Nano-copper oxide antibacterial paper, its preparation method and application

Abstract

The application discloses a kind of nano copper oxide antibacterial paper, its preparation method and application, the antibacterial paper includes paper base, and the paper base is attached with nano copper oxide and the antibacterial active ingredient extracted from pomegranate peel.The preparation method of the nano copper oxide antibacterial paper includes the following steps: S1 paper is soaked in copper sulfate aqueous solution, and copper sulfate impregnated paper is obtained;S2 copper sulfate impregnated paper is put into pomegranate peel extract, heated, and stirred at impregnation temperature, to obtain nano copper oxide antibacterial paper.The nano copper oxide antibacterial paper prepared by the preparation method described above is used to make wound plaster.The pomegranate peel in the application is reacted with copper ions to generate nano copper oxide with antibacterial effect on paper base, and other antibacterial active ingredients contained in the pomegranate peel attached to the paper base can enhance the antibacterial effect, and play the role of 1+1>2 combined synergistic bacteriostasis.

Description

Technical Field

[0001] This invention relates to the field of chemical materials technology, and in particular to a nano-copper oxide antibacterial paper, its preparation method and application. Background Technology

[0002] The skin, located on the surface of the human body, is in direct contact with the external environment. It protects against external damage and prevents the loss of nutrients, serving as a protective barrier. While the skin effectively blocks most bacteria and viruses from entering the body, it is also fragile. Wounds on the skin's surface can easily allow bacteria to invade. Some superficial wounds can heal through the body's own defense system, but for chronic wounds and skin damage in patients with certain diseases, improper wound care can lead to bacterial invasion, causing inflammation, ulceration, or even more serious consequences.1 Although bandages can effectively stop bleeding from small wounds and prevent direct exposure to the external environment, most bandages do not have antibacterial properties, which can easily lead to further infection.

[0003] my country is one of the world's major pomegranate producers, with a planting area of ​​1.75 million mu (approximately 116,667 hectares) and a total national output exceeding 1 million tons in 2019. Globally, 1.5 million tons of pomegranate peel are processed annually. If the active ingredients in pomegranate peel could be recycled, waste management would be improved and environmental impact reduced.

[0004] Pomegranates have been used in traditional medicine since ancient times. They can promote human health and have antioxidant, anti-inflammatory, antibacterial, and anti-cancer effects. Pomegranate fruit can be eaten or juiced; its vitamin C and carotene content can prevent cell carcinogenesis. Because it is rich in various organic acids, eating pomegranate fruit can also increase appetite and promote digestion and absorption. Traditional Chinese medicine believes that the peel is a powerful anti-inflammatory and astringent agent that can treat traumatic bleeding and infection. Pomegranate peel (PGP) can be used medicinally; its rich minerals, pomegranate polyphenols, and anthocyanins can resist inflammation and damage from oxygen free radicals, thus delaying aging and preventing cardiovascular diseases. In addition, studies have shown that the antibacterial active substances in pomegranate peel have inhibitory effects on 10 Gram-positive bacteria, 2 Gram-negative bacteria, and 1 yeast strain (such as Salmonella enterica, Escherichia coli, Shigella sonnei, Enterococcus faecalis, Staphylococcus aureus, and Bacillus subtilis 8), demonstrating a wide range of effects.

[0005] Pomegranates are rich in phenolic compounds. The antibacterial mechanism of plant polyphenols has always been a research hotspot. Due to the differences in plant polyphenol components and test strains, it is difficult to elucidate the antibacterial mechanism of plant polyphenols from a single perspective. At present, the antibacterial mechanism of plant polyphenols mainly includes the following aspects: (1) The cell wall and cell membrane play a crucial role in maintaining the cell morphology of bacteria, while plant polyphenols can destroy the integrity of the cell wall and the permeability of the cell membrane, thereby destroying the cell morphology of microorganisms; (2) Abnormal membrane potential can lead to disordered physiological activities of microorganisms. Under normal circumstances, the sodium and potassium ion channels of the cell membrane are closed, making the cell membrane potential in a polarized state. Plant polyphenols can affect the membrane potential of the tested strains, causing depolarization or hyperpolarization of the membrane potential, thereby inhibiting the growth and reproduction of microorganisms; (3) The content of intracellular ATP directly affects the normal energy metabolism of microorganisms. Studies have shown that plant polyphenols can inhibit the growth of microorganisms by reducing the content of intracellular ATP; (4) Biomacromolecules such as proteins, DNA and RNA are the basis for microorganisms to maintain their life activities, while plant polyphenols can exert their antibacterial effect by inhibiting the synthesis of biomacromolecules.

[0006] Copper metal ions also have good antibacterial effects. There may be two bactericidal mechanisms of metal ions: (1) Copper metal ions are positively charged. When they reach the bacterial cell membrane, because the cell membrane is negatively charged, copper metal ions can firmly adsorb onto the cell membrane by Coulomb attraction and further penetrate the cell wall, causing the cell wall to rupture, causing the cytoplasm to flow out, hindering the reproduction of bacteria, and ultimately leading to the death of bacteria; (2) Copper metal ions can act as a catalytic active center to stimulate oxygen in water or air to produce hydroxyl radicals (·OH) and reactive oxygen ions (O2). - This leads to oxidative stress, which impairs the bacteria's reproductive capacity and causes their death.

[0007] Therefore, it is necessary to develop an antibacterial material that combines both of these properties for use in making bandages. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a nano-copper oxide antibacterial paper, its preparation method and application, in order to address the shortcomings of the prior art.

[0009] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0010] A nano-copper oxide antibacterial paper includes a paper base, wherein the paper base is coated with nano-copper oxide and an antibacterial active ingredient extracted from pomegranate peel.

[0011] The preparation method of the aforementioned nano-copper oxide antibacterial paper includes the following steps:

[0012] S1. Filter paper is soaked in an aqueous solution of copper sulfate to obtain copper sulfate-impregnated paper;

[0013] S2. Copper sulfate-impregnated paper is placed in pomegranate peel extract, heated, and stirred at the impregnation temperature to obtain nano-copper oxide antibacterial paper.

[0014] As a preferred embodiment, the extraction method of pomegranate peel extract in S2 includes the following steps:

[0015] A) The pomegranate peel is first rinsed with tap water, then rinsed a second time with deionized water, and after drying and crushing, pomegranate peel powder is obtained.

[0016] B) Dissolve the pomegranate peel powder obtained in step A) in methanol, extract it by Soxhlet extraction, filter the filtrate to obtain pomegranate peel extract.

[0017] As a preferred embodiment, the concentration of the copper sulfate aqueous solution in S1 is 0.5~2.0 mol / L.

[0018] As a preferred embodiment, the concentration of the copper sulfate aqueous solution in S1 is 1 mol / L.

[0019] As a preferred embodiment, the impregnation temperature in S2 is 40℃~60℃.

[0020] As a preferred embodiment, the impregnation temperature in S2 is 60°C.

[0021] As a preferred embodiment, the immersion time in S2 is 300~1200s.

[0022] As a preferred embodiment, the immersion time in S2 is 600s.

[0023] Nano-copper oxide antibacterial paper prepared by the method described above is used to make wound dressings.

[0024] Antibacterial mechanism: Pomegranate peel contains pungent glycosides, which have a large number of phenolic hydroxyl groups. These react with copper ions on a paper base to synthesize nano-copper oxide with antibacterial effects. At the same time, pomegranate peel also contains other antibacterial active ingredients (such as tannins), which can enhance the antibacterial effect, resulting in a synergistic antibacterial effect greater than the sum of its parts (1+1>2).

[0025] The beneficial effects of this invention are as follows: by reacting pungent glycosides in pomegranate peel with copper ions, nano-copper oxide with antibacterial effect is generated on the paper base. At the same time, other antibacterial active ingredients contained in pomegranate peel attached to the paper base can enhance the antibacterial effect, achieving a synergistic antibacterial effect of 1+1>2. Using pomegranate peel as raw material to make wound dressings results in low production cost and good antibacterial effect. Attached Figure Description

[0026] Figure 1 This is the mass spectrometry characterization spectrum of the pomegranate extract obtained in Example 1 of the present invention;

[0027] Figure 2 The images show the appearance of the following nano-copper oxide antibacterial paper products of the present invention: (1) obtained in Example 2, (2) obtained in Example 3, (3) obtained in Example 4, (4) obtained in Example 5, (5) obtained in Example 6, (6) obtained in Example 7, (7) obtained in Example 8, (8) obtained in Example 9, (9) obtained in Example 10, (10) obtained in Example 11, (11) obtained in Example 12, and (12) obtained in Example 13.

[0028] Figure 3 The XRD patterns of the paper-based cellulose, pomegranate peel powder, CuO standard, and nano-copper oxide antibacterial paper obtained from Example 11 are shown below.

[0029] Figure 4 This is a particle size distribution diagram of the nano-copper oxide antibacterial paper obtained in Example 11 of the present invention;

[0030] Figure 5 SEM images of nano-copper oxide antibacterial paper 1 (A and B) obtained in Example 2, nano-copper oxide antibacterial paper 4 (C and D) obtained in Example 5, and nano-copper oxide antibacterial paper 10 (E and F) obtained in Example 11 of the present invention;

[0031] Figure 6 This is a graph showing the effect of the nano-copper oxide antibacterial paper prepared in Examples 2-13 of the present invention on inhibiting Escherichia coli;

[0032] Figure 7 The graph shows the effect of the blank paper of the present invention, the paper obtained by soaking in 75% ethanol solution, and the paper obtained by soaking in pomegranate peel extract obtained in Example 1 on inhibiting Escherichia coli.

[0033] Figure 8 This is an analysis diagram of the effect of the nano-copper oxide antibacterial paper prepared in Examples 2-13 of the present invention on inhibiting Staphylococcus aureus;

[0034] Figure 9 The graph shows the effect of the blank paper of the present invention, the paper obtained by soaking in 75% ethanol solution, and the paper obtained by soaking in pomegranate peel extract obtained in Example 1 on inhibiting Staphylococcus aureus. Detailed Implementation

[0035] The structural and working principles of the present invention will be further described in detail below with reference to the accompanying drawings. Example 1

[0036] Preparation of pomegranate peel extract

[0037] S11. Rinse the pomegranate peel with tap water for the first time, then rinse it with deionized water for the second time, dry it at 40°C, and then grind it in a pulverizer to obtain pomegranate peel powder.

[0038] S12. Dissolve 10g of pomegranate peel powder obtained from S11 in 100mL of methanol, extract by Soxhlet extraction, filter the filtrate to obtain pomegranate peel extract, labeled as PPE. Example 2

[0039] Preparation of nano-copper oxide antibacterial paper

[0040] Filter paper was immersed in a 0.5 mol / L CuSO4 solution for 300 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 40 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled as 1. Example 3

[0041] Preparation of nano-copper oxide antibacterial paper

[0042] Filter paper was immersed in a 1 mol / L CuSO4 solution for 600 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 40 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled as 2. Example 4

[0043] Preparation of nano-copper oxide antibacterial paper

[0044] Filter paper was immersed in a 1.5 mol / L CuSO4 solution for 900 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 40 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled 3. Example 5

[0045] Preparation of nano-copper oxide antibacterial paper

[0046] Filter paper was immersed in a 2 mol / L CuSO4 solution for 1200 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 40 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled as 4. Example 6

[0047] Preparation of nano-copper oxide antibacterial paper

[0048] Filter paper was immersed in a 0.5 mol / L CuSO4 solution for 300 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 50 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled as 5. Example 7

[0049] Preparation of nano-copper oxide antibacterial paper

[0050] Filter paper was immersed in a 1 mol / L CuSO4 solution for 600 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 50 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled 6. Example 8

[0051] Preparation of nano-copper oxide antibacterial paper

[0052] Filter paper was immersed in a 1.5 mol / L CuSO4 solution for 900 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 50 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled 7. Example 9

[0053] Preparation of nano-copper oxide antibacterial paper

[0054] Filter paper was immersed in a 2 mol / L CuSO4 solution for 1200 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 50 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled as 8. Example 10

[0055] Preparation of nano-copper oxide antibacterial paper

[0056] Filter paper was immersed in a 0.5 mol / L CuSO4 solution for 300 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 60 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled as 9. Example 11

[0057] Preparation of nano-copper oxide antibacterial paper

[0058] Filter paper was immersed in a 1 mol / L CuSO4 solution for 600 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 60 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled as 10. Example 12

[0059] Preparation of nano-copper oxide antibacterial paper

[0060] Filter paper was immersed in a 1.5 mol / L CuSO4 solution for 900 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 60 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled 11. Example 13

[0061] Preparation of nano-copper oxide antibacterial paper

[0062] Filter paper was immersed in a 2 mol / L CuSO4 solution for 1200 s, then removed and washed to remove residual CuSO4 solution from the fiber surface, yielding copper sulfate-impregnated paper. The prepared copper sulfate-impregnated paper was added to 50 ml of pomegranate peel extract prepared in Example 1 under continuous stirring. After heating at 80 °C for 10 minutes, the mixture was continuously stirred at 60 °C for 4 hours. After cooling to room temperature, the filter paper was removed, its surface was washed with deionized water, and dried to obtain nano-copper oxide antibacterial paper, labeled 12.

[0063] Test Example 1

[0064] Mass spectrometry analysis of pomegranate peel extract

[0065] In the mass spectrometer, the ionization mode was set to electrospray positive ion mode, with an ion source voltage of 5500 V, an ion source temperature of 600 °C, a declustering voltage (DP) of 100 V, a collision energy (CE) of 35 eV, and a collision energy spread (CES) of 15 eV. Nitrogen was used as the nebulizer gas, with auxiliary gas 1 at 60 PSI, auxiliary gas 2 at 50 PSI, and curtain gas at 40 PSI. The primary mass spectrometry precursor ion scan range was 100–1500 cps. The IDA was set to detect the six peaks with response values ​​exceeding 100 cps for secondary mass spectrometry scanning, with the daughter ion scan range also from 100–1500 cps. Dynamic background subtraction (DBS) was enabled. The pomegranate peel extract obtained in Example 1 was then tested, and the results are as follows: Figure 1 As shown.

[0066] Depend on Figure 1 It can be seen that polyphenolic substances such as punicin (1107.0540) were successfully extracted from pomegranate peel extract.

[0067] Test Example 2

[0068] Appearance analysis of nano copper oxide antibacterial paper

[0069] The appearance of the nano-copper oxide antibacterial paper obtained in Examples 2-13 was observed, and the results are as follows: Figure 2 As shown.

[0070] Depend on Figure 2 It can be seen that as the concentration of copper sulfate solution increases, the color of the synthesized nano-copper oxide antibacterial paper gradually changes from light yellow to dark brown; as the impregnation temperature increases, copper ions more easily enter the paper-based cellulose, and the synthesized antibacterial paper is also more dark brown than other paper sheets under the same conditions; as the impregnation time increases, under the same conditions, the amount of Cu ions entering the paper-based cellulose increases. 2+ The increased content leads to larger particle size of the synthesized copper oxide particles, resulting in a darker brown color in the antibacterial paper.

[0071] Test Example 3

[0072] XRD analysis of nano-copper oxide antibacterial paper

[0073] X-ray diffraction (XRD) was used to analyze the samples (paper-based cellulose, pomegranate peel powder, CuO standard, and nano-copper oxide antibacterial paper obtained in Example 11). Test conditions: CuKα rays (λ=1.54184 Å) were used as the incident radiation; the test voltage and current were 40 kV and 40 mA, respectively; the scanning speed was 2° / min; and the scanning range was 5°–40°. The results are as follows: Figure 3 As shown.

[0074] Depend on Figure 3 It can be seen that the XRD curve of the nano-copper oxide antibacterial paper includes the characteristic peaks of paper-based cellulose, pomegranate peel powder, and nano-copper oxide standards. This also indicates that nano-copper oxide was successfully synthesized on paper-based cellulose using pomegranate peel extract (PPE).

[0075] Test Example 4

[0076] Particle size analysis of nano copper oxide antibacterial paper

[0077] Five mg of copper oxide nanoparticles were scraped from the surface of the antibacterial paper obtained in Example 11 and dissolved in 7 ml of methanol solution. The solution was ultrasonically dispersed until transparent. Nanoparticle size data were analyzed using a dynamic light scattering particle size analyzer. Data for the same sample were measured three times, and the results are as follows: Figure 4 As shown.

[0078] Depend on Figure 4 It is known that the average particle size of the copper oxide nanoparticles on the antibacterial paper is 138 nm, which reaches the nanoscale and can penetrate the cell membrane of bacteria, thereby destroying their biological structure.

[0079] Test Example 5

[0080] SEM analysis of nano-copper oxide antibacterial paper

[0081] The microstructures of the nano-copper oxide antibacterial paper 1 obtained in Example 2, the nano-copper oxide antibacterial paper 4 obtained in Example 5, and the nano-copper oxide antibacterial paper 10 obtained in Example 11 were analyzed using a Regulus 8100 scanning electron microscope. The sample surfaces were sputtered with gold to enhance conductivity, and the morphology of the materials was analyzed at 100 nm and 50 nm. The results are as follows: Figure 5 As shown.

[0082] Depend on Figure 5 A~B shows that the antibacterial paper synthesized from nano-copper oxide antibacterial paper 1 contains fewer nano-copper oxide particles. Figure 5 As can be seen from C to D, the nano-copper oxide antibacterial paper 4 has a relatively large number of copper oxide particles synthesized, but some particles show agglomeration, which affects its antibacterial properties. Figure 5 As can be seen from E to F, the nano copper oxide antibacterial paper 10 has a large number of nano copper oxide particles attached to it, and the distribution is relatively uniform.

[0083] Test Example 6

[0084] Analysis of the antibacterial properties of nano-copper oxide antibacterial paper

[0085] 1) The nano-copper oxide antibacterial paper prepared in Examples 2-13 was excited under ultraviolet light for later use. After a period of time, under aseptic conditions, *Escherichia coli* or *Staphylococcus aureus* was inoculated onto the culture medium using a triangular scraper. The culture medium was divided into four equal parts, and four antibacterial paper discs were placed on each part. The culture medium was then placed in an incubator at a controlled temperature of 37°C and humidity of 72% for 24 hours. The results were observed, and the diameter of the inhibition zone was measured. The data are shown in Table 1. A bar graph was plotted with the experiment number as the x-axis and the diameter of the inhibition zone as the y-axis. Figure 6 and Figure 8 As shown.

[0086] 2) Blank paper discs, paper discs soaked in 75% ethanol solution, and paper discs soaked in pomegranate peel extract obtained in Example 1 were placed under UV light for excitation. After a period of time, under aseptic conditions, *Escherichia coli* or *Staphylococcus aureus* were inoculated onto the culture medium using a triangular scraper. The culture medium was divided into four equal portions, and four antibacterial paper discs were placed on each portion. The culture medium was then placed in an incubator at a controlled temperature of 37°C and humidity of 72% for 24 hours. The results were observed, and the diameter of the inhibition zone was measured. A bar graph was plotted with the experimental name as the x-axis and the diameter of the inhibition zone as the y-axis. Figure 7 and Figure 9 As shown.

[0087] Table 1

[0088]

[0089] From Table 1, Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, the antibacterial paper synthesized in experimental group 10 exhibited significant antibacterial effects against both bacterial species. However, the antibacterial paper in experimental group 1 showed no significant inhibitory effect against *Escherichia coli*, and the antibacterial paper in experimental group 4 showed no significant inhibitory effect against *Staphylococcus aureus*. The antibacterial effect was attributed not only to nano-copper oxide but also to the active ingredients in pomegranate peel extract. Therefore, the antibacterial effect of Cu in paper-based cellulose... 2+ Controlling the content of Cu and the content of pomegranate peel extract is particularly important, as it affects the content of Cu. 2+ The main factors affecting the content of cellulose in paper-based cellulose include impregnation time, impregnation temperature, and the concentration of the copper sulfate solution used for impregnation. If Cu... 2+ Excessive CuO content in paper-based cellulose leads to an excessive amount of nano-CuO in the final paper matrix, with larger particle sizes. This results in nano-copper oxide dominating the antibacterial effect, leading to less than ideal antibacterial performance. If Cu... 2+ A low content of copper oxide in paper-based cellulose leads to a lower final concentration of nano-copper oxide in the paper base. In this case, the active substances (polyphenols) in the pomegranate peel extract play a dominant antibacterial role, resulting in a less than ideal antibacterial effect. When Cu... 2+ When the content of paper-based cellulose reaches a moderate level, the content of nano-copper oxide particles in the paper base and the content of active substances (polyphenols) in pomegranate peel extract reach the optimal balance. At this time, the nano-copper oxide particles have a good particle size, and the two substances can play a synergistic inhibitory role against bacteria, achieving an antibacterial effect of 1+1>2.

[0090] The above description is merely a preferred embodiment of the present invention. Any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical solution of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A nano-copper oxide antibacterial paper, characterized in that, The paper base includes nano-copper oxide and antibacterial active ingredients extracted from pomegranate peel; the preparation method of the nano-copper oxide antibacterial paper includes the following steps: S1. Filter paper is soaked in an aqueous solution of copper sulfate to obtain copper sulfate-impregnated paper, wherein the concentration of the aqueous solution of copper sulfate is 0.5~2.0 mol / L; S2. Copper sulfate-impregnated paper is placed in pomegranate peel extract, heated, and stirred at the impregnation temperature. Pomegranate peel contains pungent glycoside, which contains phenolic hydroxyl groups. It reacts with copper ions on the paper base to synthesize nano-copper oxide with antibacterial effect, thus obtaining nano-copper oxide antibacterial paper. The impregnation temperature is 40℃~60℃, and the impregnation time is 300~1200s. The preparation method of the pomegranate peel extract includes the following steps: A) The pomegranate peel is first rinsed with tap water, then rinsed a second time with deionized water, and after drying and crushing, pomegranate peel powder is obtained. B) Dissolve the pomegranate peel powder obtained in step A) in methanol, extract it by Soxhlet extraction, filter the filtrate to obtain pomegranate peel extract.

2. A nano-copper oxide antibacterial paper as described in claim 1 for use in making wound dressings.

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