Device and method for eliminating wrinkles of graphene film

Abstract

The invention discloses a device and method for eliminating wrinkles of a graphene film, and relates to the technical field of graphene material treatment.The device for eliminating the wrinkles of the graphene film comprises a fixing mechanism and an inflation mechanism, an air cavity is formed in the fixing mechanism, an opening is formed in one side of the air cavity, and the inflation mechanism is arranged in the air cavity; the substrate on which the graphene film grows is used for being placed at the opening and covering the opening so as to seal the air cavity; the fixing mechanism is provided with an air inlet and an air outlet which are communicated with the air cavity, and the air outlet is provided with a pressure release valve; the air inflation mechanism is communicated with the air inlet, and the air inflation mechanism is used for inflating the air cavity to increase the air pressure in the air cavity, so that the substrate is elastically deformed in the direction away from the air cavity to stretch and unfold the folds of the graphene film. According to the wrinkle eliminating device for the graphene film, the graphene film can be uniformly stretched, the effect is good, and risks such as tearing of the graphene film can be effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of graphene material processing technology, and in particular to a device and method for eliminating wrinkles in graphene films. Background Technology

[0002] Graphene, a two-dimensional material with excellent electrical, optical, and mechanical properties, has shown great potential for applications in electronic devices, sensors, and composite materials. Graphene films prepared on substrates (such as copper and nickel) using chemical vapor deposition (CVD) suffer from compressive stress and wrinkle formation during cooling due to the mismatch in thermal expansion coefficients between the graphene film and the substrate. These wrinkles severely degrade the electrical and mechanical properties of graphene and introduce the risk of breakage during micro / nano fabrication and transfer, representing a key defect limiting its high-performance applications.

[0003] Currently, researchers both domestically and internationally have proposed several methods to reduce or eliminate wrinkles in graphene films, but all have significant limitations: High-temperature annealing involves reheating the sample to near its growth temperature, using thermal expansion to temporarily stretch the substrate and smooth out wrinkles. However, this method is extremely energy-intensive, and prolonged high-temperature heating can lead to metal grain coarsening, graphene quality degradation, and even cracking. Furthermore, it is unsuitable for flexible device fabrication processes that are not heat-resistant. Chemical intercalation involves inserting molecules or ions between the graphene film and the substrate using chemical means to open up the wrinkles. This method may introduce impurities and is difficult to precisely control the intercalation process. Mechanical stretching / rolling involves mechanically stretching or rolling the metal substrate with the graphene film attached or the transferred graphene film. This method makes it difficult to ensure uniform stress application, easily leading to tearing or new damage to the graphene film. Therefore, existing methods for eliminating wrinkles in graphene films are generally ineffective. Summary of the Invention

[0004] The main objective of this invention is to provide a device and method for eliminating wrinkles in graphene films, aiming to solve the technical problem that existing methods for eliminating wrinkles in graphene films are ineffective.

[0005] To achieve the above objectives, the present invention provides a wrinkle-eliminating device for graphene films, comprising: A fixing mechanism is provided, wherein an air cavity is formed within the fixing mechanism, and an opening is formed on one side of the air cavity. A substrate on which the graphene film is grown is placed at the opening and covers the opening to seal the air cavity. An air inlet and an air outlet communicating with the air cavity are provided on the fixing mechanism, and a pressure relief valve is provided at the air outlet. An inflation mechanism is provided, which is connected to the air inlet. The inflation mechanism is used to inflate the air cavity to increase the air pressure in the air cavity, so that the substrate undergoes elastic deformation in a direction away from the air cavity, thereby stretching and unfolding the folds of the graphene film.

[0006] In one embodiment, the fixing mechanism includes a base and a fastening assembly. The base forms the air cavity, and the top of the base has the opening. The base supports the edge of the opening and covers the opening. The base has the air inlet and the air outlet near its bottom. The fastening assembly is used to fasten the edge of the base to the base.

[0007] In one embodiment, the fastening assembly includes an annular cap and a fastening bolt. The annular cap forms a clearance opening, and the fastening bolt passes through the annular cap. The base has a threaded hole, and the fastening bolt is threaded into the threaded hole to clamp the base by the cooperation of the cap and the base. The clearance opening is directly opposite the opening.

[0008] In one embodiment, the top of the base is provided with an annular sealing groove, and the annular sealing groove surrounds the opening. An annular sealing gasket is provided in the annular sealing groove, and the top of the annular sealing gasket protrudes from the annular sealing groove. The annular sealing gasket is used to seal the air cavity when the gland and the base are engaged to clamp the base.

[0009] In one embodiment, the inflation mechanism includes a gas cylinder, a gas path, a gas valve, a pressure gauge, and a pressure reducing valve. The gas cylinder is connected to one end of the gas path via the pressure reducing valve, and the other end of the gas path is connected to the air inlet. The gas valve is disposed on the gas path and is used to open or close the gas path. The pressure gauge is disposed on the gas path and is located between the gas valve and the air inlet. The pressure gauge is used to detect the gas pressure in the gas path. The gas cylinder is used to inflate the gas chamber through the gas path and the air inlet when the gas valve opens the gas path.

[0010] The present invention also proposes a method for eliminating wrinkles in a graphene film, wherein the method employs the graphene film wrinkle elimination device described above, and the wrinkle elimination method includes the following steps. The substrate on which the graphene film is grown is fixed to the fixing mechanism; The air chamber is inflated by the inflation mechanism, and the air pressure in the air chamber is increased to a first preset air pressure, so that the substrate undergoes elastic deformation in the direction away from the air chamber, thereby stretching and unfolding the folds of the graphene film. The inflation mechanism stops inflating the air chamber and maintains the pressure for a preset time, so that the wrinkles of the graphene film are completely stretched and eliminated. Open the pressure relief valve to reduce the air pressure in the air chamber to atmospheric pressure; Remove the substrate and the graphene film thereon from the fixing mechanism.

[0011] In one embodiment, the preset time is 5 minutes to 30 minutes; the first preset air pressure is 0.5 MPa to 2.0 MPa.

[0012] In one embodiment, the inflation mechanism includes a gas cylinder, a gas path, a gas valve, a pressure gauge, and a pressure reducing valve. The gas cylinder is connected to one end of the gas path via the pressure reducing valve, and the other end of the gas path is connected to the air inlet. The gas valve is disposed on the gas path and is used to open or close the gas path. The pressure gauge is disposed on the gas path and is located between the gas valve and the air inlet. The pressure gauge is used to detect the gas pressure in the gas path. The gas cylinder is used to inflate the gas chamber through the gas path and the air inlet when the gas valve opens the gas path. The step of inflating the air chamber with air through the inflation mechanism and increasing the air pressure in the air chamber to a first preset air pressure includes: The outlet pressure of the gas cylinder is adjusted to a preset outlet pressure by means of the pressure reducing valve; Open the gas valve to allow the gas cylinder to fill the gas chamber through the gas passage and the gas inlet; Adjust the pressure reducing valve and determine whether the air pressure in the air circuit has increased to the first preset air pressure by reading the pressure value of the pressure gauge; If so, the procedure of stopping the inflation mechanism from inflating the air chamber and maintaining pressure for a preset time shall continue.

[0013] In one embodiment, the step of stopping the inflation mechanism from inflating the air chamber specifically involves: Close the gas valve and adjust the pressure reducing valve to stop the gas cylinder from filling the gas passage and the gas chamber.

[0014] In one embodiment, before the step of adjusting the pressure reducing valve and determining whether the air pressure in the air circuit has increased to the first preset air pressure by reading the pressure value of the pressure gauge, the method further includes: The pressure in the air chamber is determined by the reading of the pressure gauge to determine whether the pressure has increased to the second preset pressure, wherein the second preset pressure is less than the first preset pressure; If so, close the gas valve to stop the gas cylinder from filling the gas chamber; The pressure is maintained for a second preset time, and the pressure value of the pressure gauge is read to determine whether the pressure value of the pressure gauge has changed; If so, the air chamber is determined to be in a completely closed state, and the air valve is opened. The step of adjusting the pressure reducing valve is continued, and the pressure value of the pressure gauge is read to determine whether the air pressure in the air circuit has increased to the first preset air pressure. If not, the air chamber is determined to be in an incompletely closed state, and the air valve remains closed. The process then returns to the step of fixing the substrate with the graphene film grown on it onto the fixing mechanism.

[0015] The graphene film wrinkle elimination device of this invention includes a gas cavity formed within a fixing mechanism, with an opening on one side of the gas cavity. By fixing a substrate with a graphene film grown on it to the opening and covering the opening, the gas cavity is sealed. An air inlet and an air outlet communicating with the gas cavity are provided on the fixing mechanism. An air inflation mechanism inflates the gas cavity through the air inlet, increasing the air pressure inside the gas cavity. Under the action of the increased air pressure, the substrate undergoes elastic deformation in the direction away from the gas cavity, thereby stretching the graphene film grown on the substrate surface. This stretches and eliminates the wrinkles in the graphene film, resulting in a smooth, wrinkle-free graphene film. As can be seen, this invention stretches and unfolds the wrinkles on the graphene film by physically increasing the air pressure. The air pressure applies a uniform force to the substrate, causing the graphene film to be stretched evenly. This not only has a good effect but also effectively avoids the risk of graphene film tearing. Furthermore, the entire process is carried out at room temperature, avoiding the performance degradation of graphene film caused by high-temperature annealing, perfectly preserving the intrinsic properties of graphene material, and eliminating the need to introduce any chemical reagents or intercalation substances, thus ensuring the cleanliness of the graphene film. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a wrinkle-eliminating device for graphene film provided in an embodiment of the present invention; Figure 2 This is a frontal view of a wrinkle-eliminating device using a graphene film before and after stretching, according to an embodiment of the present invention. Figure 3 A schematic flowchart of the wrinkle elimination method for graphene film provided in the first embodiment of the present invention; Figure 4 A schematic flowchart of the wrinkle elimination method for graphene film provided in the second embodiment of the present invention; Figure 5 A schematic flowchart of the wrinkle elimination method for graphene film provided in the third embodiment of the present invention; Figure 6An optical microscope illustration of a graphene film on a 25µm copper foil substrate before and after stretching, according to an embodiment of the present invention. Figure 7 A schematic diagram of the Raman spectra of a graphene film on a 25µm copper foil substrate before and after stretching, provided in an embodiment of the present invention. Figure 8 This is an optical microscope illustration of a graphene film on a 50µm copper foil substrate before and after stretching, as provided in an embodiment of the present invention.

[0018] Explanation of icon numbers: 100. Elimination device; 1. Fixing mechanism; 11. Base; 111. Air chamber; 112. Opening; 113. Pressure relief valve; 12. Fastening assembly; 121. Gland; 122. Fastening bolt; 13. Annular sealing gasket; 2. Inflation mechanism; 21. Gas cylinder; 22. Gas passage; 23. Gas valve; 24. Pressure gauge; 25. Pressure reducing valve; 200. Substrate; 201. Graphene film.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] This invention proposes a wrinkle-eliminating device 100 for a graphene film 201.

[0024] Please see Figure 1 In one embodiment of the present invention, the wrinkle-eliminating device 100 of the graphene film 201 includes a fixing mechanism 1 and an inflation mechanism 2. An air cavity 111 is formed in the fixing mechanism 1, and an opening 112 is formed on one side of the air cavity 111. The substrate 200 on which the graphene film 201 is grown is used to place at the opening 112 and cover the opening 112 to close the air cavity 111. An air inlet and an air outlet communicating with the air cavity 111 are provided on the fixing mechanism 1, and a pressure relief valve 113 is provided at the air outlet. The inflation mechanism 2 is connected to the air inlet and is used to inflate the air cavity 111 to increase the air pressure in the air cavity 111, so that the substrate 200 undergoes elastic deformation in the direction away from the air cavity 111 to stretch and unfold the wrinkles of the graphene film 201.

[0025] The graphene film 201 wrinkle-eliminating device 100 of the present invention includes a gas cavity 111 formed within a fixing mechanism 1, with an opening 112 formed on one side of the gas cavity 111. The gas cavity 111 is sealed by fixing the substrate 200 on which the graphene film 201 is grown at the opening 112 and covering the opening 112. An air inlet and an air outlet communicating with the gas cavity 111 are provided on the fixing mechanism 1. An air inflation mechanism 2 inflates the gas cavity 111 through the air inlet, increasing the air pressure within the gas cavity 111. Under the increased air pressure, the wrinkle-eliminating device 100 eliminates wrinkles in the graphene film 201. The substrate 200 undergoes elastic deformation in the direction away from the air cavity 111, thereby stretching the graphene film 201 grown on the surface of the substrate 200. This stretches and eliminates the wrinkles in the graphene film 201, resulting in a smooth, wrinkle-free graphene film 201. It is evident that this invention stretches and unfolds the wrinkles on the graphene film 201 using physical air pressure. The air pressure applies a uniform force to the substrate 200, ensuring uniform stretching of the graphene film 201. This not only yields excellent results but also effectively avoids risks such as tearing of the graphene film 201. Furthermore, the entire process is carried out at room temperature, avoiding the performance degradation of the graphene film 201 caused by high-temperature annealing, perfectly preserving the intrinsic properties of the graphene material. Moreover, it eliminates the need for any chemical reagents or intercalation substances, ensuring the cleanliness of the graphene film 201.

[0026] Secondly, after the folds of the graphene film 201 are fully stretched and unfolded, the air pressure in the air chamber 111 is released through the pressure relief valve 113 set at the air outlet, which makes it easier to remove the substrate 200. Since the substrate 200 is a metal substrate 200, its elastic deformation recovery is small, so that the stretched and unfolded graphene film 201 continues to maintain a stretched state.

[0027] It should be noted that the graphene film 201 in this embodiment is an example of a graphene film 201 prepared on a metal substrate 200 (such as copper or nickel) by chemical vapor deposition (CVD). For example, one preparation method involves providing a polycrystalline copper foil and subjecting it to high-temperature annealing to allow the grains to grow and achieve surface monocrystallization, providing a flat catalytic substrate 200 for the subsequent preparation of high-quality graphene. Subsequently, a monolayer graphene film 201 is grown on the monocrystallized copper foil substrate 200 using chemical vapor deposition. After growth, the film is cooled to room temperature in the furnace. Due to the difference in thermal expansion coefficients between graphene and copper foil, compression wrinkles form on the surface of the graphene film 201.

[0028] In one embodiment, the fixing mechanism 1 includes a base 11 and a fastening assembly 12. The base 11 forms an air cavity 111, and an opening 112 is provided on the top of the base 11. The base 200 is supported on the edge of the opening 112 and covers the opening 112. An air inlet and an air outlet are provided near the bottom of the base 11. The fastening assembly 12 is used to fasten the edge of the base 200 to the base 11.

[0029] Understandably, by forming an air cavity 111 on the base 11, when the substrate 200 is placed on the base 11, the opening 112 is covered by the substrate 200. Then, the substrate 200 is fastened to the base 11 by the fastening component 12. When the air cavity 111 is filled with air, the center of the base 11 undergoes elastic deformation upward because the fastening component 12 fixes the edge of the substrate 200 to the edge of the opening 112, causing its surface area to stretch and increase. Due to the strong van der Waals force between the graphene and the surface of the substrate 200, the graphene film 201 will be stretched synchronously by the tightly attached substrate 200.

[0030] Furthermore, the base 11 is usually made of rigid material, such as stainless steel base 11, iron base 11, etc. The rigid base 11 is not easily deformed under the increased air pressure environment in the air cavity 111, and has better reliability.

[0031] In one embodiment, the fastening assembly 12 includes an annular cover 121 and a fastening bolt 122. The annular cover 121 forms a clearance opening, and the fastening bolt 122 passes through the annular cover 121. The base 11 has a screw hole, and the fastening bolt 122 is threadedly engaged with the screw hole. The base 200 is clamped by the cooperation of the cover 121 and the base 11, and the clearance opening is directly opposite the opening 112.

[0032] Understandably, after the base 200 is placed on the base 11 and the base 200 closes the opening 112, the annular cap 121 is placed on top of the base 200, and the fastening bolts 122 on the cap engage with the screw holes on the base 11, thereby clamping the base 200 between the annular cap 121 and the base 11, preventing the base 200 from moving, and enhancing the airtightness of the air chamber 111. The annular cap 121 also forms a clearance opening, which is used to allow the base 200 to pass through during upward elastic deformation.

[0033] In one embodiment, the top of the base 11 is provided with an annular sealing groove, and the annular sealing groove is arranged around the opening 112. An annular sealing gasket 13 is provided in the annular sealing groove, and the top of the annular sealing gasket 13 protrudes out of the annular sealing groove. The annular sealing gasket 13 is used to seal the air cavity 111 when the pressure cap 121 and the base 11 cooperate to clamp the base 200.

[0034] Understandably, by setting an annular sealing groove and placing an annular sealing gasket 13 inside the annular sealing groove, the annular sealing groove is mainly used to limit the position of the annular sealing gasket 13 and prevent the annular sealing gasket 13 from falling off and being lost. When the annular cover 121 and the base 11 cooperate to press the base 200, the annular sealing gasket 13 is compressed simultaneously, thereby sealing the gap between the base 200 and the base 11, and further improving the airtightness of the air chamber 111.

[0035] In one embodiment, the inflation mechanism 2 includes a gas cylinder 21, an air passage 22, an air valve 23, a pressure gauge 24, and a pressure reducing valve 25. The gas cylinder 21 is connected to one end of the air passage 22 through the pressure reducing valve 25, and the other end of the air passage 22 is connected to the air inlet. The air valve 23 is disposed on the air passage 22 and is used to open or close the air passage 22. The pressure gauge 24 is disposed on the air passage 22 and is located between the air valve 23 and the air inlet. The pressure gauge 24 is used to detect the air pressure in the air passage 22. The gas cylinder 21 is used to inflate the air chamber 111 through the air passage 22 and the air inlet when the air valve 23 opens the air passage 22.

[0036] Understandably, the gas cylinder 21 is mainly filled with inert gases, such as nitrogen and argon. The gas cylinder 21 is connected to the gas passage 22 through the pressure reducing valve 25, and the gas passage 22 is also connected to the air inlet. By adjusting the pressure reducing valve 25, the gas output rate of the gas cylinder 21 can be adjusted, thereby controlling the rate of increase of the gas pressure in the gas chamber 111. A gas valve 23 is installed on the gas passage 22, which can completely close the gas passage 22 to maintain the gas pressure in the gas chamber 111. The gas pressure in the gas passage 22 is detected by a pressure gauge 24, which is located between the gas valve 23 and the air inlet. The gas pressure at this location also reflects the gas pressure in the gas chamber 111. Based on the reading of the pressure gauge 24, the gas pressure in the gas chamber 111 can be accurately controlled, thereby applying a uniform strain force to the substrate 200 and effectively avoiding the problem of tearing of the graphene film 201 due to stress concentration.

[0037] Furthermore, by adjusting the air pressure inside the air chamber 111, it can adapt to substrates 200 with different thicknesses and mechanical strengths, thus improving its versatility.

[0038] The present invention also proposes a method for eliminating wrinkles in graphene films, which is mainly achieved by the above-mentioned graphene film wrinkle elimination device.

[0039] It should be noted that, for better illustration, this embodiment uses a graphene film grown on a 25µm thick commercial copper foil substrate as an example.

[0040] Please see Figure 3 In the first embodiment of the present invention, the method for eliminating wrinkles in the graphene film includes the following steps: S100: Fix the substrate on which the graphene film is grown to the fixing mechanism; During fixation, the side of the substrate away from the graphene film is oriented towards the opening of the air cavity, and the substrate closes the opening, thereby forming a sealed air cavity.

[0041] Furthermore, the fixing mechanism includes a base, a pressure cap, and fastening bolts. During fixing, the substrate on which the graphene film is grown is first placed on the base, and the opening is closed by the base. Then, the annular pressure cap is placed on top of the substrate, and the fastening bolts on it cooperate with the screw holes on the base, thereby clamping the substrate together with the annular pressure cap and the base.

[0042] S200: The air chamber is inflated by the inflation mechanism, and the air pressure in the air chamber is increased to a first preset air pressure, so that the substrate undergoes elastic deformation in the direction away from the air chamber, thereby stretching and unfolding the folds of the graphene film. Inflate the air chamber with an inflation mechanism to increase the air pressure inside the air chamber to a first preset air pressure. Under the action of the increased air pressure, the substrate undergoes elastic deformation in the direction away from the air chamber, thereby stretching the graphene film grown on the substrate surface and causing the wrinkles of the graphene film to be stretched and unfolded.

[0043] It should be noted that the first preset air pressure ranges from 0.5 MPa to 2.0 MPa. In actual operation, the first preset air pressure is mainly related to the choice of substrate. In this embodiment, the first preset air pressure is mainly 0.8 MPa to ensure that the 25 μm thick copper foil substrate can undergo elastic deformation.

[0044] S300: The inflation mechanism stops inflating the air chamber and maintains the pressure for a preset time, so that the wrinkles of the graphene film are completely stretched and eliminated. The inflation mechanism stops inflating, maintaining the air pressure in the air chamber at the first preset air pressure until the folds of the graphene film are fully stretched and unfolded.

[0045] It should be noted that the preset holding time ranges from 5 minutes to 30 minutes. In this embodiment, the holding time is set to 5 minutes to ensure that the wrinkles of the graphene film grown on the 25µm thick copper foil substrate are completely stretched and eliminated.

[0046] S400: Open the pressure relief valve to reduce the air pressure in the air chamber to atmospheric pressure; S500: Remove the substrate and the graphene film thereon from the fixing mechanism.

[0047] The air pressure in the air chamber is reduced to atmospheric pressure by a pressure relief valve, so that the substrate can be easily removed from the fixing mechanism; and since the substrate is a metal substrate, its elastic deformation recovery is small, so that the graphene film continues to maintain a stretched state after stretching and unfolding.

[0048] Furthermore, when releasing pressure through the pressure relief valve, the pressure is usually released at a relatively slow rate. In this embodiment, the pressure in the air chamber 104 is reduced to atmospheric pressure at a rate of approximately 0.02 MPa / s.

[0049] like Figure 6 The image shows optical images of a graphene film grown on a 25µm thick copper foil substrate before and after treatment, as observed by an optical microscope. It can be seen that the visible wrinkles of the stretched graphene film are significantly reduced, the surface is smoother and flatter, and there is no tearing.

[0050] like Figure 7 As shown, the Raman spectra of the graphene film grown on a 25µm thick copper foil substrate before and after treatment are obtained. It can be seen that the positions of the 2D peak and G peak in the Raman spectrum are significantly red-shifted before stretching compared to before stretching, indicating that the strain of the graphene is released and the crystal quality is restored.

[0051] Furthermore, the inflation mechanism includes a gas cylinder, an air circuit, an air valve, a pressure gauge, and a pressure reducing valve. The gas cylinder is connected to one end of the air circuit through the pressure reducing valve, and the other end of the air circuit is connected to the air inlet. The air valve is located on the air circuit and is used to open or close the air circuit. The pressure gauge is located on the air circuit and is positioned between the air valve and the air inlet. The pressure gauge is used to detect the air pressure in the air circuit. The gas cylinder is used to inflate the air chamber through the air circuit and the air inlet when the air valve opens the air circuit. Please see Figure 4 In the second embodiment of the present invention, which is based on the first embodiment, step S200 includes: S210: Adjust the outlet pressure of the gas cylinder to a preset outlet pressure using the pressure reducing valve; The outlet pressure of the gas cylinder is adjusted by a pressure reducing valve to regulate the inflation rate into the gas path, thereby steadily increasing the gas pressure within the gas chamber and ensuring gradual elastic deformation of the substrate, preventing tearing of the graphene film. In one specific embodiment, the preset outlet pressure is 1.0 MPa.

[0052] S220: Open the gas valve to allow the gas cylinder to fill the gas chamber through the gas passage and the gas inlet; S230: Adjust the pressure reducing valve and determine whether the air pressure in the air circuit has increased to the first preset air pressure by reading the pressure value of the pressure gauge; if so, continue to execute step S300.

[0053] After opening the air valve, the rate of increase in air pressure within the air chamber is controlled by adjusting the pressure reducing valve. In one specific embodiment, the pressure reducing valve 109 is slowly adjusted to steadily increase the air pressure within the air chamber to 0.8 MPa at a rate of approximately 0.05 MPa / s. During the inflation process, the pressure gauge reading needs to be continuously monitored so that the air valve can be immediately closed to maintain pressure once the reading reaches the first preset air pressure.

[0054] Furthermore, step S300 specifically includes: Close the gas valve; and adjust the pressure reducing valve to stop the gas cylinder from filling the gas path and the gas chamber. Understandably, after closing the gas valve, the pressure reducing valve is also adjusted to stop the gas cylinder from filling the gas line, so as to avoid the pressure in the gas line located between the pressure reducing valve and the gas valve gradually increasing.

[0055] Please see Figure 5 This is the third embodiment of the present invention. The third embodiment is based on the second embodiment, and before step S230, it further includes: S221: Determine whether the air pressure in the air chamber has increased to the second preset air pressure by the reading of the pressure gauge, wherein the second preset air pressure is less than the first preset air pressure; S222: If so, close the gas valve to stop the gas cylinder from filling the gas chamber; If the pressure does not increase to the second preset level, continue to fill the gas path through the gas cylinder.

[0056] S223: Hold pressure for a second preset time, and determine whether the pressure value of the pressure gauge has changed by reading the pressure value of the pressure gauge; if yes, determine that the air chamber is in a completely closed state, open the air valve, and continue to execute step 230; if no, determine that the air chamber is in a partially closed state, keep the air valve closed, and return to execute step 100.

[0057] Understandably, increasing the air pressure in the air chamber to a second preset pressure and then closing the air valve stops the gas cylinder from filling the chamber. This is primarily to verify the airtightness of the air chamber. If the airtightness is good, the pressure gauge reading will not change during pressure holding. If the airtightness is poor, the air chamber will leak, causing the pressure gauge reading to change. Poor airtightness requires re-fixing the base. By checking the airtightness of the air chamber, it is ensured that the air pressure applies appropriate strain force to the base, thereby ensuring that the base can undergo elastic deformation, resulting in better reliability.

[0058] To further illustrate, in another embodiment, a 50µm thick electrolytic copper foil substrate is used as an example. The processing steps are the same as those described above, except that, since the substrate is thicker and more rigid, the first preset air pressure is set to 1.6 MPa and the pressure holding time is set to 30 minutes to ensure that the 50µm thick substrate can fully deform elastically.

[0059] like Figure 8 As shown, the graphene film grown on a 50µm thick electrolytic copper foil substrate is observed by an optical microscope before and after treatment. It can be seen that the visible wrinkles of the stretched graphene film are significantly reduced, the surface is smoother and flatter, and there is no tearing.

[0060] Therefore, the wrinkle-eliminating device of this graphene film can be applied to metal substrates of different thicknesses, making it more versatile.

[0061] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A wrinkle-eliminating device for graphene films, characterized in that, include: A fixing mechanism is provided, wherein an air cavity is formed within the fixing mechanism, and an opening is formed on one side of the air cavity. A substrate on which the graphene film is grown is placed at the opening and covers the opening to seal the air cavity. An air inlet and an air outlet communicating with the air cavity are provided on the fixing mechanism, and a pressure relief valve is provided at the air outlet. An inflation mechanism is provided, which is connected to the air inlet. The inflation mechanism is used to inflate the air cavity to increase the air pressure in the air cavity, so that the substrate undergoes elastic deformation in a direction away from the air cavity, thereby stretching and unfolding the folds of the graphene film.

2. The wrinkle-eliminating device for graphene films as described in claim 1, characterized in that, The fixing mechanism includes a base and a fastening assembly. The base forms the air cavity, and the top of the base has the opening. The base supports the edge of the opening and covers the opening. The base has the air inlet and the air outlet near the bottom. The fastening assembly is used to fasten the edge of the base to the base.

3. The wrinkle-eliminating device for graphene films as described in claim 2, characterized in that, The fastening assembly includes an annular cover and a fastening bolt. The annular cover forms a clearance opening, and the fastening bolt passes through the annular cover. The base has a threaded hole, and the fastening bolt is threaded into the threaded hole to clamp the base through the cooperation of the cover and the base. The clearance opening is directly opposite the opening.

4. The wrinkle-eliminating device for graphene films as described in claim 3, characterized in that, The base has an annular sealing groove at its top, and the annular sealing groove surrounds the opening. An annular sealing gasket is provided inside the annular sealing groove, and the top of the annular sealing gasket protrudes from the annular sealing groove. The annular sealing gasket is used to seal the air cavity when the cover and the base are engaged to clamp the base.

5. The wrinkle-eliminating device for graphene films as described in claim 1, characterized in that, The inflation mechanism includes a gas cylinder, a gas path, a gas valve, a pressure gauge, and a pressure reducing valve. The gas cylinder is connected to one end of the gas path through the pressure reducing valve, and the other end of the gas path is connected to the air inlet. The gas valve is located on the gas path and is used to open or close the gas path. The pressure gauge is located on the gas path and between the gas valve and the air inlet. The pressure gauge is used to detect the gas pressure in the gas path. The gas cylinder is used to inflate the gas chamber through the gas path and the air inlet when the gas valve opens the gas path.

6. A method for eliminating wrinkles in a graphene film, characterized in that, The graphene film wrinkle elimination method employs the wrinkle elimination device for graphene films as described in any one of claims 1 to 5, and the wrinkle elimination method includes the following steps: The substrate on which the graphene film is grown is fixed to the fixing mechanism; The air chamber is inflated by the inflation mechanism, and the air pressure in the air chamber is increased to a first preset air pressure, so that the substrate undergoes elastic deformation in the direction away from the air chamber, thereby stretching and unfolding the folds of the graphene film. The inflation mechanism stops inflating the air chamber and maintains the pressure for a preset time, so that the wrinkles of the graphene film are completely stretched and eliminated. Open the pressure relief valve to reduce the air pressure in the air chamber to atmospheric pressure; Remove the substrate and the graphene film thereon from the fixing mechanism.

7. The method for eliminating wrinkles in a graphene film as described in claim 6, characterized in that, The preset time is 5 minutes to 30 minutes; the first preset air pressure is 0.5 MPa to 2.0 MPa.

8. The method for eliminating wrinkles in a graphene film as described in claim 6, characterized in that, The inflation mechanism includes a gas cylinder, a gas path, a gas valve, a pressure gauge, and a pressure reducing valve. The gas cylinder is connected to one end of the gas path through the pressure reducing valve, and the other end of the gas path is connected to the air inlet. The gas valve is located on the gas path and is used to open or close the gas path. The pressure gauge is located on the gas path and between the gas valve and the air inlet. The pressure gauge is used to detect the gas pressure in the gas path. The gas cylinder is used to inflate the gas chamber through the gas path and the air inlet when the gas valve opens the gas path. The step of inflating the air chamber with air through the inflation mechanism and increasing the air pressure in the air chamber to a first preset air pressure includes: The outlet pressure of the gas cylinder is adjusted to a preset outlet pressure by means of the pressure reducing valve; Open the gas valve to allow the gas cylinder to fill the gas chamber through the gas passage and the gas inlet; Adjust the pressure reducing valve and determine whether the air pressure in the air circuit has increased to the first preset air pressure by reading the pressure value of the pressure gauge; If so, the procedure of stopping the inflation mechanism from inflating the air chamber and maintaining pressure for a preset time shall continue.

9. The method for eliminating wrinkles in a graphene film as described in claim 8, characterized in that, The specific steps for the inflation mechanism to stop inflating the air chamber are as follows: Close the gas valve and adjust the pressure reducing valve to stop the gas cylinder from filling the gas passage and the gas chamber.

10. The method for eliminating wrinkles in a graphene film as described in claim 9, characterized in that, Before the step of adjusting the pressure reducing valve and determining whether the air pressure in the air circuit has increased to the first preset air pressure by reading the pressure value of the pressure gauge, the method further includes: The pressure in the air chamber is determined by the reading of the pressure gauge to determine whether the pressure has increased to the second preset pressure, wherein the second preset pressure is less than the first preset pressure; If so, close the gas valve to stop the gas cylinder from filling the gas chamber; The pressure is maintained for a second preset time, and the pressure value of the pressure gauge is read to determine whether the pressure value of the pressure gauge has changed; If so, the air chamber is determined to be in a completely closed state, and the air valve is opened. The step of adjusting the pressure reducing valve is continued, and the pressure value of the pressure gauge is read to determine whether the air pressure in the air circuit has increased to the first preset air pressure. If not, the air chamber is determined to be in an incompletely closed state, and the air valve remains closed. The process then returns to the step of fixing the substrate with the graphene film grown on it onto the fixing mechanism.

Images