Patterned preparation method of self-assembled thin films of micro-nano materials

Abstract

The present invention provides a patterned preparation method for a micro-nano material self-assembled film, comprising: preparing a micro-nano material dispersion; shielding a portion of a support film using a shielding pattern, and then placing the support film with the shielding pattern facing downward on the surface of the micro-nano material dispersion; heating the micro-nano material dispersion, allowing micro-nano material particles to self-assemble on the lower surface of the support film to form a micro-nano material patterned self-assembled structure; and drying the micro-nano material patterned self-assembled structure. The present invention uses a cut pattern to immerse the dispersion in the dispersion, shielding a portion of the support film, converting the gas-liquid interface in the shielded area into a liquid-solid interface, hindering water evaporation, and causing the micro-nano material particles in the dispersion to form a self-assembled structure only in the unshielded area on the lower surface of the support film, thereby achieving the preparation of a patterned film; the patterned film with a larger area can be prepared by adjusting the size of the support film, and the preparation process is simple and low-cost.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano material films, and in particular to a patterned preparation method of a micro-nano material self-assembled film. Background Art

[0002] Micro-nano materials refer to a class of materials with particle sizes at the micron and nanometer levels. Since materials at the micro-nano scale often have unique properties that are different from those at the macroscale, the use of micro-nano materials to prepare high-performance functional materials has become one of the hot topics in scientific research and industrial production. According to different needs, various micro-nano processing technologies have emerged and are constantly developing, such as photolithography, electron beam exposure, focused ion beam, scanning probe processing, and nanoimprinting. Various patterned functional materials can be produced by the above technical solutions. For example, CN104221168A in the prior art - a method for manufacturing a nano-patterned substrate for high-efficiency nitride light-emitting diodes, discloses a technical solution for manufacturing nano- to micron-sized patterns on a light-emitting diode substrate by nanoimprinting technology.

[0003] However, among these technologies, except for photolithography, there are problems of low efficiency and high cost when preparing uniform patterns of micro-nano materials over large areas. Although photolithography can prepare uniform patterns of micro-nano materials over larger areas, its expensive equipment and complex exposure system will result in higher production costs, and the area of ​​the patterned micro-nano material prepared will be limited by the processing size of the equipment.

[0004] Therefore, there is an urgent need for a process that can quickly generate large-area patterned thin films of micro-nano materials, and that can meet the large-area requirements while also being low-cost. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention proposes the following technical solutions:

[0006] In a first aspect, a method for patterning a self-assembled thin film of micro-nano materials is provided, comprising the following steps:

[0007] preparing a micro-nano material dispersion, wherein the dispersion comprises one or more micro-nano material particles;

[0008] Using a shielding pattern to shield the through-holes in a portion of the support film, and then placing the support film with the shielding pattern facing downward on the surface of the micro-nano material dispersion, so that the shielding pattern is immersed in the dispersion;

[0009] The micro-nano material dispersion is heated while the support membrane and the micro-nano material dispersion are in a static state, so that the micro-nano material particles self-assemble on the lower surface of the support membrane to form a micro-nano material patterned self-assembled structure;

[0010] The micro-nano material patterned self-assembled structure is dried to obtain a micro-nano material patterned self-assembled film.

[0011] Furthermore, the micro-nano materials include MXene, carbon nanotubes, polystyrene microspheres, molybdenum disulfide, boron nitride or graphene oxide.

[0012] Furthermore, the concentration of the micro-nano material dispersion is 0.1 g / L to 5 g / L.

[0013] Furthermore, the support membrane includes an organic membrane or an inorganic membrane.

[0014] Furthermore, the organic membrane includes a polyethersulfone membrane or a polypropylene membrane, and the inorganic membrane is an aluminum oxide inorganic membrane.

[0015] Furthermore, the diameter of the through hole is 20 nanometers to 5 micrometers.

[0016] Furthermore, when the support membrane and the micro-nano material dispersion are in a static state, the micro-nano material dispersion is heated in a water bath, the heating temperature is 40 to 85° C., and the heating time is 30 minutes to 12 hours.

[0017] Furthermore, the drying process includes natural air drying or vacuum drying.

[0018] Furthermore, when preparing the micro-nano material dispersion, a polymer material is added.

[0019] It can be seen from the above technical solution that the beneficial technical effects of the present invention are as follows:

[0020] 1. The principle of using water molecule evaporation to drive micro-nano material particles to form a self-assembled structure on the lower surface of the support membrane is used. By using a cut pattern to block the through-holes in part of the support membrane, the gas-liquid interface in the blocked area is converted into a liquid-solid interface, which hinders water evaporation. As a result, the micro-nano material particles in the dispersion only form a self-assembled structure in the unblocked area on the lower surface of the support membrane, realizing the preparation of patterned films.

[0021] 2. In specific applications, the size of the support film can be adjusted to prepare a large-area patterned film of micro-nano materials without the need for other instruments and equipment, and the preparation process cost is low.

[0022] In a second aspect, a micro-nano material patterned film is provided, which is prepared by using the method provided in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0024] Figure 1 This is a flow chart of a method for preparing a patterned thin film of micro-nano materials according to an embodiment of the present invention;

[0025] Figure 2 Schematic diagram of the principle of patterned self-assembly of micro-nano materials according to one embodiment of the present invention;

[0026] Figure 3 This is a rendering of a patterned thin film of micro-nano material prepared according to an embodiment of the present invention;

[0027] Reference numerals:

[0028] 1-support film, 2-through hole of support film, 3-micro-nano material dispersion, 4-micro-nano material particles, 5-shielding pattern. DETAILED DESCRIPTION

[0029] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0030] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0031] Example 1

[0032] This embodiment provides a method for patterning and preparing a self-assembled thin film of micro-nano materials. Figure 1 As shown, follow these steps:

[0033] The materials required for the thin film preparation method include: micro-nano materials, dispersants, support films and shielding patterns.

[0034] In a specific embodiment, the micro-nano material includes: MXene, carbon nanotubes (CNTs), polystyrene microspheres (PS microspheres), molybdenum disulfide (MoS2), boron nitride (BN), or graphene oxide (GO). MXene is a two-dimensional inorganic compound composed of transition metal carbides, nitrides, or carbonitrides with a thickness of several atomic layers.

[0035] When the above-mentioned micro-nano material is solid, it needs to be pretreated. The pretreatment method is: seal the opening of the container where the micro-nano material is placed with filter paper or filter membrane that can pass water vapor, place the container in a vacuum drying oven, and then dry it at a temperature not exceeding 40°C to remove moisture, thereby reducing the impact of moisture when the micro-nano material is subsequently weighed.

[0036] The support membrane, in a specific embodiment, is a membrane with multiple through holes, such as a microporous filter membrane. The material, size, and thickness of the support membrane are not limited; in a specific embodiment, the support membrane is selected based on different micro-nano material dispersions, and an organic membrane or an inorganic membrane can be selected; the organic membrane is preferably a polyethersulfone membrane or a polypropylene membrane, and the inorganic membrane is preferably an alumina (Al2O3) inorganic membrane. The support membrane can be in roll form (wrapped into a roll) or sheet form; the pore size of the through holes on the support membrane is larger than the diameter of the solvent molecules and smaller than the diameter of the micro-nano material particles, and the pore size of the through holes is preferably 20 nanometers to 5 microns. Because the support membrane may curl or fold during storage, the pretreatment of the support membrane includes leveling and cleaning the support membrane. The form of the leveled support membrane is not limited. In a specific embodiment, the organic membrane can be leveled by mechanical means (such as pressing with a metal plate), and the inorganic membrane can be leveled by scraping or grinding.

[0037] The masking pattern is used to be attached to a local area of ​​the support film. In a specific embodiment, the material of the pattern is not limited. In one embodiment, the pattern can be attached to the support film using transparent adhesive or self-adhesive tape, wherein the transparent adhesive or self-adhesive tape does not contain through holes.

[0038] 1. Prepare a micro-nano material dispersion, which includes one or more micro-nano material particles

[0039] In a specific embodiment, the solvent of the micro-nano material dispersion is not limited, as long as the micro-nano material can be evenly dispersed, such as water or ethanol, with water being preferred. The micro-nano material dispersion can be prepared using any method of the prior art, preferably using ultrasonic dispersion. During ultrasonic dispersion, the equipment used is an ultrasonic cleaning machine, and the time is determined according to the desired degree of dispersion of the micro-nano material dispersion, until uniform dispersion is achieved. In one embodiment, the ultrasonic dispersion time is 30 minutes. In a specific embodiment, the concentration of the micro-nano material dispersion is adjusted by controlling the solute mass, and the concentration is preferably 0.1 g / L to 5 g / L.

[0040] During the ultrasonic dispersion process, the micro-nano material dispersion needs to be cooled to prevent the high temperature caused by ultrasound from damaging the structure of the micro-nano material. In a specific embodiment, an ice water bath is used to cool the dispersion for 2 to 3 minutes, and the cooling temperature can be slightly lower than room temperature.

[0041] The prepared dispersion may contain only one type of micro-nano material particles or multiple types of micro-nano material particles, as long as they are evenly dispersed.

[0042] In one embodiment, when preparing the micro-nano material dispersion, one or more polymer materials may be added, preferably polyacrylic acid. The addition of polymer materials can significantly improve the mechanical properties of the micro-nano material film, making it more convenient to prepare large-area films.

[0043] 2. Use a blocking pattern to block the through holes in part of the support film, and then place the support film with the blocking pattern facing down on the surface of the micro-nano material dispersion, so that the blocking pattern is immersed in the dispersion.

[0044] In a specific embodiment, the support membrane is a polyethersulfone membrane. The polyethersulfone membrane is laid out flat, and a shielding pattern is attached to the corresponding area of ​​the support membrane with transparent tape to shield the through-holes in this area of ​​the support membrane. The polyethersulfone membrane is then placed with the shielding pattern facing downward into an open container. The polyethersulfone membrane will automatically float on the liquid surface due to the surface tension of the liquid and be laid flat at the gas-liquid interface of the micro-nano material dispersion. At this time, the shielding pattern is immersed in the dispersion, as shown in FIG. Figure 2 shown.

[0045] The size of the open container is not limited and can be selected based on the desired film area. In cases where the support membrane cannot float due to gravity (such as inorganic aluminum oxide membranes and glass fiber membranes), an additional suspension device is required to secure the support membrane at the gas-liquid interface.

[0046] 3. Heat the micro-nano material dispersion while the support film and the micro-nano material dispersion are in a static state, and the micro-nano material particles self-assemble on the lower surface of the support film to form a micro-nano material patterned self-assembled structure

[0047] The micro-nano material dispersion in the open container is heated to a preset temperature and for a preset time. The heating method is not limited. In a specific embodiment, heating is preferably performed in a water bath. The water bath temperature is preset to 40-85°C, preferably 80°C; the preset time is 30 minutes to 12 hours. The specific preset time is related to the preset temperature. When the preset temperature is 50°C, the preset time is 1.5-2 hours; when the preset temperature is 80°C, the preset time is 20-60 minutes.

[0048] like Figure 2As shown, under heating at a preset temperature, in areas without a masking pattern, water molecules in the micro-nano material dispersion will evaporate and move toward the air-liquid interface. Simultaneously, this upward movement of water molecules will drive the micro-nano material particles toward the support membrane. Because the diameter of water molecules is smaller than the pore size of the support membrane, they will evaporate out of the pores. Meanwhile, the diameter of micro-nano material particles is larger than the pore size of the support membrane and will be blocked by the membrane, thereby adhering to the lower surface of the support membrane and forming a self-assembled structure.

[0049] For the area where the shielding pattern is pasted, water molecules cannot evaporate upward in the area, so a self-assembled structure cannot be formed on the lower surface of the support film, in the area where the shielding pattern is pasted.

[0050] Different patterned self-assembled structures can be obtained by different blocking patterns.

[0051] 4. Dry the micro-nano material patterned self-assembled structure to obtain a micro-nano material patterned self-assembled film

[0052] The method for drying the patterned self-assembled structure of micro-nano materials is not limited, and can be dried by natural air drying or vacuum drying. In a specific embodiment, the support film with the patterned self-assembled structure of micro-nano materials attached thereto is removed from the open container, with the side of the support film with the patterned self-assembled structure of micro-nano materials attached thereto facing upward. After drying, a patterned self-assembled film of micro-nano materials is obtained.

[0053] The following examples illustrate the parameters and process for preparing patterned thin films using micro-nano materials:

[0054] (1) Single-component micro-nano material patterned films

[0055] Prepare a uniformly dispersed GO aqueous dispersion and transfer it to a clean, open container for later use. Place a piece of clear tape cut into a masking pattern (e.g., Tai Chi) on a microporous filter membrane. Place the membrane at the air-liquid interface in the open container, immersing the tape-covered side in the dispersion. Heat the filter in an 80°C hot water bath for 30 minutes. Remove the membrane from the liquid surface and place it with the GO self-assembled structure facing up to dry.

[0056] (2) Multi-component micro-nano material patterned films

[0057] Prepare a mixed dispersion of micro-nanomaterials: GO and MXene in a 1:1 ratio (blend concentration 1 g / L) to obtain a uniform dispersion. Adhere the cutout pattern to a PP filter membrane (pore size 0.22 μm) using self-adhesive tape. Place the PP filter membrane at the air-liquid interface in an open container, immersing the surface with the masking pattern in the dispersion. Heat in an 80°C water bath for 40 minutes, then place the membrane with the GO self-assembled structure facing up and dry.

[0058] Using the technical solution of this embodiment, the film obtained after drying is as follows Figure 3 As shown, Figure 3 These are multiple examples of patterned films prepared using graphene oxide as the micro-nano material.

[0059] The technical solutions provided in the above embodiments utilize the principle that water evaporation drives the formation of self-assembled structures of micro-nanomaterial particles on the lower surface of a support membrane. By immersing a pre-cut pattern in a dispersion, partially blocking the through-holes in the support membrane, the air-liquid interface in the blocked area is transformed into a liquid-solid interface, hindering water evaporation. As a result, the micro-nanomaterial particles in the dispersion form self-assembled structures only in the unblocked areas of the support membrane's lower surface, achieving the preparation of a patterned film. In specific applications, large-area patterned micro-nanomaterial films can be prepared by adjusting the size of the support membrane, eliminating the need for additional equipment and resulting in a low-cost preparation process.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A method for patterning a self-assembled thin film of micro-nano materials, characterized in that: The following steps are involved: preparing a micro-nano material dispersion, wherein the dispersion comprises one or more micro-nano material particles; Use a shielding pattern to shield the through holes in a portion of the support film, then place the support film on the surface of the micro-nano material dispersion with the shielding pattern facing downward, so that the shielding pattern is immersed in the dispersion; The micro-nano material dispersion is heated while the support membrane and the micro-nano material dispersion are in a static state, so that the micro-nano material particles form a micro-nano material patterned self-assembled structure on the lower surface of the support membrane; The micro-nano material patterned self-assembled structure is dried to obtain a micro-nano material patterned self-assembled film.

2. The method for preparing a patterned self-assembled thin film of micro-nano materials according to claim 1, characterized in that: The micro-nano material includes MXene, carbon nanotubes, polystyrene microspheres, molybdenum disulfide, boron nitride or graphene oxide.

3. The method for preparing a patterned micro-nano material self-assembled thin film according to claim 2, characterized in that: The concentration of the micro-nano material dispersion is 0.1 g / L to 5 g / L.

4. The method for preparing a patterned self-assembled thin film of micro-nano materials according to claim 1, characterized in that: The supporting film includes an organic film or an inorganic film.

5. The method for preparing a patterned self-assembled thin film of micro-nano materials according to claim 4, characterized in that: The organic membrane includes a polyethersulfone membrane or a polypropylene membrane, and the inorganic membrane is an aluminum oxide inorganic membrane.

6. The method for preparing a patterned micro-nano material self-assembled thin film according to claim 1, characterized in that: The through hole has a pore diameter of 20 nanometers to 5 micrometers.

7. The method for preparing a patterned self-assembled thin film of micro-nano materials according to claim 1, characterized in that: When the support membrane and the micro-nano material dispersion are in a static state, the micro-nano material dispersion is heated in a water bath, the heating temperature is 40 to 85° C., and the heating time is 30 minutes to 12 hours.

8. The method for patterning the self-assembled thin film of micro-nano materials according to claim 1, characterized in that: The drying process includes natural air drying or vacuum drying.

9. The method for patterning the preparation of a micro-nano material self-assembled thin film according to claim 1, characterized in that: When preparing the micro-nano material dispersion, a polymer material is added.

10. A micro-nano material patterned film, characterized in that: It is prepared by using the method according to any one of claims 1 to 9.

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