Preparation method of metal organic framework antibacterial non-woven material

Abstract

The invention discloses a preparation method of a metal organic framework antibacterial non-woven material. The method comprises the following steps: firstly, pretreating the surface of the non-woven fabric to enable the surface of the non-woven fabric to have more contact sites, sequentially dipping metal ions and an organic ligand solution containing an antibacterial substance, and fixing the antibacterial substance on the fiber surface of the textile along with synthesis of ZIF-8 through an in-situ growth method, so as to obtain the antibacterial non-woven fabric. Therefore, the textile with good antibacterial performance is prepared. The antibacterial substance is encapsulated in pores of the ZIF-8, the forbidden bandwidth of the ZIF-8 is improved, electron transfer is promoted to generate ROS, the antibacterial substance and metal ions play a synergistic antibacterial role, the antibacterial property is excellent, and meanwhile, the method is simple, convenient, wide in applicability and huge in industrialization potential.

Description

Technical Field

[0001] The invention belongs to the field of functional nonwoven material preparation, and relates to a specific method for modifying the antibacterial function of a nonwoven material. Background Art

[0002] Antimicrobial agents are mainly divided into two types: inorganic antimicrobial agents and organic antimicrobial agents. Organic antimicrobial agents have a fast sterilization speed and long-lasting effect; however, some organic antimicrobial agents are highly toxic, can produce microbial resistance, have poor heat resistance, and are easily precipitated in the environment. Inorganic antimicrobial agents have the advantages of safety, heat resistance, durability, and sustainability. However, their disadvantages are that they are expensive, and some antimicrobial agents have heavy metal toxicity problems. ZIF-8 crystals, as a type of nanoparticle, can transfer Zn 2+ It is slowly released into the environment, has good antibacterial activity and good biocompatibility, and its cytotoxicity is almost negligible. It can effectively kill bacteria and reduce bacterial growth. Its porosity and high specific surface area can be used to prepare efficient drug carriers, and thus can be used in drug controlled release, photothermal therapy, photodynamic therapy, etc., with great application prospects.

[0003] At present, the research mainly focuses on the antibacterial modification of MOF or the method of loading MOF on the substrate material. The modified ZIF-8 metal organic framework cannot be directly loaded on the substrate material, and is often combined with the material by impregnation or adhesive, which cannot give full play to the antibacterial properties of MOF materials. Publication No. CN118105520A modifies ZIF-8 by loading antibacterial substances into ZIF-8 nanoparticles to enhance the antibacterial properties of ZIF-8, but lacks practical application carriers, making it difficult to give full play to its antibacterial properties, and the nanoparticles are difficult to recycle and reuse; Publication No. CN117867861A uses alkalization or polydopamine for pretreatment, so that ZIF-8 is attached to the non-woven fabric in an in-situ growth manner. Although the method is rapid and simple, the ZIF-8 band gap is wide, the antibacterial properties are poor in the dark state, and the antibacterial effect is not ideal. Publication No. CN117888367A prepared ZIF-8 particles loaded with imidazole drugs, which were further cross-linked and solidified onto a substrate. However, the process is cumbersome and complex, which affects the material's air permeability, feel and other properties.

[0004] At present, the antibacterial materials loaded with ZIF-8 on nonwoven fabrics are still difficult to apply in practice. The main reasons are: (1) The low loading amount makes ZIF-8 unable to function. (2) ZIF-8 is greatly limited in photocatalytic antibacterial applications due to its wide bandgap and its reaction only to ultraviolet light. The dependence on light still largely limits the antibacterial application of ZIF-8. (3) ZIF-8 nanoparticles are easy to fall off during actual use, and the loading stability is poor. How to avoid these problems is still the key to the research and development of multifunctional and high value-added nonwoven materials. Summary of the invention

[0005] The present invention successfully prepares a MOF-based antibacterial nonwoven material, solving the technical problems of the existing modified MOF-based antibacterial nonwoven material, such as the complicated preparation process and poor antibacterial performance. The present invention uses a one-step in-situ growth method to prepare an antibacterial nonwoven material while combining ZIF-8 with fibers. The material encapsulates the antibacterial agent in the pores of ZIF-8, improves the bandgap width of ZIF-8, promotes electron transfer to generate ROS, and has excellent antibacterial performance. At the same time, the method is simple and convenient, has wide applicability, and has great industrialization potential. The specific preparation method comprises the following steps:

[0006] 1. Ultrasonic cleaning of the nonwoven material in a solution and vacuum drying to remove excess impurities;

[0007] 2. Prepare a strong alkaline solution of a certain concentration and put the washed and dried nonwoven fabric into it to modify the fiber;

[0008] 3. Place the modified nonwoven fabric into the prepared zinc ion aqueous solution and perform ultrasonic treatment to uniformly and quickly load the zinc ions on the fiber surface;

[0009] 4. The mixed solution containing the antibacterial agent and the organic ligand is mixed evenly, and an appropriate amount of alkaline solution is added to enhance the deprotonation ability of imidazole, and the nonwoven material in step 3 is immersed in the mixed organic ligand solution to perform in-situ growth on the fiber surface;

[0010] 5. Wash and dry the sample to obtain the modified nonwoven material.

[0011] Wherein, the nonwoven material in step 1 includes one of polypropylene meltblown cloth and polyester needle-punched cloth.

[0012] Wherein, the ultrasonic power in step 1 is 300-2000W, the time is 5-20min, and the temperature is 15-35°C; the cleaning solvent can be one of methanol, ethanol, acetone or deionized water.

[0013] Wherein, the strong alkaline solution in step 2 is one or more of sodium hydroxide or potassium hydroxide, the concentration is 0.1-1 mol / L, the ultrasonic power is 300-2000 W, the time is 5-40 min, and the temperature is 15-35° C.

[0014] Wherein, the solvent containing zinc ions in step 3 may be methanol or deionized water, the molar ratio of zinc nitrate hexahydrate to the solvent is 1:200-1:2400, the ultrasonic power is 300-2000W, the time is 5-40min, and the temperature is 15-35°C.

[0015] Wherein, the solvent in step 4 may be methanol or deionized water, the molar ratio of dimethylimidazole to the solvent is 1:30-1:75, the ultrasonic power is 300-2000W, the time is 5-40min, and the temperature is 15-35°C.

[0016] Wherein, the mass fraction of the antibacterial agent in step 4 is controlled within a range of 0.05%-20% of the mass of zinc nitrate hexahydrate.

[0017] The alkaline solution for increasing the protonation concentration in step 4 may be one of sodium hydroxide or potassium hydroxide, with a concentration of 0.2 mol / L and an amount of 0.5%-5% of the mass fraction of the solvent.

[0018] Among them, the antibacterial agent in the mixed solution in step 4 can be a photosensitizer or inorganic nanoparticles, the photosensitizer is any one of curcumin and riboflavin sodium phosphate; the inorganic nanoparticles are any one of nano-ZnO, nano-SiO2, and nano-CuO, and the particle size of the inorganic nanoparticles is between 1-200nm.

[0019] Beneficial effects of the present invention:

[0020] Compared with other MOF-based fabric inventions, the present invention adopts a one-step in-situ growth method, adding the antibacterial agent to the ligand solution and fixing it to the fabric surface along with the in-situ growth of MOF. The operation is simple and convenient, the time consumption is short, and the influence of external environmental factors is small. It is suitable for scaled-up experiments and industrial production.

[0021] The present invention introduces an alkaline solution to modify the nonwoven material before in-situ growth, thereby improving the hydrophilicity to a certain extent and increasing the Zn + Contact point with the nonwoven substrate.

[0022] In the process of in-situ growth on the non-woven substrate, the present invention introduces an appropriate amount of alkaline solution and an ultrasonic environment. The alkaline solution in the ligand can increase the protonation degree and accelerate the reaction of zinc ions with organic ligands. The ultrasonic environment promotes the formation of crystals, which is conducive to the uniform loading of antibacterial substances and shortens the reaction time required for the growth of ZIF-8. Compared with other in-situ growth methods, the material preparation time is shortened from 3-5h to 1h, and the MOF loading rate is higher and more uniform, reaching up to 15% of the substrate mass.

[0023] The present invention adds antibacterial ingredients such as inorganic nanoparticles or photosensitizers to enhance the antibacterial effect, cause membrane damage and oxidative stress to bacterial cells, have good bactericidal ability under sunlight, and improve the ZIF-8 band gap width. It can also promote electron transfer to generate ROS under dark conditions, and play a synergistic bactericidal role with the released metal ions. The antibacterial rate against Escherichia coli and Staphylococcus aureus reaches 99%, and compared with pure ZIF-8 samples, it has better antibacterial performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the scanning electron microscopy (SEM) image of polypropylene nonwoven fabric loaded with ZnO@ZIF-8;

[0025] Figure 2 Transmission electron microscopy (TEM) image of ZnO@ZIF-8 nanoparticles;

[0026] Figure 3 Schematic diagram of the antibacterial performance test of blank control group, PP, and PP@ZnO@ZIF-8 against Staphylococcus aureus from left to right;

[0027] Figure 4 Schematic diagram of the antibacterial performance test of blank control group, PP, and PP@ZnO@ZIF-8 against Escherichia coli from left to right. DETAILED DESCRIPTION

[0028] The following is a further detailed description of a method for preparing a metal organic framework antibacterial nonwoven material provided by the present invention in conjunction with specific embodiments. It should be understood that the specific examples are only used to explain and introduce the present invention and cannot limit the scope of application of the present invention. Any modifications and changes made to the present invention fall within the scope of protection of the present invention without departing from the purpose and scope of the present invention.

[0029] Embodiment 1:

[0030] Step 1: Take a polypropylene meltblown fabric sample, cut the polypropylene nonwoven fabric into a square of 10cm×10cm, then put the cut polypropylene nonwoven fabric into a methanol solution, and then ultrasonically clean it at an ultrasonic power of 1000w for 10 minutes. Finally, wash the sample three times with distilled water and dry it in a conventional oven at 70℃ for 6 hours to remove excess impurities.

[0031] Step 2: Place the dried sample in a 0.2 mol / L NaOH solution, with an ultrasonic power of 1500w and an ultrasonic time of 8min. After taking out the sample, wash it two to three times with deionized water for later use.

[0032] Step 3: Accurately weigh 5.948 g of zinc nitrate hexahydrate and put it into 100 mL of aqueous solution, stirring until dissolved; put the sample washed in step 2 into the zinc ion solution, and then transfer it to an ultrasonic constant temperature machine, with an ultrasonic power of 1500 W, a time of 15 min, and a temperature of 15-25 ° C to make Zn + Evenly load onto the polypropylene fiber surface.

[0033] Step 4: Accurately weigh 1g ZnO and 13.2g dimethylimidazole and put them into 226mL methanol solution and stir until dissolved; + The resulting polypropylene meltblown cloth was placed in a dimethylimidazole ligand solution, and 2 ml of 0.2 mol / L NaOH solution was added, and in-situ growth was carried out under an ultrasonic environment with an ultrasonic power of 1500 W, a time of 15 min, and a temperature of 15-35 °C.

[0034] Step 5: The polypropylene meltblown cloth after the reaction is completed is washed with ethanol and deionized water for three times respectively to remove excess monomers, and then dried in a conventional oven at 70°C for 6 hours.

[0035] Embodiment 2:

[0036] Step 1: Take a polypropylene meltblown cloth sample, cut it into a 10cm×10cm square, and then put the cut polypropylene meltblown cloth into a methanol solution, and then perform ultrasonic cleaning at an ultrasonic power of 1200w for 12 minutes. Finally, wash the sample three times with distilled water and dry it in a conventional oven at 60℃ for 8 hours to remove excess impurities.

[0037] Step 2: Place the dried sample in a 0.3 mol / L NaOH solution, with an ultrasonic power of 1200w and an ultrasonic time of 10min. Take out the sample and wash it two to three times with deionized water for later use.

[0038] Step 3: Accurately weigh 1.4665 g of zinc nitrate hexahydrate and put it into 100 mL of deionized water solution, stirring until dissolved; put the sample washed in step 2 into the zinc ion solution, and then transfer it to an ultrasonic thermostat, with an ultrasonic power of 1500 W, a time of 15 min, and a temperature of 15-25 ° C to make Zn + Evenly load onto the polypropylene fiber surface.

[0039] Step 4: Accurately weigh 1.2 g of riboflavin sodium phosphate and 16.225 g of dimethylimidazole into 100 mL of deionized water solution and stir until dissolved; + The resulting polypropylene meltblown cloth was placed in a dimethylimidazole ligand solution, and 3 ml of a 0.2 mol / L NaOH solution was added, and in-situ growth was performed under an ultrasonic environment with an ultrasonic power of 1500 W, a time of 15 min, and a temperature of 15-35 °C.

[0040] Step 5: The polypropylene meltblown cloth after the reaction is completed is washed with deionized water for 3 times to remove excess monomers, and then dried in a conventional oven at 60°C for 8 hours.

[0041] Embodiment 3:

[0042] Step 1: Take a polyester needle-punched fabric sample, cut the polyester needle-punched fabric into a square of 10cm×10cm, then put the cut polyester needle-punched fabric into an ethanol solution, and then pre-treat it at an ultrasonic power of 1500w for 20 minutes. Finally, wash the sample three times with distilled water and dry it in a conventional oven at 70℃ for 7 hours to remove excess impurities.

[0043] Step 2: Place the dried sample in a 0.4 mol / L NaOH solution, with an ultrasonic power of 1500w and an ultrasonic time of 10min. Take out the sample and wash it two to three times with deionized water for later use.

[0044] Step 3: Accurately weigh 5.948 g of zinc nitrate hexahydrate and put it into 200 mL of deionized water solution, stirring until dissolved; put the sample washed in step 2 into the zinc ion solution, and then transfer it to an ultrasonic constant temperature machine, with an ultrasonic power of 1500 W, a time of 10 min, and a temperature of 15-25 ° C to make Zn + Evenly load onto the polyester fiber surface.

[0045] Step 4: Accurately weigh 1g of curcumin and 13.2g of dimethylimidazole and put them into 226ml of methanol solution and stir until dissolved; +The resulting polypropylene meltblown cloth was placed in a dimethylimidazole ligand solution, and 3 ml of a 0.25 mol / L NaOH solution was added, and in-situ growth was performed under an ultrasonic environment with an ultrasonic power of 1500 W, a time of 10 min, and a temperature of 15-35 °C.

[0046] Step 5: The polyester needle-punched cloth after the reaction was completed was washed with ethanol and deionized water for three times respectively to remove excess monomers, and then dried in a conventional oven at 65° C. for 7 hours.

[0047] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and improvement made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a metal organic framework antibacterial nonwoven material, characterized in that: Here are the steps: 1) ultrasonically cleaning the nonwoven material in a solution and vacuum drying it to remove excess impurities; 2) preparing a strong alkaline solution of a certain concentration, placing the washed and dried nonwoven fabric into the solution to modify the fibers; 3) placing the modified nonwoven fabric into a prepared zinc ion aqueous solution and subjecting it to ultrasonic treatment, so that the zinc ions are evenly and quickly loaded on the fiber surface; 4) mixing the mixed solution containing the antibacterial agent and the organic ligand evenly under an ultrasonic environment, adding an appropriate amount of alkaline solution to protonate the nonwoven material in step 3 into the mixed organic ligand solution, and performing in situ growth on the fiber surface; 5) washing and drying the sample to obtain a modified nonwoven material.

2. The method for preparing a metal organic framework antibacterial nonwoven material according to claim 1, characterized in that: The nonwoven material in step 1) includes one of polypropylene meltblown cloth and polyester needle-punched cloth.

3. The method for preparing a metal organic framework antibacterial nonwoven material according to claim 1, characterized in that: In the step 2), the ultrasonic power is 300-2000W, the time is 5-20min, and the temperature is 15-35°C; the cleaning solvent can be one of methanol, ethanol, acetone or deionized water.

4. The method for preparing a metal organic framework antibacterial nonwoven material according to claim 1, characterized in that: In the step 2), the strong alkaline solution is one or more of sodium hydroxide or potassium hydroxide, the concentration is 0.1-1 mol / L, the ultrasonic power is 300-2000 W, the time is 5-20 min, and the temperature is 15-35° C.

5. The method for preparing a metal organic framework antibacterial nonwoven material according to claim 1, characterized in that: The solvent containing zinc ions in step 3) can be methanol or deionized water, the molar ratio of zinc nitrate hexahydrate to the solvent is 1:200-1:2400, the ultrasonic power is 300-2000W, the time is 5-40min, and the temperature is 15-35°C.

6. The method for preparing a metal organic framework antibacterial nonwoven material according to claim 1, characterized in that: In step 4), the solvent may be methanol or deionized water, the molar ratio of dimethylimidazole to the solvent is 1:30-1:75, the ultrasonic power is 300-2000W, the time is 5-40min, and the temperature is 15-35°C.

7. The method for preparing a metal organic framework antibacterial nonwoven material according to claim 1, characterized in that: In the step 4), the mass fraction of the antibacterial agent is controlled to be 0.05%-20% of the mass of the zinc nitrate hexahydrate.

8. The method for preparing a metal organic framework antibacterial nonwoven material according to claim 1, characterized in that: The alkaline solution for increasing the protonation concentration in step 4) can be one of sodium hydroxide or potassium hydroxide, with a concentration of 0.2 mol / L and an amount of 0.5%-5% of the mass fraction of the solvent.

9. The method for preparing a metal organic framework antibacterial nonwoven material according to claim 1, characterized in that: The antibacterial agent in the mixed solution in step 4) can be a photosensitizer or inorganic nanoparticles, the photosensitizer is any one of curcumin and riboflavin sodium phosphate; the inorganic nanoparticles are any one of nano ZnO, nano SiO2, and nano CuO, and the particle size of the inorganic nanoparticles is between 1-200nm.

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