A MOF sterilizing agent, preparation method and application

Abstract

The application relates to the technical field of bactericidal materials, in particular to a MOF bactericide, a preparation method and application. The bactericide is prepared by the method. The method comprises the following steps: synthesizing zinc ion slow-release MOF material; treating the zinc ion slow-release MOF material by loading quaternary ammonium salt to obtain zinc ion slow-release MOF material loaded with quaternary ammonium salt; and carrying out hydrophobic treatment to obtain MOF bactericide with a surface modified by hydrophobicity. The application is applied to the preparation of automobile interior materials, vehicle-mounted air purification materials and air conditioner filter elements. The bactericide prepared by the application has high bactericidal efficiency, is resistant to inactivation, has long drug efficacy and low volatility.

Description

Technical Field

[0001] This invention relates to the field of bactericidal materials technology, and in particular to a MOF bactericide, its preparation method, and its application. Background Technology

[0002] Bacteria and mold can easily grow inside vehicles (such as in air conditioning systems and seat fabrics). Some existing disinfectants require light or heat activation to kill bacteria, and their disinfection efficiency at room temperature is less than 50%; insufficient light inside vehicles further reduces disinfection efficiency. Existing silver ion disinfectants are not only costly to produce, but also easily deactivate silver ions upon contact with sulfides. Existing quaternary ammonium salt disinfectants have short-lived effects, require high dosages, are highly volatile, and pose health risks.

[0003] Therefore, it is necessary to provide an MOF bactericide, its preparation method, and its application to solve the problems of low bactericidal efficiency, easy inactivation, short duration of action, and high volatility of existing bactericides. Summary of the Invention

[0004] The purpose of this invention is to provide a MOF bactericide, its preparation method, and its application. The specific technical solution is as follows: In a first aspect, the present invention provides a method for preparing a MOF bactericide, comprising: Step S1: Synthesize zinc ion slow-release MOF material; Zinc salt, terephthalic acid, N,N-dimethylformamide, and acetic acid are added to a reaction vessel. The reaction vessel is then sealed and placed at 115-125°C for 10-12 hours to obtain a pre-prepared MOF material. The pre-prepared MOF material is then subjected to separation, washing, and first vacuum drying to obtain a zinc ion slow-release MOF material. Step S2: Loading quaternary ammonium salt; The zinc ion slow-release MOF material was impregnated in a diecryldimethylammonium chloride alcohol solution and subjected to vacuum impregnation treatment; after the vacuum impregnation treatment, it was successively centrifuged and then vacuum dried to obtain the zinc ion slow-release MOF material loaded with quaternary ammonium salt. Step S3: Hydrophobic treatment; The zinc ion slow-release MOF material loaded with quaternary ammonium salt is laid flat in the deposition chamber. After the air is replaced by an inert atmosphere, the vaporized environmentally friendly fluorinated silane monomer is deposited on the surface of the zinc ion slow-release MOF material loaded with quaternary ammonium salt using chemical vapor deposition to obtain a surface-hydrophobic modified MOF bactericide. The environmentally friendly fluorinated silane monomer includes perfluorooctyltriethoxysilane.

[0005] Optionally, the molar ratio of the zinc salt, the terephthalic acid, the N,N-dimethylformamide, and the acetic acid is 3:2:40~50:8~10.

[0006] Optionally, the washing process includes sequentially cleaning the prefabricated MOF material with N,N-dimethylformamide and ethanol; wherein the prefabricated MOF material is cleaned with N,N-dimethylformamide at least twice, and the solid-liquid ratio of the two during cleaning is 1:8~15; the prefabricated MOF material is cleaned with ethanol at least twice, and the solid-liquid ratio of the two during cleaning is 1:8~15.

[0007] Optionally, the first vacuum drying process uses a drying temperature of 120~150℃ and a drying time of 6~8h.

[0008] Optionally, the mass ratio of the zinc ion slow-release MOF material to the dialcdimethylammonium chloride solution is 1:15~25; The alcohol reagent used in the dialcyldimethylammonium chloride alcohol solution includes ethanol; The mass concentration of dialcyldimethylammonium chloride in the dialcyldimethylammonium chloride alcohol solution is 8%~12%.

[0009] Optionally, the vacuum impregnation treatment uses a vacuum degree of -0.08 to -0.1 MPa, an impregnation temperature of 55 to 65°C, and an impregnation time of 2 to 4 hours.

[0010] Optionally, the second vacuum drying process uses a drying temperature of 75~85℃ and a drying time of 1~3h.

[0011] Optionally, the inert gas used in the inert atmosphere has a flow rate of 30~60 mL / min; the inert gas includes nitrogen. The chemical vapor deposition method used employs a processing temperature of 100~130℃ and a processing time of 1~2h. The perfluorooctyltriethoxysilane is dissolved in an alcohol reagent before vaporization, and the mass concentration of the perfluorooctyltriethoxysilane in the alcohol reagent is 0.3%~0.5%.

[0012] In a second aspect, the present invention provides a MOF bactericide, which is prepared by the aforementioned method for preparing MOF bactericides.

[0013] In a third aspect, the present invention provides an application of MOF bactericide in the preparation of automotive interior materials, in-vehicle air purification materials, and air conditioning filters.

[0014] The application of the technical solution of the present invention has at least the following beneficial effects: (1) The present invention provides a method for preparing an MOF bactericide, which can produce a bactericide with high bactericidal efficiency, resistance to inactivation, long-lasting effect, and low volatility. The specific principle is as follows: Regarding high sterilization efficiency, the zinc ion slow-release MOF material synthesized in this invention not only possesses a high specific surface area, providing physical capture sites for bacteria and fungi, but also precisely controls the pore size to 3.8±0.2 nm, facilitating matching with the molecular dynamics size (~3.7 nm) of dialc-dimethylammonium chloride, forming a spatial confinement effect that restricts the free turning and disordered aggregation of dialc-dimethylammonium chloride within the pores. Furthermore, a polar microenvironment composed of Zn metal sites and carboxyl ligands exists on the inner wall of the pores of the zinc ion slow-release MOF material, which generates electrostatic adsorption and hydrogen bonding with the hydrophilic cationic head group of dialc-dimethylammonium chloride, forcing the dialc-dimethylammonium chloride molecules to oriented: the hydrophobic alkyl chain faces the pore center, and the cationic head group faces the pore opening, achieving ordered confinement and fixation; wherein, the cationic head group is a dimethyl quaternary ammonium cation (-N + (CH3)2-), this positively charged group can target and bind to the negatively charged cell membranes of bacteria and fungi through electrostatic interactions, disrupting the phospholipid bilayer structure, leading to cell membrane barrier disruption and intracellular leakage. Zinc ions released by the zinc ion-releasing MOF material interfere with the enzyme systems (such as dehydrogenases) of bacteria and fungi, disrupting metabolic functions and thus killing bacteria. Furthermore, the zinc ions released by the zinc ion-releasing MOF material can also bind to peptidoglycans and teichoic acid / lipopolysaccharides in the cell walls of bacteria and fungi, disrupting the structural cross-linking and rigidity of the cell walls, leading to loosening, damage, and cracks. Further, zinc ions penetrating the damaged cell walls bind to phospholipids and membrane proteins on the cell membrane, disrupting the fluidity and structural integrity of the cell membrane, causing pores. This, synergistically with the cationic head group of didecyldimethylammonium chloride, accelerates the disruption of the phospholipid bilayer structure of the cell membrane, increasing the rate of intracellular leakage, thereby accelerating zinc ion interference with enzyme systems, disrupting metabolic functions, and improving bactericidal efficiency.

[0015] In terms of resistance to inactivation, low volatility, and long-lasting efficacy, the present invention utilizes a perfluorooctyltriethoxysilane hydrophobic layer vapor-deposited on the surface of a zinc ion slow-release MOF material loaded with quaternary ammonium salt. This layer effectively blocks water molecules, preventing the quaternary ammonium salt (i.e., dialcyldimethylammonium chloride) from hydrolyzing and inactivating upon contact with water. This hydrophobic layer maintains a controllable slow-release rate of zinc ions, avoids burst release, protects the MOF crystal structure of the bactericide from water erosion and collapse, and reduces the dissolution and volatilization of the quaternary ammonium salt to strictly control VOC release. In addition, under humid and hot conditions, this hydrophobic layer can block the oxidative decomposition of the quaternary ammonium salt by oxygen, H2S gas, and other oxidizing substances through its dense, low-surface-energy cross-linked network structure, allowing the bactericide to maintain high bactericidal activity and long-lasting stability in high-humidity vehicle interior environments. Furthermore, the hydrophobic layer prepared by this invention has a strong covalent bond with the zinc ion slow-release MOF material loaded with quaternary ammonium salt, making it less prone to powdering and detachment. Specifically, the surface of the zinc ion slow-release MOF material loaded with quaternary ammonium salt is rich in hydroxyl groups (derived from zinc ion coordination water and terephthalic acid ligand carboxyl hydroxylation). Perfluorooctyltriethoxysilane undergoes hydrolysis under vapor deposition conditions, and the ethoxy group is converted into silanol (-Si-OH). The silanol undergoes a dehydration condensation reaction with the hydroxyl groups on the MOF surface to generate Si-O-Zn (with the MOF metal zinc site) and Si-OC (with the MOF organic ligand), achieving chemical anchoring. Condensation also occurs between perfluorooctyltriethoxysilane molecules to form a three-dimensional network cross-linked hydrophobic layer, which firmly coats the surface of the zinc ion slow-release MOF material loaded with quaternary ammonium salt, making it less prone to powdering and detachment. Furthermore, the hydrophobic layer molecule prepared by this invention contains CF bonds with a bond energy as high as 485 kJ / mol. It has extremely strong chemical stability and inertness, and does not undergo hydrolysis, oxidation, or bond breakage under humid and hot environments, thus maintaining the structural stability of the hydrophobic layer.

[0016] (2) The MOF bactericide provided by this invention has the following properties: In terms of bactericidal rate, it has a 24-hour bactericidal rate of ≥98.3% (GB / T 21551.3-2010) against Escherichia coli (ATCC 25922 standard strain), without the need for light / heat activation; in terms of long-term stability, after being stored in a 90% humidity environment for 30 days, the retention rate of dialcyldimethylammonium chloride is greater than or equal to 97.2%; in terms of resistance to loss of activity, after being exposed to 10 ppm H2S for 24 hours, the bactericidal rate is greater than 97%; and in terms of volatility, the VOC release is less than or equal to 0.008 mg / m³. 3 (GB / T 27630-2011).

[0017] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The present invention will now be described in further detail with reference to specific embodiments. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: A method for preparing an MOF bactericide, comprising: Step S1: Synthesize zinc ion slow-release MOF material; Zinc salt (specifically Zn(NO3)2·6H2O), terephthalic acid, N,N-dimethylformamide, and acetic acid were added to a reaction vessel. The reaction vessel was then sealed and placed at 115-125°C (specifically 120°C) for 10-12 hours to obtain a pre-prepared MOF material. The pre-prepared MOF material was then subjected to separation (centrifugation at 8000 rpm for 10 minutes), washing, and a first vacuum drying process to obtain a white zinc ion-releasing MOF material (specific surface area 1820 m²). 2 / g, pore size 3.82nm); Step S2: Loading quaternary ammonium salt; The zinc ion slow-release MOF material was impregnated in a diecryldimethylammonium chloride alcohol solution and subjected to vacuum impregnation treatment; after the vacuum impregnation treatment, it was successively centrifuged and then vacuum dried to obtain the zinc ion slow-release MOF material loaded with quaternary ammonium salt. Step S3: Hydrophobic treatment; The zinc ion slow-release MOF material loaded with quaternary ammonium salt is laid flat in the deposition chamber. After the air is replaced by an inert atmosphere, the vaporized environmentally friendly fluorinated silane monomer is deposited on the surface of the zinc ion slow-release MOF material loaded with quaternary ammonium salt using chemical vapor deposition to obtain a surface-hydrophobic modified MOF bactericide. The environmentally friendly fluorinated silane monomer is perfluorooctyltriethoxysilane.

[0020] The molar ratio of the zinc salt, the terephthalic acid, the N,N-dimethylformamide and the acetic acid is 3:2:40~50:8~10 (specifically 3:2:45:9).

[0021] The washing process includes sequentially cleaning the prefabricated MOF material with N,N-dimethylformamide and ethanol; wherein the prefabricated MOF material is cleaned three times with N,N-dimethylformamide, and the solid-liquid ratio of the two during cleaning is 1:10; the prefabricated MOF material is cleaned three times with ethanol, and the solid-liquid ratio of the two during cleaning is 1:10.

[0022] The first vacuum drying process uses a drying temperature of 150℃ and a drying time of 6~8 (specifically 8) hours.

[0023] The mass ratio of the zinc ion slow-release MOF material to the dialcyldimethylammonium chloride alcohol solution is 1:20; The alcohol reagent used in the dialcyldimethylammonium chloride alcohol solution is ethanol; The mass concentration of dialcdimethylammonium chloride in the dialcdimethylammonium chloride alcohol solution is 8%~12% (specifically 10%).

[0024] The vacuum impregnation process uses a vacuum degree of -0.095 MPa, an impregnation temperature of 55~65 (specifically 60) °C, and an impregnation time of 2~4 (specifically 3) h.

[0025] The second vacuum drying process uses a drying temperature of 75~85 (specifically 80)℃ and a drying time of 2 hours.

[0026] The inert atmosphere uses an inert gas flow rate of 50 mL / min; the inert gas includes nitrogen. The vapor deposition process is performed at a temperature of 120°C for 1 to 2 hours (specifically 1.5 hours). The perfluorooctyltriethoxysilane is dissolved in an alcohol reagent (specifically ethanol) before vaporization, and the mass concentration of the perfluorooctyltriethoxysilane in the alcohol reagent is 0.5%.

[0027] Example 2: Unlike Example 1, the mass concentration of dialcdimethylammonium chloride in the dialcdimethylammonium chloride alcohol solution is 8%.

[0028] Example 3: Unlike Example 1, the mass concentration of dialcdimethylammonium chloride in the dialcdimethylammonium chloride alcohol solution is 12%.

[0029] Comparative Example 1: Unlike Example 1, step S2, loading the quaternary ammonium salt, is omitted.

[0030] Comparative Example 2: Unlike Example 1, step S3, hydrophobic treatment, is omitted.

[0031] The bactericides prepared in Examples 1-3 and Comparative Examples 1-2 were sampled and subjected to bactericidal rate tests, diecrystal dimethylammonium chloride retention rate tests, VOC release tests, and anti-activation tests. The test results are shown in Table 1.

[0032] The sterilization rate test method was performed according to Section 2 of Chapter 6 of GB / T 21551.3-2010 "Special Requirements for Air Purifiers with Antibacterial, Sterilizing and Purifying Functions for Household and Similar Electrical Appliances"; the bacterial strain used was Escherichia coli (ATCC25922); the bacterial concentration was 1×10⁻⁶. 6 CFU / mL; Test conditions: 25℃, 60% RH, contact time 24h.

[0033] The retention rate test method for didecyldimethylammonium chloride was a liquid chromatography analysis method, using an Agilent 1260 liquid chromatograph with a C18 column and a mobile phase acetonitrile to water volume ratio of 80:20. Before the didecyldimethylammonium chloride retention rate test, the bactericide sample needed to be stored in a 90% RH environment for 30 days.

[0034] The VOC emission test method was performed in accordance with GB / T 27630-2011 "Guidelines for Evaluating Air Quality in Passenger Cars"; the equipment used was a 40L environmental chamber, and the temperature and humidity inside the environmental chamber were controlled at 25℃ and 50%RH; the detection equipment used was a Thermo TRACE310 gas chromatography-mass spectrometry (GC-MS) instrument, and the sampling time was 24 hours.

[0035] The method for testing the resistance to loss of activity is to expose the bactericide sample to a 10 ppm hydrogen sulfide atmosphere for 24 hours and then test its bactericidal rate. The method for testing the bactericidal rate is the same as the bactericidal rate test method described above.

[0036] Table 1 Test Results

[0037] As shown in Table 1, comparing Example 1 and Comparative Example 1, the bactericide prepared by loading quaternary ammonium salt in step S2 of Example 1 exhibits a significantly higher bactericidal rate over 24 hours. This is because: The bactericide prepared in Example 1 accelerates the disruption of the phospholipid bilayer structure of the cell membrane through the synergistic effect of the slow-released zinc ions and the cationic head group of dialcyldimethylammonium chloride, increasing the intracellular leakage rate and thus accelerating the zinc ion interference with the enzyme system, disrupting metabolic function and improving bactericidal efficiency, showing a significant advantage in 24-hour bactericidal rate. In contrast, Comparative Example 1 did not employ step S2 to load the quaternary ammonium salt, resulting in a bactericide that did not contain dialcyldimethylammonium chloride, failing to synergistically kill bacteria with the slow-released zinc ions, thereby significantly reducing its bactericidal efficiency.

[0038] Comparing Example 1 and Comparative Example 2, it is evident that the bactericide prepared using the hydrophobic treatment in step S3 of Example 1 exhibits significantly higher bactericidal rates at 24 hours, higher retention rates of dialcyldimethylammonium chloride, and higher bactericidal rates after 24 hours of exposure to a 10 ppm hydrogen sulfide atmosphere, while showing a significant reduction in VOC emissions. This is because: In Example 1, the hydrophobic treatment in step S3 forms a hydrophobic layer on the surface of the bactericide, reducing the dissolution and volatilization of quaternary ammonium salts and strictly controlling VOC release. This results in a significant reduction in VOC release and a significant increase in the retention rate of dialc-dimethylammonium chloride. Under humid and hot conditions, this hydrophobic layer, with its dense, low-surface-energy cross-linked network structure, can block the oxidative decomposition of quaternary ammonium salts by H2S gas, allowing the bactericide to maintain high bactericidal activity and long-term stability in high-humidity vehicle environments. This results in a significantly increased bactericidal rate after 24 hours of exposure to 10 ppm hydrogen sulfide atmosphere. Furthermore, the bactericide prepared in Example 1, through the synergistic effect of the slow-released zinc ions and the cationic head group of dialc-dimethylammonium chloride, accelerates the disruption of the phospholipid bilayer structure of the cell membrane, increases the intracellular leakage rate, and further accelerates the zinc ion interference with the enzyme system, disrupting metabolic function and improving bactericidal efficiency, thus showing a significant increase in the 24-hour bactericidal rate. In Comparative Example 2, the hydrophobic treatment in step S3 was not used, which prevented the formation of a hydrophobic layer on the surface of the bactericide. This led to the dissolution and volatilization of the quaternary ammonium salt, an increase in VOC release, a decrease in the retention rate of dialcyldimethylammonium chloride, and a decrease in the 24-hour bactericidal rate. In addition, the bactericide prepared in Comparative Example 2 had no hydrophobic layer on its surface, which could not prevent the oxidative decomposition of the quaternary ammonium salt by H2S gas. As a result, the bactericide's bactericidal rate was significantly reduced after exposure to a 10 ppm hydrogen sulfide atmosphere for 24 hours.

[0039] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention. All equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A method for preparing a MOF fungicide, characterized by, include: Step S1: Synthesize zinc ion slow-release MOF material; Zinc salt, terephthalic acid, N,N-dimethylformamide, and acetic acid are added to a reaction vessel. The reaction vessel is then sealed and placed at 115-125°C for 10-12 hours to obtain a pre-prepared MOF material. The pre-prepared MOF material is then subjected to separation, washing, and first vacuum drying to obtain a zinc ion slow-release MOF material. Step S2: Loading quaternary ammonium salt; The zinc ion slow-release MOF material was impregnated in a diecryldimethylammonium chloride alcohol solution and subjected to vacuum impregnation treatment; after the vacuum impregnation treatment, it was successively centrifuged and then vacuum dried to obtain the zinc ion slow-release MOF material loaded with quaternary ammonium salt. Step S3: Hydrophobic treatment; The zinc ion slow-release MOF material loaded with quaternary ammonium salt is laid flat in the deposition chamber. After the air is replaced by an inert atmosphere, the vaporized environmentally friendly fluorinated silane monomer is deposited on the surface of the zinc ion slow-release MOF material loaded with quaternary ammonium salt using chemical vapor deposition to obtain a surface-hydrophobic modified MOF bactericide. The environmentally friendly fluorinated silane monomer includes perfluorooctyltriethoxysilane.

2. The method for preparing an MOF bactericide as described in claim 1, characterized in that, The molar ratio of the zinc salt, the terephthalic acid, the N,N-dimethylformamide, and the acetic acid is 3:2:40~50:8~10.

3. The method for preparing a MOF bactericide as described in claim 1, characterized in that, The washing process includes sequentially cleaning the prefabricated MOF material with N,N-dimethylformamide and ethanol; wherein the prefabricated MOF material is cleaned with N,N-dimethylformamide at least twice, and the solid-liquid ratio of the two during cleaning is 1:8~15; the prefabricated MOF material is cleaned with ethanol at least twice, and the solid-liquid ratio of the two during cleaning is 1:8~15.

4. The method for preparing an MOF bactericide as described in claim 1, characterized in that, The first vacuum drying process uses a drying temperature of 120~150℃ and a drying time of 6~8h.

5. The method for preparing a MOF bactericide as described in claim 1, characterized in that, The mass ratio of the zinc ion slow-release MOF material to the dialcyldimethylammonium chloride alcohol solution is 1:15~25; The alcohol reagent used in the dialcyldimethylammonium chloride alcohol solution includes ethanol; The mass concentration of dialcyldimethylammonium chloride in the dialcyldimethylammonium chloride alcohol solution is 8%~12%.

6. The method for preparing an MOF bactericide as described in claim 1, characterized in that, The vacuum impregnation treatment uses a vacuum degree of -0.08 to -0.1 MPa, an impregnation temperature of 55 to 65°C, and an impregnation time of 2 to 4 hours.

7. The method for preparing a MOF bactericide as described in claim 1, characterized in that, The second vacuum drying process uses a drying temperature of 75~85℃ and a drying time of 1~3h.

8. The method for preparing a MOF bactericide as described in claim 1, characterized in that, The inert atmosphere uses an inert gas flow rate of 30-60 mL / min; the inert gas includes nitrogen. The chemical vapor deposition method used employs a processing temperature of 100~130℃ and a processing time of 1~2h. The perfluorooctyltriethoxysilane is dissolved in an alcohol reagent before vaporization, and the mass concentration of the perfluorooctyltriethoxysilane in the alcohol reagent is 0.3%~0.5%.

9. A MOF bactericide, characterized in that, It is prepared using the preparation method of any one of claims 1 to 8 for a MOF bactericide.

10. The application of the MOF bactericide as described in claim 9 in the preparation of automotive interior materials, in-vehicle air purification materials, and air conditioning filters.

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