Refrigerator and preparation method thereof

Abstract

The invention discloses a refrigerator and a preparation method thereof, the refrigerator comprises a shell and an inner container, and a containing space is defined in the shell; the inner container is arranged in the accommodating space; a functional coating is arranged on the outer surface of the shell; the functional coating comprises mesoporous silicon dioxide of which the interior is coated with antibacterial substances and the exterior is grafted with hydrophobic substances. According to the refrigerator disclosed by the invention, the functional coating on the shell has antibacterial property and super-hydrophobicity, so that the stability and the long-term effect of the antibacterial property are effectively improved, and the antibacterial effect of the shell in a humid environment is also improved.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment technology, and in particular to a refrigerator and its manufacturing method. Background Technology

[0002] When food is stored together in a refrigerator, it can cause cross-contamination of odors. Fresh fish, meat, seafood, fruits and vegetables may carry bacteria, which can lead to the growth of bacteria and unpleasant smells inside the refrigerator, increasing the risk to health.

[0003] In related technologies, the shell of a refrigerator has a relatively simple function, which is difficult to meet the needs of modern refrigerators. Therefore, there is an urgent need for a shell with multiple functions, such as a shell that has both hydrophobic and antibacterial properties. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a refrigerator in which the functional coating on the outer shell has both antibacterial and superhydrophobic properties, effectively improving the stability and longevity of the antibacterial performance, and also improving the antibacterial effect of the outer shell in humid environments.

[0005] A refrigerator according to a first aspect of the present invention includes: An outer casing, wherein an accommodating space is defined within the outer casing; Inner liner, wherein the inner liner is disposed in the receiving space; A functional coating is provided on the outer surface of the housing: The functional coating comprises mesoporous silica with an internal antibacterial substance and an externally grafted hydrophobic substance.

[0006] The refrigerator according to embodiments of the present invention enriches the functionality of the outer shell and improves the refrigerator's performance. By providing a functional coating, which possesses both superhydrophobicity and excellent antibacterial properties, it effectively reduces the penetration of moisture from the environment into the interior of the functional coating, thereby preventing moisture from directly contacting the outer shell and preventing rust, thus extending the refrigerator's lifespan. Furthermore, it reduces the contact between moisture and antibacterial substances, thereby enhancing the effectiveness of the antibacterial substances in humid environments, ensuring the safety of food inside the refrigerator, and meeting user needs. In addition, it improves the release stability of the antibacterial substances, allowing them to function more effectively and persistently, ensuring long-lasting antibacterial performance, and thus improving the refrigerator's overall performance.

[0007] According to some embodiments of the present invention, the mesoporous silica is modified mesoporous silica, which is aminated mesoporous silica with silver ions loaded on its surface.

[0008] The specific advantages or beneficial effects of the above scheme are as follows: the pore structure and surface amino groups of aminated mesoporous silica can achieve stable loading of silver ions and effectively control the release rate of silver ions, thereby achieving a highly efficient and stable antibacterial effect.

[0009] According to some embodiments of the present invention, the antibacterial substance comprises an antibacterial essential oil selected from at least one of oregano essential oil, patchouli essential oil, cinnamon essential oil, litsea cubeba essential oil, clove essential oil, thyme essential oil, geranium essential oil, garlic essential oil, tea tree essential oil, calamus essential oil, lemongrass essential oil, clove basil essential oil, turmeric essential oil, West Indian sandalwood essential oil, and violet essential oil.

[0010] The specific advantages or beneficial effects of the above scheme are as follows: the antibacterial essential oils are all plant essential oils with broad-spectrum antibacterial properties, thus effectively reducing bacterial adhesion and reproduction. Furthermore, the process of encapsulating antibacterial essential oils within mesoporous silica is relatively simple and low-cost, which helps to reduce the difficulty and cost of preparing functional coatings.

[0011] According to some embodiments of the present invention, the hydrophobic material includes fluorine-free alkylsilanes.

[0012] The specific advantages or beneficial effects of the above scheme are as follows: Fluorine-free alkylsilanes can be grafted onto the surface of mesoporous silica, significantly improving its hydrophobicity. They can also act as functionalizing agents to introduce organic molecules (such as antibacterial essential oils) into the surface or pores of inorganic materials, thereby increasing the coating rate of antibacterial essential oils. The halogens on the fluoroalkylsilanes can undergo affinity substitution reactions with the amino groups on the modified mesoporous silica surface, effectively reducing the steric hindrance hindering the grafting of fluoroalkylsilanes and modified mesoporous silica, improving grafting efficiency, and achieving synergistic optimization of hydrophobicity and amino group activation, further enhancing the hydrophobicity of the functional coating. Furthermore, it does not contain perfluorinated / polyfluoroalkyl compounds, possessing non-toxic and biodegradable properties, avoiding bioaccumulation, carcinogenicity, and environmental pollution problems.

[0013] According to some embodiments of the present invention, the fluorine-free alkylsilane is selected from at least one of octadecyltrichlorosilane, dodecyltrichlorosilane, and chloro(dimethyl)octadecylsilane.

[0014] The specific advantages or beneficial effects of the above scheme are as follows: The aforementioned fluorine-free alkylsilanes all have relatively long alkyl chains, thus exhibiting strong hydrophobicity. Furthermore, fluorine-free alkylsilanes can optimize the pore structure and surface properties of mesoporous silica materials, thereby improving the loading efficiency and release performance of silver ions, forming a mesoporous silica composite material that combines antibacterial and hydrophobic properties.

[0015] The method for preparing a refrigerator according to the first aspect embodiment of the present invention includes the following steps: Obtain the shell; Obtain mesoporous silica; First dip coating treatment: The shell is immersed in the first suspension for a first time to obtain the shell coated with the first coating. After drying, it is aged in air. The first suspension is a mesoporous silica solution grafted with hydrophobic substances. Repeat the first dip-coating treatment at least once; Drying process; Second dip coating treatment: The outer shell coated with the first coating is immersed in a first solution for a second time, wherein the first solution is a solution containing antibacterial substances; The shell is cleaned to obtain a functional coating.

[0016] The specific advantages or beneficial effects of the above solution are as follows: The outer shell coated with a functional coating possesses both antibacterial and superhydrophobic properties. The release of antibacterial substances can effectively kill bacteria, and the construction of the superhydrophobic surface can prevent the decline in antibacterial efficiency due to bacterial deposition. It can also ensure the antibacterial performance of antibacterial essential oils in humid environments, improve the controllable and slow-release properties of antibacterial substances, and thus achieve long-lasting antibacterial effects, effectively improving the performance of the refrigerator.

[0017] According to some embodiments of the present invention, the mesoporous silica includes modified mesoporous silica, and the preparation of the modified mesoporous silica includes the following steps: The mesoporous silica is dispersed in a second solvent to obtain a second suspension. An amino-containing silane coupling agent, propyltriethoxysilane, is added to the second suspension, and the mixture is refluxed for a third time to obtain aminated mesoporous silica. The aminated mesoporous silica is dispersed in a solution containing Ag. + The modified mesoporous silica was obtained by stirring in a salt solution at room temperature.

[0018] The specific advantages or beneficial effects of the above scheme are as follows: By amylating the surface of mesoporous silica, the efficient loading of silver ions is achieved, which significantly improves the bactericidal efficiency and safety of the functional coating. In synergy with the antibacterial essential oil encapsulated inside the mesoporous silica, an all-round integrated antibacterial effect is achieved, which effectively improves the performance of the refrigerator.

[0019] According to some embodiments of the present invention, the preparation of the first suspension includes the following steps: The modified mesoporous silica is dispersed in a first solvent, a fluorine-free alkylsilane is added to the first solvent, and the mixture is ultrasonically treated for a fourth time. The amino groups on the modified mesoporous silica are nucleophilically substituted with chlorine elements on the fluorine-free alkylsilane to graft hydrophobic substances onto the outside of the modified mesoporous silica.

[0020] The specific advantages or beneficial effects of the above scheme are as follows: Grafting of fluorine-free alkyl silanes onto the exterior of modified mesoporous silica gives it superhydrophobic properties, allowing the antibacterial substance to fully exert its antibacterial effect even in humid environments, improving the controllable sustained release of the antibacterial substance, and prolonging its action time. Furthermore, the preparation process is simple and the reaction rate is relatively high.

[0021] According to some embodiments of the present invention, the third time is t3, wherein t3 satisfies: 6h ≤ t3 ≤ 24h; and / or The first solvent includes at least one selected from toluene, ethanol, diethyl ether, chloroform, and acetone; and / or The second solvent includes at least one of ethanol, methanol, acetone, and n-butanol; and / or The fourth time is t4, where t4 satisfies: 1h≤t4≤3h.

[0022] The specific advantages or beneficial effects of the above scheme are as follows: The reasonable setting of the third and fourth time ranges is conducive to the reaction, and can improve the reaction rate and reduce production costs. The reasonable selection of the first and second solvents is beneficial to promoting the reaction, reducing the occurrence of side reactions, and lowering production costs.

[0023] According to some embodiments of the present invention, the first time is t1, wherein t1 satisfies: 0.1min ≤ t1 ≤ 1min; and / or The drying temperature for the drying process is T1, and the drying time is t, wherein T1 and t respectively satisfy: 80℃≤T1≤120℃, 10min≤t≤120min; and / or The solvent of the first solution includes at least one selected from ethanol, methanol, acetone, and n-butanol; and / or The second time is t2, where t2 satisfies: 0.5h ≤ t2 ≤ 24h.

[0024] The specific advantages or beneficial effects of the above scheme are as follows: The reasonable setting of the first and second time ranges facilitates the reaction, thereby improving the hydrophobicity and antibacterial properties of the functional coating and enhancing its performance. The reasonable selection of the solvent for the first solution improves its homogeneity, thus promoting the reaction and enhancing the antibacterial properties of the functional coating.

[0025] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0026] The embodiments of the present invention are described in detail below, and a refrigerator according to a first aspect of the present invention is described below.

[0027] A refrigerator according to a first aspect of the present invention includes an outer shell and an inner liner.

[0028] Specifically, the outer shell defines an accommodating space. The inner liner is located within the accommodating space. The outer surface of the outer shell is provided with a functional coating, which includes mesoporous silica with an internal antibacterial substance and an externally grafted hydrophobic substance.

[0029] For example, the refrigerator's outer shell defines the space for accommodating the inner liner. This protects the inner liner, extending the refrigerator's lifespan. Furthermore, the outer shell also limits the installation position of the inner liner, preventing displacement due to external factors and ensuring performance and stability.

[0030] The outer surface of the refrigerator's outer shell has a functional coating. The "outer surface" primarily refers to the outer circumferential surface of the outer shell, that is, the surface exposed to the air, not limited to the exterior of the refrigerator. After the refrigerator is assembled, both the exterior and interior surfaces are covered with the functional coating. This functional coating is a mesoporous silica material with an internally encapsulated antibacterial substance and an externally grafted hydrophobic substance. In other words, the material of the functional coating is mesoporous silica with an internally encapsulated antibacterial substance and an externally grafted hydrophobic substance, thus giving the functional coating both antibacterial and superhydrophobic properties. For example, mesoporous silica has a small pore size and a highly ordered pore structure, resulting in a very high specific surface area. This allows for the efficient loading of antibacterial substances (such as plant-based antibacterial essential oils) and enables the controlled, sustained release of these substances within the functional coating, facilitating a long-lasting antibacterial effect. Furthermore, the porous structure of mesoporous silica also makes it possible to graft hydrophobic substances, which is beneficial for the preparation of the functional coating material.

[0031] Based on the test results in Table 2, the contact angles of the functional coatings in Examples 1-4 are all greater than 160° (when the contact angle is greater than 150°, the material exhibits superhydrophobicity), meaning that the shell with the functional coating of this application is superhydrophobic. Furthermore, combining the test results for antibacterial effect and bacterial adhesion rate, the functional coatings in Examples 1-5 all have antibacterial rates of over 95% against Escherichia coli and Staphylococcus aureus, with the functional coating in Example 4 reaching over 99%, demonstrating excellent antibacterial effects. Moreover, the bacterial adhesion rate of the functional coatings in Examples 1-5 is all less than 20%, indicating that the functional coatings effectively reduce bacterial adhesion. Therefore, the shell with the functional coating of this application exhibits good overall performance, combining superhydrophobicity and good antibacterial properties, enriching the functionality of the shell and improving the performance of the refrigerator.

[0032] Furthermore, the inventors discovered that the antibacterial substances encapsulated within the functional coating can effectively kill bacteria and reduce the bacterial adhesion rate on the outer surface of the functional coating. The external grafting of hydrophobic substances onto the mesoporous silica gives the functional coating surface superhydrophobic properties, preventing the functional coating from losing its antibacterial efficiency due to bacterial deposition and achieving long-lasting antibacterial effects. Moreover, it ensures the antibacterial effect of the antibacterial substances in humid environments, preventing sudden release or failure due to moisture, thereby further improving the performance of the casing.

[0033] In summary, the functional coating combines superhydrophobicity and excellent antibacterial properties, effectively reducing the penetration of moisture from the environment into the coating's interior and minimizing contact between moisture and antibacterial substances. This enhances the effectiveness of the antibacterial substances in humid environments, ensuring the safety of food inside the refrigerator and meeting user needs. Furthermore, it improves the release stability of the antibacterial substances, allowing them to function more effectively and for longer, guaranteeing long-lasting antibacterial performance. Additionally, it prevents moisture from penetrating the functional coating and directly contacting the outer casing, preventing rust and extending the refrigerator's lifespan.

[0034] The refrigerator according to embodiments of the present invention enriches the functionality of the outer shell and improves the refrigerator's performance. By providing a functional coating, which possesses both superhydrophobicity and excellent antibacterial properties, it effectively reduces the penetration of moisture from the environment into the interior of the functional coating, thereby preventing moisture from directly contacting the outer shell and preventing rust, thus extending the refrigerator's lifespan. Furthermore, it reduces the contact between moisture and antibacterial substances, thereby enhancing the effectiveness of the antibacterial substances in humid environments, ensuring the safety of food inside the refrigerator, and meeting user needs. In addition, it improves the release stability of the antibacterial substances, allowing them to function more effectively and persistently, ensuring long-lasting antibacterial performance, and thus improving the refrigerator's overall performance.

[0035] According to some embodiments of the present invention, the mesoporous silica is modified mesoporous silica, which is aminated mesoporous silica with silver ions loaded on its surface.

[0036] For example, modified mesoporous silica can be obtained by adding an amino-containing silane coupling agent (e.g., aminopropyltriethoxysilane) to functionalize the surface of the mesoporous silica with amino groups, forming amino (-NH2) groups, thereby forming aminated mesoporous silica. These amino groups can react with metal ions (e.g., Ag) +(e.g.,) forming stable complexes, thereby achieving high metal ion loading efficiency. For example, aminated mesoporous silica can be dispersed in a silver salt (e.g., silver nitrate AgNO3) solution. Utilizing the electrostatic or coordination interactions between the amino groups and silver ions, the silver ions are adsorbed onto the channels or surface of the mesoporous silica. The porous structure of the mesoporous silica allows silver ions to be uniformly dispersed on the surface of the aminated mesoporous silica, preventing rapid oxidation or aggregation, thus achieving a slow release of silver ions.

[0037] Therefore, by modifying mesoporous silica, aminated mesoporous silica is formed, and silver ions are further uniformly loaded onto its surface. The pore structure and surface amino groups of aminated mesoporous silica enable stable loading of silver ions and effectively control the release rate of silver ions. The silver ions and the antibacterial substances within the pores of the mesoporous silica work synergistically to further improve the antibacterial effect of the functional coating, thereby achieving a more efficient and stable antibacterial effect. In addition, aminated mesoporous silica can also be used to load other antibacterial agents, working synergistically with organic antibacterial substances from plant essential oils to achieve a comprehensive and integrated antibacterial effect, effectively improving the antibacterial performance of the functional coating and enhancing the performance of the refrigerator.

[0038] According to some embodiments of the present invention, the antibacterial substance includes antibacterial essential oil, which is selected from at least one of oregano essential oil, patchouli essential oil, cinnamon essential oil, litsea cubeba essential oil, clove essential oil, thyme essential oil, geranium essential oil, garlic essential oil, tea tree essential oil, calamus essential oil, lemongrass essential oil, clove basil essential oil, turmeric essential oil, West Indian sandalwood essential oil, and violet essential oil.

[0039] For example, antibacterial essential oils are all plant essential oils that can disrupt the integrity of bacterial cell membranes, causing the cell contents to leak out, thereby achieving an antibacterial effect. Moreover, plant essential oils have broad-spectrum antibacterial properties, effectively reducing bacterial adhesion and reproduction. Furthermore, as natural ingredients, plant essential oils are harmless to humans and the environment, can be used in materials that come into contact with food, and have a slow-release property. When a functional coating internally encapsulates these plant essential oils on the refrigerator exterior, it can ensure the safety of food inside the refrigerator and improve the user experience. In addition, the slow-release properties of these plant essential oils can improve the stability and durability of the antibacterial effect of the functional coating, thereby achieving long-term antibacterial action and improving the performance of the functional coating. Furthermore, the process of encapsulating antibacterial essential oils within mesoporous silica is relatively simple and low-cost, which helps to reduce the difficulty and cost of preparing functional coatings.

[0040] It should be noted that the antibacterial substance can be one or more of the aforementioned antibacterial essential oils. That is, the antibacterial substance can be one of the aforementioned antibacterial essential oils alone, or a combination of two or more antibacterial essential oils. For example, the antibacterial substance can be oregano essential oil and patchouli essential oil, or oregano essential oil, patchouli essential oil and cinnamon essential oil, or oregano essential oil, patchouli essential oil, cinnamon essential oil and litsea cubeba essential oil, or oregano essential oil, patchouli essential oil, cinnamon essential oil, litsea cubeba essential oil and clove essential oil, etc. But it is not limited to these.

[0041] For example, oregano essential oil is derived from plants, and its main active ingredients are terpenoids (such as thymol and carawayol) and phenolic acids. These have low toxicity to humans and are unlikely to leave residues in food or refrigerators, thus helping to ensure food safety within the refrigerator. Furthermore, the antibacterial active ingredients in oregano essential oil can disrupt the integrity of microbial cell membranes and interfere with their metabolic processes, inhibiting various common foodborne pathogens and spoilage bacteria, such as various bacteria, fungi, and viruses, thereby improving the antibacterial properties of functional coatings. Additionally, the volatile components of oregano essential oil can neutralize odors in the refrigerator (such as mixed food odors and unpleasant smells produced by bacterial metabolism), while its own herbal aroma can improve the odor environment inside the refrigerator, enhancing the user experience.

[0042] Cinnamon essential oil is a natural essential oil extracted from the bark, branches, and leaves of the cinnamon tree. It exerts its antibacterial effect by disrupting microbial cell membranes, interfering with energy metabolism, and inhibiting the synthesis of genetic material. It has a broad-spectrum inhibitory effect on common harmful microorganisms found in refrigerators. In addition, cinnamaldehyde and phenolic substances have strong antioxidant properties, which can inhibit the oxidation of oils in food (such as nuts and meats turning rancid) and the degradation of vitamin C (such as fruit browning), thus improving the freshness of ingredients.

[0043] Clove essential oil is a natural essential oil extracted from clove flower buds. It is highly effective against various drug-resistant bacteria and stubborn microorganisms. Its mechanism of action includes disrupting bacterial cell membranes, inhibiting enzyme activity, and interfering with DNA replication, thereby achieving antibacterial effects. When the antibacterial essential oil in the functional coating is a targeted essential oil, it can enhance the antibacterial properties of the functional coating, enabling it to inhibit various drug-resistant bacteria and stubborn microorganisms.

[0044] Tea tree oil is a natural essential oil extracted from the leaves of the Australian tea tree (Melaleuca alternifolia). Its antibacterial spectrum covers bacteria, fungi, and viruses, with particularly outstanding effects against foodborne pathogens that easily proliferate in refrigerators. When used as a functional antibacterial coating, tea tree oil can effectively inhibit the growth of foodborne pathogens in the refrigerator, improving food safety and enhancing the user experience.

[0045] Violet essential oil can interfere with the activity of microbial membrane proteins and inhibit energy metabolism enzymes, thereby achieving an antibacterial effect. It has a certain inhibitory effect on fungi (such as Aspergillus and Penicillium, which cause food spoilage) and Gram-positive bacteria (such as Staphylococcus aureus and Staphylococcus epidermidis). When violet essential oil is used as an antibacterial essential oil in functional coatings, it can significantly improve the antibacterial effect of the functional coating. For example, referring to Tables 1 and 2, in Example 4, the functional coating achieved an inhibition rate of over 99% against Escherichia coli and Staphylococcus aureus, and the bacterial adhesion rate of Escherichia coli and Staphylococcus aureus was also relatively low. It can be seen that when violet essential oil is used as an antibacterial essential oil in functional coatings, it has excellent comprehensive antibacterial properties.

[0046] According to some embodiments of the present invention, the hydrophobic material includes a fluorinated alkylsilane. For example, a fluorinated alkylsilane can be grafted onto the surface of mesoporous silica, and its general structural formula is shown in formula (1), which significantly improves its hydrophobicity. The covalent bonding (such as hydrolytic condensation) between the fluorinated alkylsilane and the inorganic material can significantly improve the chemical stability of the mesoporous silica material, enabling it to maintain its structural integrity under harsh conditions such as high temperature and acid / alkali. In addition, by adjusting the type and amount of fluorinated alkylsilane, the pore structure and surface properties of the mesoporous silica material can be optimized, thereby improving the loading efficiency and controllable release performance of the antibacterial substance. Moreover, the fluorinated alkylsilane can not only be used as a hydrophobic material, but also as a functionalizing agent to introduce organic molecules (such as antibacterial essential oils) into the surface or pores of inorganic materials, thereby improving the coating rate of antibacterial essential oils and improving the antibacterial effect of the functional coating. In addition, the fluorinated alkylsilane does not contain perfluorinated / polyfluoroalkyl compounds, has non-toxic and degradable properties, and can avoid bioaccumulation, carcinogenicity and environmental pollution problems.

[0047]

[0048] Equation (1).

[0049] In formula (1), R is a halogen atom, and R1 and R2 can be halogen atoms or alkyl groups.

[0050] Furthermore, the halogens on the fluorine-free alkylsilanes can undergo affinity substitution reactions with the amino groups on the modified mesoporous silica surface, and the reaction rate is fast. Moreover, this effectively reduces the steric hindrance hindering the grafting of the fluorine-free alkylsilanes and modified mesoporous silica, improving grafting efficiency and thus effectively enhancing the hydrophobic properties of the functional coating, making it superhydrophobic. Simultaneously, it avoids side reactions during the hydrolysis-condensation process, achieving synergistic optimization of hydrophobicity and amino group activation, further improving the hydrophobicity of the functional coating.

[0051] According to some embodiments of the present invention, the fluorine-free alkylsilane is selected from at least one of octadecyltrichlorosilane, dodecyltrichlorosilane, and chloro(dimethyl)octadecylsilane.

[0052] Fluorine-free alkylsilanes can chemically react with mesoporous silica to form stable siloxane bonds, creating a hydrophobic film on the silica surface and significantly improving the hydrophobic properties of the functional coating. When fluorine-free alkylsilanes are grafted onto the mesoporous silica surface, they form a dense hydrophobic layer, significantly increasing the contact angle of the functional coating and thus enhancing its hydrophobicity. Furthermore, fluorine-free alkylsilanes can form a stable three-dimensional network structure, effectively preventing the corrosion of moisture and salt, extending the service life of the functional coating, and ensuring the refrigerator's performance.

[0053] For example, octadecyltrichlorosilane, dodecyltrichlorosilane, and chloro(dimethyl)octadecylsilane all have long alkyl chains, thus exhibiting strong hydrophobicity. Furthermore, fluorine-free alkylsilanes can optimize the pore structure and surface properties of mesoporous silica materials, thereby improving the loading efficiency and release performance of silver ions, forming mesoporous silica composite materials that possess both antibacterial and hydrophobic properties. When used as functional coatings for refrigerator exteriors, they can significantly improve the hydrophobic properties of the refrigerator exterior. In addition, the aforementioned fluorine-free alkylsilanes do not contain fluorine and are non-toxic and non-corrosive materials, which helps improve the safety of the functional coatings and thus enhances user safety.

[0054] A method for manufacturing a refrigerator according to a second aspect of the present invention includes the following steps: Obtain the shell; Obtain mesoporous silica; First dip coating treatment: The shell is immersed in the first suspension for a first time to obtain a shell coated with the first coating. After drying, it is aged in air. The first suspension is a mesoporous silica solution grafted with hydrophobic substances. Repeat the first dip-coating treatment at least once; Drying process; Second dip coating treatment: The outer shell coated with the first coating is immersed in the first solution for a second time, wherein the first solution is a solution containing antibacterial substances; The cleaning process is used to obtain a shell coated with a functional coating.

[0055] Specifically, the obtained casing can be a conventionally used casing, which can be homemade or purchased. Furthermore, the casing can be cleaned before use, for example, by using ultrasound to clean the casing, such as an aluminum sheet, with water and acetone respectively. For the first suspension, the obtained mesoporous silica, a hydrophobic substance such as a fluorine-free alkyl silane, and a first solvent such as toluene can be added to a 20 mL glass bottle and ultrasonically treated for 3 hours to obtain a homogeneous first suspension.

[0056] The first dip-coating process can be understood as follows: the outer casing is immersed in the first suspension for an initial dip-coating treatment, thereby obtaining an outer casing coated with the first coating. The casing is then dried for 2 minutes and aged in air. It is important to note that to ensure the first suspension is fully and evenly coated on the outer surface of the casing, the first dip-coating process needs to be repeated twice, or even multiple times. Thus, the dip-coating method allows mesoporous silica grafted with hydrophobic substances to be evenly coated on the outer surface of the casing, giving the casing excellent hydrophobic properties. This effectively improves the casing's resistance to moisture and pollutants in the environment, ensuring the refrigerator's performance and extending its service life. Furthermore, the dip-coating process is simple, which helps reduce the difficulty of refrigerator production and improves production efficiency.

[0057] The shell coated with the first coating is dried to allow the first solvent to evaporate fully, forming a stable and uniform solid first coating on the shell surface. Furthermore, the structure-directing agent in the mesoporous silica is effectively removed, creating an open pore structure that increases the contact angle and improves the hydrophobic properties of the functional coating. Moreover, the coating rate of the antibacterial substance is increased, enhancing the antibacterial properties of the functional coating.

[0058] Furthermore, the outer shell coated with the first coating is immersed in a first solution containing an antibacterial substance for a second time. For example, the first solution is obtained by dissolving the antibacterial substance in 5 mL of ethanol. Thus, the antibacterial substance is encapsulated within the pores of the mesoporous silica through dip-coating, thereby achieving a synergistic antibacterial effect with silver ions and effectively improving the antibacterial performance of the functional coating. In addition, the dip-coating process is simple, inexpensive, and highly efficient, which helps reduce the difficulty of refrigerator production and improve production efficiency. Moreover, the mesoporous silica has a porous structure, allowing the antibacterial essential oil to be fully loaded and exert its effect more effectively and for a longer period.

[0059] Finally, the outer shell is cleaned with 2 mL of ethanol (other solvents can also be used in different amounts) to remove excess antibacterial substances from the surface, thus obtaining an outer shell coated with a functional coating. Therefore, the outer shell coated with the functional coating possesses both antibacterial and superhydrophobic properties. The release of antibacterial substances effectively kills bacteria, while the construction of the superhydrophobic surface prevents a decrease in antibacterial efficiency due to bacterial deposition. It also ensures the antibacterial properties of the antibacterial oil in humid environments, improves the controllable and sustained release of antibacterial substances, and achieves long-lasting antibacterial effects, effectively improving the performance of the refrigerator.

[0060] According to some embodiments of the present invention, mesoporous silica includes modified mesoporous silica, and the preparation of modified mesoporous silica includes the following steps: Mesoporous silica is dispersed in a second solvent to obtain a second suspension. An amino-containing silane coupling agent is added to the second suspension, and the mixture is refluxed for a third time to obtain aminated mesoporous silica. Aminated mesoporous silica is dispersed in a substrate containing Ag. + Modified mesoporous silica was obtained by stirring in a salt solution at room temperature.

[0061] Specifically, mesoporous silica can be dispersed in a second solvent, such as ethanol, containing an amino-containing silane coupling agent (e.g., aminopropyltriethoxysilane), and refluxed to obtain aminated mesoporous silica. The aminopropyltriethoxysilane-modified mesoporous silica was collected after centrifugation and washing with ethanol. Further, the aminated mesoporous silica was dispersed in a solvent containing Ag... + A salt solution. For example, it is dispersed in deionized water containing AgNO3 and stirred at room temperature for 24 hours to adsorb silver ions, thus preparing modified mesoporous silica. Of course, the stirring time can be reduced according to actual needs, for example, stirring at room temperature for 1 hour (the stirring time can be limited to 1-24 hours). Thus, amino groups are strongly polar groups that can adsorb metal ions (such as Ag). + Stable coordination bonds are formed (etc.). High-efficiency loading of silver ions is achieved through ammoniation treatment of the mesoporous silica surface, significantly improving the bactericidal efficiency and safety of the functional coating. This, combined with the antibacterial essential oils encapsulated within the mesoporous silica, achieves a comprehensive, integrated antibacterial effect, effectively improving the performance of the refrigerator.

[0062] In addition, the aforementioned amino-containing silane coupling agents can also be aminopropyltriethoxysilane, aminopropyltrimethoxysilane, triethoxysilylpropylγ-triethoxysilylpropylamine, N-phenyl-γ-aminopropyltrimethoxysilane, etc. In actual preparation, the amino-containing silane coupling agent can be selected according to the specific circumstances.

[0063] According to some embodiments of the present invention, the preparation of the first suspension includes the following steps: Modified mesoporous silica is dispersed in a first solvent, a fluorine-free alkylsilane is added to the first solvent, and the mixture is ultrasonically treated for a fourth time. The amino groups on the modified mesoporous silica are nucleophilically substituted with chlorine elements on the fluorine-free alkylsilane to graft hydrophobic substances onto the outside of the modified mesoporous silica.

[0064] Specifically, when the mesoporous silica is modified, after obtaining the modified mesoporous silica, it is dispersed in a first solvent containing a fluorine-free alkyl silane under continuous stirring at room temperature. The reaction is carried out under ultrasonic treatment for a fourth time, resulting in the grafting of hydrophobic substances onto the modified mesoporous silica, thus obtaining a uniform suspension. Furthermore, the amino groups on the modified mesoporous silica undergo a nucleophilic substitution reaction with the chlorine elements on the fluorine-free alkyl silane, causing the hydrophobic substances to be grafted onto the exterior of the modified mesoporous silica, thereby further improving the hydrophobic properties of the functional coating. This configuration, with the grafting of fluorine-free alkyl silane onto the exterior of the modified mesoporous silica, gives it excellent hydrophobic properties, allowing the antibacterial substances to fully exert their antibacterial effects even in humid environments, improving the controllable and sustained release of the antibacterial substances, and prolonging their duration of action. Furthermore, the halogens on the fluorine-free alkylsilane can undergo affinity substitution reactions with the amino groups on the modified mesoporous silica surface. This rapid reaction reduces steric hindrance and improves reaction efficiency, while simultaneously avoiding side reactions during hydrolysis. This achieves synergistic optimization of hydrophobicity and amino group activation, resulting in a superhydrophobic coating. Additionally, the grafting reaction is carried out under ultrasonic treatment, effectively shortening the reaction time, reducing side reactions, and further improving reaction efficiency.

[0065] According to some embodiments of the present invention, the third time is t3, wherein t3 satisfies: 6h≤t3≤24h; and / or, the first solvent includes at least one of toluene, ethanol, diethyl ether, chloroform and acetone; and / or, the second solvent includes at least one of ethanol, methanol, acetone and n-butanol; and / or, the fourth time is t4, wherein t4 satisfies: 1h≤t4≤3h.

[0066] For example, the modification of mesoporous silica using silane coupling agents follows a three-stage mechanism of hydrolysis-condensation-grafting. First, the ethoxy group (-OEt) of the silane coupling agent hydrolyzes to a silanol group (-SiOH), forming an active intermediate. Then, the hydrolyzed silanol group undergoes a condensation reaction with the silanol group (-SiOH) on the surface of the mesoporous silica, forming a Si-O-Si covalent bond, accompanied by intermolecular condensation to generate oligomeric siloxanes. Finally, amino groups (-NH2) are fixed on the surface of the mesoporous silica, thereby generating aminated mesoporous silica.

[0067] When the third time t3 is less than 6 hours, the third time is too short, meaning the reflux time is too short. This results in insufficient hydrolysis of the silane coupling agent, leading to a low concentration of effective silanol groups. Consequently, there is insufficient substrate for the subsequent condensation reaction, and the condensation reaction is not fully carried out. This causes the amino groups to attach via physical adsorption (hydrogen bonds / van der Waals forces) rather than chemical bonding, resulting in weak binding. Ultimately, this reduces the degree of amylation of the mesoporous silica, meaning the amino loading of the mesoporous silica is insufficient, which will affect subsequent processes such as silver ion loading. When the third time t3 is greater than 24 hours, the third time is too long. Under prolonged reflux conditions, side reactions are easily triggered. For example, the silanol groups (-SiOH) of the silane coupling agent molecules not only condense with the hydroxyl groups on the silica surface but also undergo excessive intermolecular condensation within the pores of the mesoporous silica, forming a dense silicon-oxygen bond network (-Si-O-Si-). This leads to pore blockage, reducing the loading of subsequent antibacterial essential oils and affecting the antibacterial effect of the functional coating. Moreover, pore blockage prevents antibacterial essential oils from fully penetrating the pores, causing them to adhere only to the surface of mesoporous silica particles, resulting in poor sustained-release effects and short duration of antibacterial activity or uneven release.

[0068] Therefore, when the third time t3 satisfies 6h≤t3≤24h, the third time setting is reasonable and beneficial to increasing the amination degree of mesoporous silica, thereby promoting the subsequent reaction. Furthermore, it avoids excessive cross-linking of silicon-oxygen bonds, allowing the modified mesoporous silica to exist in a monodisperse or slightly aggregated state, which is beneficial to increasing the loading of antibacterial essential oils, improving the antibacterial effect of the functional coating and the controllable slow-release of antibacterial substances, thus improving the performance of the refrigerator.

[0069] For example, when toluene is the first solvent, it is a non-polar solvent with similar miscibility to the long carbon chains of fluorinated alkyl silanes, thus improving the uniformity of dissolution and inhibiting pre-hydrolysis aggregation. Furthermore, toluene has extremely low water content, which delays the hydrolysis of fluorinated alkyl silanes and facilitates the gradual adsorption of fluorinated alkyl silane molecules onto the surface of aminated mesoporous silica, forming an ordered monolayer. In addition, toluene has low surface tension, which significantly reduces the liquid pressure within the mesoporous silica pores, protecting the structural integrity of the mesoporous silica and facilitating the subsequent loading of hydrophobic antibacterial essential oils. Moreover, toluene can be directly mixed with fluorinated alkyl silanes without adjusting the water content or pH, thereby reducing the complexity of the reaction process.

[0070] Fluorine-free alkylsilanes typically contain polar groups (such as siloxane bonds) and nonpolar alkyl chains. Ethanol, as a polar solvent, allows its hydroxyl groups (-OH) to form hydrogen bonds or intermolecular forces with the polar groups of the fluoroalkylsilane, thus enhancing dissolution. Simultaneously, its nonpolar ethyl chains exhibit compatibility with the alkyl chains of the silane, resulting in a uniform and stable first suspension. This ensures the fluoroalkylsilane is fully dispersed in the first solvent, facilitating subsequent preparation and applications. Furthermore, the volatility of ethanol helps accelerate the drying process, thereby improving the efficiency of functional coating preparation.

[0071] When the first solvent is diethyl ether (molecular formula C2H5OC2H5), it is a low-polarity organic solvent. While the ether bonds (-O-) in its molecular structure have some polarity, the overall polarity is weak. The alkyl chains (non-polar portion) of fluorine-free alkylsilanes are highly compatible with the non-polar groups of diethyl ether, allowing for thorough dispersion through van der Waals forces. Furthermore, the polar groups of fluorine-free alkylsilanes (such as siloxane bonds) can form weak intermolecular forces with the ether bonds of diethyl ether, thus achieving uniform dissolution of the fluorine-free alkylsilane in diethyl ether and forming a stable first suspension. In addition, diethyl ether has an extremely low boiling point and is one of the fastest evaporating solvents among common organic solvents. During the fluorine-free alkylsilane treatment, the solvent can completely evaporate in a short time, significantly shortening the film-forming time and improving the efficiency of the drying process. Moreover, rapid evaporation reduces solvent residue, avoiding coating defects (such as pores and cracks) caused by solvent retention, thereby ensuring the performance of the functional coating and improving the production yield of refrigerator shells.

[0072] Chloroform is a polar organic solvent. The high electronegativity of the chlorine atoms in its molecular structure allows it to form dipole-dipole interactions with the polar groups (such as siloxane bonds and hydroxyl groups) of non-fluorinated alkyl silanes. Simultaneously, it also possesses some solubility for the non-polar alkyl chains within the silane molecule (through van der Waals forces). This dual "polar-nonpolar" dissolution mechanism gives it superior solubility for some structurally complex non-fluorinated alkyl silanes (such as those containing multiple branches or polar substituents), thus improving the versatility of the primary solvent.

[0073] Acetone is a highly polar organic solvent. Its carbonyl group (C=O) can form hydrogen bonds or dipole-dipole interactions with the polar groups (such as silanoxy and hydroxyl groups) of non-fluorinated alkyl silanes. Simultaneously, it exerts a swelling effect on the non-polar alkyl chains in the silane molecule (through van der Waals forces). This strong polar interaction gives it excellent solubility for non-fluorinated alkyl silanes containing polar substituents (such as aminosilanes and epoxysilanes), enabling the rapid preparation of high-concentration, transparent first suspension solutions at room temperature, thus improving preparation efficiency.

[0074] When the second solvent is ethanol, that is, ethanol is used to disperse the mesoporous silica in the second suspension. Ethanol is a polar solvent, miscible with water, and the hydrolysis rate of silanes can be controlled by adjusting the ethanol / water ratio. The trace amount of water in ethanol (which needs to be added separately) can hydrolyze the amino-containing silane coupling agent to generate silanol groups (-SiOH). At the same time, ethanol stabilizes the silanol intermediate through hydrogen bonding, preventing excessive condensation and the formation of polymer precipitation, which is beneficial to the subsequent reaction. Moreover, it can also regulate the hydrolysis rate of the silane coupling agent, allowing silane molecules to be gradually adsorbed on the surface of mesoporous silica to form a uniform monolayer. In addition, using ethanol as the second solvent helps to reduce the cost of the preparation process.

[0075] When the second solvent is methanol, methanol is a highly polar organic solvent. The hydroxyl groups (-OH) in its molecules can form hydrogen bonds with the silanol groups (Si-OH) on the surface of mesoporous silica. At the same time, it stabilizes the dispersion state of the mesoporous silica particles through polar solvation, thereby effectively improving the stability and uniformity of the second suspension.

[0076] Acetone is a highly polar organic solvent, but the carbonyl group (C=O) in its molecular structure can form a weak dipole-dipole interaction with the silanol group (Si-OH) on the surface of mesoporous silica, thereby allowing the mesoporous silica to dissolve fully and form a stable second suspension.

[0077] When the second solvent is n-butanol, n-butanol (C4H9OH) has both polar hydroxyl groups (which can form hydrogen bonds with silanol groups) and non-polar butyl chains (hydrophobic). This "amphiphilicity" gives it a special solubility in mesoporous silica systems.

[0078] The fourth time refers to the reaction time for grafting fluorine-free alkyl silanes onto modified mesoporous silica under ultrasonic reaction conditions. The bursting of bubbles generated by ultrasound releases energy, enhancing medium disturbance and promoting the diffusion of fluorine-free alkyl silane molecules onto the surface of aminated mesoporous silica, accelerating the condensation reaction between silane hydrolysis products and surface amino groups (-NH2). When the fourth time t4 is less than 1 hour, it is too short, meaning the reaction time of the aminated mesoporous silica with the fluorine-free alkyl silane under ultrasonic conditions is too short. This results in a smaller amount of fluorine-free alkyl silane grafted onto the exterior of the modified mesoporous silica, thus affecting the hydrophobicity of the functional coating. Furthermore, the bonding stability between the fluorine-free alkyl silane and the modified mesoporous silica is poor, and the fluorine-free alkyl silane easily detaches from the modified mesoporous silica, thus affecting the stability of the hydrophobic properties of the functional coating. When the fourth time (t4) exceeds 3 hours, the excessively long fourth time will increase the hydrolysis rate of amino groups, thereby reducing the amino group retention rate on the mesoporous silica surface. This affects the grafting rate of fluorine-free alkyl silanes and reduces the hydrophobic properties of the functional coating. Furthermore, an excessively long fourth time can easily lead to the collapse of the mesoporous structure of the mesoporous silica, thus affecting the efficiency of subsequent coating with antibacterial substances and reducing the antibacterial and hydrophobic properties of the functional coating. Additionally, it will increase production costs and reduce production efficiency.

[0079] Therefore, when the fourth time t4 satisfies 1h ≤ t4 ≤ 3h, the fourth time setting is reasonable and beneficial to improving the grafting rate of fluorine-free alkyl silanes on the surface of aminated mesoporous silica, thereby improving the hydrophobic properties of the functional coating. Furthermore, it can also improve the bonding stability between fluorine-free alkyl silanes and modified mesoporous silica, thus improving the stability of the hydrophobic properties of the functional coating. In addition, it is beneficial to reduce production costs and improve production efficiency.

[0080] According to some embodiments of the present invention, the first time is t1, wherein t1 satisfies: 0.1 min ≤ t1 ≤ 1 min; and / or, the drying temperature of the drying treatment is T1, and the drying time is t, wherein T1 and t respectively satisfy: 80℃ ≤ T1 ≤ 120℃, 10 min ≤ t ≤ 120 min; and / or, the solvent of the first solution includes at least one of ethanol, methanol, acetone and n-butanol; and / or, the second time is t2, wherein t2 satisfies: 0.5 h ≤ t2 ≤ 24 h.

[0081] When the initial time t1 is less than 0.1 min, the immersion time of the outer shell in the first suspension is too short, resulting in insufficient coating time. This limits the adsorption of mesoporous silica grafted with hydrophobic substances on the outer surface of the refrigerator shell, easily leading to an ultra-thin coating or localized missed coating, resulting in insufficient hydrophobicity and poor wear resistance. When the initial time t1 is greater than 1 min, the immersion time in the first suspension is too long. Excessive coating time leads to excessive adhesion of mesoporous silica grafted with hydrophobic substances. After drying, the functional coating may crack or sag due to shrinkage stress (especially on vertical surfaces), affecting the appearance and performance of the refrigerator. Therefore, when the initial time t1 satisfies the condition 0.1 min ≤ t1 ≤ 1 min, the initial time setting is reasonable, which is beneficial for forming a uniform and moderately thick modified mesoporous silica coating on the outer surface of the shell, improving the hydrophobicity of the functional coating on the refrigerator shell. Furthermore, it facilitates the second immersion coating process, increasing the coating amount of antibacterial essential oil. In addition, it helps to shorten the coating time of the functional coating, improving the production efficiency and yield of the refrigerator shell.

[0082] When the drying temperature T1 is below 80℃, the drying speed is too slow, and incomplete drying is likely to occur, which is detrimental to subsequent reactions. When the drying temperature T1 is above 120℃, the drying temperature is too high, and the first solvent evaporates rapidly, which can affect the structure of the mesoporous silica grafted with hydrophobic substances, thereby reducing the hydrophobic properties of the functional coating. Therefore, when the drying temperature T1 meets the following condition: 80℃≤T1≤120℃, the drying temperature setting is reasonable, which can fully evaporate the first solvent and form a stable and uniform solid coating on the outer shell surface. Moreover, it can also effectively remove the structure-directing agent in the mesoporous silica, forming an open mesoporous structure, thereby increasing the contact angle and improving the hydrophobic properties of the functional coating. In addition, the dense silica skeleton formed by drying can prevent corrosive media such as water, oxygen, and salt spray from penetrating to the outer shell, thereby extending the service life of the outer shell and ensuring the performance of the refrigerator. It should be noted that the drying temperature setting is related to the type of the first solvent and the amount of structure-directing agent used. In the actual preparation process, the temperature can be set according to the actual situation to improve the drying rate and drying effect.

[0083] When the drying time t is less than 10 min, the drying time is too short, and the residual first solvent will affect the structural strength of the functional coating. Furthermore, the residual first solvent fills the mesopores, easily forming hydrophilic microregions, thus reducing the hydrophobicity of the functional coating. In addition, if the drying time is too short, the conversion rate of silanol groups (-SiOH) to form silicon-oxygen bonds (-Si-O-Si-) is low, resulting in limited hardness and impact resistance of the functional coating. This can easily lead to blistering, scratches, and other phenomena during subsequent use, thereby reducing the refrigerator's lifespan and affecting the user experience. When the drying time t is greater than 120 min, the drying time is too long, easily triggering side reactions or excessive aging, thus affecting the performance of the functional coating. Furthermore, it will reduce production efficiency and increase production costs. Therefore, when the drying time t meets the condition of 10 min ≤ t ≤ 120 min, the drying time setting is reasonable, allowing for sufficient evaporation of the first solvent and the formation of a stable and uniform solid coating on the outer shell surface. Furthermore, it can effectively remove the structure-directing agents from mesoporous silica, forming an open mesoporous structure, thereby increasing the contact angle and improving the hydrophobic properties of the functional coating. In addition, it can improve the hardness and impact resistance of the functional coating, ensuring its performance, extending the refrigerator's lifespan, and enhancing the user experience. Moreover, it can improve production efficiency and reduce production costs.

[0084] For example, ethanol is a solvent with both polar and nonpolar properties, and the main components of antibacterial essential oils (plant essential oils) (such as terpenes, phenols, and alcohols) are mostly fat-soluble compounds. When ethanol is used as a solvent for antibacterial essential oils, it can form hydrogen bonds with polar groups (such as phenolic hydroxyl groups) in the essential oil through hydroxyl groups (-OH), and van der Waals forces with nonpolar terpenoid molecules through carbon chains. This achieves efficient dissolution of the antibacterial essential oil, forming a stable and homogeneous solution. This facilitates the second dip-coating process, allowing the antibacterial essential oil to be uniformly coated within the mesoporous silica, thereby improving the release stability of the antibacterial essential oil. Furthermore, it can improve the efficiency of coating the modified mesoporous silica with antibacterial essential oil, thus enhancing the antibacterial properties of the functional coating. In addition, ethanol has a lower production cost, which helps reduce the production cost of the functional coating.

[0085] Methanol is the most polar monohydric alcohol. Its hydroxyl group (-OH) can form strong hydrogen bonds with polar components in antibacterial essential oils (such as phenols, alcohols, and aldehydes), while the hydrophobicity of the methyl group (-CH3) can interact with the carbon chain portion of terpenoid compounds. Therefore, when methanol is used as the solvent in the first solution, the antibacterial essential oil can achieve synergistic dissolution of both polar and nonpolar components with methanol, forming a homogeneous and stable first solution. This is beneficial for improving the coating rate of the modified mesoporous silica on the antibacterial essential oil, thereby enhancing the antibacterial effect of the functional coating.

[0086] Acetone is a typical polar aprotic solvent, possessing both a polar carbonyl group (which can form hydrogen bonds with phenolic and alcoholic hydroxyl groups) and a nonpolar methyl group (which is miscible with terpene carbon chains). This broad solubility range allows for the dissolution of complex components in antibacterial essential oils, thus improving the solubility of various antibacterial essential oils and enhancing the homogeneity and stability of the first solution. For example, acetone shows significantly better solubility than ethanol in terpenes in tea tree oil and aldehydes in cinnamon oil. Furthermore, at low temperatures, the weak interaction between acetone molecules and antibacterial essential oils lowers the lattice energy of the essential oils, effectively inhibiting the elution of active ingredients and further improving the stability of the first solution.

[0087] n-Butanol is a polar organic solvent with both polar hydroxyl groups (-OH) and nonpolar carbon chains (C4H9-) in its molecular structure. This "amphiphilic" property allows it to simultaneously dissolve both polar components (such as phenols and alcohols, such as thymol and carvacrol) and nonpolar components (such as terpenes, such as limonene and α-pinene) in antibacterial essential oils. This ensures the full dispersion of the active ingredients in the antibacterial essential oils, avoids precipitation or stratification due to insufficient solubility, and improves the stability and homogeneity of the first solution. Furthermore, n-Butanol has relatively mild chemical properties and does not readily react with antibacterial active substances such as phenols and aldehydes in antibacterial essential oils at room temperature (e.g., oxidation, esterification), thus reducing the degradation of active ingredients and maintaining the durability of the antibacterial effect.

[0088] When the second time t2 is less than 0.5 hours, the second time is too short, meaning the second immersion coating time is too short. This results in insufficient adsorption of the antibacterial essential oil, thus reducing the antibacterial performance of the functional coating. Furthermore, the physically adsorbed antibacterial essential oil molecules do not penetrate deeply into the pores of the mesoporous silica, making them prone to detachment during subsequent cleaning, further reducing the antibacterial performance of the functional coating and the efficiency of the antibacterial essential oil. In addition, the "surface enrichment" structure formed by the short-term coating of the antibacterial essential oil leads to a tendency for burst release, thus reducing the antibacterial stability and long-term antibacterial performance of the functional coating. When the second time t2 is greater than 24 hours, the second immersion coating time is too long. Over-coating can easily form a "deep-locked" structure, hindering the diffusion of the antibacterial essential oil and reducing the antibacterial effect of the functional coating. Furthermore, this also reduces the production efficiency of the functional coating and increases production costs. Therefore, when the second time t2 satisfies: 0.5h≤t2≤24h, the second time setting is reasonable, thereby enabling the slow and controllable release of antibacterial essential oils, optimizing the controllable and sustained release of antibacterial essential oils and enhancing the long-term antibacterial effect of the functional coating.

[0089] According to the refrigerator manufacturing method of the present invention, when the mesoporous silica is modified mesoporous silica, the method includes the following steps: Step 1: Obtain the shell.

[0090] Step 2: Obtaining Mesoporous Silica: A structure-directing agent (such as hexadecyltrimethylammonium bromide) and 4 ml of 2 mol / L NaOH were added to deionized water. The mixture was continuously stirred at 800 rpm at 85°C. A silicon source precursor (such as tetraethoxysilane) was rapidly added to the above mixture, and the reaction was continued with stirring. After the reaction was complete, the mixture was centrifuged and washed to obtain mesoporous silica particles. Subsequently, the centrifuged mesoporous silica particles were dried overnight in an oven and then calcined in a muffle furnace to remove residual organic reagents from the mesoporous silica particles.

[0091] Step 3: Obtaining modified mesoporous silica: The mesoporous silica prepared in Step 2 is dispersed in a second solvent to obtain a second suspension. An amino-containing silane coupling agent (such as aminopropyltriethoxysilane) is added to the second suspension, and the mixture is refluxed for a third time to obtain aminated mesoporous silica. The modified mesoporous silica is collected after centrifugation (centrifugation speed: 500~2000 r / min) and washing with ethanol.

[0092] Further dispersing aminated mesoporous silica in Ag-containing... + Modified mesoporous silica was obtained by stirring in a salt solution at room temperature. The modified mesoporous silica was then dispersed in a first solvent containing a fluorine-free alkylsilane and sonicated for a fourth time to obtain a first suspension.

[0093] Step 4, First dip coating treatment: Immerse the shell obtained in Step 1 into the first suspension prepared in Step 3 for a first time to obtain a shell coated with the first coating.

[0094] Step 5, Drying and Aging: After drying the shell coated with the first coating obtained in Step 4, age it in air. Repeat the processes in Steps 4 and 5 twice to obtain a nano-textured surface.

[0095] Step Six, Second Dip Coating Treatment: The shell coated with the first coating after drying and aging in Step Five is immersed in the first solution for a second time.

[0096] Step 7, Cleaning: Cleaning removes excess first solution from the surface of the outer casing to obtain an outer casing coated with a functional coating.

[0097] According to the refrigerator manufacturing method of the present invention, when the mesoporous silica is unmodified, the method includes the following steps: Step 1: Obtain the shell.

[0098] Step 2: Obtaining Mesoporous Silica: A structure-directing agent (such as hexadecyltrimethylammonium bromide) and 4 ml of 2 mol / L NaOH were added to deionized water. The mixture was continuously stirred at 800 rpm at 85°C. A silicon source precursor (such as tetraethoxysilane) was rapidly added to the above mixed solution, and the reaction was continued with stirring. After the above reaction was completed, the mixture was centrifuged and washed to obtain mesoporous silica particles. Subsequently, the mesoporous silica particles obtained by centrifugation were placed in an oven and dried overnight, and then calcined in a muffle furnace to remove residual organic reagents from the mesoporous silica particles.

[0099] Step 3: Disperse mesoporous silica in the first solvent and add a fluorine-free alkylsilane (such as octadecyltrichlorosilane) to it, and sonicate to obtain the first suspension.

[0100] Step 4, First dip coating treatment: Immerse the shell obtained in Step 1 into the first suspension prepared in Step 3 for a first time to obtain a shell coated with the first coating.

[0101] Step 5, Drying and Aging: After drying the shell coated with the first coating obtained in Step 4, age it in air. Repeat the first dip-coating treatment in Steps 3 and 4 twice to obtain a shell with a nano-textured surface.

[0102] Step Six, Second Dip Coating Treatment: The shell coated with the first coating after drying and aging in Step Five is immersed in the first solution for a second time.

[0103] Step 7, Cleaning: Cleaning removes excess first solution from the surface of the outer casing to obtain an outer casing coated with a functional coating.

[0104] This setup allows for the preparation of both modified mesoporous silica-coated antibacterial functional coatings and unmodified mesoporous silica-coated antibacterial functional coatings using the aforementioned method. This enables the selection of the functional coating based on specific application requirements, satisfying a variety of needs. Furthermore, the preparation method is simple; the hydrophobicity and antibacterial properties of the functional coating can be achieved through dip coating, facilitating large-scale production.

[0105] According to some optional embodiments of the present invention, the preparation of mesoporous silica specifically includes the following steps: Step 1: Add the structure-directing agent and sodium hydroxide to a certain volume of deionized water.

[0106] Step 2: Stir the mixture obtained above continuously at a temperature of 60~90℃ and a speed of 500~1000 rpm for 0.5~6 hours.

[0107] Step 3: Quickly add the silicon source precursor to the above solution and continue stirring for 1 hour. Separate the particles by centrifugation and wash twice with deionized water and ethanol (the molar ratio of deionized water to ethanol is 1:0.1~1:4).

[0108] Step 4: Dry the above-prepared material in an oven at 100°C overnight, and calcine it in a muffle furnace for 0.5-5 hours to eliminate any residual organic reagents.

[0109] According to some alternative embodiments of the present invention, the structure directing agent is selected from at least one of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, tetradecyltrimethylammonium bromide, dodecyltrimethylammonium bromide, hexadecylpyridine bromide, and tetradecylpyridine bromide.

[0110] The synthesis of mesoporous silica typically requires the addition of structure-directing agents to guide the self-assembly of silicon source precursors into ordered mesoporous structures (such as channels, cage-like structures, or layered structures). The choice of structure-directing agent plays a decisive role in the pore size, morphology, channel order, and surface properties of the mesoporous material. For example, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, tetradecyltrimethylammonium bromide, and dodecyltrimethylammonium bromide are cationic surfactants. The positively charged head groups interact electrostatically with negatively charged silicate ions (such as SiO3). 2- The two compounds combine to form a "silicon-surfactant" composite micelle. After calcination, the surfactant is removed to obtain mesoporous channels. Hexadecylpyridine bromide and tetradecylpyridine bromide are quaternary ammonium salt surfactants that guide the formation of a highly ordered mesoporous structure through a micelle template-electrostatic interaction mechanism. Therefore, by adding the above-mentioned structure-directing agents, mesoporous silica with a multi-channel structure is formed, which is beneficial for the subsequent encapsulation of antibacterial substances and effectively improves the antibacterial properties of the functional coating.

[0111] According to some optional embodiments of the present invention, the centrifugation speed can be 500 r / min to 2000 r / min.

[0112] For example, after mesoporous silica is generated, the solvent and unreacted silicon source precursors, structure-directing agents, and other substances can be removed by centrifugation, resulting in high-purity mesoporous silica particles. When the centrifugation speed is less than 500 r / min, the yield of mesoporous silica will be reduced, and a large amount of mesoporous silica will not be centrifuged from the solution. When the centrifugation speed is greater than 2000 r / min, the purity of the mesoporous silica product will decrease, resulting in a large amount of impurities in the mesoporous silica, which is detrimental to subsequent modification or coating with antibacterial substances. When the centrifugation speed is within the range of 500 r / min to 2000 r / min, a reasonable centrifugation speed setting can obtain high-purity mesoporous silica particles. Furthermore, it can improve the yield of mesoporous silica and reduce production costs. It should be noted that the centrifugation speed can be set according to factors such as the particle size of the mesoporous silica, and can be adjusted according to the actual situation during the preparation process.

[0113] According to some optional embodiments of the present invention, the silane precursor is selected from at least one of tetraethoxysilane, tetramethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, and aminopropyltriethoxysilane.

[0114] For example, tetraethoxysilane and tetramethoxysilane are basic silicon sources without functional group modification. Among them, tetraethoxysilane has a moderate hydrolysis rate, making it easy to control the condensation process and suitable for synthesizing highly ordered mesoporous structures. Tetramethoxysilane has an extremely fast hydrolysis rate (the methoxy group has strong electron-withdrawing properties and is easily attacked by nucleophiles), and the reaction conditions (such as low temperature and low water content) must be strictly controlled during its preparation to obtain mesoporous silica with a porous structure.

[0115] Methyltriethoxysilane, vinyltriethoxysilane, and aminopropyltriethoxysilane contain functional groups that can influence the properties of mesoporous silica. Methyltriethoxysilane, containing a methyl group, increases the hydrophobicity of the silicon source, thus modulating the surface properties of mesoporous silica and improving its hydrophobicity. Vinyltriethoxysilane, containing a vinyl group, can be further functionalized through free radical polymerization, hydrosilylation, and other reactions, endowing mesoporous materials with crosslinkability or photoresponsiveness. Aminopropyltriethoxysilane contains an amino (-NH2) functional group; the amino group readily condenses with the silanol (-SiOH) generated from the hydrolysis of the silicon source, forming an "amino-siloxane bond" covalent modification, thereby achieving one-step modification of mesoporous silica.

[0116] It should be noted that the selection of silane precursors can be set according to the actual situation. A single silicon source or a mixed silicon source system should be flexibly selected based on the target structure, functional requirements and process conditions in order to achieve precise synthesis and performance optimization of mesoporous silica.

[0117] According to some optional embodiments of the present invention, the temperature of the muffle furnace is 400°C to 800°C.

[0118] After the mesoporous silica is formed, it needs to be calcined in a muffle furnace to remove the structure-directing agent and further stabilize its mesoporous structure. When the temperature of the muffle furnace is below 400℃, the temperature is too low, and some structure-directing agent may remain. This residual structure-directing agent can block part of the pore structure, thus affecting the subsequent coating of antibacterial substances and reducing the antibacterial performance of the functional coating. Furthermore, at low temperatures, the condensation reaction of the mesoporous silica framework is insufficient, and the Si-O-Si bonds are not fully formed, making the pore structure prone to collapse, thereby affecting the antibacterial effect. When the temperature of the muffle furnace is above 800℃, the temperature is too high. Excessive condensation of the silica framework at high temperatures and drastic reconstruction of the Si-O-Si bonds may lead to a reduction in the pore size or even complete collapse of the mesoporous channels, affecting the subsequent coating of antibacterial substances. In addition, it will increase production costs and reduce production efficiency.

[0119] With this setting, when the temperature of the muffle furnace is in the range of 400℃ to 800℃, the temperature setting of the muffle furnace is reasonable, which can effectively remove the structure guiding agent and form a porous mesoporous silica structure, which is beneficial to the subsequent reaction.

[0120] The embodiments of the present invention are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known to others. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0121] The refrigerator of the present invention will be described by way of exemplary specific embodiments in conjunction with comparative examples. The following describes the performance tests performed on the outer casings of the embodiments and comparative examples.

[0122] Example 1 A method for preparing a refrigerator includes the following steps: Step 1: Obtain the outer casing. The outer casing is an aluminum sheet that has been ultrasonically cleaned with water and acetone for 30 minutes each.

[0123] Step 2: Obtaining Mesoporous Silica: Add 0.5 g of structure-directing agent (hexadecyltrimethylammonium bromide) and 4 mL of 2 mol / L NaOH to 500 mL of deionized water. Stir the mixture continuously at 800 rpm for 1 hour at 85°C. Quickly add 10 mL of silicon source precursor (tetraethoxysilane) to the above mixture and continue stirring for 1 hour. After the above reaction is complete, centrifuge at 1000 rpm to obtain mesoporous silica particles, and wash twice with deionized water and ethanol. Subsequently, place the centrifuged mesoporous silica particles in an oven at 100°C and dry overnight, then calcine in a muffle furnace at 550°C for 5 hours to remove residual organic reagents from the mesoporous silica particles.

[0124] Step 3: Obtaining modified mesoporous silica: 0.5 g of the mesoporous silica prepared in Step 2 was dispersed in 50 g of a second solvent (ethanol) to obtain a second suspension. 3 mL of an amino-containing silane coupling agent (aminopropyltriethoxysilane) was added to the second suspension, and the mixture was refluxed for 6 h (t3) to obtain aminated mesoporous silica. The modified mesoporous silica was collected after centrifugation (800 r / min) and washing with ethanol.

[0125] Step 4: Disperse the aminated mesoporous silica in 50 mL of deionized water containing 1.5 g AgNO3, and stir at room temperature for 24 h to obtain modified mesoporous silica. Collect the mesoporous silica-aminopropyltriethoxysilane / Ag by centrifugation and washing. + 0.2 g of modified mesoporous silica was dispersed in 5 mL of the first solvent (toluene), and 0.25 g of octadecyltrichlorosilane (fluorine-free alkylsilane) was added to it. The mixture was ultrasonically treated for 1 h (t4) to obtain the first suspension.

[0126] Step 5, First dip coating treatment: Immerse the shell obtained in Step 1 into the first suspension prepared in Step 4 for 0.1 min (t1) to obtain the shell coated with the first coating.

[0127] Step 6, Drying and Aging: After drying the shell coated with the first coating obtained in Step 5 for 2 minutes, age it in air. Repeat the first dip-coating treatment in Step 4 and Step 5 twice to obtain a shell with a nano-textured surface.

[0128] Step 7, Second Dip-Coating Treatment: Immerse the shell coated with the first coating after drying and aging in Step 6 into the first solution for 0.5 h (t2). The first solution is a solution in which 0.7 g of clove essential oil is dissolved in 5 mL of ethanol.

[0129] Step 8, Cleaning: Remove the outer shell from Step 7 and rinse with 2 mL of ethanol to remove excess first solution from the surface, in order to obtain an outer shell coated with a functional coating.

[0130] Examples 2-5 The preparation methods of Examples 2-5 are roughly the same as those of Example 1. The main differences are that the preparation conditions of mesoporous silica in step 2, the preparation conditions of modified mesoporous silica in step 3, and the type and concentration of the first solution in step 6 are different. The specific parameter limitations of Examples 1-5 and Comparative Examples 1-3 are shown in Table 1.

[0131] Example 6 The main difference from Example 1 is that step three is different, specifically: Step 1: Obtain the outer casing. The outer casing is an aluminum sheet that has been ultrasonically cleaned with water and acetone for 30 minutes each.

[0132] Step 2: Obtaining Mesoporous Silica: Add 0.5 g of structure-directing agent (tetradecyltrimethylammonium bromide) and 4 mL of 2 mol / L NaOH to 500 mL of deionized water. Stir the mixture continuously at 800 rpm for 1 hour at 85°C. Quickly add 10 mL of silicon source precursor (vinyltriethoxysilane) to the above mixture and continue stirring for 1 hour. After the above reaction is complete, centrifuge at 1000 rpm to obtain mesoporous silica particles, and wash twice with deionized water and ethanol. Subsequently, place the centrifuged mesoporous silica particles in an oven at 100°C and dry overnight, then calcine in a muffle furnace at 550°C for 5 hours to remove residual organic reagents from the mesoporous silica particles.

[0133] Step 3: Disperse 0.2g of mesoporous silica in 5mL of the first solvent (toluene), and add 0.25g of dodecyltrichlorosilane (fluorine-free alkylsilane) to it. Sonicate for 3h to obtain the first suspension.

[0134] Step 4, First dip coating treatment: Immerse the shell obtained in Step 1 into the first suspension prepared in Step 3 for 1 min (t1) to obtain the shell coated with the first coating.

[0135] Step 5, Drying and Aging: After drying the shell coated with the first coating obtained in Step 4 for 2 minutes, age it in air. Repeat the first dip-coating treatment in Step 4 twice to obtain a shell with a nano-textured surface.

[0136] Step Six, Second Dipping Treatment: Immerse the shell coated with the first coating after drying and aging in Step Five into the first solution for 24 hours (t2). The first solution is a solution in which 3g of violet essential oil is dissolved in 20mL of ethanol.

[0137] Step 7, Cleaning: Remove the outer shell from Step 6 and rinse with 2 mL of ethanol to remove excess first solution from the surface, in order to obtain an outer shell coated with a functional coating.

[0138] Comparative Example 1 Comparative Example 1 uses the same material as Example 1 for its outer shell, which is an aluminum sheet that has been cleaned with water and acetone for 30 minutes using ultrasonic waves, without any other treatment.

[0139] Comparative Example 2 Compared with Example 1, the preparation conditions of the mesoporous silica in step 2 were changed, and the treatment in step 7 was not performed. That is, the coating on the shell was only grafted with hydrophobic substances and was not coated with antibacterial essential oil.

[0140] Comparative Example 3 Compared with Example 1, the preparation conditions of mesoporous silica in step 2 and the preparation conditions of modified mesoporous silica in step 3 were changed, and the treatment in step 4 was not performed. That is, the coating on the shell only covers antibacterial essential oil and no hydrophobic substances are grafted on the outside.

[0141] Table 1. Settings of relevant parameters in Examples 1-6, Comparative Examples 2 and 3

[0142] Performance testing: 1. Contact angle test, the test standard refers to GB / T 30693-2014; 2. Antibacterial performance test (using Escherichia coli and Staphylococcus aureus as test bacteria to evaluate the antibacterial effect of the shell with functional coating.) D1. The functional coating material is applied to a glass slide and cured into a film, followed by 100 µL of a 10% concentration... 8 A bacterial suspension of CFU / mL was applied to the surface of the functional coating material and incubated at 37°C in a sterile environment for 24 hours.

[0143] D2. Remove the slide and rinse it repeatedly with phosphate buffer solution. Inoculate the wash solution into nutrient agar medium and incubate at 37°C for 24 hours. Record the bacterial survival status.

[0144] 3. Bacterial Adhesion Test D1. The material of the functional coating is applied to a glass slide and cured into a film (2.5 cm × 2.5 cm). The film is then immersed in 1 ml of sterile LB broth, and a small number of bacterial colonies are inoculated. The film is then incubated at 37°C with shaking at 200 rpm for 24 hours.

[0145] D2. Use a pipette to aspirate the culture solution and replenish with fresh LB broth every 24 hours. After 3 days, remove the sample from the culture and gently rinse with sterile saline.

[0146] D3. The attached bacteria were stained using the LIVE / DEAD bacterial viability assay kit and incubated for 25 minutes in the absence of ambient light. The biofilm formed on the coating surface was observed using a CLSM (Nikon Eclipse Ti-U) at 200x magnification.

[0147] D4. Calculate relative bacterial attachment using ImageJ software. The color channels of the confocal image are split into red, green, and blue channels to analyze the number of dead and live bacteria separately. Within each channel, image thresholding is performed to accurately select areas of bacterial coverage in the image. Bacterial coverage is quantified by measuring the proportion of selected pixels to the total number of pixels in the image. The relative bacterial attachment rate is calculated by summing the coverage rates of live and dead bacteria.

[0148] Table 2 Performance test results of Examples 1-6 and Comparative Examples 1-3

[0149] According to Tables 1 and 2, as shown in Examples 1-6, the contact angles in Examples 1-5 are all greater than 150°, indicating that the material exhibits superhydrophobicity. It is evident that the functional coatings prepared according to the method described in this application all possess superhydrophobicity, meaning that water adhesion to the surface of the functional coating is weak, effectively reducing the contact area between water and the functional coating. Because the mesoporous silica is encapsulated with antibacterial essential oil, the superhydrophobic property effectively prevents water vapor from entering the pores of the mesoporous silica and affecting the effect of the antibacterial essential oil. Furthermore, combining the test results of antibacterial effect and bacterial adhesion rate, it can be seen that, under unchanged conditions, increasing the reaction time, such as the reflux time of the aminated mesoporous silica and the time of the second dip-coating treatment, can increase the contact angle of the functional coating and improve the antibacterial effect. The functional coating in Example 2 has the largest contact angle, the best antibacterial effect, and the lowest bacterial adhesion rate, exhibiting the best overall performance and superior to other examples.

[0150] Comparing Examples 1-5 and Example 6, it is evident that the aminated mesoporous silica forms a functional coating with a larger contact angle, resulting in a better antibacterial effect after coating with antibacterial substances. Comparing Example 1 and Comparative Examples 1-3, it is evident that, under otherwise unchanged conditions, grafting hydrophobic substances onto the outside of the modified mesoporous silica and coating it internally with antibacterial essential oil significantly expands the contact angle of the functional coating, giving it superhydrophobic properties. Furthermore, the internal coating with antibacterial essential oil and the surface loading of silver ions achieve a synergistic antibacterial effect, effectively improving the antibacterial performance. In other words, the functional coating of this application possesses both superhydrophobicity and excellent antibacterial properties, exhibiting superior overall performance.

[0151] The refrigerator, its preparation method, and operation according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0152] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the indicated orientation or positional relationship, and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0153] In the description of this invention, "a plurality of" means two or more.

[0154] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are 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.

Claims

1. A refrigerator, comprising: An outer casing, wherein an accommodating space is defined within the outer casing; Inner liner, wherein the inner liner is disposed in the receiving space; The feature is that a functional coating is provided on the outer surface of the outer casing: The functional coating comprises mesoporous silica with an internal antibacterial substance and an externally grafted hydrophobic substance.

2. The refrigerator according to claim 1, characterized in that, The mesoporous silica is modified mesoporous silica, which is aminated mesoporous silica with silver ions loaded on its surface.

3. The refrigerator according to claim 1, characterized in that, The antibacterial substance includes antibacterial essential oils, which are selected from at least one of the following: oregano essential oil, patchouli essential oil, cinnamon essential oil, litsea cubeba essential oil, clove essential oil, thyme essential oil, geranium essential oil, garlic essential oil, tea tree essential oil, calamus essential oil, lemongrass essential oil, clove basil essential oil, turmeric essential oil, West Indian sandalwood essential oil, and violet essential oil.

4. The refrigerator according to any one of claims 1-3, characterized in that, The hydrophobic material includes fluorine-free alkylsilanes.

5. The refrigerator according to claim 4, characterized in that, The fluorine-free alkylsilane is selected from at least one of octadecyltrichlorosilane, dodecyltrichlorosilane, and chloro(dimethyl)octadecylsilane.

6. A method for preparing a refrigerator according to any one of claims 1-5, characterized in that, Includes the following steps: Obtain the shell; Obtain mesoporous silica; First dip coating treatment: The shell is immersed in the first suspension for a first time to obtain the shell coated with the first coating. After drying, it is aged in air. The first suspension is a mesoporous silica solution grafted with hydrophobic substances. Repeat the first dip-coating treatment at least once; Drying process; Second dip coating treatment: The outer shell coated with the first coating is immersed in a first solution for a second time, wherein the first solution is a solution containing antibacterial substances; The shell is cleaned to obtain a functional coating.

7. The preparation method according to claim 6, characterized in that, The mesoporous silica includes modified mesoporous silica, and the preparation of the modified mesoporous silica includes the following steps: The mesoporous silica is dispersed in a second solvent to obtain a second suspension. An amino-containing silane coupling agent is added to the second suspension, and the mixture is refluxed for a third time to obtain aminated mesoporous silica. The aminated mesoporous silica is dispersed in a solution containing Ag. + The modified mesoporous silica was obtained by stirring in a salt solution at room temperature.

8. The preparation method according to claim 7, characterized in that, The preparation of the first suspension includes the following steps: The modified mesoporous silica is dispersed in a first solvent, a fluorine-free alkylsilane is added to the first solvent, and the mixture is ultrasonically treated for a fourth time. The amino groups on the modified mesoporous silica are nucleophilically substituted with chlorine elements on the fluorine-free alkylsilane to graft hydrophobic substances onto the outside of the modified mesoporous silica.

9. The preparation method according to claim 8, characterized in that, The third time is t3, wherein t3 satisfies: 6h ≤ t3 ≤ 24h; and / or The first solvent includes at least one selected from toluene, ethanol, diethyl ether, chloroform, and acetone; and / or The second solvent includes at least one of ethanol, methanol, acetone, and n-butanol; and / or The fourth time is t4, where t4 satisfies: 1h≤t4≤3h.

10. The preparation method according to any one of claims 6-9, characterized in that, The first time is t1, wherein t1 satisfies: 0.1 min ≤ t1 ≤ 1 min; and / or The drying temperature for the drying process is T1, and the drying time is t, wherein T1 and t respectively satisfy: 80℃≤T1≤120℃, 10min≤t≤120min; and / or The solvent of the first solution includes at least one selected from ethanol, methanol, acetone, and n-butanol; and / or The second time is t2, where t2 satisfies: 0.5h ≤ t2 ≤ 24h.

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