically treated for 30 min (ultrasonic power of 100W, ultrasonic frequency of 40kHz) to obtain component A. According to the mass ratio of modified quaternized chitosan to acetic acid solution of 0.8:140, the modified quaternized chitosan was added to 1wt% acetic acid solution and stirred evenly. After degassing with nitrogen for 25 min, component B was obtained. According to the mass ratio of component A, ammonium persulfate, and component B of 3:0.2:1, component A and ammonium persulfate were added to component B. Then, the mixture was reacted in a nitrogen atmosphere and a constant temperature water bath at 55℃ for 13 h. The pH of the system was adjusted to 6.8 with 1mol / L sodium hydroxide solution. The mixture was then added to a dialysis bag (molecular weight cutoff of 12kDa) and dialyzed with deionized water for 3 days. Acetic acid was removed by vacuum distillation at 40℃. Finally, the mixture was freeze-dried at -50℃ for 24 h to obtain nano-type multifunctional negative ion material. The preparation method of modified quaternized chitosan includes the following steps: Quaternized chitosan and acetic acid solution were added to 1 wt% acetic acid solution at a mass ratio of 1:25 and stirred evenly at room temperature to obtain a chitosan solution. Phenolic acid was added to ethanol at a mass ratio of phenolic acid, ethanol, MES buffer, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide at 1:5:18:1.3:0.8, followed by MES buffer and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. The mixture was reacted at room temperature for 0.5 h, and then N-hydroxysuccinimide was added. Succinimide was reacted in an ice-water bath at 0°C for 1 hour to obtain an intermediate product. The intermediate product was added to the chitosan solution at a mass ratio of 1:1, and the mixture was stirred at room temperature for 11 hours. After the reaction, the mixture was added to a dialysis bag (molecular weight cutoff of 12 kDa) and dialyzed with deionized water for 3 days. The mixture was then centrifuged at 8000 rpm for 35 minutes and finally freeze-dried at -50°C for 24 hours to obtain modified quaternized chitosan. The phenolic acid in the modified chitosan was composed of protocatechuic acid and gallic acid in a mass ratio of 0.7:0.5.

[0045] Example 2 The specific steps for preparing nano-type multifunctional negative ion materials are as follows: S1: Preparation of composite materials, the specific steps are as follows: A1: Following a mass ratio of 1:12 (nanocomposite powder to anhydrous ethanol), the nanocomposite powder was added to anhydrous ethanol and stirred at 500 rpm for 25 minutes to obtain a suspension. Then, following a mass ratio of 2:50 (N-[3-(trimethoxysilyl)propyl]ethylenediamine), anhydrous ethanol, and deionized water), N-[3-(trimethoxysilyl)propyl]ethylenediamine was added to the mixture of anhydrous ethanol and deionized water (volume ratio of anhydrous ethanol to deionized water was 1:1). After stirring until homogeneous, a silane solution was obtained. Finally, following a mass ratio of 1:1 (suspension to silane solution), the silane solution was added to the suspension... The mixture was placed in a liquid and stirred at 50°C for 6 hours. After the reaction was completed, it was filtered and washed three times each with anhydrous ethanol and deionized water (each time the mass of anhydrous ethanol was 10 times the mass of the nanocomposite powder, and each time the mass of deionized water was 12 times the mass of the nanocomposite powder). Finally, it was vacuum dried at 80°C for 12 hours to obtain silanized nanocomposite powder. The nanocomposite powder was composed of rare earth mixed materials, nano zinc oxide powder and nano silica powder in a mass ratio of 1.1:0.75:0.55; the rare earth mixed materials were composed of nano lanthanum oxide and nano cerium oxide in a mass ratio of 1.5:1. A2: Add silanized nanocomposite powder to deionized water at a mass ratio of 1:25, and stir until homogeneous to obtain dispersion A. Add graphene oxide to deionized water at a mass ratio of 0.1:100, and sonicate for 1.5 hours (ultrasonic power 100W, ultrasonic frequency 40kHz) to obtain dispersion B. Add dispersion B to dispersion A at a mass ratio of 1:1. The mixture was stirred at 500 rpm for 2 hours. After the reaction was completed, it was filtered and washed three times with deionized water (each time the mass of deionized water was 12 times the mass of the silanized nanocomposite powder). Finally, it was vacuum dried at 80℃ for 24 hours to obtain a crude product. Then, it was ball-milled at 700 rpm for 50 minutes using zirconia balls as grinding media. The mass of the zirconia balls was 10 times the mass of the crude product (i.e., the ball-to-material ratio was 10:1). The mixture was then passed through a 1000-mesh sieve to obtain the composite material. S2: According to the mass ratio of composite material, N,N-dimethylformamide, and acid anhydride compound of 5:35:2.5, the composite material from step S1 was added to N,N-dimethylformamide and stirred evenly. Then, it was heated to 40°C, and then the acid anhydride compound was added. The mixture was stirred and reacted at 40°C for 2 hours. After the reaction was completed, it was filtered and washed 5 times with anhydrous ethanol (each time the mass of anhydrous ethanol was 5 times the mass of N,N-dimethylformamide). Finally, it was vacuum dried at 70°C for 24 hours to obtain the reinforcing material. The acid anhydride compound was composed of methacrylic anhydride and maleic anhydride mixed in a mass ratio of 0.85:0.65. S3: According to the mass ratio of reinforcing material to deionized water of 1:35, the reinforcing material from step S2 was added to deionized water and ultrasonically treated for 35 min (ultrasonic power of 100W, ultrasonic frequency of 40kHz) to obtain component A. According to the mass ratio of modified quaternized chitosan to acetic acid solution of 1:150, the modified quaternized chitosan was added to 1wt% acetic acid solution and stirred evenly. The mixture was degassed with nitrogen for 30 min to obtain component B. According to the mass ratio of component A, ammonium persulfate, and component B of 3:0.2:1, component A and ammonium persulfate were added to component B. The mixture was then reacted in a nitrogen atmosphere and a constant temperature water bath at 60℃ for 12 h. The pH of the system was adjusted to 7 with 1mol / L sodium hydroxide solution. The mixture was then added to a dialysis bag (molecular weight cutoff of 12kDa) and dialyzed with deionized water for 3 days. Acetic acid was removed by vacuum distillation at 45℃. Finally, the mixture was freeze-dried at -45℃ for 24 h to obtain nano-type multifunctional negative ion material. The preparation method of modified quaternized chitosan includes the following steps: Quaternized chitosan and acetic acid solution were added to a 1 wt% acetic acid solution at a mass ratio of 1.2:28 and stirred evenly at room temperature to obtain a chitosan solution. Phenolic acid was added to ethanol at a mass ratio of phenolic acid, ethanol, MES buffer, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide at a mass ratio of 1.1:8:20:1.4:0.9, followed by the addition of MES buffer and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. The mixture was reacted at room temperature for 0.8 h, and then N-hydroxysuccinimide was added. Succinimide was reacted in an ice-water bath at 2°C for 0.8 h to obtain an intermediate product. The intermediate product was added to the chitosan solution at a mass ratio of 1:1, and the mixture was stirred at room temperature for 12 h. After the reaction was completed, the mixture was added to a dialysis bag (molecular weight cutoff of 12 kDa) and dialyzed with deionized water for 3 days. The mixture was then centrifuged at 10,000 rpm for 30 min and finally freeze-dried at -45°C for 24 h to obtain modified quaternized chitosan. The phenolic acid in the modified chitosan was composed of protocatechuic acid and gallic acid in a mass ratio of 0.75:0.55.

[0046] Example 3 The specific steps for preparing nano-type multifunctional negative ion materials are as follows: S1: Preparation of composite materials, the specific steps are as follows: A1: The nanocomposite powder was added to anhydrous ethanol at a mass ratio of 1.2:15, and stirred at 600 rpm for 20 minutes to obtain a suspension. Then, 3-aminopropyltriethoxysilane was added to a mixed solution of anhydrous ethanol and deionized water at a mass ratio of 2.2:55 (volume ratio of anhydrous ethanol to deionized water 1:1), and stirred until homogeneous to obtain a silane solution. Finally, the silane solution was added to the suspension at a mass ratio of 1:1. The mixture was then stirred at 55℃ for 5.5 h. After the reaction was completed, it was filtered and washed three times each with anhydrous ethanol and deionized water (each time the mass of anhydrous ethanol was 10 times the mass of the nanocomposite powder, and each time the mass of deionized water was 12 times the mass of the nanocomposite powder). Finally, it was vacuum dried at 85℃ for 12 h to obtain silanized nanocomposite powder. The nanocomposite powder was composed of rare earth mixed materials, nano zinc oxide powder and nano silica powder in a mass ratio of 1.2:0.8:0.6; the rare earth mixed materials were composed of nano lanthanum oxide and nano cerium oxide in a mass ratio of 2:1. A2: Following a mass ratio of silanized nanocomposite powder to deionized water of 1.2:30, the silanized nanocomposite powder was added to deionized water and stirred until homogeneous to obtain dispersion A. Following a mass ratio of graphene oxide to deionized water of 0.12:110, graphene oxide was added to deionized water and ultrasonically treated for 2 hours (ultrasonic power 100W, ultrasonic frequency 40kHz) to obtain dispersion B. Following a mass ratio of dispersion A to dispersion B of 1:1, dispersion B was added to dispersion A. The mixture was stirred at 600 rpm for 1.5 hours. After the reaction was completed, it was filtered and washed three times with deionized water (each time the mass of deionized water was 12 times the mass of the silanized nanocomposite powder). Finally, it was vacuum dried at 85°C for 24 hours to obtain a crude product. Then, it was ball-milled at 800 rpm for 40 minutes using zirconia balls as grinding media. The mass of the zirconia balls was 10 times the mass of the crude product (i.e., the ball-to-material ratio was 10:1). The mixture was then passed through a 1000-mesh sieve to obtain the composite material. S2: According to the mass ratio of composite material, N,N-dimethylformamide, and acid anhydride compound of 5.2:40:2.7, the composite material from step S1 was added to N,N-dimethylformamide and stirred evenly. Then, it was heated to 45°C, and then the acid anhydride compound was added. The mixture was stirred and reacted at 45°C for 1.5 hours. After the reaction was completed, it was filtered and washed 5 times with anhydrous ethanol (each time the mass of anhydrous ethanol was 5 times the mass of N,N-dimethylformamide). Finally, it was vacuum dried at 75°C for 24 hours to obtain the reinforcing material. The acid anhydride compound was composed of methacrylic anhydride and maleic anhydride mixed in a mass ratio of 0.9:0.7. S3: According to the mass ratio of reinforcing material to deionized water of 1.2:40, the reinforcing material from step S2 was added to deionized water and ultrasonically treated for 40 min (ultrasonic power of 100W, ultrasonic frequency of 40kHz) to obtain component A. According to the mass ratio of modified quaternized chitosan to acetic acid solution of 1.2:160, the modified quaternized chitosan was added to 1wt% acetic acid solution and stirred evenly. It was degassed with nitrogen for 35 min to obtain component B. According to the mass ratio of component A, ammonium persulfate and component B of 3:0.2:1, component A and ammonium persulfate were added to component B. Then, the mixture was reacted in a nitrogen atmosphere and a constant temperature water bath at 65℃ for 11 h. The pH of the system was adjusted to 7.2 with 1mol / L sodium hydroxide solution. The mixture was then added to a dialysis bag (molecular weight cutoff of 12kDa) and dialyzed with deionized water for 3 days. Acetic acid was removed by vacuum distillation at 50℃. Finally, the mixture was freeze-dried at -40℃ for 24 h to obtain nano-type multifunctional negative ion material. The preparation method of modified quaternized chitosan includes the following steps: Quaternized chitosan and acetic acid solution were added to a 1 wt% acetic acid solution at a mass ratio of 1.4:30 and stirred evenly at room temperature to obtain a chitosan solution. Phenolic acid was added to ethanol at a mass ratio of phenolic acid, ethanol, MES buffer, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide at a mass ratio of 1.2:10:22:1.5:1, followed by the addition of MES buffer and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. The mixture was reacted at room temperature for 1 hour, and then N-hydroxysuccinimide was added. Succinimide was reacted in an ice-water bath at 5°C for 0.5 h to obtain an intermediate product. The intermediate product was added to the chitosan solution at a mass ratio of 1:1, and the mixture was stirred at room temperature for 13 h. After the reaction was completed, the mixture was added to a dialysis bag (molecular weight cutoff of 12 kDa) and dialyzed with deionized water for 3 days. The mixture was then centrifuged at 12,000 rpm for 25 min and finally freeze-dried at -40°C for 24 h to obtain modified quaternized chitosan. The phenolic acid in the modified chitosan was composed of protocatechuic acid and gallic acid in a mass ratio of 0.8:0.6.

[0047] Comparative Example 1 The difference between this comparative example and Example 3 is that, in the preparation of the nano-type multifunctional negative ion material, in step S1, the nanocomposite powder is composed of rare earth mixed materials and nano zinc oxide powder, while the remaining steps and raw materials are the same as in Example 3. A1: The nanocomposite powder was added to anhydrous ethanol at a mass ratio of 1.2:15, and stirred at 600 rpm for 20 minutes to obtain a suspension. Then, 3-aminopropyltriethoxysilane was added to a mixed solution of anhydrous ethanol and deionized water at a mass ratio of 2.2:55 (volume ratio of anhydrous ethanol to deionized water 1:1), and stirred until homogeneous to obtain a silane solution. Finally, the silane solution was added to the solution at a mass ratio of 1:1. The mixture was added to a suspension and stirred at 55°C for 5.5 h. After the reaction was completed, it was filtered and washed three times each with anhydrous ethanol and deionized water (each time the mass of anhydrous ethanol was 10 times the mass of the nanocomposite powder, and each time the mass of deionized water was 12 times the mass of the nanocomposite powder). Finally, it was vacuum dried at 85°C for 12 h to obtain silanized nanocomposite powder. The nanocomposite powder was composed of rare earth mixed materials and nano zinc oxide powder in a mass ratio of 1.2:1.4; the rare earth mixed materials were composed of nano lanthanum oxide and nano cerium oxide in a mass ratio of 2:1.

[0048] Comparative Example 2 The difference between this comparative example and Example 3 is that, in the preparation of the nano-type multifunctional negative ion material, in step S1, the nanocomposite powder is composed of rare earth mixed materials and nano-silica powder, while the remaining steps and raw materials are the same as in Example 3. A1: The nanocomposite powder was added to anhydrous ethanol at a mass ratio of 1.2:15, and stirred at 600 rpm for 20 minutes to obtain a suspension. Then, 3-aminopropyltriethoxysilane was added to a mixed solution of anhydrous ethanol and deionized water at a mass ratio of 2.2:55 (volume ratio of anhydrous ethanol to deionized water 1:1), and stirred until homogeneous to obtain a silane solution. Finally, the silane solution was added to the solution at a mass ratio of 1:1. The mixture was placed in a suspension and stirred at 55°C for 5.5 h. After the reaction was completed, it was filtered and washed three times each with anhydrous ethanol and deionized water (each time the mass of anhydrous ethanol was 10 times the mass of the nanocomposite powder, and each time the mass of deionized water was 12 times the mass of the nanocomposite powder). Finally, it was vacuum dried at 85°C for 12 h to obtain silanized nanocomposite powder. The nanocomposite powder was composed of rare earth mixed materials and nano silica powder in a mass ratio of 1.2:1.4. The rare earth mixed materials were composed of nano lanthanum oxide and nano cerium oxide in a mass ratio of 2:1.

[0049] Comparative Example 3 The difference between this comparative example and Example 3 is that, in the preparation of the nano-type multifunctional negative ion material, in step S1, the nanocomposite powder is composed of a mixture of nano zinc oxide powder and nano silicon dioxide powder, while the remaining steps and raw materials are the same as in Example 3. A1: The nanocomposite powder was added to anhydrous ethanol at a mass ratio of 1.2:15, and stirred at 600 rpm for 20 minutes to obtain a suspension. Then, 3-aminopropyltriethoxysilane was added to a mixed solution of anhydrous ethanol and deionized water at a mass ratio of 2.2:55 (volume ratio of anhydrous ethanol to deionized water 1:1), and stirred until homogeneous to obtain a silane solution. The suspension and silane solution were then... The mass ratio was 1:1. The silane solution was added to the suspension, and then stirred at 55℃ for 5.5h. After the reaction was completed, the mixture was filtered and washed three times each with anhydrous ethanol and deionized water (each time the mass of anhydrous ethanol was 10 times the mass of the nanocomposite powder, and each time the mass of deionized water was 12 times the mass of the nanocomposite powder). Finally, the mixture was vacuum dried at 85℃ for 12h to obtain silanized nanocomposite powder, which was composed of nano zinc oxide powder and nano silica powder mixed in a mass ratio of 1.2:1.4.

[0050] Comparative Example 4 The difference between this comparative example and Example 3 is that, in the preparation of the nano-type multifunctional negative ion material, in step S2, the composite material is composed of a mixture of nano-composite powder and graphene oxide, and the original step S1 is deleted. The remaining steps and raw materials are the same as in Example 3. S1: According to the mass ratio of composite material, N,N-dimethylformamide, and acid anhydride compound of 5.2:40:2.7, the composite material from step S1 was added to N,N-dimethylformamide and stirred evenly. Then, it was heated to 45°C, and the acid anhydride compound was added. The mixture was stirred and reacted at 45°C for 1.5 hours. After the reaction was completed, it was filtered and washed 5 times with anhydrous ethanol (each time the mass of anhydrous ethanol was 5 times the mass of N,N-dimethylformamide). Finally, it was vacuum dried at 75°C for 24 hours to obtain the reinforcing material. The acid anhydride compound was composed of methacrylic anhydride and maleic anhydride in a mass ratio of 0.9:0.7. The composite material was composed of nanocomposite powder and graphene oxide in a mass ratio of 1:1. The nanocomposite powder was composed of rare earth mixed material, nano zinc oxide powder, and nano silica powder in a mass ratio of 1.2:0.8:0.6. The rare earth mixed material was composed of nano lanthanum oxide and nano cerium oxide in a mass ratio of 2:1. S2: According to the mass ratio of reinforcing material to deionized water of 1.2:40, the reinforcing material from step S2 was added to deionized water and ultrasonically treated for 40 min (ultrasonic power of 100W, ultrasonic frequency of 40kHz) to obtain component A. According to the mass ratio of modified quaternized chitosan to acetic acid solution of 1.2:160, the modified quaternized chitosan was added to 1wt% acetic acid solution and stirred evenly. After degassing with nitrogen for 35 min, component B was obtained. According to the mass ratio of component A, ammonium persulfate, and component B of 3:0.2:1, component A and ammonium persulfate were added to component B. Then, the mixture was reacted in a nitrogen atmosphere and a constant temperature water bath at 65℃ for 11 h. The pH of the system was adjusted to 7.2 with 1mol / L sodium hydroxide solution. The mixture was then added to a dialysis bag (molecular weight cutoff of 12kDa) and dialyzed with deionized water for 3 days. Acetic acid was removed by vacuum distillation at 50℃. Finally, the mixture was freeze-dried at -40℃ for 24 h to obtain nano-type multifunctional negative ion material.

[0051] Comparative Example 5 The difference between this comparative example and Example 3 is that, in the preparation of nano-type multifunctional negative ion materials, in step S2, the acid anhydride compound is replaced by methacrylic anhydride in equal mass, while the remaining steps and raw materials are the same as in Example 3. S2: According to the mass ratio of composite material, N,N-dimethylformamide, and methacrylic anhydride of 5.2:40:2.7, the composite material from step S1 was added to N,N-dimethylformamide and stirred evenly. Then, it was heated to 45°C, and then methacrylic anhydride was added. The mixture was stirred and reacted at 45°C for 1.5 hours. After the reaction was completed, it was filtered and washed 5 times with anhydrous ethanol (each time the mass of anhydrous ethanol was 5 times the mass of N,N-dimethylformamide). Finally, it was vacuum dried at 75°C for 24 hours to obtain the reinforcing material.

[0052] Comparative Example 6 The difference between this comparative example and Example 3 is that, in the preparation of nano-type multifunctional negative ion materials, in step S2, the acid anhydride compound is replaced by maleic anhydride in equal mass, while the remaining steps and raw materials are the same as in Example 3. S2: According to the mass ratio of composite material, N,N-dimethylformamide, and maleic anhydride of 5.2:40:2.7, the composite material from step S1 was added to N,N-dimethylformamide and stirred evenly. Then, it was heated to 45°C, and maleic anhydride was added. The mixture was stirred and reacted at 45°C for 1.5 hours. After the reaction was completed, it was filtered and washed 5 times with anhydrous ethanol (each time the mass of anhydrous ethanol was 5 times the mass of N,N-dimethylformamide). Finally, it was vacuum dried at 75°C for 24 hours to obtain the reinforced material.

[0053] Comparative Example 7 The difference between this comparative example and Example 3 is that, in the preparation of nano-type multifunctional negative ion materials, in step S3, phenolic acid is replaced by protocatechuic acid by mass, while the remaining steps and raw materials are the same as in Example 3. The preparation method of modified quaternized chitosan includes the following steps: Quaternized chitosan and acetic acid solution were added to 1 wt% acetic acid solution at a mass ratio of 1.4:30 and stirred evenly at room temperature to obtain a chitosan solution. Protocatechuic acid, ethanol, MES buffer, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide were added to ethanol at a mass ratio of 1.2:10:22:1.5:1. Then, MES buffer and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added. The mixture was reacted at room temperature for 1 hour, and then N-hydroxysuccinimide was added. The mixture was then reacted in an ice-water bath at 5°C for 0.5 hours to obtain an intermediate product. The intermediate product was added to the chitosan solution at a mass ratio of 1:1, and the mixture was stirred at room temperature for 13 hours. After the reaction was completed, the mixture was added to a dialysis bag (with a molecular weight cutoff of 12 kDa), dialyzed with deionized water for 3 days, centrifuged at 12,000 rpm for 25 minutes, and finally freeze-dried at -40°C for 24 hours to obtain modified quaternized chitosan.

[0054] Comparative Example 8 The difference between this comparative example and Example 3 is that, in the preparation of nano-type multifunctional negative ion materials, in step S3, phenolic acid is replaced by gallic acid, while the remaining steps and raw materials are the same as in Example 3. The preparation method of modified quaternized chitosan includes the following steps: Quaternized chitosan and acetic acid solution were added to 1 wt% acetic acid solution at a mass ratio of 1.4:30 and stirred evenly at room temperature to obtain a chitosan solution. Gallic acid, ethanol, MES buffer, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide were added to ethanol at a mass ratio of 1.2:10:22:1.5:1, followed by the addition of MES buffer and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. The mixture was reacted at room temperature for 1 hour, and then N-hydroxysuccinimide was added. The mixture was then reacted in an ice-water bath at 5°C for 0.5 hours to obtain an intermediate product. The intermediate product was added to the chitosan solution at a mass ratio of 1:1, and the mixture was stirred at room temperature for 13 hours. After the reaction was completed, the mixture was added to a dialysis bag (with a molecular weight cutoff of 12 kDa), dialyzed with deionized water for 3 days, centrifuged at 12,000 rpm for 25 minutes, and finally freeze-dried at -40°C for 24 hours to obtain modified quaternized chitosan.

[0055] Comparative Example 9 The difference between this comparative example and Example 3 is that, in the preparation of nano-type multifunctional negative ion materials, in step S3, the modified quaternized chitosan is replaced by quaternized chitosan in equal mass, while the remaining steps and raw materials are the same as in Example 3. S3: According to the mass ratio of reinforcing material to deionized water of 1.2:40, the reinforcing material from step S2 was added to deionized water and ultrasonically treated for 40 min (ultrasonic power of 100W, ultrasonic frequency of 40kHz) to obtain component A. According to the mass ratio of quaternized chitosan to acetic acid solution of 1.2:160, quaternized chitosan was added to 1wt% acetic acid solution and stirred evenly. After degassing with nitrogen for 35 min, component B was obtained. According to the mass ratio of component A, ammonium persulfate, and component B of 3:0.2:1, component A and ammonium persulfate were added to component B. Then, the mixture was reacted in a nitrogen atmosphere and a constant temperature water bath at 65℃ for 11 h. The pH of the system was adjusted to 7.2 with 1mol / L sodium hydroxide solution. The mixture was then added to a dialysis bag (molecular weight cutoff of 12kDa) and dialyzed with deionized water for 3 days. Acetic acid was removed by vacuum distillation at 50℃. Finally, the mixture was freeze-dried at -40℃ for 24 h to obtain nano-type multifunctional negative ion material.

[0056] The nano-type multifunctional negative ion materials prepared in Examples 1-3 and Comparative Examples 1-9 were tested for negative ion concentration, far-infrared radiation, and antibacterial properties. Negative ion concentration test: 500g of each nano-type multifunctional negative ion material prepared in Examples 1-3 and Comparative Examples 1-9 were placed in sealed boxes, spread evenly, and sealed for 24 hours. A negative ion detector was used to measure the concentration every hour, collecting 20 data points each time. The average value of each data point was taken as the final test result. Far-infrared radiation test: 500g of each nano-type multifunctional negative ion material prepared in Examples 1-3 and Comparative Examples 1-9 were placed in sealed boxes, spread evenly, and sealed for 24 hours. The normal total emissivity was measured using a far-infrared emissivity meter. Antibacterial property test: Following the method in AATCC 100-2012 "Evaluation Methods for Antibacterial Textiles", the amount of the tested sample was OWF=1%, and the test substrate was 100% cotton textiles. Unlike the standard, a 30W fluorescent lamp was added during the test for 24 hours. The test results are shown in Table 1 below: Table 1 Performance parameters of the nano-type multifunctional negative ion materials prepared in Examples 1-3 and Comparative Examples 1-9 As shown in Table 1 above, and comparing Comparative Examples 1-4 with Example 3, in step S1, the nanocomposite powder is composed of rare earth mixed materials and nano zinc oxide powder, or rare earth mixed materials and nano silica powder, or nano zinc oxide powder and nano silica powder, or the composite material is composed of nanocomposite powder and graphene oxide. The test results of the final nano-type multifunctional negative ion material are worse than those of Example 3. This indicates that the nanocomposite powder composed of rare earth mixed materials, nano zinc oxide powder, and nano silica powder has a synergistic effect, effectively improving the negative ion release rate and concentration of the negative ion material, and significantly enhancing its antibacterial and far-infrared radiation properties. Coating the surface of the nanocomposite powder with graphene oxide improves its dispersibility, prevents agglomeration, and further enhances the negative ion release performance, far-infrared radiation performance, and antibacterial performance of the negative ion material. Comparing Comparative Examples 5-6 and Example 3, it can be seen that in step S2, replacing the acid anhydride compound with methacrylic anhydride or maleic anhydride by an equal mass, and finally preparing the nano-type multifunctional negative ion material, the test results are worse than those of Example 3. This indicates that the acid anhydride compound composed of methacrylic anhydride and maleic anhydride has a synergistic effect. It can not only improve the dispersion performance of the nanocomposite powder and prevent its agglomeration, but also further improve the negative ion release rate and increase the negative ion concentration of the negative ion material. At the same time, it has a good influence on the far-infrared radiation performance and antibacterial performance of the negative ion material. Comparing Comparative Examples 7-9 and Example 3, it can be seen that in step S3, replacing phenolic acid with protocatechuic acid or gallic acid by mass, or replacing modified quaternized chitosan with quaternized chitosan by mass, and finally preparing nano-type multifunctional negative ion materials, the test results are worse than those of Example 3. This indicates that phenolic acid, composed of a mixture of protocatechuic acid and gallic acid, plays a synergistic antibacterial role, which can effectively improve the antibacterial performance of negative ion materials and further increase the negative ion concentration. Phenolic acid-modified quaternized chitosan can better enhance the antibacterial effect of chitosan, further improve the antibacterial performance of negative ion materials, and also have a good impact on its negative ion release rate and far-infrared radiation performance.

[0057] As shown in Table 1 above, the nano-multifunctional negative ion materials prepared in Examples 1-3, compared to those prepared in Comparative Examples 1-9, achieved the required performance by combining nanocomposite powder with graphene oxide, then with acid anhydride compounds, and finally with modified quaternized chitosan. In contrast, the nano-multifunctional negative ion materials prepared in Comparative Examples 1-9 did not meet the performance requirements. This indicates that the nano-multifunctional negative ion materials prepared in this invention not only possess better negative ion release performance and stability but also better far-infrared radiation performance and antibacterial properties, expanding the application range of negative ion materials and demonstrating superior overall performance.

[0058] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined by the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a nano-type multifunctional negative ion material, characterized in that, Includes the following steps: S1: A composite material is obtained by combining nanocomposite powder with graphene oxide; S2: Combining composite materials with acid anhydride compounds yields reinforced materials; S3: By combining reinforcing materials with modified quaternized chitosan, a nano-type multifunctional negative ion material is obtained; The nanocomposite powder is composed of rare earth mixed materials, nano zinc oxide powder and nano silicon dioxide powder in a mass ratio of 1-1.2:0.7-0.8:0.5-0.6; The anhydride compound is composed of methacrylic anhydride and maleic anhydride in a mass ratio of 0.8-0.9:0.6-0.7; The preparation method of the modified quaternized chitosan includes the following steps: Quaternized chitosan was added to an acetic acid solution and stirred evenly at room temperature to obtain a chitosan solution. Phenolic acid was added to ethanol, followed by MES buffer and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and reacted at room temperature for 0.5-1 h. Then N-hydroxysuccinimide was added, and the reaction was carried out in an ice-water bath for 0.5-1 h to obtain an intermediate product. The intermediate product was added to the chitosan solution and stirred at room temperature for 11-13 h. After the reaction was completed, the mixture was dialyzed with deionized water, centrifuged for 25-35 min, and finally freeze-dried to obtain modified quaternized chitosan. The phenolic acid is composed of protocatechuic acid and gallic acid in a mass ratio of 0.7-0.8:0.5-0.

6.

2. The method for preparing a nano-type multifunctional negative ion material according to claim 1, characterized in that, Step S1 is as follows: A1: Add the nanocomposite powder to anhydrous ethanol and stir for 20-30 min to obtain a suspension. Add the silane coupling agent to a mixed solution of anhydrous ethanol and deionized water and stir until homogeneous to obtain a silane solution. Add the silane solution to the suspension and stir at 45-55℃ for 5.5-6.5 h. After the reaction is complete, filter the solution, wash with anhydrous ethanol and deionized water, and finally vacuum dry at 75-85℃ to obtain silanized nanocomposite powder. A2: Add silanized nanocomposite powder to deionized water and stir until homogeneous to obtain dispersion A. Add graphene oxide to deionized water and sonicate for 1-2 hours to obtain dispersion B. Add dispersion B to dispersion A and stir for 1.5-2.5 hours. After the reaction is complete, filter, wash with deionized water, and finally vacuum dry at 75-85℃ to obtain crude product. Then ball mill and sieve to obtain composite material.

3. The method for preparing a nano-type multifunctional negative ion material according to claim 1, characterized in that, The rare earth composite material is composed of nano-lanthanum oxide and nano-cerium oxide mixed in a mass ratio of 1-2:

1.

4. The method for preparing a nano-type multifunctional negative ion material according to claim 1, characterized in that, Step S2 is as follows: The composite material from step S1 was added to N,N-dimethylformamide and stirred until homogeneous. Then, it was heated to 35-45°C, and an acid anhydride compound was added. The mixture was stirred and reacted at 35-45°C for 1.5-2.5 hours. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and finally dried under vacuum at 65-75°C to obtain the reinforced material.

5. The method for preparing a nano-type multifunctional negative ion material according to claim 1, characterized in that, Step S3 is as follows: The reinforcing material from step S2 is added to deionized water and ultrasonically treated for 30-40 min to obtain component A. Modified quaternized chitosan is added to acetic acid solution and stirred evenly. It is then degassed with nitrogen for 25-35 min to obtain component B. Component A and catalyst are added to component B, and the mixture is reacted for 11-13 h under nitrogen atmosphere and constant temperature water bath at 55-65℃. The pH of the system is adjusted to 6.8-7.2 with sodium hydroxide solution. The mixture is dialyzed with deionized water, and acetic acid is removed by vacuum distillation. Finally, it is freeze-dried to obtain nano-type multifunctional negative ion material, wherein the catalyst is ammonium persulfate.

6. A nano-type multifunctional negative ion material prepared by the preparation method according to any one of claims 1-5.

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