Bionic super-hydrophilic graphene micro-nano structure on surface of extrafocal laser induced polymer and processing method and application of bionic super-hydrophilic graphene micro-nano structure

Abstract

The invention discloses an extrafocal laser-induced polymer surface bionic super-hydrophilic graphene micro-nano structure and a processing method and application thereof, and belongs to the technical field of graphene materials, the extrafocal laser-induced polymer surface bionic super-hydrophilic graphene micro-nano structure comprises a precursor flexible polymer film and laser-induced graphene, the micro-nano structure on the surface of the laser-induced graphene is of a zigzag-like structure with protrusions and recesses alternately appearing, the protrusions are composed of bionic structures, and the recesses are composed of vertical porous graphene structures. The invention adopts the extrafocal laser induced polymer surface bionic super-hydrophilic graphene micro-nano structure as well as the processing method and the application thereof. The prepared laser-induced graphene can be widely applied to the fields of sensors, flexible energy storage devices, electrochemical catalysis, photothermal conversion, enhanced heat transfer and the like due to the bionic micro-nano structure on the surface, high wettability, high thermal conductivity, high conductivity, excellent flexibility and good chemical stability.

Description

Technical Field

[0001] The invention relates to the technical field of graphene materials, and in particular to an out-of-focus laser-induced polymer surface bionic super-hydrophilic graphene micro-nano structure and a processing method and application thereof. Background Art

[0002] Surface wettability is an important property of graphene. Its changes have a significant impact on the adhesion, conductivity and permeability of graphene materials, and then affect the performance of application devices. For example, changes in graphene surface wettability will significantly affect the sensitivity of sensors, the energy storage performance of capacitors, the catalytic performance of catalysts, the evaporation performance of solar evaporation applications, and the liquid phase thermal conductivity of graphene adhesion layers. Therefore, studying and regulating the surface wettability of graphene is an important means to expand its application scenarios and enhance the performance of application devices.

[0003] The methods for modifying the hydrophilicity of graphene surface mainly include plasma treatment, ultraviolet irradiation and vacuum annealing. Although the above methods have improved the hydrophilicity of graphene surface to a certain extent, they all have the problems of complex treatment process, high cost and failure of the sample surface to achieve super hydrophilicity, making it difficult to apply to large-scale production. Summary of the invention

[0004] The purpose of the present invention is to provide an out-of-focus laser induced polymer surface bionic super-hydrophilic graphene micro-nano structure and a processing method and application thereof. The graphene with a surface bionic micro-nano structure is prepared by processing a flexible polymer film with an out-of-focus laser. The process is simple, the cost is low, the surface structure is diverse and controllable, and the prepared graphene has excellent surface wettability and capillary properties, which can solve the problems brought about by traditional graphene surface hydrophilic modification methods.

[0005] To achieve the above-mentioned purpose, the present invention provides an out-of-focus laser-induced polymer surface bionic super-hydrophilic graphene micro-nanostructure, comprising a precursor flexible polymer film and laser-induced graphene, wherein the laser-induced graphene surface micro-nanostructure presents a zigzag structure with alternating protrusions and depressions, wherein the protrusions are composed of bionic structures, and the depressions are composed of upright porous graphene structures.

[0006] Preferably, the flexible polymer film comprises one of polyimide, polysulfone, polyethersulfone, polyphenylsulfone, phenolic resin and polyethylene terephthalate.

[0007] Preferably, the height of the laser-induced graphene surface protrusions ranges from 5 to 500 μm, and the spacing between adjacent protrusions ranges from 50 to 500 μm.

[0008] Preferably, the bionic structure constituting the laser-induced graphene surface protrusions includes one of a flocculent bionic structure, a sheet structure and various porous structures.

[0009] Preferably, the porosity of laser-induced graphene is 90-99%.

[0010] The above-mentioned method for processing a biomimetic super-hydrophilic graphene micro-nano structure on a polymer surface induced by an out-of-focus laser comprises the following steps: Step 1: Cut the flexible polymer film, fix the film on a flat substrate using a fixing device and ensure that the film is flat, clean the surface of the flexible polymer film and perform oxygen plasma treatment for 5-20 minutes, evenly coat the surface of the flexible polymer film with an activation agent and heat and dry it; Step 2: adjust the relative position of the substrate and the laser light source, align the laser beam with the surface of the film material to be processed, adjust the defocus distance, set the processing parameters in the laser control software, and input the required engraving pattern into the software, and then perform laser processing to obtain laser-induced surface bionic super-hydrophilic micro-nanostructure graphene.

[0011] Preferably, in step 1, the thickness of the flexible polymer film is 25 μm-3 mm, and is cut into square strips with a length and width of 20-50 mm; The specific operation of the steps of cleaning the surface of the flexible polymer film is as follows: ultrasonically cleaning the flexible polymer film in anhydrous ethanol and deionized water for 5-15 minutes respectively; The activation treatment agent is one of a strong alkaline solution and a solution having a surface activation effect; wherein the strong alkaline solution includes a sodium hydroxide solution and a potassium hydroxide solution, and the solution having a surface activation effect includes a cupric chloride solution; The specific operation of drying and heating the flexible polymer film is: placing the flexible polymer film coated with the activation treatment agent together with the substrate on the surface of the heating platform and heating at 40-100° C. for 10-30 minutes.

[0012] Preferably, in step 2, the defocus distance when the laser beam is aimed at the surface of the flexible polymer film to be processed is 4mm; The wavelength range of the laser beam is one of 9.3-10.6 μm, 627-740 nm, 450-480 nm, and 1053 nm. The laser intensity range of the laser-induced graphene surface is 3 J / cm 2 -40J / cm 2 ; Laser engraving patterns include various regular and irregular graphics processed using scanning mode and vector mode.

[0013] The present invention also provides an application of an out-of-focus laser induced bionic super-hydrophilic graphene micro-nano structure on a polymer surface, and applies the above-mentioned out-of-focus laser induced bionic super-hydrophilic graphene micro-nano structure on a polymer surface to the fields of sensors, flexible energy storage devices, electrochemical catalysis, photothermal conversion and enhanced heat transfer.

[0014] Therefore, the present invention adopts the above-mentioned out-of-focus laser-induced polymer surface biomimetic super-hydrophilic graphene micro-nano structure and its processing method and application, which has the following beneficial effects: (1) Laser processing of a flexible polymer film coated with a strong base is used to manufacture a surface with a bionic micro-nano structure, which greatly improves the surface wettability and capillary properties of graphene materials. The process is simple, easy to operate, low-cost, and the surface structure is diverse and controllable, which can meet the conditions for large-scale preparation. (2) The prepared flexible polymer bionic super-hydrophilic micro-nanostructure can be widely used in sensors, flexible energy storage devices, electrochemical catalysis, photothermal conversion and enhanced heat transfer. (3) The prepared laser-induced graphene based on flexible polymer film has strong adaptability and can be cut or bent into specific shapes according to actual needs to complete the work.

[0015] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of a preparation method of an out-of-focus laser-induced polymer surface bionic super-hydrophilic graphene micro-nano structure and a processing method and application embodiment thereof; Figure 2 The invention discloses an out-of-focus laser-induced polymer surface bionic super-hydrophilic graphene micro-nano structure and a processing method thereof, and a polyimide film of an application embodiment is processed to form a graphene microstructure contour map; Figure 3 It is a schematic diagram of a sample of a graphene microstructure formed by processing a polyimide film of an out-of-focus laser-induced polymer surface bionic super-hydrophilic graphene micro-nanostructure and a processing method thereof and an application embodiment of the present invention; Figure 4 It is a Raman spectrum of a bionic super-hydrophilic micro-nanostructure graphene prepared by an out-of-focus laser-induced polymer surface bionic super-hydrophilic graphene micro-nanostructure and a processing method thereof and an application example of the present invention; Figure 5 It is a scanning electron microscope image of a bionic super-hydrophilic graphene micro-nanostructure prepared by an out-of-focus laser-induced polymer surface bionic super-hydrophilic graphene micro-nanostructure and a processing method thereof and an application example of the present invention; Figure 6It is a dynamic wetting image of a bionic super-hydrophilic micro-nanostructure graphene prepared by an out-of-focus laser-induced polymer surface bionic super-hydrophilic graphene micro-nanostructure and a processing method thereof and an application example of the present invention; Figure 7 The invention discloses a capillary climbing image of a bionic super-hydrophilic micro-nanostructure graphene prepared by an out-of-focus laser-induced bionic super-hydrophilic graphene micro-nanostructure on a polymer surface and a processing method thereof and an application example.

[0017] Reference numerals 1. Flexible polymer film; 2. Laser-induced graphene; 21. Protrusion; 211. Bionic structure; 22. Depression; 221. Vertical porous graphene structure; 3. Activation treatment agent; 4. Laser beam; 5. Substrate. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0019] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] like Figure 2 , Figure 3 As shown, the present invention provides an out-of-focus laser induced polymer surface bionic super-hydrophilic graphene micro-nano structure, including a precursor flexible polymer film 1 and laser-induced graphene 2, the surface micro-nano structure of the laser-induced graphene 2 is a zigzag structure with protrusions 21 and depressions 22 appearing alternately, the protrusions 21 are composed of bionic structures 211, and the depressions 22 are composed of upright porous graphene structures 221.

[0021] The flexible polymer film 1 includes one of polyimide, polysulfone, polyethersulfone, polyphenylsulfone, phenolic resin, polyethylene terephthalate and the like.

[0022] The height of the protrusions 21 on the surface of the laser-induced graphene 2 is in the range of 5-500 μm, and the spacing between adjacent protrusions 21 is in the range of 50-500 μm.

[0023] The bionic structure 211 constituting the protrusions 21 on the surface of the laser-induced graphene 2 includes one of a flocculent bionic structure, a sheet structure and various porous structures, and the porosity of the laser-induced graphene 2 is 90-99%.

[0024] A method for processing an out-of-focus laser-induced bionic super-hydrophilic graphene micro-nano structure on a polymer surface comprises the following steps: Step 1: cut the flexible polymer film 1, use a fixing device to fix the film on a flat substrate 5 and ensure that the film is flat, clean the surface of the flexible polymer film 1 and treat it with oxygen plasma for 5-20 minutes, evenly coat the surface of the flexible polymer film 1 with an activation agent 3 and heat and dry it.

[0025] The thickness of the flexible polymer film 1 is 25 μm-3 mm, and is cut into square strips with a length and a width of 20-50 mm.

[0026] The specific operation of the step of cleaning the surface of the flexible polymer film 1 is as follows: the flexible polymer film 1 is ultrasonically cleaned in anhydrous ethanol and deionized water respectively for 5-15 minutes.

[0027] The activation treatment agent 3 is one of a strong alkaline solution and a solution having a surface activation effect; wherein the strong alkaline solution includes a sodium hydroxide solution and a potassium hydroxide solution, and the solution having a surface activation effect includes a cupric chloride solution; The specific operation of drying and heating the flexible polymer film 1 is as follows: the flexible polymer film 1 coated with the activation treatment agent 3 and the substrate 5 are placed on the surface of a heating platform and heated at 40-100° C. for 10-30 minutes.

[0028] Step 2: adjust the relative position of the substrate 5 and the laser light source, aim the laser beam 4 at the surface of the thin film material to be processed, adjust the defocus distance, set the processing parameters in the laser control software, and input the required engraving pattern into the software, and then perform laser processing to obtain laser-induced surface bionic super-hydrophilic micro-nanostructure graphene.

[0029] Defocus distance when the laser beam 4 is aimed at the surface of the flexible polymer film 1 where the processing is to be performed 4mm; The wavelength range of the laser beam 4 is one of 9.3-10.6 μm, 627-740 nm, 450-480 nm, and 1053 nm, and the laser intensity range on the surface of the laser-induced graphene 2 is 3 J / cm 2 -40J / cm 2 .

[0030] Laser engraving patterns include various regular and irregular graphics processed using scanning mode and vector mode.

[0031] The present invention also provides an application of an out-of-focus laser induced bionic super-hydrophilic graphene micro-nano structure on a polymer surface, and applies the above-mentioned out-of-focus laser induced bionic super-hydrophilic graphene micro-nano structure on a polymer surface to the fields of sensors, flexible energy storage devices, electrochemical catalysis, photothermal conversion and enhanced heat transfer.

[0032] Example 1 In this embodiment, the flexible polymer film 1 is a polyimide film. The laser engraving machine used in this embodiment is a continuous CO2 laser. The wavelength used by the engraving machine is 9.3 μm. Any power within 0-30 W can be obtained by adjusting the parameters, and it can be considered accurate within a certain error range. The polyimide film is purchased from DuPont, the color is light yellow, and the specific thickness is 25 μm-3 mm, which can be considered accurate within a certain error range.

[0033] like Figure 2 As shown, an out-of-focus laser-induced polymer surface bionic super-hydrophilic graphene micro-nano structure includes a precursor flexible polymer film 1 and laser-induced graphene 2, and the surface micro-nano structure of the laser-induced graphene 2 is a sawtooth-like structure with protrusions 21 and depressions 22 appearing alternately. Figure 4 As shown, the protrusion 21 is composed of a large number of flocculent bionic structures, and the depression 22 is composed of an upright porous graphene structure 221. Figure 5 , 6 As shown, the prepared laser-induced graphene 2 has excellent surface wettability and capillary properties.

[0034] like Figure 1 As shown, the present invention also provides a method for processing an out-of-focus laser-induced bionic super-hydrophilic graphene micro-nano structure on a polymer surface, comprising the following steps: The polyimide film is cut into square sheets with a length and width of 50 mm, and then the film is fixed on a flat substrate 5 using a fixing device in the prior art, and the film is ensured to be flat. The polyimide film and the substrate 5 are ultrasonically cleaned in anhydrous ethanol and deionized water for 10 minutes each. After the surface of the polyimide film is dry, it is placed in a plasma cleaning machine for oxygen plasma treatment for 15 minutes to make its surface more hydrophilic. After treatment, 200 g / L of sodium hydroxide solution is evenly coated on the surface of the polyimide film 1 and placed on the surface of a heating platform in the prior art, and heated at 70°C for 15 minutes.

[0035] The relative position of the substrate 5 and the laser light source was adjusted so that the laser beam 4 was aimed at the part to be processed on the surface of the film material, and the defocus distance was adjusted to 2 mm. The pattern to be processed was drawn on the upper computer of the laser engraving machine, and the laser power was set to 4 W, the scanning speed was set to 100 mm / s, and the scanning interval was set to 150 dpi. The polyimide film was laser engraved to prepare laser-induced graphene 2 under different laser intensities.

[0036] Example 2 The difference between this embodiment and embodiment 1 is that after the polyimide film is cleaned, a cupric chloride solution is coated, and under the photothermal conditions caused by laser processing, CuO particles are deposited on the graphene surface, especially at the edge of the porous graphene, thereby enhancing the surface wettability and capillary properties of the laser-induced graphene 2.

[0037] Figure 1 The schematic diagram of the preparation process of the present invention shows that the preparation process is simple and does not require complicated processing technology. Figure 4 It can be seen that the characteristic peak position of the processed film is basically consistent with that of graphene, indicating that PI has been completely converted into laser-induced graphene; Figure 5 It can be seen that laser-induced graphene has a bionic root-like structure at the microscopic level. Figure 6 , 7 This is a diagram of the dynamic wetting and capillary climbing process of the prepared graphene surface. From the results, it can be seen that the prepared bionic micro-nanostructured graphene has excellent surface wettability.

[0038] Therefore, the present invention adopts the above-mentioned out-of-focus laser-induced polymer surface bionic super-hydrophilic graphene micro-nano structure and its processing method and application. The manufactured laser-induced graphene can be widely used in sensors, flexible energy storage devices, electrochemical catalysis, photothermal conversion and enhanced heat transfer due to its surface bionic micro-nano structure, high wettability, high thermal conductivity, electrical conductivity, excellent flexibility and good chemical stability.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. An out-of-focus laser-induced bionic super-hydrophilic graphene micro-nanostructure on a polymer surface, characterized in that: It includes a precursor flexible polymer film and laser-induced graphene. The micro-nano structure on the surface of the laser-induced graphene presents a zigzag structure with alternating protrusions and depressions. The protrusions are composed of bionic structures, and the depressions are composed of upright porous graphene structures.

2. The out-of-focus laser-induced polymer surface biomimetic super-hydrophilic graphene micro-nanostructure according to claim 1, characterized in that: The flexible polymer film includes one of polyimide, polysulfone, polyethersulfone, polyphenylsulfone, phenolic resin and polyethylene terephthalate.

3. The out-of-focus laser-induced polymer surface biomimetic super-hydrophilic graphene micro-nanostructure according to claim 1, characterized in that: The height of the laser-induced graphene surface protrusions ranges from 5 to 500 μm, and the spacing between adjacent protrusions is 50 to 500 μm.

4. The out-of-focus laser-induced polymer surface biomimetic super-hydrophilic graphene micro-nanostructure according to claim 1, characterized in that: The bionic structures constituting the laser-induced graphene surface protrusions include flocculent bionic structures, sheet structures and various porous structures.

5. The out-of-focus laser-induced polymer surface biomimetic super-hydrophilic graphene micro-nanostructure according to claim 1, characterized in that: The porosity of laser-induced graphene is 90-99%.

6. A method for processing an out-of-focus laser-induced bionic super-hydrophilic graphene micro-nanostructure on a polymer surface as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Cut the flexible polymer film, fix the film on a flat substrate using a fixing device and ensure that the film is flat, clean the surface of the flexible polymer film and perform oxygen plasma treatment for 5-20 minutes, evenly coat the surface of the flexible polymer film with an activation agent and heat and dry it; Step 2: adjust the relative position of the substrate and the laser light source, align the laser beam with the surface of the film material to be processed, adjust the defocus distance, set the processing parameters in the laser control software, and input the required engraving pattern into the software, and then perform laser processing to obtain laser-induced surface bionic super-hydrophilic micro-nanostructure graphene.

7. The method for processing an out-of-focus laser-induced polymer surface biomimetic super-hydrophilic graphene micro-nanostructure according to claim 6, characterized in that: In step 1, the thickness of the flexible polymer film is 25 μm-3 mm, and it is cut into square strips with a length and width of 20-50 mm; The specific operation of the steps of cleaning the surface of the flexible polymer film is as follows: the flexible polymer film is ultrasonically cleaned in anhydrous ethanol and deionized water for 5-15 minutes respectively; The activation treatment agent is one of a strong alkaline solution and a solution having a surface activation effect; wherein the strong alkaline solution includes a sodium hydroxide solution and a potassium hydroxide solution, and the solution having a surface activation effect includes a cupric chloride solution; The specific operation of drying and heating the flexible polymer film is: placing the flexible polymer film coated with the activation treatment agent together with the substrate on the surface of the heating platform and heating at 40-100° C. for 10-30 minutes.

8. The method for processing an out-of-focus laser-induced bionic super-hydrophilic graphene micro-nanostructure on a polymer surface according to claim 6, characterized in that: The defocus distance when the laser beam is aimed at the part to be processed on the surface of the flexible polymer film in step 2 4mm; The wavelength range of the laser beam is one of 9.3-10.6 μm, 627-740 nm, 450-480 nm, and 1053 nm. The laser intensity range of the laser-induced graphene surface is 3 J / cm 2 -40J / cm 2 ; Laser engraving patterns include various regular and irregular graphics processed using scanning mode and vector mode.

9. An application of an out-of-focus laser-induced bionic super-hydrophilic graphene micro-nanostructure on a polymer surface, characterized in that: The out-of-focus laser-induced polymer surface biomimetic super-hydrophilic graphene micro-nanostructure described in any one of claims 1 to 5 is applied to the fields of sensors, flexible energy storage devices, electrochemical catalysis, photothermal conversion and enhanced heat transfer.

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