Self-responsive odor-removing sterilization material, preparation method thereof and refrigerator

Abstract

The application discloses a self-response odor-removing and sterilization material, a preparation method thereof and a refrigerator, and belongs to the technical field of refrigerator adsorption materials. The self-response odor-removing and sterilization material comprises a main material and an auxiliary material; the main material is composed of an adsorption material and a formaldehyde removal agent; the auxiliary material is composed of a response material and a sterilization agent; the response material is selected from covalent organic frameworks; the sterilization agent is selected from benzimidazole compounds; the benzimidazole compounds present a deprotonization trend at any value of pH 2.8-7.1, and are combined with the covalent organic frameworks through electrostatic attraction; when the pH is less than 2.8, the benzimidazole compounds and the covalent organic frameworks are simultaneously protonated, and the benzimidazole compounds are released. The application is applied to refrigerator sterilization, and solves the problems that common odor-removing and sterilization materials release sterilization substances from the beginning to exert effects, so that the sterilization effect is not durable, or the sterilization material cannot release sterilization substances actively, and can only play a sterilization role when bacteria are adsorbed on the surface of the sterilization material, and cannot kill bacteria in the air.

Description

Technical Field

[0001] This invention belongs to the field of refrigerator adsorption material technology, and particularly relates to a self-responsive deodorizing and sterilizing material, its preparation method, and a refrigerator. Background Technology

[0002] Food stored in the refrigerator can breed bacteria and release formaldehyde gas, producing unpleasant odors. Refrigerator odors have become a major pain point for users, severely impacting their experience. To address this issue, odor-eliminating and antibacterial materials are typically used in refrigerators.

[0003] However, currently common odor-eliminating and sterilizing materials release sterilizing substances as soon as they are applied, even if there is no food in the refrigerator at that time; or the sterilizing materials cannot be actively released, and can only play a sterilizing role when bacteria are adsorbed on the surface of the sterilizing materials, and cannot kill bacteria in the air. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to overcome the issue that common deodorizing and sterilizing materials release sterilizing substances from the moment of application, resulting in a short-lasting sterilization effect, or that the sterilizing materials cannot actively release their substances and only exert a sterilizing effect when bacteria are adsorbed onto the surface of the sterilizing material, thus failing to kill bacteria in the air. This invention proposes a self-responsive deodorizing and sterilizing material that only responds and releases sterilizing substances when food stored in the refrigerator releases formaldehyde gas, greatly extending the service life of the sterilizing material and expanding its sterilization range, resulting in a more significant sterilization effect. The invention also includes its preparation method and a refrigerator.

[0005] To solve the aforementioned technical problem, the technical solution adopted by the present invention is as follows:

[0006] This invention provides a self-responsive odor-eliminating and bactericidal material, comprising a main material and auxiliary materials; the main material is composed of an adsorbent and a formaldehyde remover; the auxiliary material is composed of a responsive material and a bactericide; the responsive material is selected from a covalent organic framework; the bactericide is selected from benzimidazole compounds; the benzimidazole compounds exhibit a deprotonation tendency at any pH value between 2.8 and 7.1, and bind to the covalent organic framework through electrostatic attraction; the benzimidazole compounds are simultaneously protonated with the covalent organic framework at pH less than 2.8, and the benzimidazole compounds are released.

[0007] Preferably, the covalent organic framework is selected from one or more of TpPa-1, TpPa-2, TpBD, and COF-LZU1.

[0008] Preferably, the adsorbent material is a porous material, which is selected from one or more of activated carbon, molecular sieves, and diatomaceous earth; the formaldehyde removal agent is selected from one or more of nano-silver particles, nano-titanium dioxide, nano-manganese dioxide, nano-zinc oxide, and nano-zirconia.

[0009] Preferably, the mass ratio of the main material to the auxiliary material is selected from any value between 0.05 and 0.25:1.

[0010] Preferably, the mass ratio of the adsorbent material to the formaldehyde removal agent is selected from any value between 1 and 3:3; the mass ratio of the responsive material to the bactericide is selected from any value between 0.1 and 1:1.

[0011] Another aspect of the present invention provides a method for preparing the self-responsive deodorizing and bactericidal material described in any of the above technical solutions, including a preparation step of the main material, a preparation step of the auxiliary material, and a compounding step of the main material and the auxiliary material.

[0012] Preferably, the preparation steps of the main material include: adding the adsorbent material and the formaldehyde removal agent to deionized water respectively, stirring thoroughly at a speed of 600-800 rpm, washing with deionized water, and freeze-drying to obtain the main material.

[0013] Preferably, the preparation steps of the auxiliary material include: preparing a buffer solution with a pH of 3-7, adding the response material to the buffer solution, stirring and dispersing it evenly, adding the bactericide with a concentration of 500 ppm to obtain a mixed solution, stirring the mixed solution under vacuum at a speed of 600-800 rpm, washing with deionized water, and drying it in a vacuum drying oven to obtain the auxiliary material.

[0014] Preferably, the composite step of the main material and the auxiliary material includes: dispersing the main material in deionized water, stirring to obtain its aqueous dispersion, adding the auxiliary material, vigorously stirring the mixed aqueous solution of the two, washing with deionized water, and finally freeze-drying the product to obtain the self-responsive deodorizing and bactericidal material.

[0015] The present invention also provides a refrigerator, which is manufactured from the self-responsive deodorizing and sterilizing material described in any of the above technical solutions.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] This invention provides a self-responsive odor-eliminating and sterilizing material, composed of a main material and auxiliary materials. Specifically, the main material uses an adsorbent as a carrier to load a formaldehyde remover. The adsorbent captures formaldehyde molecules, and the formaldehyde remover decomposes these molecules into carbon dioxide and water, purifying the air in the refrigerator and removing odors. The auxiliary material uses a responsive material as a carrier to load a sterilizing agent. When the carbon dioxide and water obtained from the decomposition in the main material react chemically to form carbonic acid, the overall pH value of the material decreases. At this point, the responsive material releases the sterilizing agent through electrostatic repulsion under pH stimulation, thereby killing bacteria in the refrigerator. This self-responsive odor-eliminating and sterilizing material only releases sterilizing substances when food stored in the refrigerator releases formaldehyde gas, greatly extending the service life of the sterilizing material and expanding the sterilization range for a more significant sterilization effect. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the zeta potential of the covalent organic framework and benzimidazole compounds of the present invention at different pH values;

[0019] Figure 2 This is a diagram illustrating the antibacterial effect of the odor-neutralizing and sterilizing material in Embodiment 1 of the present invention. Detailed Implementation

[0020] The technical solutions in specific embodiments of the present invention will now be described in detail and completely with reference to the accompanying drawings. Obviously, the described embodiments are merely some specific implementations of the overall technical solution of the present invention, and not all implementations. Based on the overall concept of the present invention, all other embodiments obtained by those skilled in the art fall within the protection scope of the present invention.

[0021] This invention provides a self-responsive odor-eliminating and bactericidal material, comprising a main material and auxiliary materials. The main material is composed of an adsorbent and a formaldehyde remover. The auxiliary material is composed of a responsive material and a bactericide. The responsive material is selected from a covalent organic framework. The bactericide is selected from benzimidazole compounds. The benzimidazole compounds exhibit a deprotonation tendency at any pH value between 2.8 and 7.1 and bind to the covalent organic framework through electrostatic attraction. When the pH is less than 2.8, the benzimidazole compounds are simultaneously protonated with the covalent organic framework, and the benzimidazole compounds are released. This technical solution limits the types of responsive materials and bactericides, such as... Figure 1As shown, the Zeta potentials of the response material and bactericide at different pH values ​​defined by this technical solution indicate that in the pH range of 2.8-7.1, the bactericide exhibits a deprotonation trend and binds to the response material through electrostatic attraction. Therefore, this pH range is selected as the pH for the two to combine. When the pH is less than 2.8, the bactericide and the response material are protonated simultaneously, and there is an electrostatic repulsion between them. The formaldehyde removal and sterilization process is as follows: The main material uses an adsorbent as a carrier to load the formaldehyde removal agent. The adsorbent captures formaldehyde molecules, and the formaldehyde removal agent decomposes the captured formaldehyde molecules into carbon dioxide and water, purifying the air in the refrigerator and removing odors. The auxiliary material uses a responsive material as a carrier to load the sterilizer. When the carbon dioxide and water obtained from the decomposition in the main material undergo a chemical reaction to generate carbonic acid, the overall pH value of the material decreases. At this time, the responsive material releases the sterilizer through electrostatic repulsion under the stimulation of pH, thereby killing bacteria in the refrigerator. This self-responsive odor-eliminating and sterilizing material only responds and releases sterilizing substances when the food stored in the refrigerator releases formaldehyde gas, greatly extending the service life of the sterilizing material and expanding the sterilization range, resulting in a more obvious sterilization effect.

[0022] In a preferred embodiment, the covalent organic framework is selected from one or more of TpPa-1, TpPa-2, TpBD, and COF-LZU1. This technical solution specifically defines the type of covalent organic framework; however, it is understood that the covalent organic framework can also be other substances reasonably selected by those skilled in the art based on common knowledge in the field.

[0023] In a preferred embodiment, the adsorbent material is a porous material selected from one or more of activated carbon, molecular sieves, and diatomaceous earth; the formaldehyde removal agent is selected from one or more of nano-silver particles, nano-titanium dioxide, nano-manganese dioxide, nano-zinc oxide, and nano-zirconia. This technical solution specifically defines the types of adsorbent material and formaldehyde removal agent. It is understood that the adsorbent material and formaldehyde removal agent can also be other substances reasonably selected by those skilled in the art based on common knowledge in the field.

[0024] In a preferred embodiment, the mass ratio of the main material to the auxiliary material is selected from any value between 0.05 and 0.25:1. This embodiment specifically defines the mass ratio of the main material to the auxiliary material; it is understood that the mass ratio can also be 0.10:1, 0.15:1, 0.20:1, or any value within the range thereof.

[0025] In a preferred embodiment, the mass ratio of the adsorbent material to the formaldehyde removal agent is selected from any value between 1 and 3:3; the mass ratio of the responsive material to the bactericide is selected from any value between 0.1 and 1:1. This embodiment specifically defines the mass ratio of the adsorbent material to the formaldehyde removal agent and the mass ratio of the responsive material to the bactericide. It is understood that the mass ratio of the adsorbent material to the formaldehyde removal agent can also be 2:3 or any value within this range, and the mass ratio of the responsive material to the bactericide can also be 0.2:1, 0.4:1, 0.6:1, 0.8:1 or any value within this range.

[0026] Another aspect of the present invention provides a method for preparing the self-responsive deodorizing and bactericidal material described in any of the above technical solutions, including a preparation step of the main material, a preparation step of the auxiliary material, and a compounding step of the main material and the auxiliary material.

[0027] In a preferred embodiment, the preparation steps of the main material include: adding the adsorbent material and the formaldehyde removal agent to deionized water respectively, stirring thoroughly at 600-800 rpm, washing with deionized water, and freeze-drying to obtain the main material. Specifically, the adsorbent material and the formaldehyde removal agent in a mass ratio of 1-3:3 are added to deionized water respectively, stirred thoroughly at 600-800 rpm, washed three times with deionized water, and freeze-dried for 24 hours to maximize the removal of gas from the pores of the adsorbent material, thereby obtaining the main material.

[0028] In a preferred embodiment, the preparation steps of the auxiliary material include: preparing a buffer solution with a pH of 3-7, adding the responsive material to the buffer solution, stirring and dispersing it evenly, then adding the bactericide at a concentration of 500 ppm to obtain a mixed solution, stirring the mixed solution under vacuum at 600-800 rpm, washing with deionized water, and drying in a vacuum drying oven to obtain the auxiliary material. Specifically, preparing a buffer solution with a pH of 3-7, adding the responsive material to the buffer solution, stirring for 5 minutes to disperse it evenly, then adding the bactericide at a concentration of 500 ppm, stirring the mixed solution under vacuum at 600-800 rpm for 24 hours, washing with deionized water three times, and drying in a vacuum drying oven at 60°C for 24 hours.

[0029] In a preferred embodiment, the composite step of the main material and the auxiliary material includes: dispersing the main material in deionized water, stirring to obtain an aqueous dispersion, adding the auxiliary material, vigorously stirring the mixed aqueous solution, washing with deionized water, and finally freeze-drying the product to obtain the self-responsive deodorizing and bactericidal material. Specifically, the main material is dispersed in deionized water and stirred for 30 minutes to obtain an aqueous dispersion, then the auxiliary material is added, wherein the mass ratio of the main material to the auxiliary material is 0.05-0.25:1, the mixed aqueous solution is vigorously stirred for 6 hours, washed 3-5 times with deionized water, and finally freeze-drying the product for 24 hours.

[0030] This invention also provides a refrigerator manufactured using the self-responsive deodorizing and sterilizing material described in any of the above technical solutions. This refrigerator, by using the self-responsive deodorizing and sterilizing material of this invention, only releases sterilizing substances when food stored in the refrigerator releases formaldehyde gas, greatly extending the service life of the sterilizing material and expanding the sterilization range for a more significant sterilization effect.

[0031] To provide a clearer and more detailed description of the self-responsive deodorizing and sterilizing material, its preparation method, and the refrigerator provided in the embodiments of the present invention, the following description will be based on specific embodiments.

[0032] Example 1

[0033] (1) Preparation of main materials: Add an appropriate amount of concentrated nitric acid to 50 mL of deionized water until the pH of the solution is maintained between 2 and 3. Add 20 mL of tetrabutyl titanate solution dropwise and stir for 30 min. Transfer the above solution and 10 mg of activated carbon to a reaction vessel and place the reaction vessel at 180 °C for hydrothermal treatment for 6 h. After the reaction is completed, wash several times with deionized water until the aqueous solution of the reactants is neutral. Dry the product at 60 °C for 6 h.

[0034] (2) Preparation of auxiliary materials: Take an appropriate amount of 0.2 mol / L sodium dihydrogen phosphate solution, adjust the pH value to 5 with sodium hydroxide solution to prepare a buffer solution. Add 100 mg of N-isopropyl-1-(naphthyl-1-methylene)-2-(5,5,8,8-tetramethyl5,6,7,8-tetrahydronaphthyl-2-yl)-1H-benzimidazole-5-morpholinamidin to 100 mL of phosphate buffer solution containing 20 mg TpPa-1, and stir under vacuum at 800 rpm for 24 h. Wash three times with deionized water, and dry the product at 60 °C for 6 h.

[0035] (3) Combination of main material and auxiliary material: 5 mg of main material and 100 mg of auxiliary material were dispersed in 40 mL of deionized water, stirred at room temperature for 6 h, washed three times with deionized water, and dried at 60 °C for 6 h.

[0036] Example 2

[0037] (1) Preparation of main materials: Weigh 20 mg of molecular sieve and 50.7 mg of silver nitrate and dissolve them in 50 mL of deionized water. Wrap the solution in tin foil to protect it from light and stir for 1 h. Then, add 15 μL of hydrazine hydrate dropwise while stirring for another 2 h. Wash the solution three times with deionized water and freeze-dry for 24 h.

[0038] (2) Preparation of auxiliary materials: 8.34 g of potassium dihydrogen phosphate and 0.87 g of dipotassium hydrogen phosphate were dissolved in water to make 1000 ml, thus preparing a buffer solution. 90 mL of the buffer solution was placed in an Erlenmeyer flask, and 100 mg of N-isopropyl-1-(naphthyl-1-methylene)-2-(5,5,8,8-tetramethyl5,6,7,8-tetrahydronaphthyl-2-yl)-1H-benzimidazole-5-morpholinamidine and 50 mg of TpPa-2 were added. The mixture was stirred and refluxed at 30 °C for 10 h. The product was washed three times with deionized water and dried at 60 °C for 6 h.

[0039] (3) Combination of main material and auxiliary material: 10 mg of main material and 100 mg of auxiliary material were dispersed in 40 mL of deionized water, stirred at room temperature for 6 h, washed three times with deionized water, and dried at 60 °C for 6 h.

[0040] Example 3

[0041] (1) Preparation of main materials: Weigh 30 mg of diatomaceous earth, 104.8 mg of zinc nitrate hexahydrate and 109.1 mg of melamine and dissolve them in 20 mL of deionized water. Stir for 20 min to mix them evenly. Transfer the above mixed solution to a reaction vessel and heat it at 108 °C for 6 h. Then wash it three times with deionized water, dry it at 60 °C for 6 h, and calcine the product in a muffle furnace for 2 h under an inert atmosphere.

[0042] (2) Preparation of auxiliary materials: Weigh 100 mg TpBD and dissolve it in 20 mL of deionized water. Stir for 30 min to make it uniform. Add hydrochloric acid to adjust the pH value to between 4 and 5. Add 100 mg N-isopropyl-1-(naphthyl-1-methylene)-2-(5,5,8,8-tetramethyl5,6,7,8-tetrahydronaphthyl-2-yl)-1H-benzimidazole-5-morpholinamidine. Continue stirring under vacuum for 5 h. Wash three times with deionized water and dry the product at 60 °C for 6 h.

[0043] (3) Combination of main material and auxiliary material: 25 mg of main material and 100 mg of auxiliary material were dispersed in 40 mL of deionized water, stirred at room temperature for 6 h, washed three times with deionized water, and dried at 60 °C for 6 h.

[0044] Performance testing

[0045] Formaldehyde Removal Test: Apply 500mg of the odor-neutralizing and bactericidal material to a 5cm*5cm glass slide and cover it with a glass container. Introduce formaldehyde gas into the glass container at a flow rate of 1L / min. After 5 minutes of inhalation, irradiate the odor-neutralizing and bactericidal material with a 300W xenon lamp for 30 minutes. Record the formaldehyde concentration using a formaldehyde gas analyzer and calculate the formaldehyde removal rate and formaldehyde degradation rate.

[0046] Formaldehyde degradation rate = (Formaldehyde concentration after 30 minutes of irradiation - Initial formaldehyde concentration) / Initial formaldehyde concentration

[0047] Antibacterial test: The antibacterial properties of the odor-neutralizing and bactericidal material were determined by plate counting method. The viable bacterial strain used in the test was Staphylococcus aureus. 100 μL of bacterial suspension was pipetted into a plate, then the odor-neutralizing and bactericidal material and 10 mL of pure, sterile liquid agar were added. The plate was rapidly shaken and mixed. After the agar solidified, it was incubated in a 35°C cleanroom for 24 hours. The number of viable bacteria on the plate was counted. A control experiment was simultaneously conducted without the addition of the odor-neutralizing and bactericidal material.

[0048] Table 1. Formaldehyde removal rate and sterilization rate of odor-neutralizing and sterilizing materials

[0049]

[0050]

[0051] From Table 1 and Figure 2 It can be seen that the odor-removing and bactericidal material of the present invention has excellent formaldehyde removal and antibacterial properties.

Claims

1. A self-responsive odor-neutralizing and bactericidal material, characterized in that, The system comprises a main material and auxiliary materials. The main material consists of an adsorbent and a formaldehyde remover. The auxiliary materials consist of a responsive material and a bactericide. The responsive material is selected from a covalent organic framework. The bactericide is selected from benzimidazole compounds. The benzimidazole compounds exhibit a deprotonation tendency at any pH value between 2.8 and 7.1 and bind to the covalent organic framework through electrostatic attraction. When the pH is less than 2.8, the benzimidazole compounds are simultaneously protonated with the covalent organic framework, and the benzimidazole compounds are released. The covalent organic framework is selected from one or more of TpPa-1, TpPa-2, TpBD, and COF-LZU1; The benzimidazole compound is N-isopropyl-1-(naphth-1-methylene)-2-(5,5,8,8-tetramethyl5,6,7,8-tetrahydronaphth-2-yl)-1H-benzimidazole-5-morpholinamidine.

2. The self-responsive odor-neutralizing and bactericidal material according to claim 1, characterized in that, The adsorbent material is a porous material, which is selected from one or more of activated carbon, molecular sieves, and diatomaceous earth; the formaldehyde removal agent is selected from one or more of nano-silver particles, nano-titanium dioxide, nano-manganese dioxide, nano-zinc oxide, and nano-zirconia.

3. The self-responsive odor-neutralizing and bactericidal material according to claim 1, characterized in that, The mass ratio of the main material to the auxiliary material is selected from any value between 0.05 and 0.25:

1.

4. The self-responsive odor-neutralizing and bactericidal material according to claim 1, characterized in that, The mass ratio of the adsorbent material to the formaldehyde remover is selected from any value between 1 and 3:3; the mass ratio of the responsive material to the bactericide is selected from any value between 0.1 and 1:

1.

5. The method for preparing the self-responsive deodorizing and bactericidal material according to any one of claims 1-4, characterized in that, It includes the preparation steps of the main material, the preparation steps of the auxiliary material, and the composite steps of the main material and the auxiliary material.

6. The preparation method of the self-responsive odor-neutralizing and bactericidal material according to claim 5, characterized in that, The preparation steps of the main material include: adding the adsorbent material and the formaldehyde removal agent to deionized water respectively, stirring thoroughly at 600-800 rpm, washing with deionized water, and freeze-drying to obtain the main material.

7. The preparation method of the self-responsive odor-neutralizing and bactericidal material according to claim 5, characterized in that, The preparation steps of the auxiliary material include: preparing a buffer solution with a pH of 3-7, adding the response material to the buffer solution, stirring and dispersing it evenly, adding the bactericide at a concentration of 500 ppm to obtain a mixed solution, stirring the mixed solution under vacuum at a speed of 600-800 rpm, washing it with deionized water, and drying it in a vacuum drying oven to obtain the auxiliary material.

8. The preparation method of the self-responsive odor-neutralizing and bactericidal material according to claim 5, characterized in that, The composite process of the main material and the auxiliary material includes: dispersing the main material in deionized water, stirring to obtain its aqueous dispersion, adding the auxiliary material, vigorously stirring the mixed aqueous solution of the two, washing with deionized water, and finally freeze-drying the product to obtain the self-responsive deodorizing and bactericidal material.

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