Preparation method of highly ordered, soft and malleable MXene-based organic-inorganic hybrid superlattice material

Abstract

The invention relates to a preparation method of a highly ordered, soft and malleable MXene-based organic-inorganic hybrid superlattice material, which comprises the following steps: carrying out surface modification on hydrochloric acid acidified Ti3C2Tx nanosheet aqueous dispersion by using oleylamine, washing the product with ethanol, drying, and dispersing in trichloromethane; and adding small molecular ligands such as oleic acid into the dispersion liquid, and then carrying out solvent evaporation assembly to obtain the superlattice material with a long-range ordered layered structure. The film shows intrinsic flexibility and can be directly formed into a macroscopic three-dimensional block through physical folding and mold pressing. The mechanical property of the MXene material is fundamentally regulated and controlled through molecular intercalation and ordered assembly, integrated construction from a nanoscale ordered structure to a macroscopic functional material is achieved, and the obtained MXene-based organic-inorganic hybrid superlattice material has electrical conductivity, structural orderliness and good deformability; the method has important application prospects in the fields of flexible electronic devices, deformable electrodes, intelligent sensing and the like.

Description

Technical Field

[0001] This invention belongs to the field of materials and inorganic chemistry, and specifically relates to a method for preparing a highly ordered, flexible and malleable MXene-based organic-inorganic hybrid superlattice material. Background Technology

[0002] Two-dimensional transition metal carbides / nitrides (MXenes) have attracted widespread attention in fields such as energy storage, electromagnetic shielding, and catalysis due to their excellent metallic conductivity, rich surface chemistry, and tunable interlayer structure. Among them, Ti3C2T... x As the most typical MXene material, the preparation of its traditional macroscopic bulk materials (such as thin films and aerogels) mostly relies on the disordered stacking or physical / chemical cross-linking of nanosheets in an aqueous phase, resulting in certain brittleness and limited mechanical properties (especially flexibility and ductility) and functional tunability. Therefore, how to break the strong interactions between the layers of two-dimensional nanosheets, introduce soft properties, and achieve precise and ordered interlayer engineering has become a key challenge in the development of novel functional MXene-based materials.

[0003] In recent years, inspired by biomineralization and organic-inorganic hybrid materials in nature, the interlayer microenvironment of two-dimensional materials has been modified through the intercalation of small organic molecules or polymers. However, most existing research focuses on improving the mechanical strength of materials or introducing specific chemical functions, while research aimed at endowing them with intrinsic softness for easy processing remains lacking. Furthermore, the traditional top-down peeling-reassembly strategy struggles to achieve precise and ordered interlayer structure control at the molecular scale, limiting a deeper understanding of their structure-property relationships and performance optimization. Therefore, it is essential to design a method that can precisely design MXene interlayer interfaces at the molecular scale, endowing them with intrinsic softness and plastic deformation capabilities, and utilizing this property to achieve simple and green macroscopic molding. Such methods can meet the high demands of future flexible electronics and deformable devices for the synergistic effect of material mechanical properties, electrical properties, and structural designability. Summary of the Invention

[0004] The purpose of this invention is to propose a method for preparing highly ordered, flexible and malleable MXene-based organic-inorganic hybrid superlattice materials. This invention obtains MXene-based macroscopic three-dimensional bulk materials through a method of "molecular modification-liquid phase co-assembly-mechanical reconstruction".

[0005] This invention proposes a method for preparing a highly ordered, flexible, and malleable MXene-based organic-inorganic hybrid superlattice, comprising the following steps:

[0006] (1) Preparation of Ti3C2T x Aqueous dispersion of nanosheets;

[0007] (2) After the aqueous dispersion obtained in step (1) is acidified with hydrochloric acid, oleylamine and chloroform are added and stirred for 7-10 hours to obtain an oleylamine-modified mixed solution;

[0008] (3) The oleylamine-modified mixed solution obtained in step (2) was washed by centrifugation with ethanol, dried under vacuum, and then dispersed with chloroform to obtain oleylamine-modified Ti3C2T. x Dispersion;

[0009] (4) The oleylamine-modified Ti3C2T obtained in step (3) x Small molecule ligands are added to the dispersion, drop-coated onto the substrate, dried, and demolded to obtain an organic-inorganic hybrid superlattice film.

[0010] (5) The organic-inorganic hybrid superlattice film obtained in step (4) is folded, pressed and molded to obtain a highly oriented, arbitrary-shaped bulk superlattice material.

[0011] In this invention, Ti3C2T in step (1) x The concentration of the aqueous dispersion is 5-10 mg / mL, the number of sheets is 1-2 layers, and the diameter of the nanosheets is 5-10 μm.

[0012] In this invention, the concentration of hydrochloric acid solution in step (2) is 6 mol / L, the amount added is about 0.8-1.2 mL, and the pH is adjusted to 1.

[0013] In this invention, the oleylamine-modified Ti3C2T in step (3) x The concentration of the dispersion is 20-25 mg / mL.

[0014] In this invention, the substrate in step (4) is an organic mixed cellulose filter membrane or a nylon filter membrane with a pore size of 0.22 μm.

[0015] In this invention, the small molecule substance in step (4) is any one of oleic acid, oleylamine, linoleic acid or oleyl alcohol.

[0016] In this invention, the shaping process in step (5) is limited to folding and pressing along the vertical direction.

[0017] The beneficial effects of this invention are as follows: the method proposed in this invention is simple and easy to implement, and the oleylamine-modified Ti3C2T xNanosheets and functional organic small molecules synergistically self-assemble, effectively weakening interlayer interactions and constructing highly ordered and flexible organic-inorganic hybrid superlattice films. These films require no binders or high-temperature treatment; they are directly formed from two-dimensional superlattice films to macroscopic three-dimensional bulk materials through simple folding and pressing. This pioneering approach establishes a novel, performance-tunable MXene hybrid material system, demonstrating a new pathway to achieve macroscopic shaping and functional integration of two-dimensional materials through interface softening and ordered assembly. It provides a new material platform for fundamental research and application development in fields such as flexible electronics and biomimetic intelligent materials. Attached Figure Description

[0018] Figure 1 This is a small-angle X-ray diffraction pattern of the MXene superlattice prepared in Example 1 of this invention.

[0019] Figure 2 This is a rotational rheometer amplitude scan of the MXene superlattice prepared in Example 2 of this invention.

[0020] Figure 3 This is a physical image of the MXene bulk superlattice prepared in Example 3 of the present invention. Detailed Implementation

[0021] The present invention will be further illustrated by the following examples.

[0022] Example 1:

[0023] 1. Preparation of Ti3C2T x Aqueous dispersion of nanosheets: Dissolve 2 g of lithium fluoride in 30 mL of 9 M hydrochloric acid, carefully add 3 mL of hydrofluoric acid, and slowly add 2 g of 200-mesh Ti3AlC2 powder to the above solution while stirring. After reacting at 40 °C for 24 h, wash the reaction solution with deionized water at 5000 r, shaking by hand for 5 min before each centrifugation. Repeat the centrifugation step 6-7 times until the centrifuged solution is approximately neutral and the precipitate at the bottom layer should show significant swelling. Add 60 mL of water again, shake by hand for 15 min, and centrifuge the solution at 3500 r for 30 min. Collect the supernatant to obtain a monolayer of Ti3C2T with a concentration of 10 mg / mL. x Aqueous dispersion.

[0024] 2. Take 50 mL of 10 mg / mL Ti3C2T x The aqueous dispersion was adjusted to pH 1 by adding 850 μL of 6 mol / L hydrochloric acid. 10 mL of oleylamine was added with stirring, followed by 50 mL of chloroform after 10 min. The mixture was stirred for 7–10 h to obtain an oleylamine-modified mixed solution.

[0025] 3. Divide the above mixed solution into four 50 mL centrifuge tubes, add an equal volume of ethanol, and centrifuge at 5000 r for 5 min. Discard the supernatant, disperse in chloroform, add an equal volume of ethanol, and centrifuge again. Dry the resulting precipitate in a vacuum drying oven at 60℃ for 20 min, and disperse in approximately 25 mL of chloroform. At this point, the oleylamine-modified Ti3C2T... x The solid content of the dispersion is approximately 25 mg / mL.

[0026] 4. Take 200 μL of the above dispersion, add 10 μL of oleic acid, sonicate for 2 min to mix the solution evenly, and drop it onto an organic mixed cellulose filter membrane with a diameter of 50 mm and a pore size of 0.22 μm. After air drying and assembly for 2 h, carefully demold to obtain a self-supporting, flexible two-dimensional hybrid MXene superlattice film.

[0027] 5. After repeated folding, the above-mentioned superlattice thin film is placed in a mold with a diameter of 3 mm and pressed with a pressure of 0.1 t to obtain a cylindrical macroscopic MXene-based superlattice bulk material.

[0028] Figure 1 The image shows the small-angle X-ray diffraction pattern of the prepared MXene superlattice, indicating that the prepared material has a high degree of interlayer order.

[0029] Example 2:

[0030] 1. Preparation of Ti3C2T x Aqueous dispersion of nanosheets: Dissolve 2 g of lithium fluoride in 30 mL of 9 M hydrochloric acid, carefully add 3 mL of hydrofluoric acid, and slowly add 2 g of 200-mesh Ti3AlC2 powder to the above solution while stirring. After reacting at 40 °C for 24 h, wash the reaction solution with deionized water at 5000 r, shaking by hand for 5 min before each centrifugation. Repeat the centrifugation step 6-7 times until the centrifuged solution is approximately neutral and the precipitate at the bottom layer should show significant swelling. Add 80 mL of water again, shake by hand for 15 min, and centrifuge the solution at 3500 r for 30 min. Collect the supernatant to obtain a monolayer of Ti3C2T with a concentration of 8 mg / mL. x Aqueous dispersion.

[0031] 2. Take 70 mL of 8 mg / mL Ti3C2T x The aqueous dispersion was adjusted to pH 1 by adding 1.1 mL of 6 mol / L hydrochloric acid. Then, 10 mL of oleylamine was added with stirring, followed by 70 mL of chloroform after 10 min. The mixture was stirred for 7–10 h to obtain an oleylamine-modified mixed solution.

[0032] 3. Divide the above mixed solution into six 50 mL centrifuge tubes, add an equal volume of ethanol, and centrifuge at 5000 r for 5 min. Discard the supernatant, disperse in chloroform, add an equal volume of ethanol, and centrifuge again. Dry the resulting precipitate in a vacuum drying oven at 60℃ for 20 min, and disperse in approximately 25 mL of chloroform. At this point, the oleylamine-modified Ti3C2T... x The solid content of the dispersion is approximately 25 mg / mL.

[0033] 4. Take 2000 μL of the above dispersion, add 100 μL of oleic acid, sonicate for 2 min to mix the solution evenly, and drop it into a vacuum filtration device. Select an organic mixed cellulose filter membrane with a diameter of 50 mm and a pore size of 0.22 μm. After air drying and assembly for 12 h, carefully demold to obtain a self-supporting, soft, two-dimensional hybrid MXene superlattice film.

[0034] 5. After repeated folding, the above-mentioned superlattice thin film is placed in a mold with a diameter of 3 mm and pressed with a pressure of 0.1 t to obtain a cylindrical macroscopic MXene-based superlattice bulk material.

[0035] Figure 2 The image shows the amplitude scan of the prepared MXene superlattice under a rotational rheometer, indicating that the prepared material has plasticity.

[0036] Example 3:

[0037] 1. Preparation of Ti3C2T x Aqueous dispersion of nanosheets: Dissolve 2 g of lithium fluoride in 30 mL of 9 M hydrochloric acid, carefully add 3 mL of hydrofluoric acid, and slowly add 2 g of 200-mesh Ti3AlC2 powder to the above solution while stirring. After reacting at 40 °C for 24 h, wash the reaction solution with deionized water at 5000 r, shaking by hand for 5 min before each centrifugation. Repeat the centrifugation step 6-7 times until the centrifuged solution is approximately neutral and the precipitate at the bottom layer should show significant swelling. Add 100 mL of water again, shake by hand for 15 min, and centrifuge the solution at 3500 r for 30 min. Collect the supernatant to obtain a monolayer of Ti3C2T with a concentration of 6 mg / mL. x Aqueous dispersion.

[0038] 2. Take 60 mL of 6 mg / mL Ti3C2T x The aqueous dispersion was adjusted to pH 1 by adding 1 mL of 6 mol / L hydrochloric acid. 8 mL of oleylamine was added with stirring, followed by 60 mL of chloroform after 10 min. The mixture was stirred for 7–10 h to obtain an oleylamine-modified mixed solution.

[0039] 3. Divide the above mixed solution into six 50 mL centrifuge tubes, add an equal volume of ethanol, and centrifuge at 5000 r for 5 min. Discard the supernatant, disperse in chloroform, add an equal volume of ethanol, and centrifuge again. Dry the resulting precipitate in a vacuum drying oven at 60℃ for 20 min, and disperse in approximately 20 mL of chloroform. At this point, the oleylamine-modified Ti3C2T... x The solid content of the dispersion is approximately 20 mg / mL.

[0040] 4. Take 4 mL of the above dispersion, add 200 μL of oleic acid, sonicate for 2 min to mix the solution evenly, and drop it into a vacuum filtration device. Select an organic mixed cellulose filter membrane with a diameter of 50 mm and a pore size of 0.22 μm. After air drying and assembly for 24 h, carefully demold to obtain a self-supporting, soft, two-dimensional hybrid MXene superlattice film.

[0041] 5. After repeated folding, the above-mentioned superlattice thin film is placed in a mold with a diameter of 3 mm and pressed with a pressure of 0.1 t to obtain a cylindrical macroscopic MXene-based superlattice bulk material.

[0042] Figure 3 The image shown is a physical image of the prepared MXene bulk superlattice, demonstrating that the prepared material is easy to process and can be mass-produced on a large scale.

Claims

1. A method for preparing a highly ordered, flexible, and malleable MXene-based organic-inorganic hybrid superlattice material, characterized in that... Includes the following steps: (1) Preparation of Ti3C2T x Aqueous dispersion of nanosheets; (2) After the aqueous dispersion obtained in step (1) is acidified with hydrochloric acid, oleylamine and chloroform are added and stirred for 7-10 hours to obtain an oleylamine-modified mixed solution; (3) The oleylamine-modified mixed solution obtained in step (2) was washed by centrifugation with ethanol, dried under vacuum, and then dispersed with chloroform to obtain oleylamine-modified Ti3C2T. x Dispersion; (4) The oleylamine-modified Ti3C2T obtained in step (3) x Small molecule ligands are added to the dispersion, drop-coated onto the substrate, dried, and demolded to obtain an organic-inorganic hybrid superlattice film. (5) The organic-inorganic hybrid superlattice film obtained in step (4) is folded, pressed and molded to obtain a highly oriented, arbitrary-shaped bulk superlattice material.

2. The preparation method according to claim 1, characterized in that: In step (1), Ti3C2T x The concentration of the aqueous dispersion is 5-10 mg / mL, the number of sheets is 1-2 layers, and the diameter of the nanosheets is 5-10 μm.

3. The preparation method according to claim 1, characterized in that: In step (2), the concentration of hydrochloric acid solution is 6 mol / L, the amount added is about 0.8-1.2 mL, and the pH is adjusted to 1.

4. The preparation method according to claim 1, characterized in that: In step (3), oleylamine-modified Ti3C2T x The concentration of the dispersion is 20-25 mg / mL.

5. The preparation method according to claim 1, characterized in that: The substrate in step (4) is an organic mixed cellulose filter membrane or a nylon filter membrane with a pore size of 0.22 μm.

6. The preparation method according to claim 1, characterized in that: The small molecule in step (4) is any one of oleic acid, oleylamine, linoleic acid or oleyl alcohol.

7. The preparation method according to claim 1, characterized in that: The shaping process in step (5) is limited to folding and pressing along the vertical direction.

Images