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KR-20260063410-A - An adsorptive coating method for 2D materials, films and membranes fabricated from the method

KR20260063410AKR 20260063410 AKR20260063410 AKR 20260063410AKR-20260063410-A

Abstract

The present invention relates to a technology related to a two-dimensional material coating method, and more specifically, to a method for forming a two-dimensional material coating film that can uniformly and densely coat the surface of a material to be coated in a simple manner by using a two-dimensional material dispersed in water and having surface activity, a material to be coated having a hydrophobic surface or a surface modified to be hydrophobic, a two-dimensional material coating film formed by the said method, and an application product including the same.

Inventors

  • 김동훈
  • 박석호
  • 오서은

Assignees

  • 전남대학교산학협력단

Dates

Publication Date
20260507
Application Date
20241030

Claims (20)

  1. A step of preparing a coating dispersion solution by uniformly dispersing a two-dimensional material in water; A step of preparing a hydrophobic coating material having a hydrophobic surface or modified to have a hydrophobic surface; and A method for forming a two-dimensional material coating film, comprising the step of exposing the above-mentioned hydrophobic material to be coated to a coating dispersion solution to form a coating film on the surface of the above-mentioned material to be coated.
  2. In Article 1, A method for forming a two-dimensional material coating film, characterized by comprising: a step of forming the coating film by adsorbing the two-dimensional material at an interface with the hydrophobic material to be coated, thereby distributing the two-dimensional material continuously or discontinuously on the surface of the hydrophobic material to be coated; and a step of separating the material to be coated on which the two-dimensional material is distributed on its surface from the coating dispersion liquid and drying it.
  3. In Article 1, A method for forming a coating film of a two-dimensional material, wherein the above-mentioned two-dimensional material is a planar material having an aspect ratio of 10 or more or a planar material having an average thickness of 100 nm or less, and is characterized by being dispersible in water and having surface activity.
  4. In Paragraph 3, A method for forming a two-dimensional material coating film, characterized in that the above two-dimensional material comprises one or more selected from the group consisting of zeolite, graphene oxide (including monolayer and multilayer), nanosheets of transition metal chalcogenide compounds ( WS₂ , MoS₂ ), hexagonal boron nitride nanosheets, MXene, nanosheets of metal-organic frameworks (MOFs), nanosheets of organic frameworks (COFs), 2D polymers, and layered double hydroxides.
  5. In Paragraph 3, A method for forming a two-dimensional material coating film characterized in that the above two-dimensional material is composed of zeolite.
  6. In Article 1, A method for forming a two-dimensional material coating film, characterized in that the above-mentioned coating material has a surface structure selected from a group consisting of a planar structure, a curved structure (including hollow fiber structure, spherical structure, and tubular structure), a porous structure, and combinations thereof.
  7. In Article 1, A method for forming a two-dimensional material coating film characterized by using a silane coupling agent or a polymer coating to modify the surface of the above-mentioned coating material to be hydrophobic.
  8. In Article 1, A method for forming a two-dimensional material coating film, characterized in that the coverage rate of the coating film on the surface of the above-mentioned coating material is proportional to the hydrophobicity of the surface of the above-mentioned coating material and the concentration of the coating dispersion liquid.
  9. In Article 8, A method for forming a two-dimensional material coating film characterized in that the surface of the above-mentioned coating material has a contact angle of 90° or more.
  10. In Article 8, A method for forming a two-dimensional material coating film characterized by the concentration of the coating dispersion being 0.02 wt% or higher.
  11. In Article 1, A method for forming a two-dimensional material coating film, characterized by further including a post-treatment step of performing one or more of heat treatment, hydrothermal treatment, chemical treatment, and mechanical treatment on a coating film formed on the surface of the above-mentioned coating material.
  12. In Article 11, A method for forming a two-dimensional material coating film, characterized in that when the coating film is formed as a zeolite nanofilm, the post-treatment step is heat treatment, and the heat treatment is performed by calcination at 350°C to 500°C.
  13. In Article 1, A method for forming a two-dimensional material coating film, characterized by repeating the steps of: a step of hydrophobically modifying the coating film; and a step of exposing a material to be coated, on which the hydrophobically modified coating film is formed, to a coating dispersion liquid to form an additional coating film on the surface of the coating film and the material to be coated, one or more times.
  14. In any one of paragraphs 1 to 13, A method for forming a two-dimensional material coating film, characterized by further including the step of secondarily growing a coating film or an additional coating film formed on the surface of the above-mentioned coating material.
  15. A two-dimensional material coating film formed by the method of any one of claims 1 to 13.
  16. In Article 15, A two-dimensional material coating film characterized by comprising two or more different types of two-dimensional materials.
  17. In Article 15, A two-dimensional material coating film characterized by acting as a protective film that improves one or more properties among mechanical properties, chemical properties, and thermal durability properties of the coated material.
  18. An application product comprising a two-dimensional material coating film formed by the forming method of any one of claims 1 to 13.
  19. In Article 18, An application product characterized by having one or more selected from the group consisting of electrodes, separators, catalysts, membrane reactors, and sensors.
  20. An application product comprising a two-dimensional material coating film formed by the forming method of claim 14.

Description

An adsorptive coating method for 2D materials, films and membranes fabricated from the method The present invention relates to a technology related to a two-dimensional material coating method, and more specifically, to a method for forming a two-dimensional material coating film capable of uniformly and densely coating the surface of a substrate with a two-dimensional material that is dispersed in water and simultaneously has surface activity, a two-dimensional material coating film formed by the said method, and an application product including the same. Two-dimensional (2D) materials possess unique properties stemming from their nanometer-thickness and high aspect ratios, offering unprecedented opportunities in many application fields. When continuous coatings are fabricated using these 2D materials as a base structure, they can be utilized as functional films and membranes. For example, graphene exhibits superior electrical conductivity compared to graphite, which has a three-dimensional structure. By coating the surface of a support to form a continuous thin film, it can be used as an electrode, transparent electrode, or heat sink; to achieve this, graphene synthesized in large quantities via chemical methods must be coated onto the support surface. Since this graphene coating layer (film) is influenced by the surface structure and properties of the support, a specific coating method is required to obtain the desired physical properties. Furthermore, porous crystalline 2D materials, including zeolites, metal-organic frameworks, and covalent-organic frameworks, have been used to fabricate high-performance membranes for separation applications. The uniform pore size of these materials ensures high selectivity, while their thin thickness significantly reduces diffusion path lengths and improves the concentration gradient across the membrane, thereby generating high permeation flux. To leverage these characteristics, porous 2D materials can be used by uniformly coating them onto the surface of a porous support, or by eliminating the interlayer space of the fabricated 2D material coating layer to reduce non-selective diffusion paths. The quality of porous crystalline membranes fabricated by tiling porous 2D materials depends heavily on the nanostructure of the stacked thin film layers. Specifically, for the fabricated membrane to achieve high separation performance, the layers must possess i) a high coverage rate of porous 2D materials without voids and ii) a minimum thickness. To achieve this, coating techniques capable of effectively arranging porous 2D materials on a substrate are critical. Various techniques have been applied to create uniform and dense coatings of 2D materials with minimized thickness. These techniques include vacuum-assisted filtration, the Langmuir-Blodgett/-Schaefer method, layer-by-layer deposition, hot drop casting, electrophoretic deposition, and spin coating. However, the large-scale implementation of these techniques for coating 2D materials onto substrates remains limited because the coating quality of these materials cannot be guaranteed on large substrate surfaces. Specifically, the Langmuir-Blodgett and Langmuir-Schaefer methods, which involve forming a single layer at the interface and then transferring it, require equipment and specialized personnel to precisely control surface pressure and the area of the interface; methods utilizing interactions between surface charges, such as layer-by-layer deposition, have limited material utilization for introducing high-density charges to the surface; filtration methods are applicable only to porous supports (not to non-porous ones); and methods such as spin coating or spray coating are not suitable for controlling the density of nanofilms. Therefore, there is a need to develop a simple yet effective coating method that can properly apply a two-dimensional (2D) material to the surface of a coated material. Figure 1a is a schematic diagram showing a method for forming a two-dimensional material coating film in which a nanosheet, which is a two-dimensional material, is adsorbed and coated on the surface of a substrate, which is a coating material modified with a hydrophobic surface. FIG. 1b is a schematic diagram showing the process of forming a two-dimensional material coating film on the surface of a powder using a method for forming a two-dimensional material coating film. Figure 2 shows the results of analyzing the structure of zeolite MFI nanosheets used in a method for forming a two-dimensional material coating film. (ac) SEM image, (d) nitrogen adsorption isotherm, and (e) powder X-ray diffraction pattern of zeolite MFI nanosheets are shown along with the calculated pattern for the MFI material. Figure 3 shows the contact angle measurement results of a surface-modified silicon wafer. Figure 4 shows the adsorption of zeolite MFI nanosheets onto a bare silicon wafer and a surface-modified silicon wafer using triethoxy(octyl)sila