Graphene composite film and preparation method thereof

Abstract

The application relates to the technical field of filtration, in particular to a graphene composite membrane and a preparation method thereof. The graphene composite membrane comprises a graphene layer and support layers arranged on both sides of the graphene layer, a gap is arranged in the graphene layer and communicates with the upper surface and the lower surface of the graphene layer, a through hole is arranged on the support layer, and the through holes on both sides of the graphene layer are staggered with each other. The graphene composite membrane provided by the scheme has the characteristics of higher durability and higher utilization rate of graphene.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of filtration, in particular to a graphene composite membrane and a preparation method thereof. BACKGROUND

[0002] In the prior art, when graphene membranes are used for filtration, they are usually attached to a substrate, which not only facilitates fixation but also provides support.

[0003] When graphene filtration membranes are prepared, a dispersion or slurry of graphene powder is usually added, rather than attaching a complete graphene film to a perforated or mesh substrate. The impact resistance of a filtration membrane made of graphene powder is much lower than that of a complete graphene film. For current production technology, the largest graphene film that can be produced is 350mm x 350mm, but it is still in the laboratory stage. Even if a small amount of graphene film produced is used for industrial production, the cost is extremely high. Since the area of a filtration plate is usually large, and the filtration equipment is usually large-scale equipment, the filtration plate must also be designed to have a large filtration area to match the power consumption and production capacity of the large-scale equipment. Therefore, filtration membranes prepared from graphene powder are commonly used in industrial applications.

[0004] For the arrangement of the substrate, if it is a mesh substrate, it is usually made of metal wires. The contact area between the metal wires and the filtration membrane is small, and although only a small area of the filtration membrane is blocked, the pressure on the contact part of the filtration membrane is increased, which is similar to line-surface contact. The support force of the filtration membrane is similar to cutting, which causes the metal wires to gradually embed into the filtration membrane over a long period of time under fluid impact, making the contact part of the filtration membrane prone to breakage. To reduce the stress pressure on the contact part, the distance between the filtration holes on the substrate can be appropriately increased, i.e., the contact area between the substrate and the filtration membrane can be increased, but this will reduce the proportion of the area occupied by the filtration holes on the substrate, making the filtration holes smaller and reducing the utilization rate and filtration efficiency of the filtration membrane. SUMMARY

[0005] The present application aims to provide a graphene composite membrane to solve the problem of possible damage to the graphene filtration membrane or reduction of filtration efficiency in the prior art.

[0006] To solve the above problems, the present application adopts the following technical scheme: a graphene composite membrane, comprising a graphene layer and a support layer arranged on both sides of the graphene layer, a gap is arranged in the graphene layer, the gap is connected to the upper surface and the lower surface of the graphene layer, a through hole is arranged on the support layer, and the through holes on both sides of the graphene layer are staggered.

[0007] Advantages: Compared with the prior art, the basic scheme of the present application can obtain the following advantages.

[0008] 1. Extended lifespan of the graphene layer. The graphene layer, subjected to fluid impact, is supported on both sides by support layers, which buffer the impact and reduce the flow velocity within the graphene layer. Since the graphene composite membrane in this application can withstand greater impact, by applying external force or increasing the fluid volume on one side of the membrane (e.g., accumulating more liquid on that side), the flow velocity can be accelerated under the influence of gravitational potential energy, thus compensating for the reduced flow velocity due to buffering and accelerating the filtration speed, resulting in higher filtration efficiency for the graphene filter membrane. On the other hand, the graphene layer above the outflowing through-hole is unsupported below, but since it is not subjected to downward fluid impact, the adhesion provided by the support layer above and the support force provided by the support layer below around the through-hole are sufficient to resist the pulling force generated when the fluid flows downwards and leaves the graphene layer. This gives the graphene composite membrane good strength and makes it less prone to damage during use.

[0009] 2. Improved utilization rate of graphene layers for filtration. Since fluid is filtered as it flows through the pores within the graphene layer, the longer the distance traveled, the better the adsorption and filtration effect; however, excessive distance reduces the filtration speed. Theoretically, if the support layer has no through-holes, the fluid can enter from one edge of the two support layers and flow out from the other edge, maximizing the distance the fluid can travel. However, to ensure the fluid travels such a long distance smoothly, a significant amount of power is required. Without gravity, continuous power is needed, consuming substantial energy. Using gravity, the graphene layer is thin and has a small cross-section; while arranging multiple graphene layers in an overlapping manner increases the total cross-sectional area, it creates a cubic-like structure, occupying a large space and consuming a large amount of graphene material, resulting in high cost. The graphene composite membrane structure provided in this solution allows adjustment of the flow channel length by adjusting the staggered distance between the through-holes in the upper and lower support layers, thus balancing the utilization rate of the graphene layer and the filtration efficiency.

[0010] 3. It exhibits symmetrical effects. The above-mentioned beneficial effects can be obtained by the fluid entering from either side of the support layer. Therefore, the graphene composite film can be easily backwashed; after a long period of using one side as the entry surface, it can be changed to the other side as the entry surface, thereby balancing the stress on the graphene composite film and helping to maintain the internal three-dimensional structure of the graphene layer, so that the internal pores will not be damaged by long-term impact from one side.

[0011] By changing the existing graphene filter membrane from vertical filtering to horizontal filtering, the stability of the graphene layer is ensured, and the area of the graphene layer for filtering is expanded. On the basis of fully exerting the beneficial effects of each layer, the possible obstacles between adjacent layers are avoided as much as possible, and the situation of no supporting force at the filtering hole is also avoided, so that the graphene composite membrane as a whole can exert an effect much greater than the simple combination of each layer, that is, 1+1+1>>3.

[0012] Further, the support layers on both sides of the graphene layer are fused at the periphery of the graphene layer. Advantageous effect: the fusion of the support layers on both sides at the periphery can avoid the fluid flowing out of the graphene layer after entering it, and the fluid flows out of the through holes of the support layer on the outflow side, facilitating the collection of the filtered fluid. Especially in the case of liquid, the filtrate can be easily collected.

[0013] Further, the number of through holes of the support layer on one side of the graphene layer is greater than that of the support layer on the other side. Advantageous effect: when entering from the support layer with more through holes, the fluid can enter the graphene layer faster, and when flowing out from the lower layer, it has the effect of converging flow; when entering from the support layer with fewer through holes, the fluid diffuses to multiple nearby through holes, having the effect of diverging flow, which can relieve the pressure of the fluid flowing out of one side of the support layer; it can also limit the filtered impurities to fewer through holes, reducing the workload of subsequent flushing and purification.

[0014] Further, the pore size of the through holes of the support layer on one side of the graphene layer is greater than that of the support layer on the other side. Advantageous effect: when entering from the support layer with larger through holes, the fluid can enter the graphene layer faster, and when flowing out from the lower layer, it has the effect of converging flow; when entering from the support layer with smaller through holes, the fluid diffuses to larger nearby through holes, allowing the fluid to flow out of the graphene composite membrane quickly, which can relieve the pressure of the fluid flowing out of one side of the support layer; it can also limit the filtered impurities to smaller through holes, reducing the workload of subsequent flushing and purification.

[0015] Further, the graphene layer extends to the same level as the upper edge of the through hole at the through hole of the support layer. Advantageous effect: it can increase the filtering distance of the fluid, increase the surface area of the connecting part between layers, improve the connection strength of the graphene layer and the support layer, make the structure more stable, and prevent the through hole from being blocked by the accumulation of filtered impurities. If there is no graphene layer in the through hole, a large number of overlapping graphene composite membranes may produce indentations at the overlapping part of the through hole, even damaging the structure of the graphene layer.

[0016] Further, the support layer contains a polymer and a graphene-based component, and the mass percentage of the graphene-based component is 0.5% to 3%. Advantage: The main component of the support layer is a polymer, and 0.5% to 3% of a graphene-based component is added. After the graphene layer is coated, the surface tension between the layers can be broken at the interface by the graphene-based component contained in each layer, and a bridge for mutual fusion is connected, so that the connection between the layers is more firm.

[0017] Further, the graphene layer contains a graphene-based component and a polymer, and the mass percentage of the graphene-based component is 5% to 10%. Advantage: The addition of 5% to 10% of a polymer in the graphene layer can not only reinforce the structure of the graphene layer, but also enable the graphene-based components to be bonded together through the polymer as a skeleton. Such a setting can also appropriately increase the thickness of the graphene layer, for example, to 300μm, thereby expanding the space of the flow channel and improving the quality of adsorption and filtration. The polymer at the interface between the layers can also strengthen the fusion of the layers and further strengthen the connection between the layers.

[0018] Further, the raw material for forming the graphene layer also contains a water-soluble pore-forming agent. Advantage: The pore-forming agent can expand the voids in the graphene layer, so that the fluid can pass through more quickly, thereby accelerating the filtration speed.

[0019] Further, the polymer is one of polyethylene, polypropylene, polyvinyl alcohol, polyacrylonitrile, polyester, polylactic acid, chitosan, and polyphenylene sulfide; and the graphene-based component is one or more of graphene, graphene oxide, and a modified product of graphene oxide. Advantage: The above polymer components have viscosity under certain conditions and can be solidified after changing the conditions, so they can be used to prepare the support layer. The properties of the components are different, and they can be selected according to the needs. Different graphene-based components can be selected according to the properties of the fluid to be filtered.

[0020] The application also provides a preparation method of the graphene composite membrane. The method comprises the following steps: step 1: preparing a raw material for forming a support layer and a raw material for forming a graphene layer; step 2: oppositely arranging two rollers to form a roller structure, and coating a polytetrafluoroethylene layer on the surface of the rollers, and forming a support layer on the surface of the two rollers in a 3D printing manner; step 3: rotating the two rollers oppositely, and when the initial edge of the support layer rotates to the connecting line of the center points of the two rollers, the raw material for preparing the graphene layer is coated on the gap between the two rollers, and the through holes on the two support layers are staggered with each other after the two support layers are overlapped; and step 4: solidifying to form a graphene layer between the two support layers, then soaking in water for 20 to 30 minutes to dissolve the pore-forming agent, then washing with deionized water, then drying, and thus the graphene composite membrane is obtained.

[0021] Beneficial effects: taking the roller as the carrier can realize the synchronous preparation of the support layer and the synchronous combination of the graphene layer and the two side support layers, thereby improving the preparation efficiency. The polytetrafluoroethylene coating on the surface of the roller makes the support layer more easily peeled off from the surface of the roller. The 3D printing manner facilitates the setting of the position of the through hole, so that the through holes on the two side support layers are staggered, thereby also simplifying the preparation steps. The pore-forming agent can form a three-dimensional structure with voids in the graphene layer, and the voids can communicate the upper surface and the lower surface of the graphene layer, so that the graphene composite film has good filtering effect. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A longitudinal sectional view schematic diagram of the graphene composite film provided by Example One is shown.

[0023] Figure 2 A top view schematic diagram of the graphene composite film provided by Example Two is shown.

[0024] Figure 3 A longitudinal sectional view schematic diagram of the graphene composite film provided by Example Three is shown.

[0025] Figure 4 A longitudinal sectional view schematic diagram of the graphene composite film provided by Example Six is shown.

[0026] Figure 5 A schematic diagram of preparing the graphene composite film provided by Example One with a pair of rollers is shown. DETAILED DESCRIPTION

[0027] It should be understood that the "upper", "middle", "lower", "left", "right", "inner", "outer", and similar words indicating directions in the specification are intended to facilitate the understanding of the embodiments of the present application, and are not a limitation on the scope of protection required by the present application. For example, "upper" can be directly contacting upper, or non-directly contacting upper, and there can be other structures therebetween.

[0028] The schemes of the present application are specifically described below through examples.

[0029] The reference signs in the drawings of the specification include: graphene layer 1, support layer 2, through hole 21 of the upper layer support layer, and through hole 22 of the lower layer support layer.

[0030] Example One

[0031] As Figure 1As shown, the graphene composite film provided by Example One includes a graphene layer 1 and support layers 2 arranged on both sides of the graphene layer 1. The graphene layer 1 has voids that are connected to the upper surface and the lower surface of the graphene layer 1. The support layers 2 are provided with through holes 20. The through holes on both sides of the graphene layer 1 are staggered. The through holes 21 of the upper support layer and the through holes 22 of the lower support layer have the same aperture. The cross section of the through holes is square, and the side length is 100 µm. Figure 1 The graphene composite film provided by Example One includes a graphene layer 1 and support layers 2 arranged on both sides of the graphene layer 1. The graphene layer 1 has voids that are connected to the upper surface and the lower surface of the graphene layer 1. The support layers 2 are provided with through holes 20. The through holes on both sides of the graphene layer 1 are staggered. The through holes 21 of the upper support layer and the through holes 22 of the lower support layer have the same aperture. The cross section of the through holes is square, and the side length is 100 µm.

[0032] The edges of the support layers 2 are flush with the periphery of the graphene layer 1. The number of through holes of the two support layers 2 is equal, and the aperture of the through holes is also equal. The support layers 2 are made of a high polymer, which is polylactic acid.

[0033] Preparation method: Figure 5 A schematic diagram of the preparation of the graphene composite film by a pair of rollers is shown.

[0034] Step 1: Prepare the raw material for forming the support layer and the raw material for forming the graphene layer. Specifically, the raw material for forming the support layer is polylactic acid (melting point 176 ℃), and the raw material for forming the graphene layer includes graphene aqueous slurry (purity of graphene > 98%, containing 1.5wt% of graphene and 0.3wt% of dispersant, and the dispersant is sodium pyrene sulfonate) and polyethylene glycol as a pore-forming agent. The weight ratio of graphene and polyethylene glycol is 10:1. The slurry can be obtained by purchase, and its preparation method also belongs to the prior art, which is not described here. Gradually add the aqueous solution of polyethylene glycol to the graphene aqueous slurry while continuously stirring, and then ultrasonic treatment for 10-20 min, ultrasonic power 100 W, to make them uniformly mixed.

[0035] Step 2: oppositely arrange two rollers 3 to form a pair of rollers. The surface of the roller has a polytetrafluoroethylene coating (which can be coated on the surface of a stainless steel roller, or a roller with the coating is used). The support layer is easy to peel off from the surface of the roller after being formed. The roller cylinder is 30 cm high and 5 cm in diameter. After melting the polylactic acid, the molten polylactic acid is used to form the support layer 2 on the surface of the two rollers in a 3D printing manner. The length and width of the printing head are 100 µm x 100 µm. After printing each column, the surface of the roller cylinder is rotated by 100 µm. The printing speed is 1-2 cm / s. The distance between the nozzle and the surface of the roller cylinder is 0.5-1 mm. The nozzle can print in both directions, i.e. it can print back and forth, thereby improving the printing efficiency.

[0036] Step 3: The two rollers 3 rotate relative to each other. When the initial edge of the support layer 2 rotates to the center line connecting the two rollers, the graphene slurry is applied downwards above the gap between the two rollers 3. After the two support layers 2 overlap, the through holes on them are staggered. Specifically, heating wires 35 are provided on the inner side of the roller surface (the part corresponding to the 3D printing head and the upper half of the opposite surface of the rollers, i.e., the part covering the support layer), so that the surface temperature can be adjusted. The roller surface is heated, and the graphene layer 1 is applied before the support layer solidifies, which facilitates the rapid fusion of the graphene layer with polylactic acid at the interface and allows moisture to evaporate. The method of applying the graphene-containing material is spraying, with a nozzle distance of 8 cm. Spraying is performed intermittently. After one spraying, the sprayed part is rotated to below the center of the rollers before the next spraying is performed.

[0037] Step 4: Curing, thereby forming a graphene layer 1 between the two support layers 2. Then, immersion in water for 20-30 minutes dissolves the pore-forming agent, rinses with deionized water, and dries to obtain the graphene composite film. Specifically, the temperature of the support layer surface on the roller is maintained at 130℃-150℃. After spraying the material used to prepare the graphene layer, the water evaporates, and the polyethylene glycol melts, causing the graphene sprayed on the two support layers to fuse into a single layer under the action of the molten polyethylene glycol. Cooling solidifies the support layer and the graphene layer. Since polyethylene glycol is soluble in water, immersion in water removes it, allowing the graphene layer to form a three-dimensional structure containing numerous pores.

[0038] Example 2

[0039] like Figure 2 As shown, the graphene composite film provided in Example 2 differs from that in Example 1 in that the composition of the polymer and the structure of the support layer are different.

[0040] The polymer is polyethylene. The support layer comprises 97% polyethylene and 3% graphene, both by weight, excluding solvent (applicable to the following examples). The weight ratio of graphene to polyethylene glycol is 10:1.5. The number of through-pores in the support layer on one side of the graphene layer is greater than the number of through-pores on the other side. The support layers on both sides of the graphene layer are fused at the periphery of the graphene layer, making the connection of this layered structure more robust. The thickness of the graphene layer is 100µm, and the thickness of the support layer on both sides of the graphene layer is 200µm. The dimensions are 20cm x 30cm. Figure 2 This is a top view of the graphene composite film. The solid squares represent the through holes 21 in the upper support layer, and their number is less than the number of through holes 22 in the lower support layer represented by the dashed squares.

[0041] The difference between the preparation methods is that the N,N-dimethylformamide (DMF) slurry of graphene (purity of graphene > 98%, concentration of 2wt%, dispersant of perylene derivative, concentration of 0.8wt%) is added into the low-density polyethylene in a molten state (melting point of 105-115°C), and then stirred and ultrasonically treated to prepare a uniform mixture for preparing the support layer. Because DMF can dissolve polyethylene and has a boiling point higher than the melting point of polyethylene, DMF can be dissolved in the molten polyethylene. After cooling and solidification, washing and drying, the graphene composite film is obtained.

[0042] Example Three

[0043] As shown in Figure 3 Example Three, the difference between the graphene composite film provided by Example Three and Example Two is that the composition of the high-molecular polymer, the composition and structure of the support layer and the graphene layer are different.

[0044] The high-molecular polymer is polypropylene (melting point of 189°C, softening at about 155°C). The support layer comprises 98% of polypropylene and 2% of graphene. The graphene layer comprises 94% of polypropylene, 5% of graphene and 1% of polyvinylpyrrolidone. The polyvinylpyrrolidone is an aqueous pore-forming agent. The through holes of the support layer on one side of the graphene layer have a length-width size of 100µm x 100µm, and the through holes of the support layer on the other side have a length-width size of 100µm x 150µm. The number of the through holes of the two support layers is the same. The thickness of the graphene layer is 200µm, and the thickness of the support layer on both sides of the graphene layer is 300µm. The length-width size is 25cm x 30cm.

[0045] The difference between the preparation methods is that the raw material for preparing the support layer is a uniform mixture of graphene NMP (N-methyl pyrrolidone) slurry (purity of graphene > 98%, concentration of 1.5wt%, dispersant of perylene derivative, concentration of 0.75wt%) and molten polypropylene. Because NMP has a boiling point of 202°C and can dissolve polypropylene, it can be dissolved in the molten polypropylene. The raw material for preparing the graphene layer is a uniform mixture of graphene DMF slurry, polypropylene DMF solution and polyvinylpyrrolidone DMF solution. The heating temperature of the calender is adjusted to control the cooling speed of the support layer. After spraying the material for preparing the graphene layer, DMF volatilizes, polyvinylpyrrolidone melts, and the graphene on the two support layers after being overlapped fuses into the graphene layer. After cooling and solidification, the graphene composite film is obtained.

[0046] Example Four

[0047] The difference between the graphene composite film provided by Example Four and Example Three is that the composition of the high-molecular polymer, the composition of the support layer and the graphene layer are different.

[0048] The high molecular polymer is polyethylene terephthalate (melting point 250-255 °C), which belongs to polyester. The support layer includes 95% polyethylene terephthalate and 5% isophthalic acid. The graphene layer includes graphene DMF slurry and DMF solution of polyvinylpyrrolidone, with a weight ratio of 7:1. The length and width dimensions are 25 cm x 40 cm.

[0049] The difference in the preparation method is that, since the melting point of polyethylene terephthalate is 250-255 °C, and the melting point of polyvinylpyrrolidone is 130 °C and the boiling point is 217.6 °C, i.e. the melting point of the former is higher than the boiling point of the latter. In order to avoid the latter from evaporating due to boiling after being added to the former in a molten state as a pore-forming agent, the former needs to be modified. For example, isophthalic acid is added, so that the melting point of the mixture can be reduced to below 200 °C. After spraying the material for preparing the graphene layer, the DMF volatilizes, the polyvinylpyrrolidone melts, and the graphene on the two support layers can be fused into a layer after the two support layers are overlapped. After cooling and solidification, washing and drying are performed to obtain the graphene composite film.

[0050] Example Five

[0051] The graphene composite film provided in Example Five is different from that in Example Three in that the composition of the high molecular polymer, the composition of the support layer, and the composition and structure of the graphene layer are different.

[0052] The high molecular polymer is polyacrylonitrile. The support layer includes 99.2% polyacrylonitrile and 0.8% graphene. The raw material for preparing the graphene layer includes 8% graphene, 90% polyacrylonitrile, and 2% polyvinylpyrrolidone. The thickness of the graphene layer is 300 µm, and the thickness of the support layer on both sides of the graphene layer is 400 µm. The length and width dimensions are 25 cm x 40 cm.

[0053] The difference in the preparation method is that the DMF solution of polyacrylonitrile and the graphene DMF slurry are uniformly mixed to prepare the support layer. The DMF solution of polyvinylpyrrolidone is added to the DMF solution of polyacrylonitrile and the graphene DMF slurry in a certain proportion, and then uniformly mixed to prepare the graphene layer. The surface of the heating roller can adjust the volatilization speed of DMF, so as to solidify the support layer and the graphene layer. After washing and drying, the graphene composite film is obtained.

[0054] Example Six

[0055] As shown in Figure 4 The graphene composite film provided in Example Six is different from that in Example Five in that the composition of the high molecular polymer, the composition and structure of the support layer, and the composition and structure of the graphene layer are different.

[0056] The high polymer is chitosan (dissolved in trifluoroacetic acid). The support layer comprises 99.5% chitosan and 0.5% graphene. The material used to prepare the graphene layer comprises 9% graphene, 90% chitosan and 1% polyvinylpyrrolidone. The length and width dimensions are 30 cm x 50 cm. The graphene layer extends to the same level as the upper edge of the through hole of the support layer at the through hole of the support layer.

[0057] The difference between the preparation methods is that the trifluoroacetic acid solution of chitosan and the aqueous graphene slurry are uniformly mixed to prepare the support layer. After mixing the above two components, polyvinylpyrrolidone is added to dissolve it and then used to prepare the graphene layer. Excess graphene-containing mixture is coated to fill the through hole of the support layer. The surface of the heated rollers is heated to volatilize the trifluoroacetic acid and water, and after curing, it is rinsed and dried.

[0058] Preferably, the graphene layer contains graphene-based components such as one or more of graphene, graphene oxide, and modified products of graphene oxide. Since most of the oxygen atoms in graphene oxide form an epoxy bond with carbon atoms, the hydrophilicity of the epoxy bond is not as good as that of hydroxyl, carboxyl, amino, and mercapto groups, etc. Therefore, graphene oxide mainly exhibits amphiphilicity. Further modification of graphene oxide can open the epoxy bond and combine with hydrophilic groups such as hydroxyl, carboxyl, amino, and mercapto groups, etc. to enhance hydrophilicity and thus adapt to different use scenarios.

[0059] In use, the graphene composite film can be fixed to an external structure at its periphery, or it can be placed on a mesh or perforated substrate, with the positions of the holes on the substrate corresponding to the positions of the through holes on the support layer of the outflow side, so that the fluid can flow smoothly through the through holes.

[0060] The above detailed description of the embodiments of the present application is only a preferred embodiment of the present application, and the present application is not limited to the above-described embodiments. It should be noted that, for those skilled in the art, various changes and improvements can be made within the scope of knowledge possessed by those skilled in the art without departing from the inventive concept of the present application. These should also be considered to fall within the scope of protection of the present application, and these will not affect the patentability and implementation effect of the present application. The omitted technical, shape, and structure parts of the present application are all known technologies.

Claims

1. A graphene composite film, characterized by, The graphene composite film comprises a graphene layer and support layers arranged on both sides of the graphene layer, the graphene layer is provided with a gap communicating with the upper surface and the lower surface of the graphene layer, the support layers are provided with through holes, and the through holes on both sides of the graphene layer are staggered with each other; the support layers contain a high polymer and a graphene component, and the mass percentage of the graphene component is 0.5%-3%; the graphene layer contains the graphene component and the high polymer, and the mass percentage of the graphene component is 5%-10%; the raw material for forming the graphene layer further contains a water-soluble pore-forming agent; the high polymer is one of polyethylene, polypropylene, polyvinyl alcohol, polyacrylonitrile, polyester, polylactic acid, chitosan and polyphenylene sulfide; the graphene component is one or both of graphene and graphene oxide; and the graphene composite film is prepared by the following preparation method comprising the following steps: Step 1: preparing a raw material for forming the support layer and a raw material for forming the graphene layer; Step 2: oppositely arranging two rollers to form a roller structure, the surfaces of the rollers are provided with polytetrafluoroethylene coatings, and the support layers are formed on the surfaces of the two rollers in a 3D printing manner; Step 3: rotating the two rollers oppositely, when the initial edges of the support layers rotate to the connecting line of the center points of the two rollers, the raw material for preparing the graphene layer is coated on the upper surface and the lower surface of the gap between the two rollers, and the through holes on the two support layers are staggered with each other after the two support layers are overlapped; Step 4: solidifying to form the graphene layer between the two support layers, then soaking in water to dissolve the pore-forming agent, washing with deionized water, and drying to obtain the graphene composite film.

2. The graphene composite film according to claim 1, wherein, The support layers on both sides of the graphene layer are fused at the periphery of the graphene layer.

3. The graphene composite film according to claim 1, wherein The number of through holes of the support layer on one side of the graphene layer is greater than that of the support layer on the other side of the graphene layer.

4. The graphene composite film according to claim 1, wherein The aperture of the through hole of the support layer on one side of the graphene layer is greater than that of the support layer on the other side of the graphene layer.

5. The graphene composite film according to claim 1, wherein The graphene layer extends to the upper edge of the through hole at the through hole of the support layer.

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