Nano Tesla valve based on graphene modification and preparation method thereof

Abstract

The invention relates to the field of nano processing, in particular to a graphene modification-based nano Tesla valve and a preparation method thereof. The nanometer Tesla valve comprises a metal substrate, a Tesla valve-shaped channel etched on the metal substrate, a graphene layer attached to the surface of the Tesla valve-shaped channel, and a graphene sheet covering the etching surface of the metal substrate. A specific Tesla valve-shaped channel is etched on a metal substrate by applying a nano etching technology, and graphene is utilized to modify and cover the channel, so that the graphene modification-based nano Tesla valve is successfully designed and prepared, and the graphene modification-based nano Tesla valve has the characteristics of specific structure, excellent performance, unique manufacturing method and the like; under the control of an electric field, the transportation of water molecules can be effectively regulated and controlled, and the method has a wide application prospect in the fields of nanofluids, biomedicine, seawater desalination and the like.

Description

Technical Field

[0001] The present invention relates to the field of nano - processing, and particularly to a graphene - modified nano - Tesla valve and a preparation method thereof. Background Art

[0002] In the era of rapid technological development today, nanotechnology is constantly promoting innovation and transformation in various industries. The research and development and application of nano - devices have become the focus of many researchers, and they show great potential in the fields of nanofluid control, biomedicine, seawater desalination, etc. In nanofluid control, precise regulation of fluid flow is crucial for the realization of many key technologies. As a special fluid - control structure, the Tesla valve has been applied in some specific fields at the macroscopic scale. However, shrinking the Tesla valve to the nanoscale and endowing it with specific functions and performances still faces many challenges.

[0003] Although existing nano - processing technologies have made certain progress, there are still many technical problems in constructing nano - devices with specific structures and functions. For example, how to select suitable materials to modify nano - channels to achieve specific regulation of fluids; how to ensure the stability and reliability of nano - devices to meet the requirements of practical applications, etc. Therefore, how to design and obtain a nano - Tesla valve with specific functions and performances is of great significance. Summary of the Invention

[0004] In view of the above - mentioned deficiencies of the prior art, the purpose of the present invention is to provide a graphene - modified nano - Tesla valve and a preparation method thereof. The graphene - modified nano - Tesla valve provided by the present invention has the characteristics of specific structure, excellent performance, and unique manufacturing method. It can effectively regulate the transport of water molecules under electric - field control and has broad application prospects in the fields of nanofluids, biomedicine, seawater desalination, etc.

[0005] The technical solution of the present invention is as follows:

[0006] In the first aspect of the present invention, a graphene - modified nano - Tesla valve is provided, which includes: a metal substrate, a Tesla - valve - shaped channel etched on the metal substrate, a graphene layer attached to the surface of the Tesla - valve - shaped channel, and a graphene sheet covering the etched surface of the metal substrate.

[0007] Optionally, the Tesla - valve - shaped channel includes an inflow channel, an outflow channel, and a reflux channel, and the angle at the intersection of the inflow channel and the reflux channel is the same as the angle at the intersection of the inflow channel and the outflow channel.

[0008] Optionally, the angle at the intersection of the inflow channel and the reflux channel and the angle at the intersection of the inflow channel and the outflow channel are 15° - 90°.

[0009] Optionally, the etching depth of the Tesla valve-shaped channel on the metal substrate is 50% to 90%.

[0010] Optionally, the material of the metal substrate is copper, titanium or aluminum.

[0011] In a second aspect of the present invention, there is provided a method for preparing a nano Tesla valve based on graphene modification according to the present invention, which includes the steps of:

[0012] S1. Provide a metal substrate;

[0013] S2. Etch a Tesla valve-shaped channel on the metal substrate by using a nano-etching process;

[0014] S3. Form a graphene layer on the surface of the Tesla valve-shaped channel by using a chemical vapor deposition method;

[0015] S4. Cover the etched surface of the metal substrate with a pre-prepared graphene sheet to obtain the nano Tesla valve based on graphene modification.

[0016] Optionally, the step S2 specifically includes:

[0017] Coat a photoresist on the metal substrate, place it in an electron beam lithography system, and perform exposure and development processing on the photoresist according to the pattern of the Tesla valve-shaped channel;

[0018] Put the developed metal substrate into a dry etching system, introduce a mixed gas of argon and chlorine, and etch the metal substrate under the conditions of a radio frequency power of 50 to 150 W, a gas pressure of 1 to 5 Pa, and an etching time of 5 to 10 min, that is, etch a Tesla valve-shaped channel on the metal substrate.

[0019] Optionally, the etching depth of the Tesla valve-shaped channel etched on the metal substrate is 50% to 90%.

[0020] Optionally, the chemical vapor deposition process is: under the condition of introducing a carbon source gas and a carrier gas, the temperature of the chemical vapor deposition is 900 to 1000 °C, the pressure of the chemical vapor deposition is 10 to 50 Pa, and the time of the chemical vapor deposition is 10 to 30 min.

[0021] Optionally, the carbon source gas is methane, ethylene or acetylene, and the carrier gas is hydrogen, argon or nitrogen.

[0022] Beneficial effects: By using nano-etching technology on a metal substrate to etch out a specific Tesla valve-shaped channel and using graphene to modify and cover the channel, the present invention successfully designs and prepares the graphene-modified nano Tesla valve. It has characteristics such as a specific structure, excellent performance, and a unique manufacturing method. Under the control of an electric field, it can effectively regulate the transport of water molecules and has broad application prospects in the fields of nanofluids, biomedicine, desalination, etc. Brief Description of the Drawings

[0023] Figure 1 It is a schematic diagram of a graphene-modified nano Tesla valve provided by the present invention.

[0024] Figure 2 It is a side view of a graphene-modified nano Tesla valve provided by the present invention.

[0025] Figure 3 It is a schematic diagram of the Tesla valve-shaped channel in a graphene-modified nano Tesla valve provided by the present invention.

[0026] Figure 4 It is a flow chart of the preparation method of a graphene-modified nano Tesla valve provided by the present invention.

[0027] Figure 5 It is a model diagram of the nano Tesla valve prepared in Example 1 and Comparative Example 1.

[0028] Figure 6 It is a flow rate detection and comparison diagram of water flowing through the Tesla valve channel in the nano Tesla valve of Example 1 and the Tesla valve channel in the nano Tesla valve of Comparative Example 1. Detailed Embodiments

[0029] The present invention provides a graphene-modified nano Tesla valve and its preparation method. To make the purpose, technical solution and effects of the present invention clearer and more definite, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] As Figure 1 and Figure 2 shown, an embodiment of the present invention provides a graphene-modified nano Tesla valve, which includes: a metal substrate 1, a Tesla valve-shaped channel 2 etched on the metal substrate, a graphene layer 3 attached to the surface of the Tesla valve-shaped channel, and a graphene sheet 4 covering the etched surface of the metal substrate.

[0031] An embodiment of the present invention provides a nano Tesla valve with a specific structure and excellent performance. It uses a high-strength metal substrate as the support structure of the entire nano Tesla valve, which has good strength and stability and can withstand subsequent nano-etching and processing processes. Then, a specific Tesla valve-shaped channel is etched on the metal substrate through nano-etching technology, and special control of fluid can be achieved through the principle of the Tesla valve. Then, a graphene layer attached to the channel surface is grown on the Tesla valve-shaped channel. The graphene layer can change the properties of the channel surface and affect the transmission behavior of water molecules in the channel. Finally, a graphene sheet is covered on the etched surface of the metal substrate to form a closed Tesla valve-shaped channel with a graphene surface. The graphene sheet can not only protect the channel but also play a synergistic role with the graphene layer on the surface of the Tesla valve-shaped channel to further enhance the regulation ability of water molecule transport.

[0032] In the present invention, the etched surface of the metal substrate refers to the surface of the metal substrate on which the Tesla valve-shaped channel is etched.

[0033] As Figure 3 shown, in some embodiments, the Tesla valve-shaped channel 2 includes an inflow channel 6, an outflow channel 5, and a reflux channel 7. The angle (α) at the intersection of the inflow channel 6 and the reflux channel 7 is the same as the angle (α) at the intersection of the inflow channel 6 and the outflow channel 5. As Figure 3 shown, parameters L0, L01, L02, L2, L3, L4, L41, R1, R2, d, α are defined in the Tesla valve-shaped channel 2. The independent parameters are L01, L02, L3, L41, d, α. Among them, L01 and L4 control the total length of the channel, and L0, L2, L3, L02, d, and α control the overall width of the channel, specifically reflected in the channel width and the reflux angle;

[0034] Total length: L01×cosα + L4

[0035] Total width: (L0 + L2 + L3 + L02×tanα / 2 + d)×sinα

[0036] The geometric relationships of the remaining parameters are as follows:

[0037] L0 = L01 + L02 + d / sinα

[0038] R1 = L02×tanα / 2

[0039] R2 = L02×tanα / 2 + d

[0040] L2 = d / tanα

[0041] L4 = d / tanα + L02×cosα + d / sinα + L41

[0042] In this embodiment, special control of fluid can be achieved through the principle of the Tesla valve. At the nanoscale, due to the enhanced surface effect, the fluid properties change, the unidirectional conductivity decreases, and reverse leakage occurs; the flow rate is unstable and fluctuates; the flow velocity distribution is abnormal, with local areas being too fast or too slow. However, it can be regulated by graphene modification to complete the control of flow rate and pressure.

[0043] In some embodiments, the angle at the intersection of the inflow channel and the return channel and the angle at the intersection of the inflow channel and the outflow channel are 15° to 90° (for example, it can be 15°, 30°, 45°, 60°, 90°, etc.).

[0044] In some embodiments, the etching depth of the Tesla valve-shaped channel on the metal substrate is 50% to 90% (which means the depth of the Tesla valve-shaped channel is 50% to 90% of the thickness of the metal substrate); preferably, the etching depth is 80%. When the etching depth is within this range, it is beneficial to improve the process stability and optimize the structural performance of the nano-Tesla valve, and at the same time, it can reduce the cost and process difficulty while ensuring the function.

[0045] In some embodiments, the material of the metal substrate is copper, titanium, or aluminum. When the material of the metal substrate is selected as copper, titanium, or aluminum, the metal substrate has high strength and high stability, can serve as a support structure, and can withstand nano-etching and subsequent processing processes.

[0046] As Figure 4 shown, the embodiment of the present invention provides a preparation method of the nano-Tesla valve based on graphene modification described in any one of the foregoing embodiments, which includes the steps:

[0047] S1. Provide a metal substrate;

[0048] S2. Use a nano-etching process to etch a Tesla valve-shaped channel on the metal substrate;

[0049] S3. Use a chemical vapor deposition method to form a graphene layer on the surface of the Tesla valve-shaped channel;

[0050] S4. Cover the etched surface of the metal substrate with a pre-prepared graphene sheet to obtain the nano-Tesla valve based on graphene modification.

[0051] In the embodiment of the present invention, a specific Tesla valve-shaped channel is etched on a metal substrate by using a nano-etching process, and then a graphene layer is formed on the surface of the Tesla valve-shaped channel by using a chemical vapor deposition method. Finally, a graphene sheet is covered on the etched surface of the metal substrate, thus successfully preparing the graphene-modified nano-Tesla valve. The method is simple to operate and realizes the preparation of nano-Tesla valves with specific functions and excellent performance by using nano-processing technology.

[0052] In step S1, in some embodiments, the metal substrate is a metal substrate with a clean and flat surface. Specifically, the metal substrate is first placed in an ultrasonic cleaner and ultrasonically cleaned for 15 minutes. The substrate cleaning solvent is preferably acetone, ethanol, isopropanol, dilute hydrochloric acid, sodium hydroxide, etc. to remove the oil and impurities on the substrate surface. Then the metal substrate is rinsed with deionized water and then placed in a vacuum drying oven and dried at 80-100 °C for 15-30 minutes to ensure that the substrate surface is clean and flat, and to prepare for the subsequent nano-etching operation.

[0053] In step S2, in some embodiments, step S2 specifically includes:

[0054] A photoresist is coated on the metal substrate and placed in an electron beam lithography system. The photoresist is exposed and developed according to the pattern of the Tesla valve-shaped channel;

[0055] The developed metal substrate is placed in a dry etching system, and a mixed gas of argon and chlorine is introduced. The metal substrate is etched under the conditions of a radio frequency power of 50-150 W, a gas pressure of 1-5 Pa, and an etching time of 5-10 minutes, that is, a Tesla valve-shaped channel is etched on the metal substrate.

[0056] In the present invention, the exposure and development processes are conventional techniques in the art and are not limited herein.

[0057] In some embodiments, the photoresist is preferably polymethyl methacrylate (PMMA), poly(1-butene sulfone) (PBS), poly(dimethylglutarimide) (PMGI), and more preferably polymethyl methacrylate (PMMA).

[0058] In some embodiments, the etching depth of the Tesla valve-shaped channel etched on the metal substrate is 50%-90%, preferably 80%. When the etching depth is within this range, it is beneficial to improve the process stability and optimize the structural performance of the nano-Tesla valve, and at the same time, it can reduce the cost and process difficulty while ensuring the function.

[0059] In step S3, in some embodiments, the process of chemical vapor deposition is as follows: under the condition of introducing a carbon source gas and a carrier gas, the temperature of chemical vapor deposition is 900 - 1000 °C, the pressure of chemical vapor deposition is 10 - 50 Pa, and the time of chemical vapor deposition is 10 - 30 min. Under the process conditions of the chemical vapor deposition, the carbon source gas decomposes at high temperature to generate carbon atoms, and the carbon atoms deposit on the surface of the Tesla valve-shaped channel to form graphene sheets.

[0060] In some embodiments, step S3 specifically includes:

[0061] Put the metal substrate obtained through step S2 into a chemical vapor deposition reaction furnace, introduce a carbon source gas and a carrier gas, and react for 10 - 30 min under the conditions of a temperature of 900 - 1000 °C and a pressure of 10 - 50 Pa, that is, a graphene layer is formed on the surface of the Tesla valve-shaped channel.

[0062] In some embodiments, the carbon source gas is methane, ethylene or acetylene, and the carrier gas is hydrogen, argon or nitrogen; preferably, the carbon source gas is methane and the carrier gas is hydrogen.

[0063] In step S4, in some embodiments, the pre-prepared graphene sheets can be prepared according to conventional methods in the art, which will not be limited herein.

[0064] In some embodiments, the preparation method of the pre-prepared graphene sheets includes the steps of:

[0065] Put a copper foil into a chemical vapor deposition reaction furnace, inject a carbon source gas and a carrier gas, and react for 10 - 30 min under the conditions of a temperature of 900 - 1000 °C and a pressure of 10 - 50 Pa to obtain a copper foil with graphene sheets grown on its surface;

[0066] Spin-coat a layer of polymethyl methacrylate (PMMA) on the surface of the copper foil with the grown graphene sheets as a support layer, and then soak it in a solution containing an etchant (preferably ammonium persulfate or ferric chloride) to dissolve the copper foil, obtaining a graphene sheet - PMMA layer composite material;

[0067] Put the graphene sheet - PMMA layer composite material into an acetone solution to dissolve the PMMA layer, that is, obtain graphene sheets.

[0068] In some embodiments, step S4 specifically includes:

[0069] Put a copper foil into a chemical vapor deposition reaction furnace, inject a carbon source gas and a carrier gas, and react for 10 - 30 min under the conditions of a temperature of 900 - 1000 °C and a pressure of 10 - 50 Pa to obtain a copper foil with graphene sheets grown on its surface;

[0070] Spin-coat a layer of polymethyl methacrylate (PMMA) on the surface of the copper foil grown with graphene sheets as a support layer, and then immerse it in a solution containing an etchant (preferably ammonium persulfate or ferric chloride) to dissolve the copper foil, obtaining a graphene sheet-PMMA composite material.

[0071] Transfer the graphene sheet-PMMA composite material to the etched surface of the metal substrate obtained in step S3, then place it in an acetone solution to dissolve the PMMA layer, so that the graphene sheets cover the etched surface of the metal substrate, and then through cleaning and drying treatments, the graphene-modified nano Tesla valve is obtained.

[0072] In some embodiments, the cleaning uses deionized water to clean the metal substrate to remove residual acetone and PMMA fragments.

[0073] In some embodiments, the drying temperature is 80-100 °C and the drying time is 15-30 min.

[0074] The present invention will be further described below through specific examples.

[0075] Example 1

[0076] This example provides a preparation method of a graphene-modified nano Tesla valve S1, which is specifically as follows:

[0077] Step 1: Select a 15 mm × 15 mm × 3 mm copper plate as the metal substrate, place the copper plate in an ultrasonic cleaner for ultrasonic cleaning for 15 min, then rinse it with deionized water, and then put it into a vacuum drying oven and dry it at 100 °C for 30 min to obtain a copper plate with a clean and flat surface.

[0078] Step 2: Coating photoresist PMMA on the copper plate obtained in step 1, put it into an electron beam lithography system, and according to the pattern of the Tesla valve-shaped channel (see Figure 3 ) expose the photoresist, where α = 45°, the total length is The total width is Then put it into a developer for development treatment to remove the exposed photoresist and expose the surface of the copper plate to be etched; put the developed copper plate into a dry etching system, introduce a mixed gas of argon and chlorine, and etch the copper plate under the conditions of a radio frequency power of 150 W, a gas pressure of 15 Pa, and an etching time of 10 min, that is, etch a Tesla valve-shaped channel with an etching depth of 80% on the copper plate.

[0079] Step 3: Place the copper plate obtained in Step 2 into a chemical vapor deposition reactor, introduce methane and hydrogen, and react for 30 min under the conditions of a temperature of 900 °C and a pressure of 10 Pa, thereby forming a graphene layer on the surface of the Tesla valve-shaped channel.

[0080] Step 4: Select another copper foil, place it into a chemical vapor deposition reactor, introduce methane and hydrogen, and react for 30 min under the conditions of a temperature of 900 °C and a pressure of 10 Pa to obtain a copper foil with graphene flakes grown on its surface;

[0081] Spin-coat a layer of PMMA on the surface of the copper foil with the graphene flakes grown thereon as a support layer, and then soak it in a solution containing ammonium persulfate or ferric chloride as an etchant to dissolve the copper foil, thereby obtaining a graphene flake-PMMA composite material;

[0082] Transfer the graphene flake-PMMA composite material to the etched surface of the copper plate obtained in Step S3, then place it into an acetone solution to dissolve the PMMA layer, such that the graphene flakes cover the etched surface of the copper plate, then wash it with deionized water, and then place it into a vacuum drying oven to dry at 100 °C for 30 min to obtain the final graphene-modified nano Tesla valve S1.

[0083] Comparative Example 1

[0084] The preparation method of Comparative Example 1 is the same as that of Example 1, except that Step 3 in Example 1 is omitted, and finally the nano Tesla valve D1 is obtained.

[0085] Figure 5 Figure is the model diagram of the nano Tesla valves prepared in Example 1 and Comparative Example 1. It can be seen that a graphene layer is formed on the surface of the Tesla valve-shaped channel of the nano Tesla valve prepared in Example 1. However, no graphene layer is formed on the surface of the Tesla valve-shaped channel of the nano Tesla valve prepared in Comparative Example 1.

[0086] Figure 6 Figure is the flow rate detection and comparison diagram of water flowing through the Tesla valve channel in the nano Tesla valve of Example 1 and the Tesla valve channel in the nano Tesla valve of Comparative Example 1. According to this figure, it can be known that when the nano Tesla valve channel is placed in the forward and reverse directions, at the same pressure, the stable flow rate of the forward nano Tesla valve channel is greater than or equal to that of the reverse nano Tesla valve channel, and the graphene-modified nano Tesla valve channel in Example 1 has faster transport characteristics and a larger flow rate compared to Comparative Example 1, which indicates that graphene modification has an enhancing effect on the transport of the Tesla valve.

[0087] In summary, a nano Tesla valve based on graphene modification provided by the present invention includes: a metal substrate, a Tesla valve-shaped channel etched on the metal substrate, a graphene layer attached to the surface of the Tesla valve-shaped channel, and a graphene sheet covering the etched surface of the metal substrate. The nano Tesla valve has characteristics such as a specific structure and excellent performance, and can effectively regulate the transport of water molecules under the control of an electric field, and has broad application prospects in the fields of nanofluids, biomedicine, seawater desalination, etc.

[0088] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present invention.

Claims

1. A graphene-modified nano Tesla valve, characterized in that: include: A metal substrate, a Tesla valve-shaped channel etched on the metal substrate, a graphene layer attached to a surface of the Tesla valve-shaped channel, and a graphene sheet covering the etched surface of the metal substrate.

2. The graphene-modified nano Tesla valve according to claim 1, characterized in that: The Tesla valve-shaped channel includes an inlet channel, an outlet channel and a return channel, wherein the angle at which the inlet channel and the return channel meet is the same as the angle at which the inlet channel and the outlet channel meet.

3. The graphene-modified nano Tesla valve according to claim 2, characterized in that: The angle at the intersection of the inlet channel and the return channel and the angle at the intersection of the inlet channel and the outlet channel are 15° to 90°.

4. The graphene-modified nano Tesla valve according to claim 1, characterized in that: The etching depth of the Tesla valve-shaped channel on the metal substrate is 50% to 90%.

5. The graphene-modified nano Tesla valve according to claim 1, characterized in that: The material of the metal substrate is copper, titanium or aluminum.

6. A method for preparing a graphene-modified nano Tesla valve according to any one of claims 1 to 5, characterized in that: Includes steps: S1. Provide a metal substrate; S2, etching a Tesla valve-shaped channel on the metal substrate using a nano-etching process; S3, forming a graphene layer on the surface of the Tesla valve-shaped channel by a chemical vapor deposition method; S4. Covering the etched surface of the metal substrate with the prepared graphene sheet to obtain the graphene-modified nano Tesla valve.

7. The preparation method according to claim 6, characterized in that: The step S2 specifically includes: Applying photoresist on the metal substrate, placing it in an electron beam lithography system, and exposing and developing the photoresist according to the pattern of the Tesla valve-shaped channel; The developed metal substrate is placed in a dry etching system, a mixed gas of argon and chlorine is introduced, and the metal substrate is etched under the conditions of a radio frequency power of 50 to 150 W, a gas pressure of 1 to 5 Pa, and an etching time of 5 to 10 minutes, so that a Tesla valve-shaped channel is etched on the metal substrate.

8. The preparation method according to claim 6, characterized in that: The etching depth of etching the Tesla valve-shaped channel on the metal substrate is 50% to 90%.

9. The preparation method according to claim 6, characterized in that: The chemical vapor deposition process is as follows: under the condition of introducing carbon source gas and carrier gas, the temperature of chemical vapor deposition is 900-1000° C., the pressure of chemical vapor deposition is 10-50 Pa, and the time of chemical vapor deposition is 10-30 min.

10. The preparation method according to claim 9, characterized in that: The carbon source gas is methane, ethylene or acetylene, and the carrier gas is hydrogen, argon or nitrogen.

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