Heterogeneous microrib membrane and preparation method thereof

Abstract

The present invention provides a heterogeneous micro-rib membrane and a preparation method thereof, comprising a front and a back surface, wherein the front surface is provided with a vortex generator array and a rib array, wherein the vortex generator array is arranged in series with the rib array, wherein the vortex generator array includes a plurality of flatly arranged vortex generators, and the rib array includes a plurality of flatly arranged ribs. From the front surface to the back surface, the membrane comprises a first protective layer, a second protective layer, a support layer, a backing layer, and a bottom film layer, wherein the first protective layer is made of a super-hydrophobic modified material, the second protective layer is formed by argon ion bombardment of a chromium target and deposition of chromium atoms, the support layer is made of an epoxy resin material, and the backing layer is prepared by corona treating the surface of the support layer and applying glue; the bottom film layer is removable. The heterogeneous micro-rib membrane provided by the present invention has high overall strength, wear resistance, corrosion resistance, and significant drag reduction effect.

Description

Technical Field

[0001] The present invention relates to the technical field of thin films, in particular to a heterogeneous micro-rib membrane and a preparation method thereof. Background Art

[0002] When an aircraft is flying at high speeds, the frictional drag generated by fluid viscosity plays a significant role in the aircraft's total aerodynamic drag, accounting for up to 50%. This considerable frictional drag primarily stems from the turbulent boundary layer attached to the aircraft's surface. This turbulent boundary layer contributes significantly to the drag, especially when large aircraft are flying at high speeds. Therefore, developing technologies to reduce the drag generated by the turbulent boundary layer has become key to improving aircraft performance and fuel efficiency, and is also one of the important research directions in the current aviation field.

[0003] The micro-rib structure was first proposed by Walsh and others at NASA's Langley Research Center in the 1980s, inspired by the two-dimensional simplification of the shark skin scale array structure. This structure not only has a significant drag reduction effect, but also has a simple preparation process, is easy to apply in engineering, and does not require additional energy consumption. It can effectively control the small-scale flow structure within the boundary layer, reducing the frictional resistance between the fluid and the aircraft surface. However, the actual flight conditions of aircraft are far more complex than laboratory conditions, and the flow state and the scale of the turbulent boundary layer structure vary greatly under different flight conditions. Under medium and high characteristic Reynolds numbers, the large-scale flow structure in the outer region of the turbulent boundary layer plays a significant role, and it is difficult to achieve a significant friction reduction effect by controlling the small-scale flow structure alone. Summary of the Invention

[0004] By configuring a multi-scale microstructured surface film structure, the surface friction reduction effect can be effectively improved. Compared with a single-scale microstructured surface, it can work over a wider range of Reynolds numbers. Traditional heterogeneous micro-rib film preparation processes, such as ultraviolet (UV) transfer, roll forming, and flatbed embossing, produce multi-scale microstructured surface films that are difficult to meet the high-performance requirements of anti-friction film materials under extreme operating conditions such as high-altitude and high-speed flight of aircraft. Their microstructure strength, wear resistance, and high-temperature tolerance all need to be further improved.

[0005] The present invention is completed in view of the above-mentioned existing situation, and its purpose is to provide a heterogeneous micro-rib membrane and a preparation method thereof, wherein the heterogeneous micro-rib membrane includes a front side and a back side, wherein the front side is provided with a vortex generator array and a rib array, wherein the vortex generator array is provided in series with the rib array, wherein the vortex generator array includes a plurality of vortex generators arranged in a flat manner, and the rib array includes a plurality of ribs arranged in a flat manner, and wherein the heterogeneous micro-rib membrane includes a first protective layer, a second protective layer, a support layer, a back adhesive layer and a base film layer in sequence from the front side to the back side, wherein:

[0006] The first protective layer is made of super hydrophobic modified material.

[0007] The second protective layer is formed by bombarding a chromium target with argon ions and depositing chromium atoms.

[0008] The supporting layer is made of epoxy resin material.

[0009] The back adhesive layer is prepared by corona treating the surface of the support layer and then applying adhesive;

[0010] The base film layer is removable.

[0011] In this case, the first protective layer has low surface energy and excellent hydrophobicity, thereby preventing the accumulation of scale and dust and enhancing the membrane's self-cleaning function. The second protective layer, combined with the support layer, provides strong heat and wear resistance. The adhesive layer uses corona treatment to roughen the back of the support layer to improve the adhesion of the adhesive. The base film layer is used to prevent contamination of the adhesive layer and can be easily removed during use of the heterogeneous micro-ribbed membrane. The five-layer structure of the heterogeneous micro-ribbed membrane effectively improves the overall strength, wear resistance, and corrosion resistance of the membrane.

[0012] In which, the vortex generator includes a first facade and a second facade arranged opposite to each other, and the vortex generator also includes a third inclined surface. The first facade and the second facade are both right-angled triangles. The first facade and the second facade are arranged perpendicular to the front surface. The first facade and the second facade are connected at an acute angle. The third inclined surface is an isosceles triangle. The two isosceles sides of the third inclined surface are respectively connected to the hypotenuse of the first facade and the hypotenuse of the second facade. The third inclined surface is arranged at an acute angle to the front surface. The bottom edge of the third inclined surface is connected to the front surface. The first facade and the second facade are both perpendicular to the third inclined surface. The connection between the first facade and the second facade is adjacent to the rib array. The connection is 1.5 mm high and perpendicular to the front surface. The cross-section of the rib is an isosceles triangle. The rib has a prismatic structure and the rib is 30 μm high.

[0013] In this case, since the connection is perpendicular to the front, the vortex generators are millimeter-scale, and the ribs are micron-scale, a multi-scale microstructure surface is formed, which not only increases the scale of the surface flow structure of the heterogeneous micro-rib membrane, but also helps to improve the microstructure strength and enhance the friction reduction effect.

[0014] The ribs are composed of the first protective layer and the second protective layer, and the ribs are attached to the supporting layer.

[0015] In this case, the second protective layer ensures the hardness and wear resistance of the ribs, and has stronger adhesion to the supporting layer, ensuring the stability of the membrane structure. The first protective layer prevents the accumulation of scale and dust, which not only improves the self-cleaning function of the membrane, but also improves the corrosion resistance of the second protective layer.

[0016] The present invention also provides a method for preparing heterogeneous microrib membranes, which is used to prepare the heterogeneous microrib membranes as described above. The method comprises the following steps:

[0017] Step 1: preparing a negative film by imprinting a base film with a micro-ribbed plate roller and a plate pressing roller, wherein the surface of the micro-ribbed plate pressing roller is provided with the vortex generator array structure and the rib array structure, and the vortex generator array structure and the rib array structure are alternately arranged in the circumferential direction of the surface of the micro-ribbed plate roller;

[0018] Step 2: coating the epoxy resin material on the cathode film and performing UV curing to form a cured layer, pressing the cathode film and the cured layer, and demolding to obtain the support layer;

[0019] Step 3: performing magnetron sputtering chromium plating on the front surface of the support layer to prepare the second protective layer;

[0020] Step 4: spraying the super-hydrophobic modified material on the surface of the second protective layer to prepare the first protective layer;

[0021] Step 5: First, the back of the support layer is roughened using a corona machine, and then glue is applied to prepare the adhesive layer;

[0022] Step six: Cover the surface of the adhesive layer with a protective film to prepare the base film layer.

[0023] In this case, the strength of each layer structure and the stability of the overall structure are guaranteed.

[0024] Wherein, the step 2 specifically includes:

[0025] performing vacuum degassing treatment on the epoxy resin material;

[0026] The epoxy resin material is evenly coated on the negative film, and the epoxy resin material is preliminarily photocured using a UV lamp source. The epoxy resin material is repeatedly coated and photocured to form a multi-layer structure of the cured layer until the thickness of the cured layer is equal to the thickness of the vortex generator.

[0027] In this case, the integrity of the supporting layer is guaranteed and the strength of the supporting layer is enhanced.

[0028] Wherein, the step three specifically includes:

[0029] Plasma treating the support layer;

[0030] Place the support layer in a vacuum chamber and evacuate to 10 -3 Below Pa;

[0031] Argon gas is introduced into the vacuum chamber until the gas pressure reaches 0.1-1 Pa;

[0032] A chromium target is selected as a sputtering source in an electric field and a power supply is applied;

[0033] Starting the sputtering process, argon ions bombard the chromium target, chromium atoms are sputtered out and deposited on the surface of the support layer to form a chromium plating layer;

[0034] The support layer is heat-treated to prepare the second protective layer.

[0035] In this case, the surface adhesion is initially enhanced by plasma treatment of the support layer, and the adhesion and hardness of the coating are comprehensively enhanced by heat treatment of the support layer on which the chromium plating layer is deposited.

[0036] The fourth step specifically includes:

[0037] Clean the surface dust and grease of the second protective layer with isopropyl alcohol and dry it with compressed air;

[0038] Diluting fluorosilane with a fluorosilane diluent, stirring evenly and allowing to stand for degassing to obtain a fluorosilane solution;

[0039] The fluorosilane solution is sprayed onto the surface of the second protective layer using a pneumatic spray gun and then dried.

[0040] In this case, coating uniformity is ensured, the self-cleaning effect is enhanced, and the service life of the first protective layer is extended.

[0041] The epoxy resin material is an epoxy resin photocurable adhesive, which includes component A and component B. Before the epoxy resin material is subjected to vacuum degassing treatment, component A and component B are configured in a ratio of 2:1.

[0042] In this case, the support layer can achieve optimal strength and wear resistance.

[0043] The power supply is a pulsed DC power supply with a pulse frequency of 20 kHz to 100 kHz and a pulse width of 5 to 100 microseconds. The current density of the target is 10 to 50 mA / cm 2 The sputtering power is 50~300 W / cm 2 , the deposition rate is 0.1~0.5 μm / min.

[0044] In this case, the electric field environment can be effectively controlled, and the thickness of the chrome plating layer can be controlled and adjusted to 0.1~5 μm, ensuring the service life and long-term performance of the heterogeneous microrib membrane.

[0045] The heat treatment specifically includes first heating the support layer deposited to form the chrome plating layer to 80-100°C, continuously heating for 10 minutes, allowing the chrome plating layer and the support layer to thermally expand, then heating to 120°C and continuously for more than 30 minutes, and then cooling to room temperature.

[0046] In this case, the heat resistance limit of the epoxy resin substrate is fully considered, and thermal stress is avoided to cause deformation of the substrate or separation of the chrome plating layer from the support layer.

[0047] According to the heterogeneous micro-rib membrane and its preparation method provided by the present invention, the first protective layer has low surface energy and excellent hydrophobicity, thereby preventing the accumulation of scale and dust and improving the self-cleaning function of the membrane. The second protective layer is combined with the support layer to provide strong heat resistance and wear resistance. The back adhesive layer is roughened on the back of the support layer by corona treatment to increase the adhesion of the back adhesive. The bottom film layer is used to prevent the back adhesive layer from being contaminated and can be easily removed when the heterogeneous micro-rib membrane is used. The five-layer structure of the heterogeneous micro-rib membrane effectively improves the overall strength, wear resistance and corrosion resistance of the membrane, and ensures the strength of each layer structure and the stability of the overall structure, achieving a significant drag reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 FIG2 shows a schematic diagram of the axonometric structure of the heterogeneous micro-rib membrane involved in an embodiment of the present invention;

[0049] Figure 2 A longitudinal cross-sectional view of a heterogeneous microrib according to an embodiment of the present invention is shown;

[0050] Figure 3 A flow chart showing a method for preparing heterogeneous microrib membranes according to an embodiment of the present invention is shown;

[0051] Figure 4A schematic diagram of the micro-rib plate roller structure of the method for preparing heterogeneous micro-rib membranes according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0052] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, identical components will be assigned identical reference numerals, and duplicate descriptions will be omitted. Furthermore, the accompanying drawings are merely schematic, and the proportions of the dimensions of the components and the shapes of the components may differ from the actual ones.

[0053] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a heterogeneous micro-rib film 100, comprising a front surface 140 and a back surface 150. The front surface 140 is provided with a vortex generator array 120 and a rib array 130, the vortex generator array 120 and the rib array 130 are arranged in succession, the vortex generator array 120 includes a plurality of vortex generators arranged in a flat pattern, and the rib array 130 includes a plurality of ribs arranged in a flat pattern. From the front surface 140 to the back surface 150, the film comprises a first protective layer 111, a second protective layer 112, a support layer 113, an adhesive layer 114 and a base film layer 115, wherein:

[0054] The first protective layer 111 is made of super hydrophobic modified material.

[0055] The second protective layer 112 is formed by bombarding a chromium target with argon ions and depositing chromium atoms.

[0056] The support layer 113 is made of epoxy resin material.

[0057] The adhesive layer 114 is prepared by corona treating the surface of the support layer and applying adhesive;

[0058] The base film layer 115 is removable.

[0059] In this case, the first protective layer has low surface energy and excellent hydrophobicity, thereby preventing the accumulation of scale and dust and improving the self-cleaning function of the membrane. The second protective layer, combined with the support layer, provides strong heat resistance and wear resistance. The backing layer is roughened by corona treatment on the back of the support layer to increase the adhesion of the backing layer. The bottom film layer is used to prevent contamination of the backing layer and can be easily removed when using the heterogeneous micro-rib membrane. The five-layer structure of the heterogeneous micro-rib membrane effectively improves the overall strength, wear resistance and corrosion resistance of the membrane, thereby achieving a significant drag reduction effect.

[0060] In some examples, there are multiple vortex generator arrays 120 and multiple rib arrays 130 , and they are arranged alternately.

[0061] In this embodiment, the vortex generator includes a first vertical surface 121 and a second vertical surface 122 arranged opposite each other. The vortex generator also includes a third inclined surface 123. The first vertical surface 121 and the second vertical surface 122 are both right triangles. The first vertical surface 121 and the second vertical surface 122 are arranged perpendicular to the front surface 140. The first vertical surface 121 and the second vertical surface 122 are connected at an acute angle. The third inclined surface 123 is an isosceles triangle. The two isosceles sides of the third inclined surface 123 connect the hypotenuse of the first vertical surface 121 and the hypotenuse of the second vertical surface 122, respectively. The third inclined surface 123 is arranged at an acute angle to the front surface 140. The base of the third inclined surface 123 is connected to the front surface 140. The first vertical surface 121 and the second vertical surface 122 are both perpendicular to the third inclined surface 123. The connection 124 between the first vertical surface 121 and the second vertical surface 122 is located adjacent to the rib array 130. The connection 124 is 1.5 mm high and perpendicular to the front surface 140. The cross-section of the rib is an isosceles triangle. The rib has a prismatic structure. The rib is 30 μm high. In this case, because the connection is perpendicular to the front surface, the vortex generators are millimeter-scale, and the ribs are micrometer-scale, a multi-scale microstructured surface is formed. This not only increases the scale of the surface flow structure of the heterogeneous micro-rib membrane, but also helps to improve the microstructure strength and enhance the friction reduction effect.

[0062] In this embodiment, it can be understood that the vortex generator has a tetrahedral structure.

[0063] In this embodiment, the ribs are composed of the first protective layer 111 and the second protective layer 112. The ribs are attached to the support layer 113. In this case, the second protective layer ensures the hardness and wear resistance of the ribs, and has stronger adhesion to the support layer, ensuring the stability of the membrane structure. The first protective layer prevents the accumulation of scale and dust, not only improving the self-cleaning function of the membrane, but also enhancing the corrosion resistance of the second protective layer.

[0064] In this embodiment, the super hydrophobic modified material is fluorosilane (C 16 H 19 F 17 O3Si).

[0065] In this embodiment, the second protective layer 112 is formed by argon ion bombarding a chromium target, and chromium atoms are deposited. Specifically, argon gas is introduced into the vacuum chamber until the gas pressure reaches 0.1~1 Pa. A chromium target is selected as a sputtering source in an electric field, and a power supply is connected. The sputtering process is started, argon ions bombard the chromium target, chromium atoms are sputtered out and deposited on the surface of the support layer 113, forming a chromium plating layer. The support layer 113 is heat-treated to prepare the second protective layer 112. In this case, by performing plasma treatment on the support layer to initially enhance the surface adhesion, and then by heat-treating the support layer to form the chromium plating layer, the adhesion and hardness of the coating are comprehensively enhanced.

[0066] In this embodiment, the power supply is a pulsed DC power supply. The pulse frequency is 20 kHz to 100 kHz. The pulse width is 5 to 100 microseconds. The current density of the target material is 10 to 50 mA / cm 2 The sputtering power is 50~300 W / cm 2 The deposition rate is 0.1-0.5 μm / min. In this case, the electric field environment can be effectively controlled, and the thickness of the chromium plating layer can be controlled and adjusted to 0.1-5 μm, ensuring the service life and long-term performance of the heterogeneous micro-rib membrane.

[0067] In this embodiment, the epoxy resin material is an epoxy resin photocurable adhesive. The epoxy resin photocurable adhesive comprises component A and component B. The epoxy resin material is subjected to a vacuum degassing treatment. A UV lamp is used to photocure the epoxy resin material to form the support layer 113. Before the vacuum degassing treatment, component A and component B are mixed in a ratio of 2:1. In this case, the support layer can achieve optimal strength and wear resistance.

[0068] like Figure 3 and Figure 4 As shown, the present invention also provides a method 200 for preparing heterogeneous microrib membranes, which is used to prepare the heterogeneous microrib membranes described above. The method 200 for preparing heterogeneous microrib membranes comprises:

[0069] Step 1 210, preparing a negative film by embossing the base film with a micro-ribbed roller 300 and a plate pressing roller, wherein the surface of the micro-ribbed roller is provided with the vortex generator array structure 320 and the rib array structure 330, and the vortex generator array structure 320 and the rib array structure 330 are alternately arranged in the circumferential direction of the surface of the micro-ribbed roller 300;

[0070] Step 2 220 , coating the epoxy resin material on the cathode film and performing UV curing to form a cured layer, pressing the cathode film and the cured layer, and demolding to obtain the support layer;

[0071] Step three 230, performing magnetron sputtering chromium plating on the front surface of the support layer to prepare the second protective layer;

[0072] Step 4 240, spraying the super-hydrophobic modified material on the surface of the second protective layer to prepare the first protective layer;

[0073] Step five 250, firstly roughening the back surface of the support layer using a corona machine, and then applying glue to prepare the adhesive layer;

[0074] Step six 260 , covering the surface of the adhesive layer with a protective film to prepare the base film layer.

[0075] In this case, the strength of each layer of the structure and the stability of the overall structure are guaranteed, thereby achieving a significant drag reduction effect.

[0076] In some examples, the vortex generator array structure 320 and the rib array structure 330 are machined on the surface of a steel plate roller using a precision turning tool to prepare the micro-rib plate roller 300 .

[0077] In some examples, the vortex generator array structure 320 and the rib array structure 330 are both in plurality and arranged alternately.

[0078] In some examples, the base film is made of chlorinated polypropylene (CPP) resin. This imparts excellent hardness and thermoplasticity to the base film. Prior to rolling by the micro-ribbed plate roller 300 and the plate pressing roller, the base film is heated at a temperature between 120°C and 160°C for 5 to 15 minutes. Preferably, the heating temperature is 150°C for 5 minutes to achieve optimal microstructure roll-forming effects on the base film.

[0079] In some examples, after the base film is embossed by the micro-ribbed plate roller 300 and the plate pressing roller, it is cooled and shaped by a cooling roller to prepare the negative mold.

[0080] In this embodiment, the step 220 specifically includes:

[0081] performing vacuum degassing treatment on the epoxy resin material;

[0082] The epoxy resin material is evenly coated on the negative film, and the epoxy resin material is preliminarily photocured using a UV lamp source. The epoxy resin material is repeatedly coated and photocured to form a multi-layer structure of the cured layer until the thickness of the cured layer is equal to the thickness of the vortex generator.

[0083] In this case, the integrity of the supporting layer is guaranteed and the strength of the supporting layer is enhanced.

[0084] In this embodiment, the step 3 230 specifically includes:

[0085] Plasma treating the support layer;

[0086] Place the support layer in a vacuum chamber and evacuate to 10 -3 Below Pa;

[0087] Argon gas is introduced into the vacuum chamber until the gas pressure reaches 0.1-1 Pa;

[0088] A chromium target is selected as a sputtering source in an electric field and a power supply is applied;

[0089] Starting the sputtering process, argon ions bombard the chromium target, chromium atoms are sputtered out and deposited on the surface of the support layer to form a chromium plating layer;

[0090] The support layer is heat-treated to prepare the second protective layer.

[0091] In this case, the surface adhesion is initially enhanced by plasma treatment of the support layer, and the adhesion and hardness of the coating are comprehensively enhanced by heat treatment of the support layer on which the chromium plating layer is deposited.

[0092] In this embodiment, the step 4 240 specifically includes:

[0093] Clean the surface dust and grease of the second protective layer with isopropyl alcohol and dry it with compressed air;

[0094] Diluting fluorosilane with a fluorosilane diluent, stirring evenly and allowing to stand for degassing to obtain a fluorosilane solution;

[0095] The fluorosilane solution is sprayed onto the surface of the second protective layer using a pneumatic spray gun and then dried.

[0096] In this case, coating uniformity is ensured, the self-cleaning effect is enhanced, and the service life of the first protective layer is extended.

[0097] In some examples, the fluorosilane is diluted with a fluorosilane diluent at a dilution ratio of 1:10 to 1:50, stirred evenly, and then allowed to stand for 15 minutes for degassing. In this embodiment, preferably, the dilution ratio is 1:20.

[0098] In some examples, the undisturbed fluorosilane solution is sprayed onto the surface of the second protective layer using a pneumatic spray gun at a height of 10 to 30 cm above the second protective layer, at a spray rate of 50 to 200 mm / s, in a cross-spray pattern, and 2 to 3 spray passes. In this embodiment, preferably, the pneumatic spray gun is held 15 cm above the second protective layer, at a spray rate of 100 mm / s, with 3 cross-spray passes. This ensures uniform coverage of all angles of the heterogeneous microrib membrane.

[0099] In some examples, the drying process specifically includes placing the film, after spraying the super-hydrophobic modifying material, in a drying tunnel for infrared radiation drying at a temperature of 80-120°C, a drying time of 5-20 minutes, and an infrared radiation power of 500-2000 W. In this embodiment, preferably, the temperature is 120°C, the drying time is 10 minutes, and the infrared radiation power is 1000 W. This achieves the optimal post-spraying hydrophobic effect.

[0100] In this embodiment, the epoxy resin material is an epoxy resin light-curing adhesive. The epoxy resin light-curing adhesive comprises component A and component B. In some examples, before the epoxy resin material is subjected to vacuum degassing, component A and component B are mixed in a ratio of A:B = 2:1 or A:B = 3:1 to form a mixed adhesive solution. Preferably, the ratio of A:B = 2:1 is used. In this case, the support layer can achieve optimal strength and wear resistance.

[0101] In this embodiment, preferably, the atmospheric pressure of the vacuum environment for vacuum degassing treatment is -0.1 MPa, and the degassing time is 5 minutes, which can achieve the most effective removal of bubbles in the mixed glue solution.

[0102] In some examples, the surface of the female mold is cleaned with alcohol and then positioned and sprayed with the mixed glue.

[0103] In some examples, the mixed glue solution is evenly applied to the female mold by spin coating, with a rotation speed controlled at 2000-3000 rpm, a coating time of 30-120 seconds, and a coating layer thickness of 50-100 microns. The epoxy resin light-curing adhesive is then preliminarily light-cured using an LED UV lamp with a UV wavelength of 365 nm and a UV light intensity of 1000-3000 mW / cm 2 , the exposure time is 2~3 minutes.

[0104] In this embodiment, preferably, the rotation speed is controlled to 2000 rpm, the coating time is 60 seconds, the coating layer thickness is 100 microns, the UV wavelength is 365 nm, and the UV light intensity is 2000 mW / cm 2 , with an exposure time of 2 minutes. This achieves optimal, uniform curing.

[0105] In some examples, pressing the negative film and the solidified layer specifically includes applying a pressure of 0.5 to 1 MPa for 2 to 5 minutes, preferably 1 MPa for 3 minutes, to ensure that the shape of the heterogeneous microrib film is completely transferred.

[0106] In some examples, after the lamination transfer is completed, the epoxy resin photocuring adhesive is subjected to secondary UV curing using a UV mercury lamp with a UV wavelength of 365 nm and an exposure time of 5 to 10 minutes. Preferably, the UV wavelength is 365 nm and the UV light intensity is 3000 mW / cm 2 The exposure time is 5 minutes. This ensures that the solidified layer is reinforced and fully transferred. The support layer is then demoulded.

[0107] In some examples, the power supply is a pulsed DC power supply with a pulse frequency of 20 kHz to 100 kHz, a pulse width of 5 to 100 microseconds, and a current density of 10 to 50 mA / cm 2 The sputtering power is 50~300 W / cm 2 , the deposition rate is 0.1~0.5 μm / min. In this case, the electric field environment can be effectively controlled, and the thickness of the chromium plating layer can be controlled to 0.1~5 μm and adjustable, ensuring the service life and long-term performance of the heterogeneous micro-rib membrane.

[0108] In this embodiment, preferably, the pulse frequency is 100 kHz, the pulse width is 5 microseconds, and the target current density is 20 mA / cm 2 , sputtering power is 200 W / cm 2 , with a deposition rate of 0.4 μm / min. This results in a chrome layer thickness of 2 μm, achieving the best long-term performance and longest service life.

[0109] In some examples, the heat treatment specifically includes first heating the support layer on which the chrome layer is deposited to form the chrome plating layer to 80-100°C for 10 minutes to allow for thermal expansion of the chrome plating layer and the support layer, then heating to 120°C for more than 30 minutes before cooling to room temperature. In this case, the heat resistance limitations of the epoxy resin substrate are fully considered while avoiding thermal stress that could cause deformation of the substrate or separation of the chrome plating layer from the support layer. In this embodiment, preferably, the support layer on which the chrome plating layer is deposited to form the chrome plating layer is first heated to 80°C.

[0110] The above-described embodiments do not constitute a limitation on the scope of protection of this technical solution. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the above-described embodiments shall be included in the scope of protection of this technical solution.

Claims

1. A heterogeneous microrib membrane, characterized in that: The invention comprises a front surface and a back surface, wherein the front surface is provided with a vortex generator array and a rib array, the vortex generator array and the rib array are arranged in succession, the vortex generator array comprises a plurality of vortex generators arranged in a flat pattern, and the rib array comprises a plurality of ribs arranged in a flat pattern, and the invention comprises a first protective layer, a second protective layer, a support layer, a back adhesive layer and a bottom film layer in order from the front surface to the back surface, wherein: The first protective layer is made of super hydrophobic modified material. The second protective layer is formed by bombarding a chromium target with argon ions and depositing chromium atoms. The supporting layer is made of epoxy resin material. The back adhesive layer is prepared by corona treating the surface of the support layer and then applying adhesive; The base film layer is removable.

2. The heterogeneous microrib membrane according to claim 1, characterized in that The rib is composed of the first protective layer and the second protective layer, and the rib is attached to the supporting layer.

3. A method for preparing heterogeneous microrib membranes, for preparing the heterogeneous microrib membranes according to claim 1, characterized in that: The method comprises the following steps, Step 1: preparing a negative film by imprinting a base film with a micro-ribbed plate roller and a plate pressing roller, wherein the surface of the micro-ribbed plate pressing roller is provided with the vortex generator array structure and the rib array structure, and the vortex generator array structure and the rib array structure are alternately arranged in the circumferential direction of the surface of the micro-ribbed plate roller; Step 2: coating the epoxy resin material on the cathode film and performing UV curing to form a cured layer, pressing the cathode film and the cured layer, and demolding to obtain the support layer; Step 3: performing magnetron sputtering chromium plating on the front surface of the support layer to prepare the second protective layer; Step 4: spraying the super-hydrophobic modified material on the surface of the second protective layer to prepare the first protective layer; Step 5: First, the back of the support layer is roughened using a corona machine, and then glue is applied to prepare the adhesive layer; Step six: Cover the surface of the adhesive layer with a protective film to prepare the base film layer.

4. The method for preparing heterogeneous microrib membranes according to claim 3, wherein: The second step specifically includes: performing vacuum degassing treatment on the epoxy resin material; The epoxy resin material is evenly coated on the negative film, and the epoxy resin material is preliminarily photocured using a UV lamp source. The epoxy resin material is repeatedly coated and photocured to form a multi-layer structure of the cured layer until the thickness of the cured layer is equal to the thickness of the vortex generator.

5. The method for preparing heterogeneous microrib membrane according to claim 3, wherein: The step three specifically includes: Plasma treating the support layer; Place the support layer in a vacuum chamber and evacuate to 10 -3 Below Pa; Argon gas is introduced into the vacuum chamber until the gas pressure reaches 0.1-1 Pa; A chromium target is selected as a sputtering source in an electric field and a power supply is applied; Starting the sputtering process, argon ions bombard the chromium target, chromium atoms are sputtered out and deposited on the surface of the support layer to form a chromium plating layer; The support layer is heat-treated to prepare the second protective layer.

6. The method for preparing heterogeneous microrib membrane according to claim 3, wherein: The step 4 specifically includes: Clean the surface dust and grease of the second protective layer with isopropyl alcohol and dry it with compressed air; Diluting fluorosilane with a fluorosilane diluent, stirring evenly and allowing to stand for degassing to obtain a fluorosilane solution; The fluorosilane solution is sprayed onto the surface of the second protective layer using a pneumatic spray gun and then dried.

7. The method for preparing heterogeneous microrib membrane according to claim 4, wherein: The epoxy resin material is an epoxy resin light-curing adhesive, which includes a component A and a component B. Before the epoxy resin material is subjected to vacuum degassing treatment, the component A and the component B are configured in a ratio of 2:

1.

8. The method for preparing heterogeneous microrib membranes according to claim 5, wherein: The power supply is a pulsed DC power supply with a pulse frequency of 20 kHz to 100 kHz and a pulse width of 5 to 100 microseconds. The current density of the target material is 10 to 50 mA / cm 2 , sputtering power is 50~300 W / cm 2 , the deposition rate is 0.1~0.5 μm / min.

9. The method for preparing heterogeneous microrib membrane according to claim 5, wherein: The heat treatment specifically includes first heating the support layer deposited to form the chromium plating layer to 80-100° C. for 10 minutes to allow the chromium plating layer and the support layer to thermally expand, then heating to 120° C. for more than 30 minutes, and then cooling to room temperature.

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