Silica implantation loaded nano-zinc oxide composite antibacterial material and preparation method thereof

Abstract

The application discloses a phytolith-loaded nano-zinc oxide composite antibacterial material and a preparation method thereof. The following steps are included: step S1, phytolith and zinc nitrate hexahydrate are added into deionized water to form a phytolith-zinc nitrate hexahydrate mixed solution; step S2, sodium hydroxide solution is added dropwise into the mixed solution and stirred to react, so as to obtain a precursor phytolith-zinc hydroxide mixed solution; and step S3, the precursor phytolith-zinc hydroxide mixed solution is centrifuged, washed, dried and calcined under an air atmosphere to obtain the antibacterial material. In the application, the flaky phytolith mineral is used as a substrate, and the nano-zinc oxide is loaded. The two have opposite potentials, can be better loaded and adsorbed on the surface, the larger specific surface area and the existing mesoporous structure can improve the dispersity and loading rate of the nano-zinc oxide particles, so that the antibacterial performance of the material is improved. The material has very good antibacterial effect on escherichia coli and staphylococcus aureus, very low cytotoxicity and hemolysis rate, and excellent biocompatibility.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antibacterial materials, and particularly relates to a phytolith loaded nano-zinc oxide composite antibacterial material and a preparation method thereof. BACKGROUND

[0002] According to different components of the antibacterial material, the antibacterial material can be divided into three categories: inorganic antibacterial material, organic antibacterial material and natural antibacterial material. The inorganic antibacterial material has various types and is widely applied. The main component of the antibacterial agent is a metal element or a metal oxide, such as silver (Ag), copper (Cu), titanium dioxide (TiO), cerium oxide (CeO2), zinc oxide (ZnO) and the like. The inorganic antibacterial material has stable antibacterial performance, long duration, no toxicity to human body, and no drug resistance to bacteria. In addition, the inorganic antibacterial material has the advantages of simple preparation process and low cost, and thus becomes the most widely used antibacterial material. Nano-zinc oxide (ZnO) is an excellent antibacterial material, but the large specific surface energy of the nano-zinc oxide leads to easy aggregation of the nano-zinc oxide, which greatly limits the play of the antibacterial performance of the nano-zinc oxide. Therefore, the dispersion of the nano-zinc oxide is a necessary treatment means before application. SUMMARY

[0003] The present application aims at the above-mentioned deficiencies of the prior art, and provides a phytolith loaded nano-zinc oxide composite antibacterial material and a preparation method thereof.

[0004] The preparation method of the phytolith loaded nano-zinc oxide composite antibacterial material provided by the present application comprises the following steps:

[0005] Step S1: adding phytolith mineral raw material powder and zinc nitrate hexahydrate in a certain mass ratio into deionized water to form a phytolith-zinc nitrate hexahydrate mixed solution;

[0006] Step S2: adding sodium hydroxide solution into the phytolith-zinc nitrate hexahydrate mixed solution dropwise and stirring to react, so as to obtain a precursor phytolith-zinc hydroxide mixed solution;

[0007] Step S3: centrifuging, washing, drying and calcining the precursor phytolith-zinc hydroxide mixed solution under air atmosphere to obtain the phytolith loaded nano-zinc oxide composite antibacterial material.

[0008] Further, in step S2, the molar ratio of sodium hydroxide in the sodium hydroxide solution to zinc nitrate hexahydrate is 2-3:1.

[0009] Further, in step S3, the centrifugal washing speed is 8000-10000r, the centrifugal time is 5-7min, and the residual impurities are removed by washing with distilled water for three times.

[0010] Further, in step S3, the drying temperature is 60-80℃, and the drying time is 10-15h.

[0011] Further, in step S3, the calcination temperature is 400-500℃, the calcination temperature is 400-500℃, and the holding time is 2-4h.

[0012] Further, the mass ratio of the phytolith mineral raw material powder to zinc nitrate hexahydrate is 1:0.4-2.5.

[0013] The phytolith-loaded nanometer zinc oxide composite antibacterial material is prepared by the preparation method.

[0014] The present application has the following advantages:

[0015] 1. The phytolith-loaded nanometer zinc oxide composite antibacterial material prepared by the present application uses flaky phytolith minerals as a substrate, and nanometer zinc oxide is loaded by using a chemical co-precipitation method. The two have opposite potentials and can be better loaded and adsorbed on the surface. In addition, the large specific surface area and the existing mesopores can also improve the dispersity and loading rate of the nanometer zinc oxide particles, thereby improving the antibacterial performance of the material. The material has very good antibacterial effect on Escherichia coli and Staphylococcus aureus, and the antibacterial rate is more than 99%, reaching the Grade I antibacterial standard of the People's Republic of China Light Industry Standard (QB / T 2591-2003).

[0016] 2. The composite antibacterial material prepared by the present application still has strong antibacterial performance under the condition of a low loading ratio, and has high biocompatibility, weak toxicity, high cell survival rate and low hemolysis rate.

[0017] 3. The phytolith used in the present application has very little impurity content, and the content of silicon dioxide is more than 90%. The content of other components is small, which reduces the interference of other components on the loading of zinc oxide, and the original ore does not need to be treated by a complex beneficiation and purification screening process.

[0018] 4. The raw material used in the present application is a newly mined silicon-carbon ore, which has rich reserves and low price. The development of the silicon-carbon ore as an antibacterial material can reduce the cost of the antibacterial material and improve the application value of the phytolith mineral.

[0019] 5. The phytolith used in the present application is a natural mineral, which is non-toxic, harmless, environmentally friendly and non-polluting.

[0020] 6. The chemical co-precipitation method used in the present application is simple and easy to operate. DETAILED DESCRIPTION

[0021] Figure 1 The X-ray diffraction pattern of the phytolith sample;

[0022] Figure 2 The scanning electron microscope image of the phytolith sample;

[0023] Figure 3 Transmission electron microscope image of phytolith sample;

[0024] Figure 4 X-ray powder diffraction pattern of phytolith loaded nanometer zinc oxide composite antibacterial material prepared in Example 1;

[0025] Figure 5 Scanning electron microscope image of phytolith loaded nanometer zinc oxide composite antibacterial material prepared in Example 1;

[0026] Figure 6 In the figure, a is the antibacterial effect of phytolith on E. coli, b is the blank control of E. coli, c is the antibacterial effect of phytolith on S. aureus, and d is the blank control of S. aureus;

[0027] Figure 7 In the figure, a is the antibacterial effect of phytolith loaded nanometer zinc oxide composite antibacterial material on E. coli, b is the blank control of E. coli, c is the antibacterial effect of phytolith loaded nanometer zinc oxide composite antibacterial material on S. aureus, and d is the blank control of S. aureus;

[0028] Figure 8 Cell survival rate of phytolith loaded nanometer zinc oxide composite antibacterial material;

[0029] Figure 9 Hemolysis rate of phytolith loaded nanometer zinc oxide composite antibacterial material. DETAILED DESCRIPTION

[0030] The following is a specific embodiment of the present application and further describes the technical solutions of the present application in conjunction with the accompanying drawings, but the present application is not limited to these embodiments.

[0031] Phytolith refers to water-soluble silicon absorbed by plants from soil through root systems during growth, transported by vascular bundles, and precipitated in cell cavities or between cells to form amorphous silicon dioxide. After the death of plants, the active polymerization base of the deposited sediment combines with organic carbon, and carbon also becomes an important component of phytolith. Due to its corrosion resistance and stability, it forms a phytolith sedimentary layer after consolidation into rock. Phytolith ore was discovered by Jiangxi Coal Geological Bureau in 2016, and there is no phytolith mineralization precedent in the world. The inventors found that phytolith has a special sheet structure and is pure, non-toxic and harmless, and can be used as a base material for loading nanometer zinc oxide.

[0032] Phytolith is a natural micro-nano silicon-carbon mineral, and its chemical composition mainly includes silicon dioxide and a small amount of fixed carbon. Its crystal structure is sheet-like, and it is stable in chemical properties, non-toxic and harmless, and is a suitable carrier for loading nanometer zinc oxide.

[0033] Figure 1 This is the X-ray diffraction (XRD) pattern of the phytolith sample used in this invention. It can be seen that the diffraction peaks of the phytolith are sharp, indicating that the phytolith has a complete crystal structure and high crystallinity, which is basically consistent with the quartz standard card (PDF: 85-0504). Its characteristic diffraction peaks are: It largely overlaps with quartz. In summary, the phytolith sample used in this invention has high purity, and no obvious impurity peaks appear in the XRD diffraction pattern.

[0034] Table 1 shows the X-ray fluorescence (XRF) spectroscopy results of the chemical composition of the phytolith samples used in this invention (unit: mass percentage, %).

[0035] Substance SiO2 Al2O3 Fe2O3 TiO2 SO3 K2O MgO CaO Others Content 91.83 4.70 0.83 0.81 0.65 0.50 0.28 0.12 0.28

[0036] As shown in Table 1, the chemical composition of the phytolith sample is mainly SiO2, with very low levels of other impurities and no substances harmful to the human body. Combined with the XRD pattern results, it can be concluded that the phytolith sample used has high purity and few impurities, meeting the conditions for using minerals as a carrier material, and can be used as a substrate material for loading and dispersing nano-zinc oxide.

[0037] Using phytoliths from Fengcheng City, Jiangxi Province as the carrier mineral raw material, this phytolith ore is relatively pure, with few impurities and high crystallinity. Figure 1 ), by scanning electron microscope ( Figure 2 ) and transmission electron microscope ( Figure 3 As can be seen, its crystal structure is irregularly plate-like, and its chemical composition is shown in Table 1. The phytolith-supported nano zinc oxide composite antibacterial material was prepared by chemical co-precipitation method.

[0038] Example 1:

[0039] In this embodiment, a phytolithic antibacterial material (P / Z-20%) was prepared with a zinc oxide loading of 20%. The specific preparation process is as follows:

[0040] 1. Preparation of phytolith-zinc nitrate hexahydrate mixed solution: Weigh phytolith mineral raw material powder (1.0000g) and zinc nitrate hexahydrate (0.9182g) respectively, add them to deionized water (100mL) and stir for 15min to obtain phytolith-zinc nitrate hexahydrate mixed solution;

[0041] 2. Preparation of precursor phytolith-zinc hydroxide mixed solution: Weigh 0.3086g of sodium hydroxide (NaOH) and dissolve it in deionized water (250mL) according to the molar ratio of zinc nitrate hexahydrate to sodium hydroxide 1:2.5. Then, put the sodium hydroxide solution into a separatory funnel and add it dropwise to the phytolith-zinc nitrate hexahydrate mixed solution. Stir and react for 2h to obtain the precursor phytolith-zinc hydroxide mixed solution.

[0042] 3. Centrifugation and washing: The precursor phytosilicone-zinc hydroxide mixed solution is centrifuged at 8000 r / 7 min and washed three times with distilled water to remove residual impurities and obtain a mixed precipitate;

[0043] 4. Material drying: Place the washed precursor implant-zinc hydroxide mixed precipitate into an oven for drying at 60℃ for 12 hours.

[0044] 5. Calcination: The precursor implant-zinc hydroxide mixed precipitate was heated to 400℃ and held for 4 hours in an air atmosphere using a muffle furnace at a heating rate of 10℃ / min to obtain the implant-supported nano zinc oxide composite antibacterial material (P / Z-20%).

[0045] 6. Conduct antibacterial tests on the phytolith-loaded nano-zinc oxide composite antibacterial material.

[0046] See appendix Figure 4 The image shows the X-ray powder diffraction pattern of the phytolith-supported nano-zinc oxide composite antibacterial material prepared according to the technical solution of this embodiment. The main component of the phytolith is SiO2 with good crystallinity. Its XRD pattern shows sharp diffraction peaks and high diffraction intensity. Diffraction peaks of ZnO can also be seen in the image, indicating that ZnO is supported on the surface of the phytolith and there are no other impurities or substances affecting the antibacterial properties of the composite material.

[0047] See appendix Figure 5 The image shows a scanning electron microscope image of a nano-zinc oxide composite antibacterial material loaded on a phytolith. As can be seen from the image, after loading nano-ZnO onto the phytolith, the nano-ZnO particles are distributed relatively evenly and are spherical. The phytolith plates are relatively large and are well loaded on the surface of the phytolith.

[0048] See appendix Figure 6 Figure a shows the antibacterial effect of phytolith ore against Escherichia coli, Figure b shows the blank control against Escherichia coli, Figure c shows the antibacterial effect of phytolith ore against Staphylococcus aureus, and Figure d shows the blank control against Staphylococcus aureus. The comparison of the figures shows that phytolith ore has no obvious antibacterial effect against either bacterium.

[0049] See appendix Figure 7, Figure a is the antibacterial effect diagram of the phytolith loaded nanometer zinc oxide composite antibacterial material on escherichia coli, Figure b is the escherichia coli blank control, Figure c is the antibacterial effect diagram of the phytolith loaded nanometer zinc oxide composite antibacterial material on staphylococcus aureus, and Figure d is the staphylococcus aureus blank control, as can be seen from the figures, the antibacterial effect of the phytolith loaded nanometer zinc oxide composite antibacterial material on the two bacteria reaches more than 99%, reaches the Ⅰ-grade antibacterial standard of the People's Republic of China light industry standard (QB / T 2591-2003), and the zinc oxide loading amount is only 20%, and the antibacterial performance is also strong.

[0050] Referring to the accompanying drawings Figure 8 , Figure is the cell survival rate of the phytolith loaded nanometer zinc oxide composite antibacterial material, the cell survival rate of the material at two concentrations is close to 100%, which indicates that the antibacterial material has very small toxicity to cells.

[0051] Referring to the accompanying drawings Figure 9 , Figure is the hemolysis rate of the phytolith loaded nanometer zinc oxide composite antibacterial material, the hemolysis rate of the material is basically lower than 5%, which indicates that the influence on red blood cells is very small, and good biocompatibility is shown.

[0052] The above test results show that the phytolith loaded nanometer zinc oxide composite antibacterial material obtained in the embodiment has good loading condition, the antibacterial effect on escherichia coli and staphylococcus aureus reaches more than 99%, reaches the Ⅰ-grade antibacterial standard of the People's Republic of China light industry standard (QB / T 2591-2003), the cell survival rate is close to 100%, the hemolysis rate is lower than 5%, good biocompatibility is shown, and the material has broad application prospect.

[0053] Example 2:

[0054] In this embodiment, the phytolith loaded nanometer zinc oxide composite antibacterial material is prepared, the zinc oxide loading amount is 10%, and the material is recorded as P / Z-10%, and the preparation process is as follows:

[0055] 1. Prepare a phytolith-zinc nitrate hexahydrate mixed solution: respectively take phytolith mineral raw material powder (1.0000 g) and zinc nitrate hexahydrate (0.4061 g), add them into deionized water (100 mL) and stir and mix for 15 min to obtain a phytolith-zinc nitrate hexahydrate mixed solution;

[0056] 2. Prepare a precursor phytolith-zinc hydroxide mixed solution: according to the molar ratio of zinc nitrate hexahydrate to sodium hydroxide 1:2.5, take 0.1365 g of sodium hydroxide (NaOH) and dissolve it in deionized water (250 mL), then pour the sodium hydroxide solution into a separatory funnel, dropwise add it into the phytolith-zinc nitrate hexahydrate mixed solution, and stir and react for 2 h to obtain a precursor phytolith-zinc hydroxide mixed solution;

[0057] 3. Centrifugal washing: centrifugal washing of the precursor phytolith-zinc hydroxide mixture solution at 8000 r / min for 7 min, three times of distilled water washing to remove residual impurities, and obtaining a mixed precipitate;

[0058] 4. Material drying: placing the washed precursor phytolith-zinc hydroxide mixed precipitate into an oven for drying, the drying temperature being 60°C, and the drying time being 12 h;

[0059] 5. Calcination: heating and calcination in a muffle furnace under an air atmosphere, the heating rate being 10°C / min, heating the dried precursor phytolith-zinc hydroxide mixed precipitate to 400°C, and keeping the temperature for 4 h, and finally obtaining the phytolith-loaded nanometer zinc oxide composite antibacterial material (P / Z-10%).

[0060] The antibacterial effect of the P / Z-10% antibacterial material of the embodiment can reach the Ⅱ-grade antibacterial standard of the People's Republic of China Light Industry Standard (QB / T 2591-2003), and the antibacterial rate is above 90%.

[0061] Example 3:

[0062] The phytolith antibacterial material (P / Z-30%) of the embodiment is prepared, and the zinc oxide loading amount is 30%, and the preparation process thereof is as follows:

[0063] 1. Preparation of phytolith-zinc nitrate hexahydrate mixture solution: respectively taking phytolith mineral raw material powder (1.0000 g) and zinc nitrate hexahydrate (1.5738 g), adding into deionized water (100 mL) and stirring and mixing for 15 min to obtain a phytolith-zinc nitrate hexahydrate mixture solution;

[0064] 2. Preparation of precursor phytolith-zinc hydroxide mixture solution: taking 0.5290 g of sodium hydroxide (NaOH) and dissolving in deionized water (250 mL) according to a molar ratio of zinc nitrate hexahydrate to sodium hydroxide of 1:2.5, then loading the sodium hydroxide solution into a separatory funnel, adding dropwise into the phytolith-zinc nitrate hexahydrate mixture solution, stirring and reacting for 2 h to obtain a precursor phytolith-zinc hydroxide mixture solution;

[0065] 3. Centrifugal washing: centrifugal washing of the precursor phytolith-zinc hydroxide mixture solution at 8000 r / min for 7 min, three times of distilled water washing to remove residual impurities, and obtaining a mixed precipitate;

[0066] 4. Material drying: placing the washed precursor phytolith-zinc hydroxide mixed precipitate into an oven for drying, the drying temperature being 60°C, and the drying time being 12 h;

[0067] 5. Calcination: using muffle furnace heating calcination under air atmosphere, the heating rate is 10℃ / min, the dried precursor phytolith-zinc hydroxide mixed precipitate is heated to 400℃, and the temperature is kept for 4h, finally the phytolith loaded nano-zinc oxide composite antibacterial material (P / Z-30%) is obtained.

[0068] The antibacterial effect of P / Z-30% in this example can reach the I-grade antibacterial standard of the People's Republic of China Light Industry Standard (QB / T 2591-2003), and the antibacterial rate is more than 99%.

[0069] Example 4:

[0070] In this example, the phytolith antibacterial material (P / Z-40%) is prepared, and the zinc oxide loading is 40%, and the specific process flow of the preparation process is as follows:

[0071] 1. Preparation of phytolith-zinc nitrate hexahydrate mixed solution: phytolith mineral raw material powder (1.0000 g) and zinc nitrate hexahydrate (2.4487 g) are weighed respectively and added to deionized water (100 mL) for stirring and mixing for 15 min to obtain a phytolith-zinc nitrate hexahydrate mixed solution;

[0072] 2. Preparation of precursor phytolith-zinc hydroxide mixed solution: according to the molar ratio of zinc nitrate hexahydrate to sodium hydroxide 1:2.5, 0.8231 g of sodium hydroxide (NaOH) is weighed and dissolved in deionized water (250 mL), then the sodium hydroxide solution is poured into a separatory funnel and added dropwise to the phytolith-zinc nitrate hexahydrate mixed solution, and stirred for 2h to obtain a precursor phytolith-zinc hydroxide mixed solution;

[0073] 3. Centrifugal washing: the precursor phytolith-zinc hydroxide mixed solution is centrifuged at 8000r / 7min, washed with distilled water for three times, and the residual impurities are removed to obtain a mixed precipitate;

[0074] 4. Material drying: the washed precursor phytolith-zinc hydroxide mixed precipitate is placed in an oven for drying, the drying temperature is 60℃, and the drying time is 12h;

[0075] 5. Calcination: using muffle furnace (brand) heating calcination under air atmosphere, the heating rate is 10℃ / min, the dried precursor phytolith-zinc hydroxide mixed precipitate is heated to 400℃, and the temperature is kept for 4h, finally the phytolith loaded nano-zinc oxide composite antibacterial material (P / Z-40%) is obtained.

[0076] The antibacterial effect of P / Z-10% in this example can reach the I-grade antibacterial standard of the People's Republic of China Light Industry Standard (QB / T 2591-2003), and the antibacterial rate is more than 99%.

[0077] The above not involved, apply to the prior art.

[0078] Although some specific embodiments of the present application have been described in detail by way of examples, it should be understood that the examples are for illustration only and should not limit the scope of the present application. Those skilled in the art can make various modifications or additions or employ similar ways to replace the described specific embodiments without departing from the spirit of the present application or exceeding the scope of the appended claims. Those skilled in the art should understand that any modification, equivalent replacement, improvement, etc. made according to the technical essence of the present application to the above embodiments should be included in the protection scope of the present application.

Claims

1. A method for preparing a diatomite-loaded nano-zinc oxide composite antibacterial material, characterized by comprising the following steps: The method comprises the following steps: ​ S1, adding a mass ratio of phytolith mineral raw material powder and zinc nitrate hexahydrate into deionized water to form a phytolith-zinc nitrate hexahydrate mixed solution; S2, adding sodium hydroxide solution into the phytolith-zinc nitrate hexahydrate mixed solution dropwise and stirring to react, to obtain a precursor phytolith-zinc hydroxide mixed solution; S3, centrifuging, washing, drying and calcining the precursor phytolith-zinc hydroxide mixed solution in air to obtain a phytolith loaded nanometer zinc oxide composite antibacterial material; In S3, the calcining temperature is 400-500℃, the calcining heating rate is 10-15℃ / min, and the holding time is 2-4h; The mass ratio of the phytolith mineral raw material powder to the zinc nitrate hexahydrate is 1:0.9182-2.

5.

2. The preparation method of the silicon-carbide-loaded nano-zinc-oxide composite antibacterial material according to claim 1, characterized in that: In S2, the molar ratio of sodium hydroxide to zinc nitrate hexahydrate in the sodium hydroxide solution is 2-3:

1.

3. The method for preparing a silicon-carbide-supported nano-zinc-oxide composite antibacterial material according to claim 1, characterized in that: In S3, the centrifugal speed is 8000-10000r, the centrifugal time is 5-7min, and the residual impurities are removed by washing with distilled water for three times.

4. The method for preparing a silicon-carbide-supported nano-zinc-oxide composite antibacterial material according to claim 1, characterized in that: In S3, the drying temperature is 60-80℃, and the drying time is 10-15h.

5. The phytolith loaded nanometer zinc oxide composite antibacterial material prepared by the method according to any one of claims 1-4.

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