A mxene-polymer composite and a preparation method thereof

Abstract

The application discloses a kind of MXene-polymer composite material and preparation method thereof, preparation method includes the following steps: by mechanical shearing grinding including multilayer MXene particle, polymer material and magnetic nano grinding aid in raw materials, realize the in-situ exfoliation of multilayer MXene, size micronization and composite of raw material, and MXene-polymer composite material is prepared and obtained.The application realizes the in-situ exfoliation of multilayer MXene particle by shearing grinding and the auxiliary action of magnetic nano grinding aid, in the MXene-polymer composite material prepared and obtained, MXene nanosheet can form uniform stable dispersion in polymer matrix, processing and preparation MXene-polymer composite material has good conductivity and electromagnetic shielding efficiency, the method is simple and easy to operate, suitable for large-scale production.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials technology, specifically to an MXene-polymer composite material and its preparation method. Background Technology

[0002] MXene is a novel type of two-dimensional carbide or nitride nanosheet material, typically obtained by selectively etching away the atom layer of the MAX phase in a precursor ternary ceramic material using chemical etching. Its chemical formula can be represented as Mn+1Xn, where n = 1, 2, 3, or 4. MXene possesses a two-dimensional nanosheet structure and excellent electrical conductivity, electrochemical activity, and mechanical properties, making it a promising candidate for functional materials. The surface of MXene is rich in functional groups such as -F, -OH, and -O-, making it suitable for preparing functional composite materials. The main process for producing MXene nanosheets involves chemically etching the atom layer of layered MAX (where M is an early transition metal, A is a group III or IV element, and X is carbon or nitrogen) materials, peeling off multilayered MXene powder particles in organic solvents or salt solutions using methods such as hand shaking or mechanical agitation, and then repeatedly washing and centrifuging to obtain single / few-layered MXene nanosheets. These methods are costly, inefficient, and difficult to mass-produce.

[0003] Currently, MXene-polymer-based composite functional materials have been widely used. However, due to the difficulty in uniformly dispersing multilayer MXene within a polymer matrix, agglomeration easily occurs, affecting the composite material's performance. Most reported MXene-polymer composites involve etching and exfoliating to obtain single-layer MXene nanosheets, which are then dispersed in the polymer matrix. This process is lengthy, complex, and costly. Therefore, efficiently and scalably preparing MXene-polymer composites is a crucial issue. Summary of the Invention

[0004] The technical problem to be solved by this invention is that currently reported MXene-polymer composite materials all use single-layer MXene nanosheets dispersed in a polymer matrix. This requires the preparation of single-layer MXene nanosheets via liquid-phase etching and exfoliation, resulting in high production costs, low efficiency, and significant pollution, making large-scale production difficult. This invention provides an MXene-polymer composite material and its preparation method that solves the above problems. Through shearing, grinding, and the assistance of magnetic nanoparticles, in-situ exfoliation of multi-layer MXene particles is achieved. In the prepared MXene-polymer composite material, MXene nanosheets can form a uniform and stable dispersion in the polymer matrix. The resulting composite film exhibits excellent conductivity and electromagnetic shielding performance. This method is simple, easy to implement, and low in cost, making it suitable for large-scale production.

[0005] The invention is achieved through the following technical solution:

[0006] A method for preparing an MXene-polymer composite material includes the following steps: mechanically shearing and grinding raw materials including multilayer MXene particles, polymer materials and magnetic nano-grinding aids to achieve in-situ exfoliation of multilayer MXene, micro-nanoization and composite of raw materials, thereby preparing an MXene-polymer composite material.

[0007] The MXene-polymer composite material provided by this invention is a type of polymer-based conductive composite material, wherein MXene is a two-dimensional transition metal carbon / nitrogen compound. Its general chemical formula can be expressed as M... n+1 X n T z In this designation, M refers to transition metals (such as Ti, V, Cr, Zr, Hf, Nb, Ta, Sc, etc.), X refers to C and / or N, n is generally 1-3, and T... z Surface groups (such as -O-, -OH, -F, -NH2, -Cl, etc.).

[0008] Currently reported MXene-polymer composites all utilize monolayer MXene nanosheets dispersed within a polymer matrix. MXene nanosheets possess a two-dimensional layered structure, high specific surface area, high electrical conductivity, and good mechanical properties. Their abundant hydroxyl and oxygen-containing functional groups allow for stable dispersion in most common solvents, resulting in excellent solution processability and suitability for preparing polymer composite functional materials. However, current methods for preparing MXene nanosheets require organic solvents or salt solutions to assist in the intercalation and exfoliation of multiple MXene layers, followed by repeated washing and centrifugation. Consequently, the production cost of MXene nanosheets is high, the exfoliation time is long, and the efficiency is low, hindering the large-scale preparation and application of MXene-polymer composites.

[0009] This invention employs a mechanical shearing grinding method to co-grind multilayer MXene powder particles, polymer materials, and magnetic nano-grinding aids. By utilizing the strong shearing force and the grinding aid effect of magnetic nanoparticles, large-scale and efficient exfoliation of multilayer MXene particles and uniform dispersion in the polymer matrix can be achieved. At the same time, the magnetic nano-grinding aid can further enhance the electromagnetic shielding effectiveness of the resulting MXene-polymer composite material.

[0010] The MXene-polymer composite material prepared by this invention has good processability and can be added as a masterbatch to other or similar polymers to produce MXene-polymer composite materials with certain appearance and mechanical strength. The MXene-polymer composite material prepared by this invention can be applied in fields such as electrical conductivity, thermal conductivity, and electromagnetic shielding, and also has advantages such as low cost and suitability for large-scale production.

[0011] More preferably, the raw material composition, by weight, includes:

[0012] 1 to 50 parts of multilayer MXene particles;

[0013] 1 to 100 parts of polymer material;

[0014] 1 to 10 parts of magnetic nano-grinding aid.

[0015] More preferably, the raw material composition, by weight, includes:

[0016] Multilayer MXene particles: polymer material: magnetic nano-grinding aid = 1:0.5~10:0.1~0.5.

[0017] More preferably, the raw material composition, by weight, includes:

[0018] Multilayer MXene particles: polymer material: magnetic nano-grinding aid = 1:1~5:0.2~0.4.

[0019] More preferably, the polymer material comprises one or more of polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polyester, cellulose, chitosan, polyacrylic acid, polyacrylate, aramid, polyamide, polyethylene glycol, polyvinyl alcohol, alginate, epoxy resin, polyurethane, polyoxymethylene, and polyethylene oxide. More preferably, the polymer material is one of polyethylene, polypropylene, cellulose, and polyvinyl alcohol.

[0020] More preferably, the magnetic nano-grinding aid comprises at least one selected from iron oxide nanoparticles, nickel nanoparticles, and cobalt nanoparticles. More preferably, the magnetic nano-grinding aid is iron oxide nanoparticles.

[0021] More preferably, the ambient temperature for mechanical shearing and grinding is 0℃~40℃.

[0022] More preferably, a disc-type shearing and grinding device is used for shearing and grinding, with a rotation speed set to 500 RPM to 2000 RPM. More preferably, the rotation speed is set to 1000 RPM to 2000 RPM, and even more preferably, to 1500 RPM.

[0023] When the grinding disc speed is too low, the grinding and peeling effect on multilayer MXene particles and their dispersion in the polymer matrix are poor; when the grinding disc speed is too high, the shearing and grinding equipment has too obvious a destructive effect on MXene nanosheets, resulting in poor performance of the obtained MXene / polymer composite material.

[0024] Preferably, the grinding time is set to 1 min-15 min, more preferably 5 min-10 min.

[0025] Within the reasonable grinding time range designed in this invention, the longer the grinding time, the better the dispersion of multilayer MXene particles in the polymer matrix, and the better the performance of the resulting MXene / polymer composite material.

[0026] More preferably, the grinding conditions are set as follows: ambient temperature is 0℃~40℃, circulating cooling water temperature is 1℃~40℃, grinding disc speed is 1000RPM~2000RPM, and grinding time is 5min-10min.

[0027] More preferably, the method further includes preparing multilayer MXene particles for preparing MXene-polymer composites by mechanical shearing and grinding, comprising the steps of:

[0028] Multilayer ternary ceramic MAX powder is etched by hydrofluoric acid or a fluoride / acid mixture, then washed with deionized water by centrifugation until pH > 6, and dried to obtain multilayer MXene particles.

[0029] More preferably, the multilayer ternary ceramic MAX powder particles include Ti3AlC2, Ti2AlC, Ta4AlC3, TiNbAlC, (V 0.5 Cr 0.5 )3AlC2, V2AlC, Nb2AlC, Nb4AlC3, Ti3AlCN, Ti3SiC2, Ti2SiC, Ta4SiC3, TiNbSiC, (V 0.5 Cr 0.5 One or more combinations of 3SiC2, V2SiC, Nb2SiC, Nb4SiC3 or Ti3SiCN.

[0030] More preferably, the multilayer ternary ceramic MAX powder particles are made of Ti3AlC2.

[0031] More preferably, the acid is one or a combination of two or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, oxalic acid, or citric acid. More preferably, the acid is one of hydrochloric acid and sulfuric acid.

[0032] More preferably, the fluoride salt is one or a combination of two or more of lithium fluoride, calcium fluoride, sodium fluoride, or potassium fluoride. More preferably, the fluoride salt is one of lithium fluoride and sodium fluoride.

[0033] More preferably, the etching temperature is 20℃~50℃, and the etching time is 4h~72h. Preferably, the centrifugation speed is greater than 200RPM, the centrifugation time is 5min~60min, and the number of times is 5~6, until the pH is >6. Preferably, the vacuum drying temperature is 40℃~120℃, and the drying time is more than 6h.

[0034] More preferably, the etching temperature is room temperature, the etching time is 12h to 36h, the centrifugation speed is 3500RPM to 8000RPM, the centrifugation time is 5min to 60min, until the pH of the centrifuged supernatant is >6, the vacuum drying temperature is 30℃ to 80℃, and the drying time is more than 6h.

[0035] An MXene-polymer composite material is prepared using the method described above for preparing an MXene-polymer composite material.

[0036] The present invention has the following advantages and beneficial effects:

[0037] 1. This invention achieves in-situ exfoliation of multilayer MXene and micro-nano scaling of polymer materials simultaneously through mechanical shearing and grinding (e.g., by using a grinding disc type shearing and grinding device to apply enormous pressure and shear force to the material), forming a uniformly dispersed composite material; the use of magnetic nano-grinding aids can promote the exfoliation of multilayer MXene particles and improve the electromagnetic shielding performance of the composite material; it overcomes the agglomeration problem caused by the high surface energy of MXene nanosheets and solves the problems of dispersion, stability and composite formation in the polymer matrix.

[0038] 2. Compared with the traditional two-step liquid-phase method for preparing MXene-polymer composite materials, the method provided by this invention achieves in-situ exfoliation and dispersion of MXene in the polymer matrix in the solid phase. It is environmentally friendly, suitable for large-scale continuous production, and has the advantages of low cost, high yield, high efficiency, simple process, and excellent electromagnetic shielding performance. It has great application prospects in large-scale production.

[0039] 3. The MXene-polymer composite material prepared by this invention has the advantages of easy processing, excellent conductivity and electromagnetic shielding performance, and has broad application prospects in the fields of electrochemical energy storage devices and electromagnetic shielding. Attached Figure Description

[0040] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0041] Figure 1 The diagram shows the separation and dispersion of multilayer MXene in the polymer matrix in various embodiments; where 1 represents the grinding surface of the grinding disc, and the curved surface is used to simulate the roughness of the grinding disc surface; 2 represents the multilayer MXene block; and 3 represents the polymer matrix.

[0042] Figure 2 The image shows the microstructure of the ternary ceramic MAX particles used in Example 1 under a scanning electron microscope (SEM).

[0043] Figure 3The image shows the microstructure of the multilayer MXene particles prepared in Example 1 under SEM.

[0044] Figure 4 The image shows the microstructure of the single / few-layer MXene nanosheets prepared in Example 1 under atomic force microscopy (AFM).

[0045] Figure 5 The image shows the microstructure of the MXene / polyethylene composite material prepared in Example 1 under SEM. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0047] Example 1

[0048] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0049] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0050] Then, 10g of multilayer Ti3C2 powder particles, 40g of polyethylene particles, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min, to obtain a Ti3C2 / polyethylene composite material. The multilayer MXene particles entered the grinding surface composed of the moving and stationary grinding discs, and were gradually peeled off into single-layer few-layer MXene nanosheets during the shearing and grinding process, and gradually dispersed uniformly in the polymer matrix.

[0051] Example 2

[0052] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0053] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0054] Then, 10g of multilayer Ti3C2 powder particles, 40g of polyethylene particles, and 4g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min, to obtain Ti3C2 / polyethylene composite material.

[0055] Example 3

[0056] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0057] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0058] Then, 10g of multilayer Ti3C2 powder particles, 40g of polyethylene particles, and 1g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min to obtain Ti3C2 / polyethylene composite material.

[0059] Example 4

[0060] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0061] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0062] Then, 10g of multilayer Ti3C2 powder particles, 5g of polyethylene particles, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min to obtain Ti3C2 / polyethylene composite material.

[0063] Example 5

[0064] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0065] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0066] Then, 10g of multilayer Ti3C2 powder particles, 100g of polyethylene particles, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min to obtain Ti3C2 / polyethylene composite material.

[0067] Example 6

[0068] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0069] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0070] Then, 10g of multilayer Ti3C2 powder particles, 40g of polyvinyl alcohol powder, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500 RPM, and the grinding time was 10 min to obtain Ti3C2 / polyvinyl alcohol composite material.

[0071] Example 7

[0072] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0073] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0074] Then, 10g of multilayer Ti3C2 powder particles, 40g of bamboo pulp cellulose powder, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min to obtain Ti3C2 / cellulose composite material.

[0075] Example 8

[0076] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0077] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0078] Then, 10g of multilayer Ti3C2 powder particles, 100g of polyethylene particles, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 500RPM, and the grinding time was 10min, to obtain Ti3C2 / polyethylene composite material.

[0079] Example 9

[0080] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0081] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0082] Then, 10g of multilayer Ti3C2 powder particles, 100g of polyethylene particles, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 2000 RPM, and the grinding time was 10 min, to obtain Ti3C2 / polyethylene composite material.

[0083] Example 10

[0084] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0085] First, 50g of Ti2AlC powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti2C powder particles.

[0086] Then, 10g of multilayer Ti2C powder particles, 40g of polyethylene particles, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min to obtain Ti2C / polyethylene composite material.

[0087] Example 11

[0088] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0089] First, 50g of V2AlC powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer V2C powder particles.

[0090] Then, 10g of multilayer V2C powder particles, 40g of polyethylene particles, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min, to obtain the V2C / polyethylene composite material.

[0091] Example 12

[0092] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0093] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0094] Then, 10g of multilayer Ti3C2 powder particles, 40g of polyethylene particles, and 2g of metallic nickel nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min, which yielded the Ti3C2 / polyethylene composite material.

[0095] Example 13

[0096] This embodiment provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0097] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0098] Then, 10g of multilayer Ti3C2 powder particles, 40g of polyethylene particles, and 2g of cobalt nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min, which yielded the Ti3C2 / polyethylene composite material.

[0099] Comparative Example 1

[0100] This case study provides an MXene-polymer composite material, and the specific preparation method is shown below:

[0101] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0102] Next, 10g of multilayer Ti3C2 powder particles and 40g of polyethylene particles were added to a grinding disc type shearing and grinding equipment for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min, to obtain Ti3C2 / polyethylene composite material.

[0103] Comparative Example 2

[0104] This case study presents an MXene-polymer composite material, the specific preparation method of which is shown below:

[0105] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0106] Next, 10g of multilayer Ti3C2 powder particles, 1g of polyethylene particles, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min, to obtain the Ti3C2 / polyethylene composite material.

[0107] Comparative Example 3

[0108] This case study presents an MXene-polymer composite material, the specific preparation method of which is shown below:

[0109] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0110] Next, 10g of multilayer Ti3C2 powder particles, 200g of polyethylene particles, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 1500RPM, and the grinding time was 10min, to obtain the Ti3C2 / polyethylene composite material.

[0111] Comparative Example 4

[0112] This case study presents an MXene-polymer composite material, the specific preparation method of which is shown below:

[0113] First, 50g of Ti3AlC2 powder was slowly added to 1000mL of a 10wt% hydrofluoric acid mixed solution, and stirred continuously at room temperature for 24h. The resulting suspension was repeatedly centrifuged and washed with deionized water (5min, 3500rpm) until the pH of the supernatant was ≥6. The precipitate was then vacuum dried at 60℃ for 24h to obtain multilayer Ti3C2 powder particles.

[0114] Next, 10g of multilayer Ti3C2 powder particles, 40g of polyethylene particles, and 2g of iron oxide nanoparticles were added to a grinding disc type shearing and grinding device for grinding. Cooling circulating water was introduced during the shearing and grinding process, the grinding disc speed was 200RPM, and the grinding time was 10min, to obtain the Ti3C2 / polyethylene composite material.

[0115] I. Characterization Analysis

[0116] The material provided in Example 1 was characterized and analyzed accordingly, and the results are as follows:

[0117] like Figure 2 and Figure 3 The images show the microstructure of Ti3AlC2 particles and multilayer Ti3C2 powder particles under scanning electron microscope, respectively. This indicates that the multilayer MXene particles and MAX particles before exfoliation have similar morphological structures, both being multilayer particle structures with a micrometer size.

[0118] Figure 4 To remove the polymer component from the MXene / polymer composite, atomic force microscopy (AFM) images of the MXene sheets were obtained, showing a sheet structure with a thickness of a few nanometers.

[0119] Figure 5 The image shows a scanning electron microscope (SEM) image of the Ti3C2 / polyethylene composite material obtained after exfoliation by mechanical shearing and grinding. This illustrates that the disc-type shearing and grinding equipment can fully exfoliate multilayer Ti3C2 particles to obtain single / few-layer Ti3C2 nanosheets, which can be uniformly dispersed in the polyethylene matrix.

[0120] II. Performance Testing

[0121] 1. Testing Method

[0122] (1) Peeling effect: The polymer component of the MXene / polymer composite material was removed by extraction. The average thickness of the obtained MXene sheet component was analyzed by atomic force microscopy (AFM) to evaluate the peeling effect of solid phase shearing.

[0123] (2) Electrical conductivity: The MXene / polymer composite material was injection molded into a sample by thermoplastic processing, and the electrical conductivity of the composite material sample was determined by the four-point probe method.

[0124] (3) Electromagnetic shielding effectiveness: MXene / polymer composite material was injection molded into a sample through thermoplastic processing, and the electromagnetic shielding effectiveness of the composite material sample was measured by an Agilent vector network analyzer.

[0125] 2. Test Results

[0126] Table 1 shows the stripping effect, conductivity, and shielding effectiveness of the samples provided in Examples 1-13 and Comparative Examples 1-4 in the X-band (8.2 GHz to 12.4 GHz) electromagnetic wave range.

[0127]

[0128]

[0129] In summary, the average thickness of the MXene sheets in the composite material provided in this application is only 5.3 nm, and the electrical conductivity and shielding effectiveness against X-band (8.2 GHz to 12.4 GHz) electromagnetic waves of the MXene / polymer composite material are as high as 1325.7 Sm. -1 The results, with a conductivity of 31.4 dB, verify that the method provided in this application can effectively exfoliate multilayer MXene, and the prepared MXene / polymer composite material exhibits good electrical conductivity and electromagnetic shielding performance. In Comparative Example 1, the average thickness of the MXene sheets reached 331.4 nm, and the resulting composite material had an electrical conductivity of 5.8 S / m. -1 The shielding effectiveness against X-band (8.2–12.4 GHz) electromagnetic waves was 13.5 dB, indicating that the lack of iron oxide nanoparticles as a grinding aid resulted in poor exfoliation and dispersion of the multilayer MXene in the polymer matrix, low conductivity, and poor electromagnetic shielding performance due to the absence of iron oxide nanoparticles to provide hysteresis loss. In Comparative Example 2, the polymer content was too low, making thermoplastic molding difficult. In Comparative Example 3, the MXene content was too low; although the exfoliation and dispersion were good, the MXene failed to form a conductive network in the polymer matrix, resulting in low conductivity and electromagnetic shielding effectiveness. In Comparative Example 4, the grinding disc rotation speed was too low, failing to achieve effective exfoliation and dispersion of the multilayer MXene, thus resulting in low conductivity and electromagnetic shielding effectiveness.

[0130] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing an MXene-polymer composite material, characterized in that, Includes the following steps: By mechanically shearing and grinding raw materials including multilayer MXene particles, polymer materials and magnetic nano-grinding aids, in-situ exfoliation of multilayer MXene, micro-nanoization and compositing of raw materials are achieved in the solid phase, thus preparing MXene-polymer composite materials. By weight, the raw material composition includes: 10 parts of multilayer MXene particles; 40 parts of polymer material; Two parts of magnetic nano-grinding aid; The use of the magnetic nano-grinding agent can promote the exfoliation of multilayer MXene particles and improve the electromagnetic shielding performance of composite materials; shearing and grinding are performed using a grinding disc type shearing and grinding equipment, with a rotation speed set at 1500 RPM; the magnetic nano-grinding agent includes at least one of iron oxide nanoparticles, metallic nickel nanoparticles, and metallic cobalt nanoparticles.

2. The method for preparing an MXene-polymer composite material according to claim 1, characterized in that, The polymer material includes one or more of the following: polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, cellulose, chitosan, polyacrylic acid, polyacrylate, polyamide, polyvinyl alcohol, alginate, epoxy resin, polyurethane, polyoxymethylene, and polyethylene oxide.

3. A method for preparing an MXene-polymer composite material according to any one of claims 1 to 2, characterized in that, It also includes the preparation of multilayer MXene particles for the preparation of MXene-polymer composite materials by mechanical shearing and grinding, including the steps of etching multilayer ternary ceramic MAX powder with hydrofluoric acid or a fluoride / acid mixture, then washing it with deionized water by centrifugation until pH>6, and drying to obtain multilayer MXene particles.

4. The method for preparing an MXene-polymer composite material according to claim 3, characterized in that, The multilayer ternary ceramic MAX powder particles include Ti3AlC2, Ti2AlC, Ta4AlC3, TiNbAlC, (V 0.5 Cr 0.5 )3AlC2, V2AlC, Nb2AlC, Nb4AlC3, Ti3AlCN, Ti3SiC2, Ti2SiC, Ta4SiC3, TiNbSiC, (V 0.5 Cr 0.5 One or more combinations of 3SiC2, V2SiC, Nb2SiC, Nb4SiC3 or Ti3SiCN.

5. An MXene-polymer composite material, characterized in that, The MXene-polymer composite material was prepared using the preparation method described in any one of claims 1 to 4.

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