Self-response odor-removing and sterilizing material, preparation method thereof and refrigerator

Abstract

The invention discloses a self-response odor-removing and sterilizing material, a preparation method thereof and a refrigerator, and belongs to the technical field of refrigerator adsorption materials. Comprising main materials and auxiliary materials, the main body material is composed of an adsorption material and a formaldehyde removal agent; the auxiliary material is composed of a response material and a bactericide; the response material is selected from a covalent organic framework; the bactericide is selected from benzimidazole compounds; the benzimidazole compound shows a deprotonation trend when the pH value is any one value of 2.8-7.1, and is combined with the covalent organic framework through electrostatic attraction; when the pH value is less than 2.8, the benzimidazole compound and the covalent organic framework are protonated at the same time, and the benzimidazole compound is released. The sterilization material is applied to the refrigerator sterilization aspect, and the problems that the sterilization effect is not lasting due to the fact that a common odor-removing sterilization material plays a role to release sterilization substances from the beginning of application, or the sterilization material cannot be actively released, the sterilization effect can be achieved only when bacteria are adsorbed on the surface of the sterilization material, and the bacteria in the air cannot be killed are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of refrigerator adsorption materials, and in particular relates to a self-responsive odor-removing and sterilizing material, a preparation method thereof, and a refrigerator. Background Art

[0002] When food is stored in the refrigerator, bacteria will grow and formaldehyde gas will be released, producing odor. Currently, refrigerator odor has become one of the main pain points for users, seriously affecting the user experience. In order to solve this problem, odor-free sterilizing materials are usually used in refrigerators.

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

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to overcome the problem that common odor-free sterilizing materials release sterilizing substances from the beginning of application, resulting in a short-lasting sterilizing effect, 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. A self-responsive odor-free sterilizing material is proposed, which will only respond to release 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. The sterilization effect is more obvious, and its preparation method and refrigerator are provided.

[0005] In order to solve the technical problem, the technical solution adopted by the present invention is:

[0006] On the one hand, the present invention provides a self-responsive odor-free bactericidal material, comprising a main material and an auxiliary material; the main material is composed of an adsorbent material 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 skeleton; the bactericide is selected from benzimidazole compounds; the benzimidazole compounds show a deprotonation trend when the pH is any value between 2.8 and 7.1, and are combined with the covalent organic skeleton through electrostatic attraction; when the pH is less than 2.8, the benzimidazole compounds are protonated simultaneously with the covalent organic skeleton, 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 adsorption material is a porous material, and the porous material is selected from one or more of activated carbon, molecular sieve, 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 zirconium dioxide.

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

[0010] Preferably, the mass ratio of the adsorption material to the formaldehyde removal agent is selected from any value in the range of 1-3:3; the mass ratio of the response material to the bactericide is selected from any value in the range of 0.1-1:1.

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

[0012] Preferably, the preparation step of the main material comprises: adding the adsorbent material and the formaldehyde removal agent into deionized water respectively, stirring them sufficiently at a speed of 600-800 rpm, then washing them with deionized water, and freeze-drying them to prepare the main material.

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

[0014] Preferably, the step of compounding the main material and the auxiliary material includes: dispersing the main material in deionized water, stirring to obtain its aqueous dispersion, then 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 odor-purifying sterilization material.

[0015] The present invention also provides a refrigerator, which is manufactured using the self-responsive odor-purifying sterilization material described in any of the above technical solutions.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention provides a self-responsive odor-free sterilizing material, which consists of a main material and an auxiliary material. By limiting the composition of the main material and the auxiliary material, specifically, the main material uses an adsorption material as a carrier to load a formaldehyde removal agent, and the adsorption material captures formaldehyde molecules. The formaldehyde removal agent decomposes the captured formaldehyde molecules into carbon dioxide and water, purifies the air in the refrigerator, and removes odors. The auxiliary material uses a response material as a carrier to load a sterilizer. When the carbon dioxide and water decomposed in the main material undergo a chemical reaction to generate carbonic acid, the overall pH value of the material decreases. At this time, the response material releases the sterilizer through electrostatic repulsion under the stimulation of pH, thereby killing bacteria in the refrigerator. The self-responsive odor-free sterilizing material will respond to release the sterilizing substance only when the food stored in the refrigerator releases formaldehyde gas, which greatly prolongs the service life of the sterilizing material, while expanding the sterilization range, and the sterilization effect is more obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the Zeta potential of the covalent organic framework and the benzimidazole compound of the present invention at different pH values;

[0019] Figure 2 This is a diagram showing the antibacterial effect of the odor-free bactericidal material in Example 1 of the present invention. DETAILED DESCRIPTION

[0020] The technical scheme in the specific embodiment of the present invention will be described in detail and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are only some specific implementation methods of the overall technical scheme of the present invention, rather than all implementation methods. Based on the overall concept of the present invention, all other embodiments obtained by ordinary technicians in this field fall within the scope of protection of the present invention.

[0021] On one hand, the present invention provides a self-responsive odor-free bactericidal material, including a main material and an auxiliary material; the main material is composed of an adsorbent material and a formaldehyde removal agent; the auxiliary material is composed of a responsive material and a bactericide; the responsive material is selected from a covalent organic skeleton; the bactericide is selected from a benzimidazole compound; the benzimidazole compound shows a deprotonation trend at any pH value between 2.8 and 7.1, and is bonded to the covalent organic skeleton by electrostatic attraction; the benzimidazole compound is protonated simultaneously with the covalent organic skeleton when the pH is less than 2.8, and the benzimidazole compound is released. This technical solution limits the types of responsive materials and bactericides, such as Figure 1As shown, the Zeta potential of the response material and the bactericide defined by the present technical solution at different pH values ​​indicates that when the pH is in the range of 2.8-7.1, the bactericide tends to be deprotonated, and is combined with the response material by electrostatic attraction. Therefore, this pH range is selected as the pH of the composite of the two. When the pH is less than 2.8, the bactericide and the response material are protonated at the same time, and there is electrostatic repulsion between the two. Regarding the formaldehyde removal and sterilization process, the details are as follows: the main material uses the adsorption material as a carrier to load the formaldehyde remover, and the formaldehyde molecules are captured by the adsorption material. The formaldehyde remover decomposes the captured formaldehyde molecules into carbon dioxide and water, purifies the air in the refrigerator, and removes odors. The auxiliary material uses the response material as a carrier to load the bactericide. When the carbon dioxide and water decomposed in the main material react chemically to generate carbonic acid, the overall pH value of the material decreases. At this time, the response material releases the bactericide through electrostatic repulsion under the stimulation of pH, thereby killing the bacteria in the refrigerator. The self-responsive odor-free sterilization material will only respond to release the bactericidal substance when the food stored in the refrigerator releases formaldehyde gas, which greatly extends the service life of the sterilization material. At the same time, it expands the sterilization range and the sterilization effect is more obvious.

[0022] In a preferred embodiment, the covalent organic framework is selected from one or more of TpPa-1, TpPa-2, TpBD, and COF-LZU1. The technical solution specifically defines the type of covalent organic framework. It is understandable that the covalent organic framework can also be other substances reasonably selected by those skilled in the art in the art in combination with common knowledge in the art.

[0023] In a preferred embodiment, the adsorbent material is a porous material, and the porous material is selected from one or more of activated carbon, molecular sieve, and diatomaceous earth; the formaldehyde remover is selected from one or more of nano silver particles, nano titanium dioxide, nano manganese dioxide, nano zinc oxide, and nano zirconium dioxide. This technical solution specifically defines the types of adsorbent materials and formaldehyde removers. It is understandable that the adsorbent materials and formaldehyde removers can also be other substances reasonably selected by those skilled in the art in the art in combination with common knowledge in the art.

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

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

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

[0027] In a preferred embodiment, the preparation step of the main material includes: adding the adsorbent material and the formaldehyde removal agent to deionized water, stirring them at 600-800 rpm, washing them with deionized water, and freeze-drying them to prepare the main material. Specifically, the adsorbent material and the formaldehyde removal agent with a mass ratio of 1-3:3 are added to deionized water, stirring them at 600-800 rpm, washing them with deionized water for 3 times, and freeze-drying them for 24 hours to discharge the gas in the pores of the adsorbent material to the maximum extent, thereby preparing the main material.

[0028] In a preferred embodiment, the preparation step of the auxiliary material includes: preparing a buffer solution with a pH of 3-7, adding the response material to the above buffer solution, stirring and dispersing it evenly, and then adding the bactericide with a concentration of 500ppm to obtain a mixed solution, vacuuming and stirring the mixed solution at a speed of 600-800rpm, washing with deionized water, and drying in a vacuum drying oven to obtain the auxiliary material. Specifically, prepare a buffer solution with a pH of 3-7, add the response material to the above buffer solution, stir for 5min to disperse it evenly, and then add the bactericide with a concentration of 500ppm, vacuuming and stirring the mixed solution at a speed of 600-800rpm for 24h, washing with deionized water 3 times, and drying in a vacuum drying oven at 60°C for 24h.

[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 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 odor-free sterilization material. Specifically, the main material is dispersed in deionized water, stirred for 30 minutes to obtain its aqueous dispersion, and 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 of the two is vigorously stirred for 6 hours, washed with deionized water 3-5 times, and finally the product is freeze-dried for 24 hours.

[0030] The present invention also provides a refrigerator, which is manufactured by the self-responsive odor-free sterilizing material described in any of the above technical solutions. By using the self-responsive odor-free sterilizing material of the technical solution of the present invention, the refrigerator will respond to release sterilizing substances only when the food stored in the refrigerator releases formaldehyde gas, which greatly prolongs the service life of the sterilizing material, expands the sterilization range, and has a more obvious sterilization effect.

[0031] In order to more clearly and in detail introduce the self-responsive odor-purifying sterilization material, the preparation method thereof and the refrigerator provided in the embodiments of the present invention, a description will be given below in conjunction with specific embodiments.

[0032] Example 1

[0033] (1) Preparation of the main material: 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 minutes. Transfer the above solution and 10 mg of activated carbon to a reactor, and place the reactor at 180°C for 6 hours. After the reaction is completed, wash with deionized water several times until the aqueous solution of the reactant is neutral, and dry the product at 60°C for 6 hours.

[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, and prepare a buffer solution. Add 100 mg of N-isopropyl-1-(naphthalene-1-methylene)-2-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene-2-yl)-1H-benzimidazole-5-morpholine amidine to 100 mL of phosphate buffer solution containing 20 mg of 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) Composite 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 the main material: Weigh 20 mg of molecular sieve and 50.7 mg of silver nitrate and dissolve them in 50 mL of deionized water, wrap them with tin foil to avoid light, and stir them for 1 hour. Then, add 15 μL of hydrazine hydrate dropwise under stirring and continue stirring for 2 hours. Then, wash them with deionized water for 3 times and freeze-dry them for 24 hours.

[0038] (2) Preparation of auxiliary materials: Take 8.34g of potassium dihydrogen phosphate and 0.87g of potassium dihydrogen phosphate, add water to dissolve to 1000ml, and prepare a buffer solution. Take 90mL of the buffer solution in a conical flask, add 100mg of N-isopropyl-1-(naphthalene-1-methylene)-2-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-1H-benzimidazole-5-morpholine amidine and 50mg of TpPa-2, stir and reflux at 30°C for 10h. Wash three times with deionized water, and dry the product at 60°C for 6h.

[0039] (3) Composite 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 the main material: 30 mg of diatomaceous earth, 104.8 mg of zinc nitrate hexahydrate and 109.1 mg of melamine were weighed and dissolved in 20 mL of deionized water, and stirred for 20 min to mix them evenly. The mixed solution was transferred to a reactor, heated at 108°C for 6 h, then washed with deionized water 3 times, dried at 60°C for 6 h, and the product was placed in a muffle furnace for calcination for 2 h under an inert atmosphere.

[0042] (2) Preparation of auxiliary materials: Weigh 100 mg of TpBD and dissolve it in 20 mL of deionized water, stir for 30 min to make it uniform, add hydrochloric acid dropwise to adjust the pH value to between 4 and 5, add 100 mg of N-isopropyl-1-(naphthalene-1-methylene)-2-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-1H-benzimidazole-5-morpholine amidine, evacuate and continue stirring for 5 h. Wash with deionized water three times, and dry the product at 60° C. for 6 h.

[0043] (3) Composite 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: 500 mg of odor-free sterilization material was applied on a 5cm*5cm glass slide and covered with a glass container. Formaldehyde gas was introduced into the glass container at a gas flow rate of 1L / min. After ventilation for 5 minutes, a 300W xenon lamp was used to irradiate the odor-free sterilization material for 30 minutes. The formaldehyde concentration was recorded using a formaldehyde gas analyzer and the formaldehyde removal rate and formaldehyde degradation rate were calculated.

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

[0047] Antibacterial test: The antibacterial properties of the odor-free sterilization material were determined by the plate count method. The live bacteria used in the test were Staphylococcus aureus. 100 μL of bacterial solution was drawn into the plate, and then the odor-free sterilization material and 10 mL of pure and sterile liquid agar were added. The plate was shaken quickly and placed in a clean box at 35°C for 24 hours after the agar solidified. The number of live bacteria on the plate was calculated, and a group of experiments without odor-free sterilization material were set up as a control experiment.

[0048] Table 1 Formaldehyde removal rate and sterilization rate of odor-free sterilization materials

[0049]

[0050]

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

Claims

1. A self-responsive odor-free sterilization material, characterized in that: It 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 bactericide; the response material is selected from a covalent organic skeleton; the bactericide is selected from a benzimidazole compound; the benzimidazole compound shows a deprotonation trend when the pH is any value between 2.8 and 7.1, and is combined with the covalent organic skeleton through electrostatic attraction; when the pH is less than 2.8, the benzimidazole compound is protonated simultaneously with the covalent organic skeleton, and the benzimidazole compound is released.

2. The self-responsive odor-free sterilizing material according to claim 1, characterized in that: The covalent organic framework is selected from one or more of TpPa-1, TpPa-2, TpBD, and COF-LZU1.

3. The self-responsive odor-free sterilizing material according to claim 1, characterized in that: The adsorption material is a porous material, and the porous material is selected from one or more of activated carbon, molecular sieve, 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 zirconium dioxide.

4. The self-responsive odor-free sterilizing material according to claim 1, characterized in that: The mass ratio of the main material to the auxiliary material is selected from any value in the range of 0.05-0.25:

1.

5. The self-responsive odor-free sterilizing material according to claim 1, characterized in that: The mass ratio of the adsorption material to the formaldehyde removal agent is selected from any value in the range of 1-3:3; the mass ratio of the response material to the bactericide is selected from any value in the range of 0.1-1:

1.

6. The method for preparing the self-responsive odor-free sterilization material according to any one of claims 1 to 5, characterized in that: The method comprises the steps of preparing the main material, preparing the auxiliary material, and compounding the main material and the auxiliary material.

7. The method for preparing the self-responsive odor-free sterilization material according to claim 6, characterized in that: The preparation steps of the main material include: adding the adsorbent material and the formaldehyde removal agent into deionized water respectively, stirring them fully at a speed of 600-800 rpm, then washing them with deionized water, and freeze-drying them to prepare the main material.

8. The method for preparing the self-responsive odor-free sterilization material according to claim 6, 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 above buffer solution, stirring and dispersing it evenly, and then adding the bactericide with a concentration of 500ppm to obtain a mixed solution, vacuuming and stirring the mixed solution at a speed of 600-800rpm, washing with deionized water, and drying it in a vacuum drying oven to obtain the auxiliary material.

9. The method for preparing the self-responsive odor-free sterilization material according to claim 6, characterized in that: The compounding step of the main material and the auxiliary material comprises: dispersing the main material in deionized water, stirring to obtain its aqueous dispersion, then 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 odor-purifying sterilization material.

10. A refrigerator, characterized in that: The refrigerator is made of the self-responsive odor-free sterilization material according to any one of claims 1 to 5.

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