Large-area patterned micro-nano particle self-assembly structure and preparation method thereof

Abstract

The present invention discloses a large-area patterned micro-nano particle self-assembly structure and a preparation method thereof, wherein the method comprises: (1) adding a dispersion containing hydrophobic micro-nano particles into water to form a micro-nano particle film at a liquid-gas interface; (2) transferring the micro-nano particle film to a patterned template; (3) forming an adhesion layer on a substrate, and then transferring the patterned template with the micro-nano particle film obtained in step (2) to a substrate containing an adhesion layer and applying pressure, wherein the micro-nano particle film is in contact with the adhesion layer; (4) removing the adhesion layer at the outer edge of the structure obtained in step (3) to obtain a large-area patterned micro-nano particle self-assembly structure. Therefore, the method has the advantages of fast preparation speed, large area of ​​the prepared patterned micro-nano particle self-assembly structure, high preparation accuracy, strong shape controllability and high preparation stability.

Description

Technical Field

[0001] The invention belongs to the technical field of micro-nano particle self-assembly structure preparation, and in particular relates to a large-area patterned micro-nano particle self-assembly structure and a preparation method thereof. Background Art

[0002] Spherical micro-nanoparticles have advantages that macroscopic materials do not have in terms of light, electricity, magnetism, force, heat, etc. due to the size effect and other factors. Therefore, they have attracted extensive attention from researchers at home and abroad. The precise arrangement of micro-nanoparticles and the formation of special patterned structures are the basis for the preparation of functional devices with special optical properties, anti-counterfeiting / encryption functions, and specific wettability.

[0003] At present, the methods for forming patterned micro-nanoparticle self-assembly structures are mainly divided into step-speed controlled pulling / convective self-assembly, template-assisted pulling / convective self-assembly, laser-induced convection self-assembly and optical tweezers. Among them, step-speed controlled pulling / convective self-assembly can control the substrate movement speed during the pulling / convective self-assembly process to form a special striped periodic pattern self-assembly structure for nanoparticles at the three-phase contact line position, but due to its preparation mechanism, this method can only form a striped self-assembly structure. Template-assisted pulling / convective self-assembly prepares patterned pits or protrusions on the surface of the base, so that a patterned self-assembly structure can be formed in a special area during the pulling / convective self-assembly process. However, due to the slow preparation speed of the pulling / convective self-assembly, this method can only prepare a small area of ​​patterned self-assembly structure. Laser-induced convection self-assembly and optical tweezers induce nanoparticles to form self-assembly structures in special areas by moving the spot position, but this method usually requires complex and precise equipment, and the preparation process is slow and the preparation area is very limited. Although patterned micro-nanoparticle self-assembled structures have been developed in recent years, there are still significant problems such as slow preparation speed, small preparation area, and poor preparation accuracy, which seriously restrict the rapid development of this field.

[0004] Therefore, the existing preparation methods of patterned micro-nanoparticle self-assembled structures need to be improved. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, one purpose of the present invention is to provide a large-area patterned micro-nano particle self-assembled structure and a preparation method thereof, which has the advantages of fast preparation speed, large area of ​​the prepared patterned micro-nano particle self-assembled structure, high preparation accuracy, strong shape controllability and high preparation stability, thereby laying a foundation for preparing functional devices with special optical properties, anti-counterfeiting / encryption functions, specific wettability, etc.

[0006] In one aspect of the present invention, the present invention provides a method for preparing a large-area patterned micro-nano particle self-assembled structure. According to an embodiment of the present invention, the method comprises:

[0007] (1) adding a dispersion containing hydrophobic micro-nano particles into water to form a micro-nano particle film at the liquid-air interface;

[0008] (2) transferring the micro-nanoparticle film onto a patterned template;

[0009] (3) forming an adhesion layer on the substrate, and then transferring the patterned template having the micro-nanoparticle film obtained in step (2) to the substrate having the adhesion layer and applying pressure, wherein the micro-nanoparticle film is in contact with the adhesion layer;

[0010] (4) removing the adhesion layer at the outer edge of the structure obtained in step (3) to obtain a large-area patterned micro-nano particle self-assembled structure.

[0011] According to the method for preparing a large-area patterned micro-nano particle self-assembly structure of an embodiment of the present invention, a dispersion containing hydrophobic micro-nano particles is added to water, and under the action of surface tension, the hydrophobic micro-nano particles are suspended at the liquid-gas interface and quickly form a large-area closely arranged micro-nano particle film. Then the large-area micro-nano particle self-assembly structure closely arranged at the liquid-gas interface is transferred to the patterned template, and an adhesion layer is formed on the substrate surface at the same time. The patterned template with the micro-nano particle film is pressed against the substrate surface containing the adhesion layer, so that the closely packed and orderly large-area patterned micro-nano particle self-assembly structure is transferred to the substrate surface, and finally the adhesion layer at the outer edge of the structure is removed to obtain a large-area patterned micro-nano particle self-assembly structure, and the method of the present application has the advantages of fast preparation speed, large area of ​​the prepared patterned micro-nano particle self-assembly structure, high preparation accuracy, strong shape controllability and high preparation stability, thereby laying a foundation for preparing functional devices with special optical properties, anti-counterfeiting / encryption functions, and specific wettability.

[0012] In addition, the method for preparing a large-area patterned micro-nano particle self-assembled structure according to the above embodiment of the present invention may also have the following additional technical features:

[0013] In some embodiments of the present invention, in step (1), the hydrophobic micro-nano particles include at least one of silicon dioxide particles, polystyrene particles, gold particles and silver particles, thereby facilitating the formation of a micro-nano particle film.

[0014] In some embodiments of the present invention, in step (1), the diameter of the hydrophobic micro-nano particles is 100 nm to 100 μm, which is conducive to the formation of a micro-nano particle film.

[0015] In some embodiments of the present invention, the method for preparing the patterned template includes at least one of photolithography, laser processing and micro-nano imprinting.

[0016] In some embodiments of the present invention, the pattern shape of the patterned template includes at least one of stripes, circles and polygons. Thus, patterned templates with a variety of different patterns can be formed.

[0017] In some embodiments of the present invention, the minimum line width of the patterned template is 100 nm to 100 μm.

[0018] In some embodiments of the present invention, in step (3), the thickness of the adhesion layer is 10 nm to 10 μm.

[0019] In some embodiments of the present invention, the adhesive layer includes at least one of acrylate, epoxy resin, polyurethane, polyvinyl alcohol, silane polymer and modified silane polymer.

[0020] In some embodiments of the present invention, the substrate includes at least one of a silicon wafer, a glass wafer, a metal wafer, and a bent metal ring.

[0021] In some embodiments of the present invention, in step (4), the method of removing the adhesion layer includes oxygen deep reactive ion etching, which is helpful for removing the adhesion layer.

[0022] In some embodiments of the present invention, the ion etching power is 20W-100W and the time is 30s-10min, which is helpful to remove the adhesion layer.

[0023] In the second aspect of the present invention, the present invention proposes a large-area patterned micro-nano particle self-assembly structure. According to an embodiment of the present invention, the large-area patterned micro-nano particle self-assembly structure is prepared by the above method. Thus, the prepared large-area patterned micro-nano particle self-assembly structure has the advantages of large area and high stability, thus laying a foundation for preparing functional devices with special optical properties, anti-counterfeiting / encryption functions, specific wettability, etc.

[0024] In addition, the large-area patterned micro-nano particle self-assembly structure according to the above embodiment of the present invention may also have the following additional technical features:

[0025] In some embodiments of the present invention, the area of ​​the large-area patterned micro-nanoparticle self-assembled structure is 1 cm 2 ~1m 2 .

[0026] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] Figure 1 It is a schematic flow chart of a method for preparing a large-area patterned micro-nano particle self-assembly structure according to an embodiment of the present invention;

[0029] Figure 2 This is an electron microscope image of a striped template with micro-nano particles on its surface according to an embodiment of the present invention;

[0030] Figure 3 is an electron microscope image of an adhesion layer on the surface of a silicon wafer according to an embodiment of the present invention;

[0031] Figure 4 This is an electron microscope image of a large-area single-layer micro-nano particle self-assembly structure in a stripe shape according to an embodiment of the present invention;

[0032] Figure 5 This is an electron microscope image of a large-area single-layer micro-nano particle self-assembly structure in a stripe shape on the surface of a silicon wafer after the adhesion layer is removed according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0034] In one aspect of the present invention, the present invention provides a method for preparing a large-area patterned micro-nano particle self-assembled structure. According to an embodiment of the present invention, referring to Figure 1 , the method comprising:

[0035] S100: Adding a dispersion containing hydrophobic micro-nanoparticles into water

[0036] In this step, a dispersion containing hydrophobic micro-nano particles is added to water. Under the action of surface tension, the hydrophobic micro-nano particles are suspended at the liquid-air interface and quickly form a large-area, tightly arranged single-layer micro-nano particle film.

[0037] It should be noted that the specific type of the above-mentioned hydrophobic micro-nano particles is not particularly limited, and those skilled in the art can select according to actual needs, for example, including but not limited to at least one of silica particles, polystyrene particles, gold particles and silver particles.

[0038] Furthermore, the diameter of the hydrophobic micro-nano particles is 100 nm to 100 μm. The inventors found that if the diameter of the hydrophobic micro-nano particles is too small, the small particles are obviously affected by thermodynamic fluctuations and cannot be stably suspended at the liquid-gas interface to form a micro-nano particle film. If the diameter of the hydrophobic micro-nano particles is too large, the large particles are obviously affected by gravity and cannot form a uniform and stable colloidal solution and cannot be stably suspended at the liquid-gas interface to form a micro-nano particle film.

[0039] S200: Transferring the micro-nanoparticle film onto a patterned template

[0040] In this step, a patterned transfer template is first formed by using at least one of photolithography, laser processing and micro-nano imprinting, and then the micro-nano particle film obtained above is transferred to the patterned template by direct scooping to obtain a patterned template with a micro-nano particle film.

[0041] It should be noted that the method for preparing the above-mentioned patterned template is not particularly limited, and those skilled in the art may select a method according to actual needs, for example, including at least one of photolithography, laser processing and micro-nano imprinting.

[0042] It should be noted that the pattern shape of the above-mentioned patterned template is not particularly limited, and those skilled in the art can select it according to actual needs. For example, the pattern shape includes but is not limited to any shape such as stripes, circles and polygons, and the minimum line width size of the above-mentioned patterned template is 100nm~100μm.

[0043] S300: forming an adhesion layer on the substrate, and then transferring the patterned template with the micro-nanoparticle film obtained in step S200 to the substrate containing the adhesion layer and applying pressure

[0044] In this step, an adhesion layer is formed on the surface of the substrate by a pull-up coating method or a spin coating method, and then the patterned template with the micro-nano particle film obtained in step S200 is transferred to the substrate containing the adhesion layer and pressure is applied, wherein the micro-nano particle film contacts the adhesion layer, thereby pressing the patterned template with the densely packed and orderly micro-nano particle film on the surface to the surface of the substrate containing the adhesion layer, that is, transferring the patterned micro-nano particle film to the substrate surface.

[0045] Furthermore, the thickness of the above-mentioned adhesion layer is 10nm to 10μm. The inventors have found that if the thickness of the adhesion layer is too small, it is extremely difficult to prepare an ultra-thin adhesion layer with uniform thickness and it is not enough to provide sufficient adhesion to transfer the micro-nano particle film. If the thickness of the adhesion layer is too large, the micro-nano particles and the transfer template structure will be trapped in the adhesion layer and cannot form an ideal micro-nano particle film transfer pattern.

[0046] It should be noted that the specific types of the above-mentioned adhesion layer and substrate are not particularly limited, and technical personnel in this field can choose according to actual needs. For example, the adhesion layer includes but is not limited to at least one of acrylate, epoxy resin, polyurethane, polyvinyl alcohol, silane polymer and modified silane polymer, and the substrate includes but is not limited to at least one of silicon wafer, glass sheet, metal sheet and bent metal ring.

[0047] S400: removing the adhesive layer on the outer edge of the structure obtained in step S300

[0048] In this step, the adhesion layer at the outer edge of the structure obtained in step S300 is removed to obtain a large-area patterned micro-nano particle self-assembled structure. Specifically, during the removal process, only the adhesion layer at the outer edge is removed, and the outer edge refers to the area on the substrate without micro-nano particles, and there is a van der Waals force between the micro-nano particles and the substrate, thereby ensuring the stability of the large-area patterned micro-nano particle self-assembled structure.

[0049] It should be noted that the above-mentioned method for removing the adhesion layer can adopt conventional methods in the prior art, as long as the adhesion layer can be removed, for example, including but not limited to oxygen deep reactive ion etching. Furthermore, the power of the ion etching is 20w to 100w, and the time is 30s to 10min. The inventors found that if the power of the ion etching is too low, it is not enough to completely remove the adhesion layer in the area without micro-nanoparticles. If the ion etching time is too short or too long, it will lead to excessive removal of the adhesion layer under the particles, affecting the stability of the patterned micro-nanoparticle self-assembly structure.

[0050] In the second aspect of the present invention, the present invention proposes a large-area patterned micro-nano particle self-assembly structure. According to an embodiment of the present invention, the large-area patterned micro-nano particle self-assembly structure is prepared by the above method. Thus, the prepared large-area patterned micro-nano particle self-assembly structure has the advantage of a large area, thereby laying a foundation for preparing functional devices with special optical properties, anti-counterfeiting / encryption functions, and specific wettability. Specifically, the area of ​​the large-area patterned micro-nano particle self-assembly structure of the present application is 1 cm 2 ~1m 2 It should be noted that the features and advantages described above for the method for preparing a large-area patterned micro-nano particle self-assembled structure are also applicable to the large-area patterned micro-nano particle self-assembled structure, and will not be described in detail here.

[0051] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0052] Example

[0053] Step 1: Add a colloidal dispersion containing 900 nm silica hydrophobic nanoparticles into a liquid pool containing deionized water. Under the action of surface tension, the silica hydrophobic micro-nanoparticles are suspended at the liquid-air interface and quickly form a large-area, tightly arranged single-layer micro-nanoparticle film;

[0054] Step 2: Prepare a template with a striped pattern by using micro-imprinting technology, wherein the stripe protrusion width is 6 μm and the interval between two adjacent stripes is 14 μm, and then transfer the silica hydrophobic nanoparticle film obtained in step 1 to the template with a striped pattern (such as Figure 2 shown);

[0055] Step 3: Using the modified silane polymer, an adhesion layer with a thickness of about 80 nm is prepared on the surface of the silicon wafer by a pull-up coating method (such as Figure 3 Then, a template having a stripe pattern of a densely packed silicon dioxide hydrophobic nanoparticle film is pressed against the surface of a silicon wafer having an adhesion layer (such as Figure 4 shown);

[0056] Step 4: Remove the adhesion layer by oxygen reactive ion etching, where the ion etching power is set to 50W and the etching time is set to 1min, and finally obtain a large-area patterned micro-nano particle self-assembled structure (such as Figure 5 shown).

[0057] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0058] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a large-area patterned micro-nano particle self-assembled structure, characterized in that: include: (1) adding a dispersion containing hydrophobic micro-nano particles into water to form a micro-nano particle film at the liquid-air interface; (2) transferring the micro-nanoparticle film onto a patterned template; (3) forming an adhesion layer on a substrate, and then transferring the patterned template having the micro-nanoparticle film obtained in step (2) to the substrate having the adhesion layer and applying pressure, wherein the micro-nanoparticle film is in contact with the adhesion layer; (4) removing the adhesion layer at the outer edge of the structure obtained in step (3) to obtain a large-area patterned micro-nanoparticle self-assembled structure; in step (4), the method for removing the adhesion layer includes oxygen deep reactive ion etching; the power of the ion etching is 20W to 100W, and the time is 30s to 10min.

2. The method according to claim 1, characterized in that In step (1), the hydrophobic micro-nanoparticles include at least one of silica particles, polystyrene particles, gold particles and silver particles.

3. The method according to claim 1 or 2, characterized in that: In step (1), the diameter of the hydrophobic micro-nanoparticles is 100 nm to 100 μm.

4. The method according to claim 1, characterized in that: The method for preparing the patterned template includes at least one of photolithography, laser processing and micro-nano imprinting; Optionally, the pattern shape of the patterned template includes at least one of stripes, circles and polygons; Optionally, the minimum line width of the patterned template is 100 nm to 100 μm.

5. The method according to claim 1, characterized in that In step (3), the thickness of the adhesion layer is 10 nm to 10 μm.

6. The method according to claim 1, characterized in that In step (3), the adhesive layer includes at least one of acrylate, epoxy resin, polyurethane, polyvinyl alcohol, silane polymer and modified silane polymer.

7. The method according to claim 1, characterized in that In step (3), the substrate includes at least one of a silicon wafer, a glass wafer, a metal wafer and a bent metal ring.

8. A large-area patterned micro-nano particle self-assembly structure, characterized in that: The large-area patterned micro-nano particle self-assembly structure is prepared by the method according to any one of claims 1 to 7.

9. The self-assembled structure according to claim 8, characterized in that: The area of ​​the large-area patterned micro-nanoparticle self-assembled structure is 1 cm 2 ~1m 2 .

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