A method for preparing highly dispersible antibacterial zinc oxide

Abstract

This invention discloses a method for preparing highly dispersible antibacterial zinc oxide, relating to the field of antibacterial materials technology. The method involves slowly dripping an alkaline compound solution into a soluble zinc salt solution using a peristaltic pump, adding a dispersant while thoroughly stirring, and then placing the mixture in an ultrasonic cleaner for ultrasonic reaction. After the reaction, the mixture is filtered and dried to obtain nano-zinc oxide powder. The highly dispersible nano-zinc oxide prepared by this method, using ultrasound combined with dispersant addition, can improve its dispersibility while synthesizing nano-zinc oxide. Furthermore, the synthesized zinc oxide does not require high-temperature calcination, simplifying the preparation process and improving synthesis efficiency. The synthesized nano-zinc oxide can be utilized in nanofluid form without affecting its stability and antibacterial properties. The synthesized nano-zinc oxide exhibits excellent antibacterial effects and can be applied in fields such as coatings, polymer materials, daily chemicals, dyeing and finishing, and water treatment.

Description

Technical Field

[0001] This invention relates to the field of antibacterial materials technology, and in particular to a method for preparing highly dispersible antibacterial zinc oxide. Background Technology

[0002] Bacteria and other pathogenic microorganisms are widely distributed in nature, posing a threat to human health. The use of antibacterial agents is an important means of controlling infections and diseases caused by pathogenic microorganisms; however, the widespread use of various antibacterial drugs can lead to bacterial resistance. Currently, inorganic antibacterial materials have become the focus of research and application due to their high stability, excellent heat resistance, low biotoxicity, and low tendency to induce bacterial resistance.

[0003] Nano-zinc oxide, a white hexagonal crystalline or spherical particle, possesses extremely high chemical activity and excellent catalytic and photocatalytic activity. It also exhibits resistance to infrared and ultraviolet radiation, as well as bactericidal properties. With good flowability, it is used as a catalytic material and a semiconductor material for photochemical applications, capable of catalytically decomposing organic molecules. Nano-sized zinc oxide, with its tiny particle size, excellent stability, safety and non-toxicity, broad-spectrum antibacterial efficacy, and outstanding antibacterial activity even without ultraviolet irradiation, has become an ideal choice for antibacterial applications due to its low cost, convenient preparation, minimal dosage, and extremely high antibacterial efficiency.

[0004] Because of their small particle size, large specific surface area, and high surface energy, nano-zinc oxide is prone to agglomeration and clumping, losing its inherent properties and severely affecting the application effect of nanoparticles. Therefore, when adding nano-zinc oxide powder to systems such as coatings, it is necessary to promote its deagglomeration, i.e., improve its dispersibility, so that it is uniformly dispersed in the solvent to maintain stable properties. To this end, we propose a method for preparing highly dispersible antibacterial zinc oxide. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing highly dispersible antibacterial zinc oxide, thus solving the technical problem of the stability of nanoparticle properties.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A method for preparing highly dispersible antibacterial zinc oxide includes the following steps:

[0010] An alkaline compound solution is slowly dripped into a soluble zinc salt solution using a peristaltic pump. A dispersant is added while the solution is being thoroughly stirred. The solution is then placed in an ultrasonic cleaner for ultrasonic reaction. After the reaction, the solution is filtered and dried to obtain nano-zinc oxide powder.

[0011] Preferably, the molar ratio of the alkaline compound to the soluble zinc salt is 1 to 3:1.

[0012] Preferably, the alkaline compound can be sodium hydroxide, potassium hydroxide, hexamethylenetetramine, etc.

[0013] Preferably, the soluble zinc salt can be zinc chloride, zinc acetate, zinc sulfate, etc.

[0014] Preferably, the dispersant is one or more of sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate mixed in a certain proportion.

[0015] Preferably, the dispersant can be added before or during the synthesis of zinc oxide, and the amount of dispersant added is 0-4 wt%.

[0016] Preferably, the ultrasonic frequency of the ultrasonic reaction in the ultrasonic cleaner is 20–40 kHz.

[0017] Preferably, the ultrasonic cleaning machine has an ultrasonic power of 200-1000W, an ultrasonic time of 1-3 hours, and an ultrasonic temperature of 30-50℃.

[0018] Preferably, the synthesized nano zinc oxide can be utilized in the form of nanofluids, or it can be separated and dried to form nano zinc oxide powder.

[0019] Nano zinc oxide prepared by the preparation method and its application in antibacterial materials: Sodium hydroxide solution was slowly dripped into zinc acetate solution through a peristaltic pump, and a dispersant was added under full stirring. Then, the mixture was placed in an ultrasonic cleaner for ultrasonic reaction. After the reaction, it was filtered and dried to obtain nano zinc oxide powder.

[0020] (III) Beneficial Effects

[0021] The highly dispersible nano-zinc oxide prepared by the method of this invention uses ultrasound combined with the addition of a dispersant, which can improve the dispersibility of nano-zinc oxide while synthesizing it. At the same time, the synthesized zinc oxide does not need to be calcined at high temperature, which simplifies the preparation process of nano-zinc oxide and improves the synthesis efficiency. The synthesized nano-zinc oxide can be used in the form of nanofluid, or it can be filtered and dried at 80°C to form nano-zinc oxide powder, without affecting its stability and antibacterial properties. The synthesized nano-zinc oxide has excellent antibacterial effect and can be applied in fields such as coatings, polymer materials, daily chemicals, dyeing and finishing, and water treatment. Attached Figure Description

[0022] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0023] Figure 1 The XRD pattern of zinc oxide prepared by adding sodium polyacrylate dispersant in Example 1 of the present invention;

[0024] Figure 2 This is a TEM image of zinc oxide prepared by adding sodium polyacrylate dispersant in Example 1 of the present invention. Detailed Implementation

[0025] This application provides a method for preparing highly dispersible antibacterial zinc oxide, which solves the problem that in the prior art, nano zinc oxide has small particle size, large specific surface area, and high surface energy, making it prone to agglomeration and loss of its own properties, which seriously affects the application effect of nanoparticles. The method to improve the dispersibility of zinc oxide usually involves further adding dispersants and other additives to the synthesized zinc oxide powder, which is a complicated process and may affect the particle size and antibacterial properties of zinc oxide during the modification process.

[0026] Example 1

[0027] The technical solution in this application embodiment is to solve the above-mentioned problem of poor stability, and the overall idea is as follows:

[0028] To address the problems existing in the prior art, the present invention provides a method for preparing highly dispersible antibacterial zinc oxide, comprising the following steps:

[0029] An alkaline compound solution is slowly dripped into a soluble zinc salt solution using a peristaltic pump. A dispersant is added while the solution is being thoroughly stirred. The solution is then placed in an ultrasonic cleaner for ultrasonic reaction. After the reaction, the solution is filtered and dried to obtain nano-zinc oxide powder.

[0030] In this embodiment, the alkaline compound is sodium hydroxide, the soluble zinc salt is zinc acetate, and the molar ratio of sodium hydroxide to zinc acetate is 2:1.

[0031] In this embodiment, the dispersant is one or more of the following: no dispersant added, sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate, mixed in proportion, and the amount of dispersant added is 1 wt%.

[0032] In this embodiment, the ultrasonic conditions for the ultrasonic reaction in the ultrasonic cleaner are a frequency of 40kHz, an ultrasonic power of 300W, an ultrasonic time of 1h, and an ultrasonic temperature of 30℃.

[0033] In this embodiment, the synthesized nano zinc oxide is filtered and dried at 80°C to form nano zinc oxide powder.

[0034] The zeta potentials of zinc oxide dispersions prepared with different dispersants were measured using a zeta potential meter. The results are detailed in Table 1.

[0035] Table 1. Zeta potentials of zinc oxide prepared with different dispersants.

[0036]

[0037] The antibacterial properties were tested according to the GB / T 21510-2008 standard for testing the antibacterial properties of nano-inorganic materials. The results are detailed in Table 2.

[0038] Table 2. Test results of antibacterial properties of zinc oxide prepared with different dispersants.

[0039]

[0040]

[0041] The results of the zeta potential and antibacterial performance tests show that the zinc oxide prepared without the addition of dispersant is not much different from commercially available zinc oxide in terms of dispersibility and antibacterial effect. After the addition of dispersant, the zeta potential increases significantly. Among them, the zeta potential is the largest after the addition of sodium polyacrylate, followed by sodium dodecylbenzenesulfonate, and sodium hexametaphosphate is slightly worse, indicating that the dispersibility is the best after the addition of sodium polyacrylate.

[0042] Correspondingly, the zinc oxide prepared by adding sodium polyacrylate and sodium dodecylbenzene sulfonate showed antibacterial activity >99.9% against both Escherichia coli and Staphylococcus aureus, while the zinc oxide prepared by adding sodium hexametaphosphate showed slightly worse activity. These results also indicate that the dispersibility of nano-zinc oxide is correlated with its antibacterial performance. XRD and TEM analyses were performed on the zinc oxide prepared by adding 1% sodium polyacrylate. Figure 1 and Figure 2 The results show that zinc oxide has a typical wurtzite structure and a particle size of nanoscale.

[0043] Example 2

[0044] A method for preparing highly dispersible antibacterial zinc oxide includes the following steps:

[0045] An alkaline compound solution is slowly dripped into a soluble zinc salt solution using a peristaltic pump. A dispersant is added while the solution is being thoroughly stirred. The solution is then placed in an ultrasonic cleaner for ultrasonic reaction. After the reaction, the solution is filtered and dried to obtain nano-zinc oxide powder.

[0046] In this embodiment, the alkaline compound is sodium hydroxide, the soluble zinc salt is zinc acetate, and the molar ratio of sodium hydroxide to zinc acetate is 2:1.

[0047] In this embodiment, the dispersant is sodium polyacrylate, and the amount of dispersant added is 0, 0.5 wt%, 1 wt%, 2 wt%, and 3 wt%.

[0048] In this embodiment, the ultrasonic conditions for the ultrasonic reaction in the ultrasonic cleaner are a frequency of 40kHz, an ultrasonic power of 300W, an ultrasonic time of 1h, and an ultrasonic temperature of 30℃.

[0049] In this embodiment, the synthesized nano zinc oxide is filtered and dried at 80°C to form nano zinc oxide powder.

[0050] The zeta potential of the dispersion system was measured using a zeta potential meter, and the results are detailed in Table 3.

[0051] Table 3. Zeta potentials of zinc oxide prepared with different amounts of sodium polyacrylate.

[0052]

[0053] The antibacterial properties were tested according to the GB / T 21510-2008 standard for testing the antibacterial properties of nano-inorganic materials. The results are detailed in Table 4.

[0054] Table 4. Test results of antibacterial properties of zinc oxide prepared with different amounts of sodium polyacrylate.

[0055]

[0056] The Zeta potential test results show that when the amount of sodium polyacrylate added is 0.5%, the Zeta potential rises rapidly. However, as the amount of sodium polyacrylate added increases, the potential change is not significant. In terms of antibacterial properties, when the amount of sodium polyacrylate added is higher than 0.5%, the antibacterial performance against Escherichia coli and Staphylococcus aureus can reach over 99.9%.

[0057] Example 3

[0058] A method for preparing highly dispersible antibacterial zinc oxide includes the following steps:

[0059] An alkaline compound solution is slowly dripped into a soluble zinc salt solution using a peristaltic pump. A dispersant is added while the solution is being thoroughly stirred. The solution is then placed in an ultrasonic cleaner for ultrasonic reaction. After the reaction, the solution is filtered and dried to obtain nano-zinc oxide powder.

[0060] In this embodiment, the alkaline compound is sodium hydroxide, the soluble zinc salt is zinc acetate, and the molar ratio of sodium hydroxide to zinc acetate is 2:1.

[0061] In this embodiment, the dispersant is sodium polyacrylate, and the amount of dispersant added is 1 wt%.

[0062] In this embodiment, the ultrasonic time of the ultrasonic reaction in the ultrasonic cleaner is 1h, 2h, and 3h, the ultrasonic frequency is 40kHz, the ultrasonic power is 300W, and the ultrasonic temperature is 30℃.

[0063] In this embodiment, the synthesized nano zinc oxide is filtered and dried at 80°C to form nano zinc oxide powder.

[0064] The zeta potential of the dispersion system was measured using a zeta potential meter, and the results are detailed in Table 5.

[0065] Table 5. Zeta potentials of zinc oxide obtained at different ultrasonic times.

[0066]

[0067] The antibacterial properties were tested according to the GB / T 21510-2008 standard for testing the antibacterial properties of nano-inorganic materials. The results are detailed in Table 6.

[0068] Table 6. Test results of antibacterial properties of zinc oxide prepared by different ultrasonic times.

[0069]

[0070] The Zeta potential test results show that the Zeta potential tends to decrease with increasing sonication time. Regarding antibacterial properties, the antibacterial performance against *Escherichia coli* and *Staphylococcus aureus* reached over 99.9% when the sonication time was 1 hour and 2 hours, respectively. However, the antibacterial performance decreased when the sonication time was 3 hours, indicating that a sonication time of 1 hour was sufficient to synthesize high-performance nano-zinc oxide.

[0071] Example 4

[0072] A method for preparing highly dispersible antibacterial zinc oxide includes the following steps:

[0073] An alkaline compound solution is slowly dripped into a soluble zinc salt solution using a peristaltic pump. A dispersant is added while the solution is being thoroughly stirred. The solution is then placed in an ultrasonic cleaner for ultrasonic reaction. After the reaction, the solution is filtered and dried to obtain nano-zinc oxide powder.

[0074] In this embodiment, the alkaline compound is sodium hydroxide, the soluble zinc salt is zinc acetate, and the molar ratio of sodium hydroxide to zinc acetate is 2:1.

[0075] In this embodiment, the dispersant is sodium polyacrylate, and the amount of dispersant added is 1 wt%.

[0076] In this embodiment, the ultrasonic power of the ultrasonic reaction in the ultrasonic cleaner is 200W, 300W, and 400W, the ultrasonic time is 1 hour, the ultrasonic frequency is 40kHz, and the ultrasonic temperature is 30℃.

[0077] In this embodiment, the synthesized nano zinc oxide is filtered and dried at 80°C to form nano zinc oxide powder.

[0078] The zeta potential of the dispersion system was measured using a zeta potential meter, and the results are detailed in Table 7.

[0079] Table 7. Zeta potentials of zinc oxide obtained with different ultrasonic powers.

[0080]

[0081] The antibacterial properties were tested according to the GB / T 21510-2008 standard for testing the antibacterial properties of nano-inorganic materials. The results are detailed in Table 8.

[0082] Table 8. Test results of antibacterial properties of zinc oxide prepared under different ultrasonic powers.

[0083]

[0084] The Zeta potential test results show that the Zeta potential initially increases and then decreases with varying ultrasonic power, with better dispersion at a power of 300W. Regarding antibacterial properties, the nano-zinc oxide prepared at an ultrasonic power of 300W exhibits the best antibacterial performance, while the performance is slightly worse at powers of 200W and 400W.

[0085] In summary, the highly dispersible nano-zinc oxide prepared by the method of this invention, using ultrasound combined with dispersant addition, can improve its dispersibility while synthesizing nano-zinc oxide. Furthermore, the synthesized zinc oxide does not require high-temperature calcination, simplifying the preparation process and improving synthesis efficiency. The synthesized nano-zinc oxide can be utilized in nanofluid form or filtered and dried at 80°C to form nano-zinc oxide powder, without affecting its stability and antibacterial properties. The synthesized nano-zinc oxide exhibits excellent antibacterial effects and can be applied in coatings, polymer materials, daily chemicals, dyeing and finishing, and water treatment.

[0086] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing highly dispersible antibacterial zinc oxide, comprising the following steps: An alkaline compound solution is slowly dripped into a soluble zinc salt solution using a peristaltic pump. A dispersant is added while the mixture is fully stirred. The dispersant is one or more of sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate mixed in a certain proportion. The amount of dispersant added is 0.5-4 wt%. The mixture is then placed in an ultrasonic cleaner for ultrasonic reaction. After the reaction, the mixture is filtered and dried to obtain nano zinc oxide powder.

2. The method for preparing highly dispersible antibacterial zinc oxide according to claim 1, characterized in that: The ultrasonic frequency of the ultrasonic reaction in the ultrasonic cleaner is 20-40 kHz.

3. The method for preparing highly dispersible antibacterial zinc oxide according to claim 1, characterized in that: The ultrasonic cleaner has an ultrasonic power of 200-1000W, an ultrasonic time of 1-3 hours, and an ultrasonic temperature of 30-50℃.

4. The method for preparing highly dispersible antibacterial zinc oxide according to claim 1, characterized in that: The molar ratio of the alkaline compound to the soluble zinc salt is 1 to 3:

1.

5. The method for preparing highly dispersible antibacterial zinc oxide according to claim 1, characterized in that: The alkaline compound is one or more of sodium hydroxide, potassium hydroxide, and hexamethylenetetramine mixed in a certain proportion.

6. The method for preparing highly dispersible antibacterial zinc oxide according to claim 1, characterized in that: The soluble zinc salt is one or more of zinc chloride, zinc acetate, and zinc sulfate mixed in proportion.

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