A graphene-based composite antibacterial material and a preparation method and application thereof

Abstract

The application relates to the technical field of graphene materials, and aims to provide a graphene-based composite antibacterial material, a preparation method and application thereof.The antibacterial material comprises the following raw materials in parts by weight: 100 parts of polypropylene, 9-10 parts of inorganic fillers, 2-3 parts of graphene powder, 0.4-0.6 parts of mineral oil, 0.5-0.6 parts of a compatilizer, 0.5-0.6 parts of an antioxidant, and 0.1-0.15 parts of an ultraviolet light absorber.The graphene can fully play the advantages of antibacterial and antistatic properties, and under the same graphene dosage, the antibacterial performance and the antistatic performance of the product are more excellent, and the comprehensive performance is better.

Description

Technical Field

[0001] The present invention relates to the technical field of graphene materials, and in particular to a graphene-based composite antibacterial material, a preparation method thereof, and applications thereof. Background Art

[0002] In recent years, with the improvement of people's living standards and the development of scientific research and technology, antibacterial materials have become increasingly popular and their application scope has become increasingly wide. Traditional antibacterial materials have many limitations, such as the volatility and precipitation of organic antibacterial agents, the poor heat resistance and durability of natural antibacterial agents, the high cost of inorganic antibacterial agents, and their easy oxidation, which leads to a decrease in antibacterial performance. Graphene is a two-dimensional material with a single-layer sheet structure composed of carbon atoms. It has excellent properties such as high specific surface area, outstanding mechanical properties, thermal conductivity, and efficient electron transfer. Studies have shown that the layered structure of graphene can directly pierce the cell membrane of bacteria, causing the leakage of bacterial contents and causing their death, and has low toxicity to mammalian cells. It can be added as an effective antibacterial component to antibacterial materials.

[0003] However, existing graphene antibacterial products still have the following shortcomings: (1) insufficient hydrophilicity makes the material surface easy to absorb stains and difficult to clean; (2) limited antibacterial ability makes it inefficient in sterilization in complex environments; (3) poor antistatic effect can easily cause dust adhesion or safety hazards due to charge accumulation; (4) weak UV protection makes the material easy to age and deteriorate under light conditions, and poor anti-aging performance greatly shortens its service life. These problems have seriously limited the application of antibacterial materials in fields with high comprehensive performance requirements such as medical treatment, food packaging, and electronic equipment, especially in various medical and health care products. Summary of the Invention

[0004] The purpose of the present invention is to provide a graphene-based composite antibacterial material with good hydrophilicity, strong antibacterial, antistatic and UV protection properties, and excellent comprehensive performance.

[0005] To achieve the above-mentioned purpose of the invention, the technical solution adopted by the present invention is: a graphene-based composite antibacterial material, comprising the following raw materials in parts by weight: 100 parts of polypropylene, 9-10 parts of inorganic filler, 2-3 parts of graphene powder, 0.4-0.6 parts of mineral oil, 0.5-0.6 parts of compatibilizer, 0.5-0.6 parts of antioxidant, and 0.1-0.15 parts of ultraviolet light absorber.

[0006] Preferably, the inorganic filler is heavy calcium powder.

[0007] Preferably, the antioxidant is B215.

[0008] Preferably, the ultraviolet light absorber is UV-531.

[0009] Preferably, the compatibilizer is PP-g-MAH.

[0010] Preferably, the method for preparing the composite antibacterial material comprises the following steps:

[0011] S1. Graphene powder pretreatment:

[0012] Graphene powder is first mixed with mineral oil and then ultrasonically treated to reduce graphene powder agglomeration and improve its dispersion in the polypropylene matrix;

[0013] S2. Raw material premixing:

[0014] Pour polypropylene, inorganic filler, compatibilizer, antioxidant, and ultraviolet light absorber into a mixer and mix at 800-1000 rpm for 10 minutes to evenly disperse the powder on the surface of the polypropylene particles;

[0015] The pretreated graphene prepared in S1 was slowly added to the mixer at a speed of 300-500 rpm and the mixing was continued for 5 minutes;

[0016] S3, melt coextrusion:

[0017] The mixed materials in step S2 are put into a twin-screw extruder, the extrusion temperature is set to 180-210°C, the screw speed is set to 150-200rpm, the materials are melt-blended and then extruded from the die head, and pelletized through a water-cooled pelletizing system with a particle size controlled at 3-5mm; thus, the product graphene antibacterial masterbatch is obtained.

[0018] Preferably, in step S1, the graphene powder is first dispersed in ethanol at a mass ratio of 1:10 by mechanical stirring, ultrasonically treated for 30 minutes to make it uniformly dispersed, and then vacuum dried at 60°C until the ethanol is completely volatilized; 2 times the amount of mineral oil is added to the dried graphene powder, stirred for 5 minutes, so that the mineral oil fully wraps the graphene powder; then centrifuged at 3000rpm for 10-15 minutes, and the excess mineral oil supernatant is removed, the removal rate is not less than 85, and the total amount of mineral oil is maintained within the raw material ratio range; and pretreated graphene is obtained.

[0019] Preferably, in step S1, the graphene powder is added to mineral oil within 3 minutes after being treated with ethanol and dried to prevent secondary agglomeration.

[0020] Preferably, in step S1, after adding the graphene powder to the mineral oil, the mixture is stirred at a speed of 200-300 rpm for 5 minutes to prevent excessive shear force from damaging the graphene structure.

[0021] Preferably, the graphene antibacterial masterbatch is used as an additive, mixed with polypropylene and the non-woven fabric is prepared by a melt-blowing process.

[0022] The beneficial effects of the present invention are concentrated in:

[0023] 1. In general, the present invention can give full play to the antibacterial and antistatic advantages of graphene. Under the same amount of graphene, the antibacterial and antistatic properties of the product are more excellent, and the overall performance is better;

[0024] 2. Through special graphene pretreatment process:

[0025] Ethanol is a polar molecule. Its polar groups (hydroxyl groups) attract functional groups on the graphene surface (such as hydroxyl and carboxyl groups) through electrostatic interactions and hydrogen bonding. This allows ethanol molecules to intercalate between graphene sheets, weakening the van der Waals forces between the sheets and facilitating their exfoliation, resulting in a single- or few-layer structure. Leveraging the polarity of ethanol, combined with ultrasound to pre-disperse graphene powder, fully exfoliates the graphene sheets, maintaining good subsequent dispersion and ensuring both conductivity and antimicrobial activity. This method achieves superior exfoliation compared to dispersion using mineral oil alone.

[0026] After exfoliation with ethanol, the graphene is then wrapped with mineral oil. This, on the one hand, can inhibit the reagglomeration of the dried graphene and maintain a single / few-layer dispersion state. On the other hand, compared with simple ethanol dispersion, the non-polar properties of mineral oil can neutralize the surface polarity of the graphene after ethanol treatment, forming a stronger interface bond with the PP matrix through the PP-g-MAH compatibilizer, thereby improving strength and toughness. Mineral oil also has a lubricating effect, which can improve the fluidity of graphene and reduce extrusion torque, allowing it to be more efficiently dispersed into the PP matrix.

[0027] 3. The graphene powder is pretreated with a segmented treatment system of ethanol + mineral oil. Since the dispersion of graphene is fully guaranteed, there is no need to overly consider the exfoliation of graphene sheets during the melt co-extrusion process, which allows for reduced shear force. This also avoids the problem of graphene sheet structure damage caused by high shear force and ensures the overall performance of the product. DETAILED DESCRIPTION

[0028] This invention discloses a graphene-based composite antimicrobial material, a graphene antimicrobial masterbatch, widely used as an additive in the preparation of medical and sanitary products. In particular, it is mixed with polypropylene and melt-blown to produce non-woven fabrics. The composite antimicrobial material comprises the following raw materials by weight: 100 parts of a matrix (polypropylene), 9-10 parts of an inorganic filler (heavy calcium powder), 2-3 parts of graphene powder, 0.4-0.6 parts of a lubricant (mineral oil), 0.5-0.6 parts of a compatibilizer (PP-g-MAH), 0.5-0.6 parts of an antioxidant (B215), and 0.1-0.15 parts of a UV absorber (UV-531). The composition by mass is as follows: 87.5% polypropylene, 8.5% heavy calcium powder, 2.5% graphene powder, 0.4% mineral oil, 0.5% PP-g-MAH, 0.5% antioxidant, and 0.1% UV absorber. The addition of PP-g-MAH of the present invention can significantly improve the hydrophilicity of the hydrophobic polypropylene substrate; the addition of the ultraviolet light absorber can improve the product with the graphene ice wall effect.

[0029] The present invention also discloses a method for preparing the graphene-based composite antibacterial material, and the specific steps are as follows:

[0030] S1. Graphene powder pretreatment:

[0031] Graphene powder is first mixed with mineral oil and then ultrasonically treated to reduce graphene powder agglomeration and improve its dispersion within the polypropylene matrix. The specific method employed is to first disperse the graphene powder in ethanol at a mass ratio of 1:10 using mechanical stirring, ultrasonically treat for 30 minutes to achieve uniform dispersion, and then vacuum dry at 60°C until the ethanol is completely volatilized. Because ethanol is a polar molecule, its polar groups (hydroxyl groups) attract functional groups on the graphene surface (such as hydroxyl and carboxyl groups) through electrostatic interactions and hydrogen bonding, prompting ethanol molecules to insert between graphene sheets, weakening the van der Waals forces between the sheets and facilitating the exfoliation of the sheets, forming a single-layer or few-layer structure. By combining the polarity of ethanol with ultrasonic pre-dispersion of the graphene powder, the exfoliation of the graphene sheets is fully achieved, maintaining good subsequent dispersion and ensuring both conductivity and antibacterial activity. Compared to dispersion using mineral oil alone, the exfoliation effect is better.

[0032] Then add 2 times the amount of mineral oil to the dried graphene powder and stir for 5 minutes to allow the mineral oil to fully wrap the graphene powder. Stir at a low speed of 200-300 rpm to prevent excessive mechanical stirring shear force from damaging the graphene sheets, thereby forming smaller fragments or nanoparticles, or even destroying its SP 2The conjugated structure disrupts the conductive network of the graphene sheets, reducing their specific surface area and thus affecting their conductivity and antibacterial properties. In the method described herein, when the amount of mineral oil exceeds twice the mass of the graphene, it completely coats the π-π bond sites at the edges of the graphene sheets, inhibiting sheet stacking through an "oil film isolation effect." For example, when 2.5g of graphene is dispersed in 5g of mineral oil, the oil film thickness can reach 2-3nm, exceeding the interlayer spacing of the graphene sheets (0.34nm), creating a "colloidal protection" effect. This method of exfoliating the graphene with ethanol and then wrapping it with mineral oil can, on the one hand, inhibit the reagglomeration of the polyethylene after drying and maintain a single / few-layer dispersion state. On the other hand, compared with the use of ethanol dispersion alone, the non-polar properties of mineral oil can neutralize the surface polarity of the graphene after ethanol treatment, and subsequently form a stronger interfacial bond with the PP matrix through the PP-g-MAH compatibilizer, improving strength and toughness. Mineral oil also has a lubricating effect, which can improve the flowability of graphene and reduce the subsequent extrusion torque, allowing it to be more efficiently dispersed into the PP matrix. It should be noted that after ethanol treatment and drying, the graphene needs to be combined with mineral oil as soon as possible to avoid secondary agglomeration caused by excessive idling time. Graphene powder usually needs to be added to the mineral oil within 3 minutes.

[0033] Because the overall system requires a low mineral oil content, it can weaken the intermolecular forces of polypropylene, reducing the material's ultimate strength and hardness, increasing its flexibility excessively, and even causing problems such as stickiness and deformation. The weight ratio of mineral oil to graphene powder in the composite antibacterial material of the present invention is approximately 0.4-0.6:2-3. After the graphene is encapsulated using the excess mineral oil, the excess mineral oil should be removed to avoid adverse effects on the material. The timing of centrifugation should coincide with the premixing of the raw materials as much as possible. That is, after removing the excess mineral oil, the graphene-mineral oil should be combined with the other raw materials for premixing as soon as possible. The present invention uses low-speed centrifugation to separate the excess mineral oil from the graphene, typically at 3000 rpm for 10-15 minutes. The excess mineral oil supernatant is removed with a removal rate of no less than 85%, ultimately maintaining the total amount of mineral oil within the raw material ratio. After treatment, the pretreated graphene is obtained. During centrifugation, avoid using excessively high centrifugal speeds to prevent the graphene from agglomerating again. For example, when the amount of graphene is 3 parts, the amount of mineral oil added is 6 parts. During centrifugation, at least 5.4 parts of mineral oil should be removed, with a removal rate of 90%. When the amount of graphene is 2 parts, the amount of mineral oil added is 4 parts. During centrifugation, at least 3.4 parts of mineral oil should be removed, with a removal rate of 85%.

[0034] S2. Raw material premixing:

[0035] Pour polypropylene, inorganic filler, compatibilizer, antioxidant, and ultraviolet light absorber into a mixer and mix at 800-1000 rpm for 10 minutes to evenly disperse the powder on the surface of the polypropylene particles; slowly add the pretreated graphene prepared in S1 into the mixer at 300-500 rpm and continue mixing for 5 minutes;

[0036] S3, melt coextrusion:

[0037] The mixed materials in step S2 are put into a twin-screw extruder, the extrusion temperature is set to 180-210°C, the screw speed is set to 150-200rpm, the materials are melt-blended and then extruded from the die head, and pelletized through a water-cooled pelletizing system with a particle size controlled at 3-5mm; thus, the product graphene antibacterial masterbatch is obtained.

[0038] In order to further elaborate on the effects of the present invention, the following description will be given in conjunction with embodiments.

[0039] Example 1: A composite antibacterial material comprising the following raw materials in parts by weight: 100 parts polypropylene, 9.7 parts heavy calcium powder, 2.8 parts graphene powder, 0.57 parts compatibilizer PP-g-MAH, 0.57 parts antioxidant B215, and 0.1 parts ultraviolet light absorber UV-531. The preparation method comprises:

[0040] S1. Graphene powder pretreatment:

[0041] Graphene powder was first dispersed in ethanol at a mass ratio of 1:10 using mechanical stirring. Ultrasonic treatment was then performed for 30 minutes to achieve uniform dispersion. The powder was then vacuum dried at 60°C until the ethanol was completely evaporated. Within 3 minutes, 5.6 parts of mineral oil were added to the dried graphene powder, and the mixture was stirred at 200 rpm for 5 minutes. The mixture was then centrifuged at 3000 rpm for 10 minutes, and approximately 5.1 parts of excess mineral oil supernatant was removed, leaving approximately 0.5 parts of mineral oil, a removal rate of approximately 91%. Pretreated graphene was obtained after the treatment was completed.

[0042] S2. Raw material premixing:

[0043] Pour polypropylene, heavy calcium powder, PP-g-MAH, antioxidant B215, and ultraviolet absorber UV-531 into a mixer and mix at 800-1000 rpm for 10 minutes to evenly disperse the powder on the surface of the polypropylene particles; slowly add the pretreated graphene prepared in S1 into the mixer at 300 rpm and continue mixing for 5 minutes;

[0044] S3, melt coextrusion:

[0045] The mixed materials in step S2 are put into a twin-screw extruder, the extrusion temperature is set to 180-210°C (the temperature of the front section is 180-190°C, the middle section is 190-200°C, the rear section is 200-210°C, and the head temperature is 200°C), the screw speed is 200 rpm, the materials are melt-blended and then extruded from the die head, and pelletized by a water-cooled pelletizing system with a particle size controlled at 3 mm; thus, the graphene antibacterial masterbatch is obtained.

[0046] Example 2: The raw material components are the same as those in Example 1, and the preparation step S1 is different. The difference is that in step S1, 0.5 parts of mineral oil are directly mixed with 2.8 parts of graphene powder, and ultrasonically treated for 30 minutes to prepare mineral oil-pretreated graphene powder; the rest are processed in sequence according to steps S2 and S3.

[0047] Example 3: The raw material components are the same as those in Example 1, and the preparation step S1 is different. The difference is that in step S1, 5.6 parts of mineral oil are directly mixed with 2.8 parts of graphene powder and ultrasonically treated for 30 minutes. After the treatment is completed, centrifugation is performed in the same manner as Example 1 to remove about 5.1 parts of excess mineral oil supernatant, leaving about 0.5 parts of mineral oil to prepare mineral oil-pretreated graphene powder; the rest are processed in sequence according to steps S2 and S3.

[0048] Comparative Example 1: The raw material components are the same as those in Example 1, except that step S1 is omitted. In step S2, all raw materials are directly premixed in the same manner (mineral oil and graphene are still added at a low speed for premixing).

[0049] Comparative Example 2: The raw material components are the same as those in Example 1, and the preparation steps S1 and S2 are different. The difference is that:

[0050] In step S1, the graphene powder is directly dispersed in ethanol at a mass ratio of 1:10 by mechanical stirring, ultrasonically treated for 30 minutes to uniformly disperse it, and then vacuum dried at 60° C. until the ethanol is completely volatilized, thereby completing the pretreatment of the graphene;

[0051] In step S2, all raw materials are premixed (mineral oil and graphene are still added at a low speed for premixing).

[0052] The antibacterial particle masterbatches prepared in Example 1, Example 2 and Example 3, and Comparative Example 1 and Comparative Example 2 were observed cross-sectionally using a scanning electron microscope (SEM). The dispersion uniformity of the graphene in the polypropylene matrix in each example was compared. The cross-section was divided into four quadrants with a cross at the center of the cross-section. The uniformity was determined by judging the similarity of the images of the four quadrants under the microscope. A five-level scoring system was set: excellent, good, good, fair, and poor. The average size of the agglomerates was also calculated; the larger the size, the worse the dispersion.

[0053]

[0054] It can be clearly seen from the above table that after pre-treating graphene according to the ethanol-mineral oil combination treatment method of the present invention, the dispersion of graphene in the PP matrix is ​​greatly improved, and both the dispersion uniformity and the agglomeration size performance are extremely excellent.

[0055] The antimicrobial particle masterbatch prepared in Examples 1, 2, and 3, and Comparative Examples 1 and 2, was mixed with polypropylene and melt-blown to produce non-woven fabrics. The ratio of antimicrobial particle masterbatch to polypropylene was 1:19, and the antimicrobial particle masterbatch content was 5%. Non-woven fabrics without the antimicrobial particle masterbatch were used as a blank control group. All non-woven fabrics were tested for hydrophilicity, antistatic properties, antimicrobial properties, and UV resistance. The test methods and results are as follows:

[0056] Hydrophilicity:

[0057] Cut a 5 cm x 5 cm nonwoven fabric sample and equilibrate it in a standard environment (temperature 21 ± 1°C, humidity 65% ​​± 2%) for 24 hours. Position the sample horizontally at the mouth of a beaker. Use a burette to drip one drop of distilled water (approximately 0.05 mL) at 21 ± 3°C onto the sample surface. Simultaneously, start a stopwatch and record the time it takes for the water droplet to be completely absorbed (specular reflection disappears). Repeat the test at five different locations and calculate the average wetting time. The shorter the time, the more hydrophilic the sample.

[0058]

[0059] When the PP-g-MAH (polypropylene-grafted-maleic anhydride) compatibilizer is added, the maleic anhydride (MAH) groups carry polar carboxyl groups (-COOH). These polar groups can form hydrogen bonds with water molecules, thereby improving the material's hydrophilicity. However, pure PP resin is a non-polar polymer with poor hydrophilicity, and untreated graphene is also hydrophobic. When the two are combined, interfacial compatibility is poor, making it difficult to directly improve hydrophilicity. MAH is grafted onto the PP backbone, introducing polar sites into the non-polar PP system. When the compatibilizer is combined with PP and graphene, the polar -COOH groups are exposed on the material surface or interface, where they hydrogen bond with water molecules, reducing surface energy and increasing hydrophilicity.

[0060] Antistatic properties:

[0061] Prepare a surface resistance tester and a temperature and humidity control box; cut a 10cm×10cm sample and equilibrate it in an environment with a temperature of 23±2℃ and a humidity of 50%±5% for 4 hours; place the sample on a metal test table, press an electrode (5cm in diameter) on the sample surface, apply a 100V DC voltage, and read the surface resistance value after 10 seconds; if the resistance value is less than 10 9 Ω, the antistatic performance is better; the lower the resistance value, the stronger the antistatic performance.

[0062]

[0063] The table above shows that the addition of a graphene-containing antimicrobial particle masterbatch to a nonwoven fabric significantly improves its overall antistatic properties. This improvement is correlated with the graphene's dispersibility within the PP matrix. The nonwoven fabric prepared with the antimicrobial particle masterbatch prepared in Example 1, which pre-treated the graphene with an ethanol-mineral oil combination, exhibited the most outstanding performance.

[0064] Antimicrobial properties:

[0065] Adopt ISO 20743 "Determination of antimicrobial properties of textiles"

[0066] Activate Escherichia coli (ATCC 8739) and culture to the logarithmic growth phase to prepare a concentration of about 1*10 8 CFU / mL of bacterial suspension; cut 1cm×1cm samples, place them in a conical flask containing 10mL of bacterial suspension after sterilization, and culture them at 37℃ with shaking for 18 hours; dilute the bacterial suspension at 0 hour and 18 hours, spread it on nutrient agar plates, and culture them at 37℃ for 48 hours; calculate the results: antibacterial rate = [(control bacterial count - sample bacterial count) / control bacterial count] × 100%. An antibacterial rate > 90% is considered to have antibacterial activity.

[0067]

[0068] As can be seen from the above table, after the antibacterial particle masterbatch containing graphene is added to the non-woven fabric system, the overall antibacterial properties of the non-woven fabric are also greatly improved. This improvement is similar to the antistatic property and is also correlated with the dispersion of graphene in the PP matrix. Among them, the non-woven fabric prepared by combining the antibacterial particle masterbatch prepared in Example 1 in which the graphene is pretreated by a combination of ethanol and mineral oil has the most outstanding performance.

[0069] In addition, the present invention also tested the nonwoven fabric samples for UV resistance using GB / T 18830, "Evaluation of the UV Protection of Textiles." While the UV protection achieved was also high, its overall performance was not significantly different from that of conventional nonwoven fabrics containing the same amount of UV absorber (UV-531), so this information is not further described in this invention.

[0070] In summary, the graphene-based composite antibacterial material disclosed in the present invention, on the basis of the same amount of graphene, ensures the high dispersion of graphene in the PP substrate through a specific preparation process. This graphene-based composite antibacterial material has extremely excellent comprehensive performance.

Claims

1. A graphene-based composite antibacterial material, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of polypropylene, 9-10 parts of inorganic filler, 2-3 parts of graphene powder, 0.4-0.6 parts of mineral oil, 0.5-0.6 parts of compatibilizer, 0.5-0.6 parts of antioxidant, and 0.1-0.15 parts of ultraviolet light absorber; the compatibilizer is PP-g-MAH; The graphene powder is exfoliated with ethanol and then coated with an excess of mineral oil to prevent the graphene powder from agglomerating after the ethanol treatment and to adjust the surface polarity of the graphene powder after the ethanol treatment. The method comprises the following steps: S1. Graphene powder pretreatment: First, the graphene powder is dispersed in ethanol at a mass ratio of 1:10 by mechanical stirring, ultrasonically treated for 30 minutes to make it uniformly dispersed, and then vacuum dried at 60°C until the ethanol is completely volatilized; within 3 minutes, 2 times the amount of mineral oil is added to the dried graphene powder to prevent secondary agglomeration; stirred at a speed of 200-300 rpm for 5 minutes to allow the mineral oil to fully wrap the graphene powder and prevent excessive shear force from damaging the graphene structure; then centrifuged at 3000 rpm for 10-15 minutes to remove excess mineral oil supernatant, with a removal rate of not less than 85%, so that the total amount of mineral oil is maintained within the raw material ratio range; and pretreated graphene is obtained.

2. The graphene-based composite antibacterial material according to claim 1, characterized in that: The inorganic filler is heavy calcium powder.

3. The graphene-based composite antibacterial material according to claim 1, characterized in that: The antioxidant is B215.

4. The graphene-based composite antibacterial material according to claim 3, characterized in that: The ultraviolet light absorber is UV-531.

5. The method for preparing a graphene-based composite antibacterial material according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Graphene powder pretreatment: First, the graphene powder is dispersed in ethanol at a mass ratio of 1:10 by mechanical stirring, ultrasonically treated for 30 minutes to make it uniformly dispersed, and then vacuum dried at 60°C until the ethanol is completely volatilized; within 3 minutes, 2 times the amount of mineral oil is added to the dried graphene powder to prevent secondary agglomeration; stirring at a speed of 200-300 rpm for 5 minutes to allow the mineral oil to fully wrap the graphene powder and prevent excessive shear force from damaging the graphene structure; then centrifuged at 3000 rpm for 10-15 minutes to remove excess mineral oil supernatant, with a removal rate of not less than 85%, so that the total amount of mineral oil is maintained within the raw material ratio range; to obtain pretreated graphene; S2. Raw material premixing: Pour polypropylene, inorganic filler, compatibilizer, antioxidant, and ultraviolet light absorber into a mixer and mix at 800-1000 rpm for 10 minutes to evenly disperse the powder on the surface of the polypropylene particles; The pretreated graphene prepared in S1 was slowly added to the mixer at a speed of 300-500 rpm and the mixing was continued for 5 minutes; S3, melt coextrusion: The mixed materials in step S2 are put into a twin-screw extruder, the extrusion temperature is set to 180-210°C, the screw speed is set to 150-200rpm, the materials are melt-blended and then extruded from the die head, and pelletized through a water-cooled pelletizing system with a particle size controlled at 3-5mm; thus, the product graphene antibacterial masterbatch is obtained.

6. Application of the graphene-based composite antibacterial material prepared by the method according to claim 5, characterized in that: Graphene antibacterial masterbatch was used as an additive, mixed with polypropylene and prepared into non-woven fabric through melt-blowing process.

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