Preparation method and application of graphene / ferroferric oxide composite film
By preparing a graphene/iron tetroxide composite film, the dispersion and cost issues of graphene-based electromagnetic shielding materials were solved, achieving a high-efficiency and low-cost electromagnetic shielding effect.
Patent Information
- Application Number
- CN202510756260.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-08
- Publication Date
- 2025-11-07
AI Technical Summary
Existing graphene-based electromagnetic shielding materials suffer from poor graphene sheet dispersion, resulting in uneven conductive networks that affect electromagnetic shielding effectiveness and mechanical properties, and are also costly.
In-situ reduction technology was used to prepare graphene/ferric oxide composite film. The rGO/Fe3O4 composite material was generated by reacting graphene oxide with ferrous chloride solution and then mixed with polymer to form a uniform microscopic heterogeneous interface structure, thereby improving electromagnetic shielding performance.
It achieves high-performance, multi-purpose electromagnetic shielding, reduces material costs, and improves the dispersion of graphene sheets and the uniformity of conductive networks.
Smart Images
Figure CN120904489A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of composite materials, and particularly relates to a preparation method of a graphene / ferroferric oxide composite film and application thereof. BACKGROUND
[0002] With the rapid progress of communication technology and electronic equipment, and their widespread application in many fields such as military, medical, industrial and commercial, the problem of electromagnetic radiation pollution has become increasingly serious, becoming the fourth environmental problem after noise pollution, air pollution and water pollution. Electromagnetic radiation not only interferes with the normal function of electronic equipment, but also poses a threat to human health. Therefore, in order to reduce or avoid the adverse effects of electromagnetic radiation, high-performance electromagnetic interference (EMI) shielding materials have attracted widespread attention.
[0003] The use of graphene-based materials to develop high-performance, wide-band, light and flexible electromagnetic shielding materials has shown great application potential. In current research and application, most graphene electromagnetic shielding materials are prepared by mixing graphene as a filler with a polymer. However, this material preparation method based on filling has some significant problems. First, in order to achieve the desired shielding effect, a high proportion of graphene filler is required, which leads to an increase in material cost. Second, due to the strong van der Waals force and electrostatic force between graphene layers, their dispersion in the polymer matrix is poor. This dispersion problem further leads to the aggregation of graphene layers, making it difficult to form a uniform distribution and thus an optimal conductive network structure. This uneven conductive network not only affects the electromagnetic shielding performance of the material, but also can have a negative impact on the mechanical properties and stability of the material. SUMMARY
[0004] Therefore, the application aims to provide a graphene / ferroferric oxide composite film to solve the technical problems of uneven mixing of composite materials and poor performance.
[0005] The application provides a preparation method of a graphene / ferroferric oxide composite film, which comprises the following steps:
[0006] Step 1: ultrasonic treatment of graphene oxide solution and ferrous chloride solution to obtain a mixed solution, then add ammonia water, stir until the reaction is complete, use a magnet to separate the reaction to obtain rGO / Fe3O4 composite powder, wash the rGO / Fe3O4 composite powder with deionized water, and dry to obtain rGO / Fe3O4 composite material;
[0007] Step 2: mix the rGO / Fe3O4 composite material with polyvinylpyrrolidone, perform dry grinding treatment to obtain the required powder, and then add water-based polyurethane to obtain a mixture after stirring.
[0008] Step 3: the mixture obtained in step 2 is applied to the substrate and dried to obtain the composite film.
[0009] Further, the concentration of the graphene oxide solution in step 1 is 0.1 mg / mL to 20 mg / mL, and the concentration of the ferrous chloride solution is 10 mg / mL to 40 mg / mL.
[0010] Further, the method for obtaining graphene oxide in step 1 is: graphene oxide is dispersed in deionized water, and ultrasonic treatment is performed at 300 w to 1000 w for 0.5 h to 1 h to obtain a graphene oxide solution; the method for obtaining the ferrous chloride solution in step 1 is: ferrous chloride tetrahydrate is dispersed in deionized water, and ultrasonic treatment is performed at 300 w to 1000 w for 0.5 h to 1 h to obtain a ferrous chloride solution; the ultrasonic frequency is 300 w to 1000 w, and the time is 0.5 h to 1 h.
[0011] Further, the stirring speed in step 1 is 1000 rpm to 2500 rpm.
[0012] Further, the amount of ammonia used in step 1 is 20 ml to 25 ml of ammonia water with a concentration of 25% to 28% by mass.
[0013] Further, the mixing ratio of the rGO / Fe3O4 composite material to polyvinylpyrrolidone in step 2 is 20:1.
[0014] Further, the mass ratio of the rGO / Fe3O4 composite material powder to the polymer in step 2 is 1:(6 to 15), and the stirring is performed for 5 min, 10 min, and 15 min in three times.
[0015] Further, in step 3, the coating thickness is 30 μm to 400 μm, and the drying is performed at 40°C to 110°C for 2 h to 8 h; the substrate is a copper foil, PET, PI, or conductive cloth.
[0016] The application provides a graphene / ferroferric oxide composite film prepared by the above method.
[0017] The application provides an application of the above method or the above electromagnetic shielding composite film in shielding electromagnetism.
[0018] Compared with the prior art, the beneficial effects of the present application are: the in-situ reduction technology is adopted to successfully prepare a graphene / ferroferric oxide (rGO / Fe3O4) composite electromagnetic shielding coating film. The advantages are that the raw materials used are widely available and low in price, the preparation process is safe and easy to operate; during the reduction of graphene oxide, the surface epoxy functional groups and hydroxyl groups gradually disappear, the enhancement of van der Waals force and π-π stacking promotes the increase of the number of cross-linking between graphenes, forming a graphene (rGO) network. The in-situ reduction method makes the Fe3O4 nanospheres uniformly distributed on the graphene network, constructing a micro-heterogeneous interface "point (Fe3O4)-face (rGO)" structure. By adjusting the coating formula and coating process of the rGO / Fe3O4 composite electromagnetic shielding material, the comprehensive performance of the electromagnetic shielding product is further improved, and the development goal of multi-purpose and high-performance electromagnetic shielding products is realized. BRIEF DESCRIPTION OF DRAWINGS
[0019] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application. The accompanying drawings do not constitute an inappropriate limitation on the present application. In the drawings:
[0020] Figure 1 The graphene / ferroferric oxide (rGO / Fe3O4) composite electromagnetic shielding coating film of embodiment 1 of the present application is shown in the photos below:
[0021] Figure 2 The X-ray diffraction pattern of the graphene / ferroferric oxide (rGO / Fe3O4) composite material of embodiment 1 of the present application is shown below:
[0022] Figure 3 The micro-morphology and element surface distribution map under scanning electron microscope of embodiment 1 of the present application are shown below:
[0023] Figure 4 The micro-morphology under transmission electron microscope of embodiment 1 of the present application is shown below:
[0024] Figure 5 The electromagnetic shielding efficiency comparison spectrum of embodiment 1 of the present application is shown below: DETAILED DESCRIPTION
[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only a part of the embodiments of the present application, not all the embodiments.
[0026] Ferrous chloride tetrahydrate (cas number 13478-10-9); polyvinylpyrrolidone (cas number 9003-39-8);
[0027] Aqueous polyurethane (Macklin A909856); epoxy resin (Macklin E871955).
[0028] Obtaining graphene oxide powder: In a three-necked flask (or beaker), 1 g of flake graphite was added, followed by 45 mL of concentrated sulfuric acid and 5 mL of phosphoric acid, and cooled to 0°C in an ice water bath. 7 g of potassium permanganate was slowly added under rapid stirring, and the temperature of the ice water bath system was maintained below 15°C for 30 minutes. The temperature was raised to 50°C, and the reaction was allowed to proceed for 18 h. The reaction mixture was cooled to room temperature, and 150 mL of deionized water was slowly added under ice water bath. After the reaction was poured out, an appropriate amount of hydrogen peroxide solution (about 20 mL) was added until the solution turned golden yellow and no more bubbles were generated. The solution was allowed to stand and filter, and the product was washed with dilute hydrochloric acid (1:10 by volume, 1 L). The product was washed with deionized water until there was no sulfate radical in the filtrate (detected by BaCl2 solution). The washed graphene oxide was prepared into a graphene oxide solution for storage, and finally the product was placed in a constant temperature air drying oven for drying, thereby obtaining graphene oxide powder.
[0029] Example 1: Preparation method of graphene / ferroferric oxide electromagnetic shielding composite film in this embodiment
[0030] Step 1: In a three-necked flask (or beaker), 1 g of flake graphite was added, followed by 45 mL of concentrated sulfuric acid and 5 mL of phosphoric acid, and cooled to 0°C in an ice water bath. 7 g of potassium permanganate was slowly added under rapid stirring, and the temperature of the ice water bath system was maintained below 15°C for 30 minutes. The temperature was raised to 50°C, and the reaction was allowed to proceed for 18 h. The reaction mixture was cooled to room temperature, and 150 mL of deionized water was slowly added under ice water bath. After the reaction was poured out, an appropriate amount of hydrogen peroxide solution (about 20 mL) was added until the solution turned golden yellow and no more bubbles were generated. The solution was allowed to stand and filter, and the product was washed with dilute hydrochloric acid (1:10 by volume, 1 L). The product was washed with deionized water until there was no sulfate radical in the filtrate (detected by BaCl2 solution). The washed graphene oxide was prepared into a graphene oxide solution for storage, and finally the product was placed in a constant temperature air drying oven for drying, thereby obtaining graphene oxide powder.
[0031] Step 2: 0.03 g of graphene oxide was uniformly dispersed in 300 mL of deionized water under the condition of an ultrasonic frequency of 300 w, thereby obtaining a graphene oxide solution;
[0032] Step 3: 1 g of ferrous chloride tetrahydrate was uniformly dispersed in 100 mL of deionized water under the condition of an ultrasonic frequency of 300 w, thereby obtaining a ferrous chloride solution;
[0033] Step 4: The graphene oxide solution obtained in step 1 was ultrasonically treated for 0.5 h under the condition of an ultrasonic frequency of 300 w, and then the mixed solution was added under the condition of strong stirring (stirring speed of 1000 rpm), and then ultrasonically treated for 0.5 h under the condition of an ultrasonic frequency of 300 w;
[0034] Step 5: Then 20 ml of 25% ammonia water was added to the mixed solution, and the solution was sealed and stirred at room temperature (1000 rpm) for 12 hours until the reaction was completed. Then the reaction product was separated by a magnet to obtain the rGO / Fe3O4 composite on the magnet, and then the rGO / Fe3O4 composite was cleaned by deionized water for at least three times and then cleaned by anhydrous ethanol once. Finally, the product was placed in a constant temperature drying oven at 60 DEG C for 2 hours to obtain the rGO / Fe3O4 composite;
[0035] Fe 2+ + GO (8OH - ) → Fe3O4 + 4H2O + rGO
[0036] Step 6: 1g of rGO / Fe3O4 composite was mixed with 0.05g of polyvinylpyrrolidone K30 (PVP) and then added to a mortar for dry grinding for 40 minutes. The ground powder was placed in a 100ml beaker.
[0037] Step 7: 6g of aqueous polyurethane was added to the beaker in three times of 2g, 2g and 2g at 5min, 10min and 15min under stirring condition, and then the stirring was continued for 300min. The coating film was coated on a copper foil by a coater and then placed in a drying oven for drying for 2 hours. After drying, the coating film was cut into a sample piece with a size of 4cm*4cm and a thickness of 30um.
[0038] The actual photos of the graphene / ferroferric oxide (rGO / Fe3O4) composite electromagnetic shielding coating film and the bending actual photos of the graphene / ferroferric oxide (rGO / Fe3O4) composite electromagnetic shielding coating film of Example 1 of the application are shown in Figure 1 .
[0039] The XRD photo of Example 1 of the application is shown in Figure 2 . The XRD photo of the RGO, GO and rGO / Fe3O4 sample is shown. The peak position is consistent with the standard Fe3O4 PDF card, which confirms the successful loading of Fe3O4.
[0040] The SEM photo of Example 1 of the application is shown in Figure 3 . (a) is the rGO sample, and (b) is the microstructure of the rGO / Fe3O4. Figure 3 From the SEM photo, it can be seen that the graphene has a layered structure, and the proportion of ferroferric oxide is small, and no agglomeration phenomenon is observed. The ferroferric oxide is uniformly loaded on the surface and the interlayer gap of the graphene. This indicates that the rGO and Fe3O4 have a good composite effect, and the particle size is uniform.
[0041] The TEM photo of Example 1 of the application is shown in Figure 4As shown, it can be observed that the magnetite is uniformly loaded in the surface of graphene. This indicates that the rGO and Fe3O4 have a good composite effect and the particle size is uniform.
[0042] The electromagnetic shielding effectiveness spectrum of the electromagnetic shielding material of the embodiment 1 of the present application is shown in the figure. Figure 5 As shown in the figure, the electromagnetic shielding effectiveness test results in the X band can be known. Figure 4 The test frequency is 8.2GHz-12.4GHz, and the test sample size is 30mmx30mm. As can be seen from the figure, the average value of the electromagnetic shielding effectiveness (SE T ) reaches more than 75dB.
[0043] Embodiment 2: The preparation method of the graphene / magnetite electromagnetic shielding composite film in the embodiment
[0044] Step 1: Under the condition of an ultrasonic frequency of 300w, 0.03g of graphene oxide is uniformly dispersed into 300mL of deionized water to obtain a graphene oxide solution;
[0045] Step 2: Under the condition of an ultrasonic frequency of 300w, 4g of ferrous chloride tetrahydrate is uniformly dispersed into 100mL of deionized water to obtain a ferrous chloride solution;
[0046] Step 3: The graphene oxide solution obtained in step 1 is ultrasonically treated (ultrasonic frequency is 300w) for 0.5h under the condition of strong stirring (stirring speed is 1000rpm), then the mixed solution is added, and then ultrasonically treated (ultrasonic frequency is 300w) for 0.5h;
[0047] Step 4: Then 20ml of 25wt% ammonia water is added to the mixed solution, and the mixed solution is sealed and treated under the condition of strong stirring (stirring speed is 1000rpm) at room temperature for 12h until the reaction is completed. Then the reaction product is separated by a magnet to obtain the rGO / Fe3O4 composite material on the magnet, and then the rGO / Fe3O4 composite material is cleaned by deionized water for at least three times and then cleaned by anhydrous ethanol once. Finally, the product is placed in a constant-temperature air drying oven at 60℃ for 2h to obtain the rGO / Fe3O4 composite material;
[0048] Step 5: 1g of the rGO / Fe3O4 composite material is mixed with 0.05g of polyvinylpyrrolidone K30 (PVP) and then added into a mortar for dry grinding for 40min, and then the ground powder is placed into a 100mL beaker;
[0049] Step 6, take 6g epoxy resin, stirring under stirring 5min, 10min, 15min three times 2g, 2g, 2g into the beaker, continue to stir 300min, use the coater to coat on the copper foil, put into the drying oven and dry for 2h, after completely dry, cut into 4cm x 4cm sample, thickness is 30μm.
[0050] After testing at a test frequency of 8.2GHz-12.4GHz, the electromagnetic shielding effectiveness (SE T ) average value reaches more than 70dB.
[0051] Example 3: In this embodiment, the preparation method of graphene / ferroferric oxide electromagnetic shielding composite film
[0052] Step 1, under the condition of ultrasonic frequency of 1000w, 0.03g graphene oxide is uniformly dispersed into 300ml deionized water to obtain graphene oxide solution;
[0053] Step 2, under the condition of ultrasonic frequency of 1000w, 1g ferrous chloride tetrahydrate is uniformly dispersed into 100ml deionized water to obtain ferrous chloride solution;
[0054] Step 3, the graphene oxide solution obtained in step 1 is ultrasonic treated for 1h under the condition of ultrasonic frequency of 1000w, and then the mixed solution is added under the condition of strong stirring (stirring speed is 2500rpm), and then ultrasonic treated for 1h under the condition of ultrasonic frequency of 1000w;
[0055] Step 4: Then 25ml of 28% ammonia water is added to the mixed solution, and the mixed solution is sealed and treated, and stirred at room temperature for 12h until the reaction is completed. Then the reaction product is separated by magnet, and the rGO / Fe3O4 composite material on the magnet is obtained, and then the rGO / Fe3O4 composite material is cleaned by deionized water for at least three times and then cleaned by anhydrous ethanol once. Finally, the product is placed in a constant temperature air drying oven at 65℃ and dried for 3h, thereby obtaining the rGO / Fe3O4 composite material;
[0056] Step 5, take 1g rGO / Fe3O4 composite material, mix with 0.05g polyvinylpyrrolidone K30 (PVP) and add to the mortar for dry grinding for 40min, and then put the ground powder into a 100ml beaker,
[0057] Step 6, take 6g epoxy resin, stirring under stirring 5min, 10min, 15min three times 2g, 2g, 2g into the beaker, continue to stir 300min, use the coater to coat on the copper foil, put into the drying oven and dry for 2h, after completely dry, cut into 4cm x 4cm sample, thickness is 30μm.
[0058] The electromagnetic shielding effectiveness (SE) is tested at a test frequency of 8.2-12.4 GHz, and the average value reaches 70 dB or more. T
[0059] Embodiment 4: In this embodiment, the preparation method of the graphene / ferroferric oxide electromagnetic shielding composite film
[0060] Step 1: 6 g of graphene oxide was uniformly dispersed into 300 mL of deionized water under the condition of an ultrasonic frequency of 1000 w to obtain a graphene oxide solution;
[0061] Step 2: 4 g of ferrous chloride tetrahydrate was uniformly dispersed into 100 mL of deionized water under the condition of an ultrasonic frequency of 1000 w to obtain a ferrous chloride solution;
[0062] Step 3: The graphene oxide solution obtained in step 1 was ultrasonically treated for 1 h under the condition of an ultrasonic frequency of 1000 w, and then the mixed solution was added under the condition of strong stirring (stirring speed of 2500 rpm), and then ultrasonically treated for 1 h under the condition of an ultrasonic frequency of 1000 w;
[0063] Step 4: Then 25 mL of ammonia water with a mass fraction of 28% was added to the mixed solution, and the reaction was sealed and treated under the condition of strong stirring (stirring speed of 2500 rpm) at room temperature for 12 h until the reaction was completed. Then the reaction product was separated by a magnet to obtain the rGO / Fe3O4 composite material on the magnet, and then the rGO / Fe3O4 composite material was cleaned by deionized water for at least three times and then cleaned by anhydrous ethanol once. Finally, the product was placed in a constant-temperature drying oven at 65°C for drying for 3 h to obtain the rGO / Fe3O4 composite material;
[0064] Step 5: 1 g of the rGO / Fe3O4 composite material was mixed with 0.05 g of polyvinylpyrrolidone K30 (PVP) and then added into a mortar for dry grinding for 40 min, and then the ground powder was placed into a 100 mL beaker,
[0065] Step 6: 15 g of water-based polyurethane was added into the beaker in three times of 5 g, 5 g and 5 g at stirring conditions for 5 min, 10 min and 15 min, and then the stirring was continued for 300 min, and then the product was coated on a copper foil by a coater and then placed into a drying oven for drying for 8 h. After complete drying, the product was cut into a sample piece with a size of 4 cm×4 cm and a thickness of 400 μm.
[0066] The electromagnetic shielding effectiveness (SE) is tested at a test frequency of 8.2-12.4 GHz, and the average value reaches 70 dB or more. T
[0067] The detailed description of the application set forth above merely exemplifies the application. The detailed description set forth is not intended to be all-inclusive of the aspects of the application. A person having ordinary skill in the art can make modifications and variations to the application as described. It is contemplated that the application encompassed by the following claims can include these modifications and variations. The embodiments selected for the purposes of example are intended to illustrate the principles of the application and to enable others skilled in the art to best utilize the application.
Claims
1. A method for preparing a graphene / ferroferric oxide composite film, characterized by, The preparation method comprises the following steps: Step 1: ultrasonic treatment of the graphene oxide solution and the ferrous chloride solution to obtain a mixed solution, then adding ammonia water, stirring until the reaction is completed, using a magnet to separate the reaction to obtain rGO / Fe3O4 composite powder, washing the rGO / Fe3O4 composite powder with deionized water, and drying to obtain the rGO / Fe3O4 composite material; Step 2: mixing the rGO / Fe3O4 composite material with polyvinylpyrrolidone, dry grinding treatment to obtain the desired powder, and adding water-based polyurethane or epoxy resin to obtain a mixture after stirring; Step 3: drying the mixture obtained in step 2 on a substrate to obtain the composite film.
2. The method of claim 1, wherein, The concentration of the graphene oxide solution in step 1 is 0.1 mg / mL to 20 mg / mL; and the concentration of the ferrous chloride solution is 10 mg / mL to 40 mg / mL.
3. The method of claim 1, wherein, In step 1, the graphene oxide solution is obtained by dispersing graphene oxide in deionized water and ultrasonic treatment at 300 w to 1000 w for 0.5 h to 1 h; and the ferrous chloride solution is obtained by dispersing ferrous chloride tetrahydrate in deionized water and ultrasonic treatment at 300 w to 1000 w for 0.5 h to 1 h; the ultrasonic frequency is 300 w to 1000 w, and the time is 0.5 h to 1 h.
4. The method of claim 1, wherein, The stirring speed in step 1 is 1000 rpm to 2500 rpm.
5. The preparation method according to claim 1, characterized in that, In step 1, the amount of ammonia water used is 20 to 25 ml of ammonia water with a concentration of 25% to 28% by mass.
6. The method of claim 1, wherein, In step 2, the mixing ratio of the rGO / Fe3O4 composite material to polyvinylpyrrolidone is 20:
1.
7. The preparation method according to claim 1, characterized in that, In step 2, the mass ratio of the rGO / Fe3O4 composite material powder to water-based polyurethane or epoxy resin is 1:(6 to 15); and the stirring is performed in three times at 5 min, 10 min, and 15 min.
8. The method of claim 1, wherein, In step 3, the coating thickness is 30 μm to 400 μm, and the drying is performed at 40°C to 110°C for 2 h to 8 h; and the substrate is copper foil, PET, PI, or conductive cloth.
9. A graphene / ferroferric oxide composite film prepared by the method of any one of claims 1 to 8.
10. Use of the method of claims 1 to 8 or the electromagnetic shielding composite film of claim 9 in shielding electromagnetism.