Manganese-loaded green-illite antibacterial material, and preparation method and application thereof

Abstract

This invention relates to the field of antibacterial materials technology, and particularly to a manganese-loaded chlorodrasite antibacterial material, its preparation method, and its application. The preparation method includes the following steps: S1, ultrasonically dispersing chlorodrasite particles with a particle size no greater than 0.075 mm in deionized water to obtain a chlorodrasite-containing solution; S2, mixing and stirring a neutral solution containing divalent and tetravalent manganese ions with the chlorodrasite-containing solution, followed by aging; S3, washing and drying the aged solution to obtain the manganese-loaded chlorodrasite antibacterial material. This invention constructs Mn²⁺ by simultaneously loading divalent and tetravalent manganese onto chlorodrasite. + -Mn 4+ -Fe² + -Fe³ + A multi-valence coexistence system. In this system, manganese in different valence states and iron in the chlorite structure undergo dynamic electron transfer and valence state cycling regulation, enabling continuous and efficient triggering of Fenton-like reactions without external strong oxidants. This generates reactive oxygen free radicals, which destroy bacterial cell structures and achieve a broad-spectrum antibacterial effect.

Description

Technical Field

[0001] This invention relates to the field of antibacterial materials technology, and in particular to a manganese-loaded chlorodemistite antibacterial material, its preparation method, and its application. Background Technology

[0002] Microbial contamination control is crucial for public health. Developing inorganic antimicrobial materials that are antibiotic-free, do not easily induce drug resistance, and are environmentally friendly is a current research focus. Among these strategies, utilizing the redox activity of variable-valence metal elements (such as iron, manganese, and copper) to catalyze the generation of reactive oxygen species or directly disrupt microbial cell structures is an effective approach to achieving highly efficient sterilization.

[0003] Existing technologies often involve loading antibacterial active components onto the surface of materials with high specific surface area to improve the dispersion and antibacterial properties of the antibacterial active components. For example: Chinese Patent Application No. CN202411438093.6 discloses an antibacterial material of manganese oxide supported on black talc and its preparation method. This invention uses potassium permanganate, urea, and hexadecyltrimethylammonium bromide as raw materials, employing a hydrothermal in-situ synthesis method to load manganese oxide onto the surface of black talc to obtain the antibacterial material. However, this material mainly utilizes the Fenton-like reaction of manganese for sterilization; black talc only plays a role in promoting the conversion of Mn3O4 to MnOOH, improving the stability of manganese oxide, and reducing aggregation. Compared with the Fenton-like reaction sterilization of iron, manganese has weaker antibacterial properties and lacks an effective reduction and regeneration cycle (i.e., high-valence manganese is reduced to highly active low-valence manganese), resulting in limited and short-lasting antibacterial efficacy during use.

[0004] Chinese patent application CN103918711A discloses the preparation of an halloysite-loaded silver nanoparticle antibacterial material. Air and moisture are purged from the halloysite conduit, allowing for sufficient contact between the halloysite and silver nitrate, particularly enabling the silver nitrate to enter the conduit. The large inner surface of the halloysite is utilized to load more silver nanoparticles, enhancing the antibacterial properties. However, while the silver nanoparticles exhibit excellent antibacterial properties, they significantly increase the material's cost.

[0005] Chinese patent application CN202510187382.1 discloses an antibacterial material, its preparation method, and its application. Using boehmite as a raw material for an Al2O3 carrier and Ag and / or Cu as the antibacterial active components, the prepared antibacterial material achieves high antibacterial activity at a relatively low loading. Although the Ag content is reduced, Ag is still present; furthermore, the carrier only plays a role in anchoring and dispersing the active sites and has no antibacterial properties itself.

[0006] In summary, loading antibacterial active components onto the surface of materials with high specific surface area to improve the dispersion and antibacterial properties of the antibacterial active components is a common and effective method. However, silver ions, which have good antibacterial properties, are expensive, while single-valence metal ions such as copper and iron lack effective reduction and regeneration cycle pathways, resulting in limited and unsustainable antibacterial effects. Summary of the Invention

[0007] The purpose of this invention is to address the aforementioned shortcomings of existing technologies by providing a manganese-supported green silica antibacterial material, its preparation method, and its applications. Utilizing Mn... 2+ and Mn 4+ It is linked with the iron in green silica through a clever redox cycle, together maintaining an antibacterial microenvironment that can continuously generate highly reactive oxygen species. The material is green and environmentally friendly, low in cost, and has a highly efficient and long-lasting antibacterial effect.

[0008] The first objective of this invention is to provide a method for preparing a manganese-supported green silica antibacterial material, comprising the following steps: S1. Disperse chlorite particles with a diameter not greater than 0.075 mm in deionized water by ultrasonication to obtain a solution containing chlorite. S2. Mix and stir a neutral solution containing divalent and tetravalent manganese ions with a solution containing chlorite, and then age the mixture. S3. After washing and drying the aged solution, manganese-loaded green silica antibacterial material is obtained.

[0009] Further, MnO2 is dissolved in acid, and divalent manganese salt is added, followed by adjusting the pH value to neutral with alkali to obtain the neutral solution.

[0010] Furthermore, the molar ratio of divalent manganese ions to tetravalent manganese ions is 1:1 to 1:3.

[0011] Furthermore, the molar ratio of chlorodermite to the sum of the moles of divalent and tetravalent manganese ions is 0.25 ~ 1 g / mol.

[0012] Furthermore, in S2, stir for 20-26 hours.

[0013] Further, age for 10-16 hours.

[0014] Further, in step S3, after drying, the material is milled and screened through a 200-mesh sieve. The powder collected after sieving is the manganese-loaded green silica material.

[0015] A second objective of this invention is to provide a manganese-loaded green precipitate antibacterial material prepared using the above-described preparation method.

[0016] The third objective of this invention is to provide an application of the manganese-loaded chlorite antibacterial material as described above, which has antibacterial effects against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.

[0017] Green silicate, a natural iron-rich layered silicate clay mineral, possesses a certain Fenton-like reaction potential due to the iron element in its crystal structure. However, the Fe in natural green silicate lacks an effective reduction and regeneration cycle (i.e., from Fe...). 3+ Reduced to highly reactive Fe 2+ This results in limited and short-lasting antibacterial efficacy when used alone. Manganese has multiple valence states (Mn²). + Mn³ + Mn 4+ Mn²⁺ (e.g., manganese dioxide, manganese dioxide, etc.) has strong redox capabilities, and different valence states can be converted under mild conditions, promoting the decomposition of H₂O₂ or directly generating reactive oxygen species. This invention constructs Mn²⁺ by simultaneously loading divalent manganese (using manganese sulfate, etc., as precursors) and tetravalent manganese (using manganese dioxide, etc., as precursors) onto chlorite. + -Mn 4+ -Fe² + -Fe³ + A multi-valence coexistence system. In this system, manganese in different valence states and iron in the chlorite structure undergo dynamic electron transfer and valence state cycling regulation, enabling continuous and efficient triggering of Fenton-like reactions without external strong oxidants. This generates reactive oxygen free radicals, which destroy bacterial cell structures and achieve a broad-spectrum antibacterial effect.

[0018] The specific technical principle is: Mn² + and Mn 4+ The introduction of [a specific substance] significantly affected the redox activity of iron, specifically by promoting the redox activity of ferrous iron (Fe²⁺). 2+ ) and trivalent iron (Fe 3+ The interconversion between Mn² + / Fe² + Inside the bacteria, a Fenton or Fenton-like reaction catalyzes the generation of reactive oxygen free radicals, which are then oxidized to Mn³. + / Mn² + and Fe³ + And Mn 4+ Fe²⁺ in oxidizable chlorite + Fe³ + It is reduced to Mn³ + / Mn² + ; Reduced Mn² + Fe³ can be reduced + For Fe² + It oxidizes itself to Mn³ + / Mn 4+ In the system, Mn² + / Mn 4+ with Fe² + / Fe³ + They form an oxidation-reduction cycle network, promoting the generation and regeneration of reactive oxygen species.

[0019] The layered structure of the selected inorganic carrier, chlorite, provides a high specific surface area and loading sites. Importantly, its iron content allows it to participate in valence cycling, and iron has the potential to participate in Fenton-like reactions to achieve a bactericidal effect. Mn was selected... 2+ and Mn 4+ As a valence state regulator, it can participate in sterilization and regulate the valence state of iron in chlorodiasite, enabling continuous and efficient triggering of Fenton-like reactions without external strong oxidants. This generates reactive oxygen free radicals, destroying bacterial cell structure and achieving a broad-spectrum antibacterial effect. In addition, chlorodiasite also has good ion exchange capacity, which helps to stably anchor manganese species.

[0020] The present invention also controls Mn 2+ Mn 4+ The optimal coupling ratio between the chlorite and the chlorite achieves a good antibacterial effect.

[0021] The materials prepared by this method are green and environmentally friendly, low in cost, and have a highly efficient and long-lasting antibacterial effect. Attached Figure Description

[0022] Figure 1 XRD patterns of Nau-1, Nau-2, and montmorillonite; Figure 2 Scanning electron microscope (SEM) images of the samples prepared in Example 1 and Comparative Examples 1-2, and energy dispersive spectroscopy (EDS) distribution maps of Mn and Fe elements in the corresponding regions. Figure 3 Comparison of XPS total spectra and key elemental spectra of Nau-1, Nau-2, and montmorillonite; Figure 4 A comparison of XPS iron element peak spectra of samples prepared in Example 1 and Comparative Examples 1-3; Figure 5 A comparison of XPS aluminum element peak spectra of samples prepared in Example 1 and Comparative Examples 1-3; Figure 6 A comparison of XPS manganese elemental peak spectra of the samples prepared in Example 1 and Comparative Examples 1-3; Figure 7 The antibacterial effects of the samples prepared for Examples 1-3 and Comparative Examples 1-2 against Escherichia coli (E), Staphylococcus aureus (S) and Pseudomonas aeruginosa (P); Figure 8 The antibacterial effect of the amount of sample prepared in Example 1 on Escherichia coli (E), Staphylococcus aureus (S) and Pseudomonas aeruginosa (P); Figure 9 The antibacterial effect of the amount of sample prepared in Example 1 on Escherichia coli (E), Staphylococcus aureus (S) and Pseudomonas aeruginosa (P); Figure 10 The antibacterial effect of the amount of sample prepared in Comparative Example 2 on Escherichia coli (E), Staphylococcus aureus (S) and Pseudomonas aeruginosa (P) was determined. Figure 11 The antibacterial effect of the amount of sample prepared in Comparative Example 3 on Escherichia coli (E), Staphylococcus aureus (S) and Pseudomonas aeruginosa (P) was determined. Figure 12 The antibacterial effects of the amount of sample prepared in Example 4 on Escherichia coli (E), Staphylococcus aureus (S) and Pseudomonas aeruginosa (P). Detailed Implementation

[0023] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0024] Example 1: This example shows the preparation of φ200-Nau-1-Mn(2:2).

[0025] Dissolve 4 g of crushed, ground, and sieved Nau-1 in 1 L of deionized water and sonicate at 100 W for 30 min.

[0026] 174 g of MnO2 was dissolved in concentrated sulfuric acid, and 302 g of MnSO4 was added. The pH was then adjusted to neutral with NaOH to obtain a neutral solution.

[0027] Then, at 40℃, the neutral solution and the solution containing chlorite were stirred thoroughly for 24 h, allowed to stand and age for 12 h, washed three times with deionized water, dried at 60-80℃, ground, and passed through a 200-mesh sieve to obtain φ200-Nau-1-Mn(1:1).

[0028] Example 2: In this example, φ200-Nau-1-Mn (1:3) was prepared.

[0029] Dissolve 4 g of crushed, ground, and sieved Nau-1 in 1 L of deionized water and sonicate at 100 W for 30 min. 261 g of MnO2 was dissolved in concentrated sulfuric acid, and 151 g of MnSO4 was added. The pH was then adjusted to neutral with NaOH to obtain a neutral solution.

[0030] Then, at 40℃, the neutral solution and the solution containing chlorite were stirred thoroughly for 24 h, allowed to stand and age for 12 h, washed three times with deionized water, dried at 60-80℃, ground, and passed through a 200-mesh sieve to obtain φ200-Nau-1-Mn(1:3).

[0031] Example 3: In this example, φ200-Nau-1-Mn(3:1) was prepared.

[0032] Dissolve 4 g of crushed, ground, and sieved Nau-1 in 1 L of deionized water and sonicate at 100 W for 30 min. Dissolve 87 g of MnO2 in concentrated sulfuric acid, add 453 g of MnSO4, and then adjust the pH to neutral with NaOH to obtain a neutral solution.

[0033] Then, at 40℃, the neutral solution and the solution containing chlorite were stirred thoroughly for 24 h, allowed to stand and age for 12 h, washed three times with deionized water, dried at 60-80℃, ground, and passed through a 200-mesh sieve to obtain φ200-Nau-1-Mn(3:1).

[0034] Example 4: This example shows the preparation of φ200-Nau-2-Mn(2:2).

[0035] By replacing Nau-1 with Nau-2 in Example 1, and keeping everything else the same as in Example 1, φ200-Nau-2-Mn(1:1) was prepared.

[0036] Comparative Example 1: φ200-Nau-1-Mn(4:0) was prepared in this comparative example.

[0037] Dissolve 4 g of crushed, ground, and sieved Nau-1 in 1 L of deionized water and sonicate at 100 W for 30 min. 604 g of MnSO4 was dissolved in water, and the pH was adjusted to neutral to obtain a neutral solution.

[0038] Then, at 40℃, the neutral solution was stirred with the solution containing chlorite for 24 h, allowed to stand and age for 12 h, washed three times with deionized water, dried at 60-80℃, ground, and passed through a 200-mesh sieve to obtain φ200-Nau-1-Mn(4:0); Comparative Example 2: φ200-Nau-1-Mn(0:4) was prepared in this comparative example.

[0039] Dissolve 4 g of crushed, ground, and sieved Nau-1 in 1 L of deionized water and sonicate at 100 W for 30 min. A neutral solution was obtained by dissolving 348 g of MnO2 in concentrated sulfuric acid and adjusting the pH to neutral with NaOH.

[0040] Then, at 40℃, the neutral solution was stirred with the solution containing chlorite for 24 h, allowed to stand and age for 12 h, washed three times with deionized water, dried at 60-80℃, ground, and passed through a 200-mesh sieve to obtain φ200-Nau-1-Mn(0:4); Comparative Example 3: φ200-MMT-Mn(2:2) was prepared in this comparative example.

[0041] In Example 1, chlorodiasite was replaced with montmorillonite, and everything else was the same as in Example 1, resulting in φ200-MMT-Mn(2:2); See appendix Figure 2 The images show scanning electron microscope (SEM) morphology images of the samples prepared in Example 1 and Comparative Examples 1-2, as well as the corresponding area scan distribution maps of Mn and Fe elements (EDS). from Figure 2 It can be seen that the free iron content increased in the sample prepared in Example 1, indicating that the presence of manganese in different valence states promoted the conversion of structural iron to free iron and provided sufficient catalytic active centers.

[0042] Meanwhile, the φ200-Nau-1-Mn(2:2) material, through mixed valence state regulation, constructs a rough and porous surface morphology that is conducive to the reaction, effectively promoting the retention or enrichment of iron active sites in the matrix and providing sufficient catalytic active centers.

[0043] Figure 1 XRD patterns of Nau-1, Nau-2, and montmorillonite. See appendix. Figure 3 The image shows a comparison of the XPS total spectrum and the partial spectra of important elements in Nau-1, Nau-2, and montmorillonite (from left to right: total element spectrum, Nau-1, and Nau-2 iron element spectrum). Figure 1 and 3 It can be seen that the three minerals, MMT, NAu-1, and NAu-2, have significant differences in elemental composition. NAu-1 is an aluminum-iron coexisting chlorite, while NAu-2 is an iron-rich chlorite, and both types of chlorite contain Fe. 2+ and Fe 3+ .

[0044] Figure 4 XPS iron element peak spectra of samples prepared in Example 1, Example 4 and Comparative Examples 1-3 are compared. Figure 5 XPS aluminum element peak spectra of samples prepared in Example 1, Example 4 and Comparative Examples 1-3 are compared. Figure 6XPS manganese element peak spectra of samples prepared in Examples 1, 4 and Comparative Examples 1-3 are compared.

[0045] from Figures 4-6 It can be seen that the introduction of Mn element will enhance the redox activity of Fe element. Due to its own structure, NAu-2 is more excited by iron content. At the same time, different Mn doping ratios will enhance the excitation state of Fe. Mn element spectrum also shows that a single introduction will not be able to form a relatively stable Mn-Fe dual-ion co-synergistic system.

[0046] See appendix Figure 7 The antibacterial effects of the samples prepared in Examples 1-3 and Comparative Examples 1-2 against *Escherichia coli* (E), *Staphylococcus aureus* (S), and *Pseudomonas aeruginosa* (P) were observed. The results showed that when Mn... 2+ and Mn 4+ The antibacterial effect is relatively optimal when the loading ratio is between 1:1 and 1:3.

[0047] See appendix Figure 8-11 The diagram shows the antibacterial effects of the samples prepared in Example 1 and Comparative Examples 1-3, aiming to demonstrate the amount of material added and the antibacterial effects of different materials against Escherichia coli (E), Staphylococcus aureus (S), and Pseudomonas aeruginosa (P).

[0048] See appendix Figure 8 The antibacterial effect of the sample prepared in Example 1 on Escherichia coli (E), Staphylococcus aureus (S) and Pseudomonas aeruginosa (P) was measured by the amount of material added. The antibacterial rate increased with the amount of material added, and when the concentration of material added was 1 mg / mL, the antibacterial rates against E, S and P reached 86%, 82% and 91% respectively, which showed good antibacterial effect.

[0049] See appendix Figure 9 The amount of material added to the sample prepared in Comparative Example 1 was used to measure the antibacterial effect against Escherichia coli (E), Staphylococcus aureus (S), and Pseudomonas aeruginosa (P). The antibacterial rate increased with the increase of the amount of material added, and when the concentration of the material added was 1 mg / mL, the antibacterial rates against E, S, and P were only 49%, 52%, and 56%, respectively, which was not as good as that in Example 1.

[0050] See appendix Figure 10 The addition amount of the sample prepared in Comparative Example 2 was used to assess the antibacterial effect against Escherichia coli (E), Staphylococcus aureus (S), and Pseudomonas aeruginosa (P). The antibacterial rate increased with the addition amount of material, and when the material concentration was 1 mg / mL, the antibacterial rates against E, S, and P were only 55%, 57%, and 54%, respectively, which was not as good as that in Example 1.

[0051] See appendix Figure 11The amount of Mn added to the sample prepared in Comparative Example 3 was used to assess the antibacterial effect against Escherichia coli (E), Staphylococcus aureus (S), and Pseudomonas aeruginosa (P). The antibacterial rate increased with increasing material addition, and when the material concentration was 1 mg / mL, the antibacterial rates against E, S, and P were only 37%, 44%, and 29%, respectively. Compared to Example 1, despite loading the same concentration of Mn, the antibacterial rate was significantly lower. 2+ and Mn 4+ However, due to the different matrix materials, it cannot achieve synergistic regulation of valence state with Mn elements, resulting in poor antibacterial effect.

[0052] See appendix Figure 12 The antibacterial effect of the sample prepared in Example 4 against Escherichia coli (E), Staphylococcus aureus (S), and Pseudomonas aeruginosa (P) was observed. The antibacterial rate increased with increasing material addition, and when the material concentration was 1 mg / mL, the antibacterial rates against E, S, and P were 68%, 62%, and 71%, respectively. Compared to Example 1, although the same concentration of Mn was loaded, the antibacterial effect was significantly higher. 2+ and Mn 4+ However, due to the different matrix materials, the antibacterial effects vary.

[0053] For any points not covered above, existing technologies shall apply.

[0054] Although specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the direction of the invention or exceeding the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a manganese-supported green silica antibacterial material, characterized in that: Includes the following steps: S1. Disperse chlorite particles with a diameter not greater than 0.075 mm in deionized water by ultrasonication to obtain a solution containing chlorite. S2. Mix and stir a neutral solution containing divalent and tetravalent manganese ions with a solution containing chlorite, and then age the mixture. S3. After washing and drying the aged solution, manganese-loaded green silica antibacterial material is obtained.

2. The preparation method according to claim 1, characterized in that, The molar ratio of divalent manganese ions to tetravalent manganese ions is 1:1 to 1:

3.

3. The preparation method according to claim 1, characterized in that, The molar ratio of chlorodiazepoxide to the sum of the moles of divalent and tetravalent manganese ions is 0.25 ~ 1 g / mol.

4. The preparation method according to claim 1, characterized in that, MnO2 is dissolved in acid, and divalent manganese salt is added. The pH value is then adjusted to neutral with alkali to obtain the neutral solution.

5. The preparation method according to claim 1, characterized in that, In step S2, stir for 20-26 hours.

6. The preparation method according to claim 1, characterized in that, Aging for 10-16 hours.

7. The preparation method according to claim 1, characterized in that, In step S3, the dried material is milled and screened through a 200-mesh sieve. The powder collected after sieving is the manganese-loaded green silica material.

8. A manganese-loaded green silica antibacterial material prepared by the preparation method according to any one of claims 1-7.

9. The application of the manganese-supported green silica antibacterial material as described in claim 8, characterized in that, It has antibacterial effects against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.

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