Washable and long-acting antibacterial fabric constructed based on Cu / Zn-MOF in-situ growth strategy

Abstract

The invention provides a method based on an F-Cu / Zn MOF (Metal Organic Framework) in-situ growth strategy. The method is used for constructing a washable and long-acting antibacterial fabric. The F-Cu / Zn MOF nano structure doped with the fluorine-containing benzoic acid ligand grows on the surface of the fabric in situ, so that the fabric is endowed with excellent antibacterial performance and washable performance. Experimental results show that the fabric has a remarkable inhibition effect on common gram-positive bacteria and gram-negative bacteria, can still keep good antibacterial activity after being washed for multiple times, and has a wide application prospect in the fields of medical treatment and public health, textiles, garments and the like.

Description

Technical Field

[0001] This invention relates to the field of textile material modification and antibacterial technology, specifically to a study on the preparation of long-lasting washable antibacterial fabrics using an F-Cu / Zn MOF in-situ growth strategy. Background Technology

[0002] In daily life, fabrics are easily contaminated by bacteria, which can not only produce odors and damage fabric fibers, but also pose a threat to human health. Especially in specialized industries such as medical and health care and food processing, as well as in some public environments, there are strict requirements for the antibacterial properties of fabrics. Traditional antibacterial finishing methods, such as adding antibacterial agents, have problems such as short-lasting antibacterial effects and poor washability. With people's increasing demands for health and quality of life, developing a washable and long-lasting antibacterial fabric is of great significance.

[0003] Metal-organic frameworks (MOFs) have been extensively studied in fields such as gas adsorption, catalysis, antibacterial properties, and sensing due to their unique structure and properties. MOFs possess large specific surface areas, abundant active sites, and tunable structures, making them highly promising in the antibacterial field. Combining MOFs with fabrics holds promise for creating novel fabrics with excellent antibacterial properties. However, ensuring the firm adhesion of MOFs to the fabric surface and maintaining their antibacterial activity after multiple washes remains a challenge. This invention addresses this problem by employing an in-situ growth strategy and hydrogen bonding between fluorine groups in the ligands and the fabric, enabling F-Cu / Zn MOFs to form a tightly bound nanostructure on the fabric surface. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to design an F-Cu / Zn MOF nanozyme with excellent antibacterial properties. By introducing two metals, Cu and Zn, into the MOF structure, the prepared F-Cu / Zn MOF exhibits superior antibacterial performance compared to single F-Cu MOF and F-Zn MOF, showing significant inhibitory effects on both Gram-positive and Gram-negative bacteria, with an inhibition rate of up to 99%.

[0005] This invention is achieved through the following technical solution: 2,4-difluorobenzoic acid is introduced into the ligand, where the fluorine groups can form hydrogen bonds with the hydroxyl groups on the fabric surface, enhancing the adsorption force of F-Cu / Zn MOF on the fabric and making it less prone to detachment after multiple washes, thus maintaining good antibacterial properties. Furthermore, the fabric preparation process is simple, has minimal impact on the original properties of the fabric, and has good application prospects.

[0006] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0007] Bimetallic synergistic antibacterial: By using bimetallic F-Cu / Zn MOF, the synergistic release of Cu and Zn significantly enhances the broad-spectrum antibacterial performance against Gram-positive and Gram-negative bacteria. Compared with single-metal MOF nanozymes, it can more effectively inhibit bacterial growth.

[0008] Excellent wash resistance: The fluorine groups in the ligand form hydrogen bonds with the hydroxyl groups of the fabric cellulose, which greatly enhances the binding force between MOF and the fabric. After multiple washes, the antibacterial properties are minimally lost.

[0009] In-situ growth strategy: The fabric surface hydroxyl groups are activated by pretreatment with diazotization reaction, which promotes the nucleation and growth of MOF crystals on the fiber surface, thereby achieving chemical anchoring of MOF and fabric. Attached Figure Description

[0010] Figure 1 The results of antibacterial performance tests under F-Cu / Zn MOF, F-Cu MOF, and F-Zn MOF treatment conditions include the antibacterial effects against Gram-positive and Gram-negative bacteria. (A) LB agar plate images and survival rates of Staphylococcus aureus and Escherichia coli after co-culturing F-Cu MOF, F-Zn MOF, and F-Cu / Zn MOF. (B) Staining fluorescence images of Staphylococcus aureus and Escherichia coli after treatment with F-Cu / Zn MOF: live bacteria (green) and dead bacteria (red) and fluorescence intensity.

[0011] Figure 2 SEM images of untreated fabric and F-Cu / Zn MOF-modified fabric are shown to compare surface morphology differences. (A) SEM image of F-Cu / Zn MOF. (B) SEM images of untreated (left) and F-Cu / Zn MOF-modified (right) fabrics.

[0012] Figure 3 X-ray diffraction spectra of F-Cu / Zn-MOF grafted fabric, blank fabric, and F-Cu / Zn MOF nanozyme are shown to characterize the formation of MOF structure on the fabric surface.

[0013] Figure 4 The antibacterial rate changes of F-Cu / Zn MOF and Cu / Zn MOF grafted fabrics after different washing cycles are shown to demonstrate their wash resistance. (A) LB agar images of F-Cu / Zn MOF and Cu / Zn MOF after 1, 5, 10, 15, and 20 washing cycles and (B) antibacterial rate. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0016] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0017] Example 1

[0018] Preparation of F-Cu / Zn MOF (1) Copper acetylacetonate, zinc nitrate, terephthalic acid, fluorobenzoic acid and polyvinylpyrrolidone were dissolved in a mixed solution of DMF and ethanol and magnetically stirred at room temperature until completely dissolved.

[0019] (2) Transfer the mixed solution to a sterilizer and seal it in an oven, and heat it at 100-300 ℃ for 6-8 hours.

[0020] (3) After cooling to room temperature, the raw material is collected by centrifugation and then washed with DMF and ethanol. Finally, it is dried to obtain F-Cu / ZnMOF.

[0021] The prepared F-CuZn MOF nanomaterial is characterized in that the molar ratio of acetylacetone, zinc nitrate, pyromellitic acid, and difluorobenzoic acid in the nanomaterial is 0.03 : 0.1-0.5 : 0.01-0.05 : 0.01-0.05.

[0022] Example 2

[0023] Preparation of F-Cu MOF (F-Zn MOF): Acetylacetone, copper nitrate (zinc nitrate), terephthalic acid, fluorobenzoic acid and polyvinylpyrrolidone K-30 were dissolved in a mixed solution of DMF and ethanol and magnetically stirred at room temperature until completely dissolved.

[0024] Then, transfer the mixed solution to a sterilizer and seal it in an oven, where it is heated at 100-300 °C for 6-8 h.

[0025] After cooling to room temperature, the raw material was collected by centrifugation, washed with DMF and ethanol, and finally dried to obtain F-Cu MOF (F-Zn MOF).

[0026] Example 3

[0027] Staphylococcus aureus and Escherichia coli were selected as the main models for Gram-positive (G+) and Gram-negative (G-) bacteria, respectively. Activated bacteria were cultured in approximately 50 mL of Luria-Bertani (LB) liquid medium. The culture was incubated at 37 °C and 150 r / min for 24 h to obtain bacterial suspensions, which were then evaluated for their antibacterial properties using the plate count method.

[0028] The specific steps are as follows: (1) Dilute the prepared bacterial suspension to 1×10 -5 CFU / mL, 50 μL of bacterial suspension was mixed with F-Cu / Zn MOF solution.

[0029] (2) Shake well in a constant temperature incubator (37 ℃, 150 r / min) for 2 h. Then, coat the mixed sample on LB solid medium.

[0030] (3) Finally, the culture was placed in an incubator for 24 h and the number of colonies was counted. At the same time, F-Cu MOF and F-ZnMOF were used as control groups, and the number of colonies on the plates was observed and photographed.

[0031] 80 μL culture medium + 80 μL bacterial suspension (Group 1) 80 μL F-Cu MOF solution (2 mg / mL) + 80 μL bacterial culture (Group 2) 80 μL F-Zn MOF solution (2 mg / mL) + 80 μL bacterial culture (Group 3) 80 μL F-Cu / Zn MOF solution (2 mg / mL) + 80 μL bacterial culture (Group 4)

[0032] Sterilization rate = (number of colonies in control group - number of colonies in experimental group) / number of colonies in control group × 100%.

[0033] Example 4

[0034] NaNO2 was dissolved in 60 mL of 1 mol / L HCl solution, and then 3-aminobenzoic acid was added. The solution was then shaken in an ice-water bath to form a 3-aminobenzoic acid diazonium salt HCl solution. Cotton fabric was cut into suitable squares and soaked in the 3-aminobenzoic acid diazonium salt HCl solution. Vitamin C was then added to the above reactive solution, and the mixture was incubated at room temperature for 12 h. The textiles were thoroughly washed with water until all ungrafted chemicals were removed, and then dried at room temperature to obtain the pretreated fabric. This pretreated fabric was then soaked in an F-Cu / Zn MOF reaction solution and incubated to obtain the F-Cu / Zn MOF fabric.

[0035] Referring to the F-Cu / Zn MOF synthesis method, fluorobenzoic acid was replaced with an equimolar mass of terephthalic acid in the synthesis steps to obtain Cu / Zn MOF with a single ligand.

[0036] The pretreated fabric was immersed in the above Cu / Zn MOF solution and incubated to obtain Cu / Zn MOF fabric without fluorobenzoic acid doping.

[0037] Example 5

[0038] The antibacterial activity of fabrics was determined by the shake flask method according to GB / T 20944.3-2008.

[0039] In short, a 2×2 cm piece of fabric was placed in the bacterial suspension and co-cultured with shaking for a period of time. The mixed sample was then coated onto LB solid medium. Finally, it was incubated statically in an incubator for 24 h, and the number of colonies was observed and photographed.

[0040] Washability test shall be performed in accordance with GB / T 20944.3-2008.

[0041] Take 10g of antibacterial fabric, add 90g of accompanying fabric, and 6g of phosphate-free standard detergent. Add 3L of 40℃ water to the washing machine, wash for 2 minutes, spin dry for 30 seconds, and repeat the washing and spin-drying process once, for a total time of 5 minutes. This process is counted as one wash cycle. Repeat the above steps to reach the required number of wash cycles. Wash the F-Cu / Zn MOF antibacterial fabric and Cu / Zn MOF antibacterial fabric 1, 5, 10, 15, and 20 times, then dry them for antibacterial testing. Compare the diameter of the antibacterial zone or the antibacterial rate of the fabrics after different number of washes to analyze the wash resistance of the two fabrics.

[0042] The present invention will now be further described with reference to the accompanying drawings.

[0043] like Figure 1 As shown in Figure A, it was observed that the number of bacterial colonies of Staphylococcus aureus and Escherichia coli decreased after treatment with F-Cu MOF, F-Zn MOF and F-Cu / ZnMOF. However, compared with F-Cu MOF and F-Zn MOF alone, the survival rate of bacteria co-cultured with F-Cu / Zn MOF was significantly reduced, and the inhibition rate reached 99%.

[0044] like Figure 1 As shown in B, to further verify the antibacterial properties of F-Cu / Zn MOF, the bacterial solution treated with F-Cu / Zn MOF was stained with fluorescent staining. It can be seen that the control group had more live bacteria and the material group had more dead bacteria, which also shows that F-Cu / Zn MOF has excellent antibacterial properties.

[0045] like Figure 2 As shown in Figure A, the F-Cu / Zn MOF synthesized in this invention exhibits a microspherical morphology under a scanning electron microscope. These microspheres are formed by numerous nanoscale primary particles as building blocks, which aggregate through a self-assembly process, resulting in significant surface roughness and multi-level structural features. The overall size distribution of the microspheres is relatively uniform, approximately 146.2 nm, with a near-spherical shape, and a loose three-dimensional stacking between the spheres. To confirm the successful loading of the material onto the fabric surface, both the blank fabric and the loaded composite material were characterized using scanning electron microscopy.

[0046] like Figure 2 As shown in left B, comparative analysis reveals that the fibers of the blank fabric exhibit a smooth and clean surface morphology. In stark contrast, after loading with F-Cu / Zn MOF, the surface of the fabric fibers is covered by a rough coating, and the original smooth surface is no longer visible (e.g., ...). Figure 2 As shown in Figure B (right side), this confirms that F-Cu / Zn MOF has been successfully grown in situ and firmly loaded on the surface of fabric fibers.

[0047] To verify the successful loading of F-Cu / Zn MOF onto cotton fiber fabric (CF), X-ray diffraction analysis was performed on blank CF, F-Cu / Zn MOF powder, and the loaded F-Cu / Zn CF composite fabric.

[0048] The results are as follows Figure 3 As shown, the spectrum of blank CF exhibits only a broad, diffuse peak in the approximately 20–30° range, a typical characteristic of its amorphous structure. F-Cu / Zn MOF powder, on the other hand, displays a series of sharp and high-intensity diffraction peaks, indicating its good crystallinity. In the spectrum of the F-Cu / Zn CF composite, a broad, diffuse background originating simultaneously from CF and all characteristic diffraction peaks of F-Cu / Zn MOF can be clearly observed. The coexistence of characteristic signals from both phases, and the absence of significant shift or broadening of the MOF characteristic peaks, strongly demonstrates that F-Cu / Zn MOF has been successfully loaded onto the CF fabric surface and maintains its complete crystal structure.

[0049] To compare the antibacterial durability of the materials, wash resistance tests were conducted on Cu / Zn MOF samples doped with and undoped with fluorobenzoic acid.

[0050] The results are as follows Figure 4As shown, the agar plate assay results indicated that the undoped sample (Cu / Zn MOF) began to show obvious bacterial colonies after 5 washing cycles; while the fluorine-doped sample (F-Cu / Zn MOF) only showed a small number of colonies after 20 washing cycles, and its antibacterial rate was still as high as 98%. This result proves that the introduction of 2,4-difluorobenzoic acid significantly enhances the bonding strength between MOF and the fabric substrate, thereby effectively slowing down the decline in antibacterial performance caused by material detachment.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An application of a washable and long-lasting antibacterial fabric containing F-Cu / Zn MOF constructed based on an in-situ growth strategy.

2. The F-Cu / Zn MOF nanomaterial according to claim 1, characterized in that... Preparation of F-Cu / Zn MOF: (1) Dissolve copper acetylacetonate, zinc nitrate, pyromellitic acid, 2,4-difluorobenzoic acid and 5 μmol polyvinylpyrrolidone K-30 in a DMF-ethanol mixture with a volume ratio of 8:5, and stir magnetically at room temperature until completely dissolved. (2) Transfer the mixed solution from step (1) to a 50 mL Teflon-lined autoclave and seal it. Place it in an oven and heat at 100 °C for 8 h. (3) After cooling the solution prepared in step (2) to room temperature, collect the raw material, centrifuge at 10,000 rpm for 10 min, and then wash with DMF and ethanol respectively. (4) The material obtained in step (3) is dried overnight at 60 °C to obtain F-Cu / Zn MOF.

3. The F-Cu / Zn MOF nanomaterial according to claim 2, characterized in that, The molar ratio of acetylacetone, zinc nitrate, pyromellitic acid, and difluorobenzoic acid in the nanomaterial is 0.1-0.3 : 0.1-0.5 : 0.01-0.05 : 0.01-0.

05.

4. The application of the F-Cu / Zn MOF nanozyme bactericide according to claim 3, characterized in that... The nanoenzyme bactericide is used to inhibit Staphylococcus aureus and Escherichia coli. The process involves the following steps: mixing 80 μL of bacterial suspension with the F-Cu / Zn MOF system. The mixture is then shaken in a constant temperature incubator for 2 h. The mixed sample is then coated onto LB solid medium and finally incubated statically in an incubator for 24 h, during which the number of colonies is counted. The control groups are F-Cu MOF and F-Zn MOF.

5. Application of F-Cu / Zn MOF prepared according to claim 4: Dissolve NaNO2 in 60 mL of 1 mol / L HCl solution, then add 3-aminobenzoic acid. The solution is then shaken in an ice-water bath at 0 °C for 1 h to form a 3-aminobenzoic acid diazonium salt HCl solution. Cotton fabric is cut into 2×2 cm squares and soaked in the 3-aminobenzoic acid diazonium salt HCl solution. Vitamin C is then added to the above reactive solution and incubated at room temperature for 12 h. The textile is thoroughly washed with water until all ungrafted chemicals are removed, and then dried at room temperature to obtain the pretreated fabric. This pretreated fabric is then soaked in the F-Cu / Zn MOF reaction solution and incubated at 60 °C for 2 h to obtain the F-Cu / Zn MOF fabric.

6. The application of the F-Cu / Zn MOF antibacterial fabric according to claim 5, characterized in that... The fabric described above is used to inhibit Staphylococcus aureus and Escherichia coli, and has a significant inhibitory effect on both, with an inhibition rate of up to 99%.

7. According to claims 2 and 5, fluorinated benzoic acid is introduced into the ligand, wherein the fluorine groups can form hydrogen bonds with the hydroxyl groups on the fabric surface, enhancing the adsorption force of F-Cu / Zn MOF on the fabric, making it less prone to detachment after multiple washes and maintaining good antibacterial properties. Furthermore, the fabric preparation process is simple, has minimal impact on the original properties of the fabric, and has good application prospects.

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