A quasi-one-dimensional chain-like max phase composite material and a preparation method thereof

Abstract

The application relates to a quasi-one-dimensional chain MAX phase composite material and a preparation method thereof, which comprises the following steps: MAX phase material preparation and pretreatment; preparation of a reaction solution; and preparation of the quasi-one-dimensional chain MAX phase composite material. In the method, part of Ni ions is nucleated and grown on the surface of MAX powder in the process of being reduced into Ni elements, and other Ni ions are nucleated and grown in a liquid environment under the action of a magnetic field, forming a chain structure. Meanwhile, part of the MAX powder with Ni particles grown on the surface is together with newly reduced Ni particles to form a chain structure under the action of a specific magnetic field. The method makes the MAX phase powder form a chain structure in a quasi-one-dimensional mode, and a new material with a quasi-one-dimensional ordered structure is obtained. The quasi-one-dimensional structure increases the overall conductivity of the material, the introduction of the Ni chain makes the composite material have magnetism, and promotes the development and application in the electromagnetic shielding and absorption field.

Description

Technical Field

[0001] This invention belongs to the field of inorganic composite materials technology, specifically relating to a quasi-one-dimensional chain-like MAX phase composite material and its preparation method. Background Technology

[0002] MAX phase materials are a class of ternary or multi-component compounds with a nanolayered structure and the molecular formula M. n+1 AX n The MAX phase consists of n = 1 to 4 elements, where M is one or more early transition metal elements (Cr, Ti, V, Nb, Mo, etc.), A is a group 13 or 14 element (Al, Si, Ga, etc.), and X is one or a combination of C or N. MAX phase materials belong to the hexagonal crystal system with space group P63 / mmc. MAX phase materials possess excellent thermal stability, corrosion resistance, electrical conductivity, and electrochemical properties, making them highly promising for applications in high-temperature environments, chemical corrosion protection, and electromagnetic absorption shielding.

[0003] Currently, the structural design of MAX phase materials remains at the microscopic level, and the prepared MAX phases are still limited to lamellar granular structures, lacking a one-dimensional macroscopic structure. With the maturation of our understanding of particle orientation behavior under magnetic fields, magnetic fields have become a new driving force for self-assembly. Utilizing magnetic fields to prepare new materials with ordered structures has become a highly effective method. Therefore, the preparation of MAX phase composite materials with quasi-one-dimensional chain structures remains a major research direction. Summary of the Invention

[0004] To address the current research gaps in quasi-one-dimensional chain-like MAX phase composite materials, the present invention aims to provide a quasi-one-dimensional chain-like MAX phase composite material and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing a quasi-one-dimensional chain-like MAX phase composite material, comprising the following steps:

[0007] (1) Preparation and pretreatment of MAX phase materials:

[0008] MAX phase materials were prepared and then subjected to grinding, sieving, and ball milling to obtain MAX phase materials.

[0009] (2) Preparation of the reaction solution:

[0010] Nickel chloride hexahydrate, polyvinylpyrrolidone, and sodium hydroxide were added sequentially to ethylene glycol and stirred until dissolved. The stirring time was T1.

[0011] Add the MAX phase material, first sonicate for time T2, then stir for time T3;

[0012] Add hydrazine hydrate and stir for 4 hours to obtain the reaction solution;

[0013] (3) Preparation of quasi-one-dimensional chain-like MAX phase composite materials:

[0014] The reaction solution is placed in a reaction vessel, and an external magnetic field is applied to induce the reaction for time T5 and the reaction temperature T6. After washing and drying, the product is obtained.

[0015] Preferably, the molecular formula of the MAX phase material is M n+1 AX n Where M is any one or two or more of Cr, Ti, V, Nb or Mo, A is Al, Si or Ga, X is C and / or N, and n is 1, 2, 3 or 4.

[0016] Preferably, the preparation method of the MAX phase material is as follows: the elements involved in the MAX phase material are mixed in a molar ratio and sintered at 1400°C for 2 hours in a vacuum tube furnace under argon atmosphere protection.

[0017] Preferably, the sieving in step (1) is sieving through a 500-mesh sieve; the ball milling is ball milling at a speed of 300 rpm / min for 8 hours, with a ball-to-material ratio of 15:1; and the median particle size D50 of the MAX phase material after ball milling is 0.5-0.8 μm.

[0018] Preferably, in step (2), the mass ratio of nickel chloride hexahydrate to polyvinylpyrrolidone is 3:5;

[0019] The concentrations of nickel chloride hexahydrate, polyvinylpyrrolidone, and sodium hydroxide in ethylene glycol were 10 g / L-15 g / L, 15 g / L-25 g / L, and 1 g / L-2 g / L, respectively.

[0020] The mass ratio of MAX phase material to polyvinylpyrrolidone is 1:10;

[0021] The volume ratio of hydrazine hydrate to nickel chloride hexahydrate is 8-12 mL: 3 g;

[0022] The mass percentage concentration of hydrazine hydrate is ≥80%.

[0023] Preferably, the stirring time T1 in step (2) is 30-60 min; the ultrasonic treatment time T2 is 10-20 min; the stirring time T3 is 10-20 min; and the stirring time T4 is 10-20 min.

[0024] Preferably, the applied magnetic field strength in step (3) is 40-80 mT, the reaction time T5 is 0.5-1.5 h, and the reaction temperature T6 is 70-90 °C.

[0025] Preferably, in step (3), when half of the reaction time T5 has elapsed under the induction of an external magnetic field, the direction of the magnetic field is changed by 90° and the reaction continues.

[0026] Preferably, in step (3), the supernatant is rinsed with deionized water until the pH value is 7, and then rinsed twice with alcohol solution, and then placed in a vacuum drying oven at 60°C for 12 hours.

[0027] This invention provides a quasi-one-dimensional chain-like MAX phase composite material, which is prepared using the aforementioned preparation method.

[0028] Beneficial effects:

[0029] This invention provides a method for preparing a quasi-one-dimensional chain-like MAX phase composite material, and proposes the concept of a quasi-one-dimensional chain-like MAX phase composite material for the first time. The method involves slowly adding appropriate amounts of nickel chloride hexahydrate, polyvinylpyrrolidone, and sodium hydroxide sequentially to ethylene glycol under the induction of an external magnetic field. After complete dissolution, an appropriate amount of MAX phase powder is added. During the reduction of elemental Ni using a hydrothermal method, the direction and strength of the magnetic field are controlled to cause the MAX phase powder to form a chain-like structure in a quasi-one-dimensional manner, resulting in a new material with a quasi-one-dimensional ordered structure.

[0030] In the preparation process of the quasi-one-dimensional chain-like MAX phase composite material of the present invention, some Ni ions first nucleate and grow on the surface of MAX powder during the reduction to elemental Ni, while other Ni ions nucleate and grow in a liquid environment under the influence of a magnetic field, forming a chain-like structure. During this process, some MAX powder with Ni particles growing on its surface will, together with the newly reduced Ni particles, form a chain-like structure under the influence of a specific magnetic field.

[0031] This invention enriches the structural design of MAX phase materials. The MAX phase composite material prepared by this method has the following advantages compared with traditional MAX phase materials: the quasi-one-dimensional structure increases the overall electrical conductivity of the material. The introduction of Ni chains enables the composite material to acquire the magnetism lacking in MAX phase materials, promoting its development and application in the fields of electromagnetic shielding and absorption.

[0032] The method of this invention is simple and applicable not only to the preparation of quasi-one-dimensional chain-like MAX phase composite materials, but also to the preparation of other materials with particle sizes ranging from 200 nm to 1000 nm (e.g., Mo2C-Ni composite materials), providing a reference for the preparation of quasi-one-dimensional composite materials. Attached Figure Description

[0033] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:

[0034] Figure 1 The Cr after ball milling in Example 1 of this invention 1.5 V 0.5 Microscopic morphology of AlC material.

[0035] Figure 2 The Cr after ball milling in Example 1 of this invention 1.5 V 0.5 Particle size distribution diagram of AlC material.

[0036] Figure 3 Cr in Embodiment 1 of the present invention 1.5 V 0.5 Microstructure of AlC-Ni composite material.

[0037] Among them, (a) is a microscopic morphology diagram with a scale of 10 μm; (b) is a microscopic morphology diagram with another scale of 10 μm; that is, the length of the scale in (a) and (b) is different.

[0038] Figure 4 Cr in Embodiment 1 of the present invention 1.5 V 0.5 Mapping diagram of AlC-Ni composite material.

[0039] Figure 5 Cr in Embodiment 1 of the present invention 1.5 V 0.5 XRD pattern of AlC-Ni composite material.

[0040] Figure 6 The images show the microstructure and mapping diagram of the Ti3AlC2-Ni composite material in Example 2 of this invention.

[0041] Figure 7 The image shows the XRD pattern of the Ti3AlC2-Ni composite material in Example 2 of this invention.

[0042] Figure 8 The Cr obtained in Example 3 of this invention 1.5 V0.5 Microstructure and mapping diagram of AlC-Ni composite material.

[0043] Figure 9 The Cr obtained in Comparative Example 1 of this invention 1.5 V 0.5 Microstructure of AlC-Ni composite material.

[0044] Figure 10 The Cr obtained in Comparative Example 2 of this invention 1.5 V 0.5 Microstructure of AlC-Ni composite material.

[0045] Figure 11 The Cr obtained in Comparative Example 3 of this invention 1.5 V 0.5 Microstructure of AlC-Ni composite material.

[0046] Figure 12 The Cr obtained in Comparative Example 4 of this invention 1.5 V 0.5 Microstructure of AlC-Ni composite material.

[0047] Figure 13 The Cr obtained in Comparative Example 5 of this invention 1.5 V 0.5 Microstructure of AlC-Ni composite material.

[0048] Figure 14 The Cr obtained in Example 1 of this invention 1.5 V 0.5 AlC-Ni composite materials and Cr 1.5 V 0.5 Electromagnetic parameter diagram of AlC MAX phase.

[0049] Figure 15 The Cr obtained in Example 1 of this invention 1.5 V 0.5 AlC-Ni composite materials and Cr 1.5 V 0.5 Attenuation constant and minimum reflection loss diagram of AlC MAX phase. Detailed Implementation

[0050] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0051] The present invention will now be described in detail with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0052] This invention addresses the existing problems by providing a method for preparing quasi-one-dimensional chain-like MAX phase composite materials, comprising the following steps:

[0053] (1) Preparation and pretreatment of MAX phase materials:

[0054] MAX phase materials were prepared and then ground, sieved, and ball-milled to obtain MAX phase materials with a median particle size D50 of 0.5-0.8 μm.

[0055] (2) Preparation of the reaction solution:

[0056] Nickel chloride hexahydrate, polyvinylpyrrolidone, and sodium hydroxide were added sequentially to ethylene glycol and stirred until dissolved. The stirring time was T1.

[0057] Add the MAX phase material, first sonicate for time T2, then stir for time T3;

[0058] Add hydrazine hydrate and stir for 4 hours to obtain the reaction solution;

[0059] (3) Preparation of quasi-one-dimensional chain-like MAX phase composite materials:

[0060] The reaction solution is placed in a reaction vessel, and an external magnetic field is applied to induce the reaction for time T5 and the reaction temperature T6. After washing and drying, the product is obtained.

[0061] In a preferred embodiment of the present invention, the molecular formula of the MAX phase material is M n+1 AX n Where M is one or a combination of two or more of Cr, Ti, V, Nb or Mo, A is any one of Al, Si or Ga, X is C and / or N, and n is 1, 2, 3 or 4.

[0062] In a preferred embodiment of the present invention, the MAX phase material is Cr. 1.5 V 0.5 AlC, Cr2AlC, V2AlC or Ti3AlC2.

[0063] In a preferred embodiment of the present invention, the preparation method of the MAX phase material is as follows: the elements involved in the MAX phase material are mixed in a molar ratio and sintered at 1400°C for 2 hours in a vacuum tube furnace under argon atmosphere protection to obtain the MAX phase material.

[0064] In a preferred embodiment of the present invention, the sieving in step (1) is sieving through a 500-mesh sieve; the ball milling is ball milling at a speed of 300 rpm / min for 8 hours, with a ball-to-material ratio of 15:1.

[0065] Among them, ball milling can further reduce the particle size of MAX phase material so that MAX powder with Ni particles grown on the surface can form a chain structure with the newly reduced Ni particles.

[0066] In a preferred embodiment of the present invention, the mass ratio of nickel chloride hexahydrate to polyvinylpyrrolidone in step (2) is 3:5;

[0067] The concentrations of nickel chloride hexahydrate, polyvinylpyrrolidone, and sodium hydroxide in ethylene glycol are 10 g / L-15 g / L (e.g., 10 g / L, 12 g / L, or 15 g / L), 15 g / L-25 g / L (e.g., 15 g / L, 20 g / L, or 25 g / L), and 1 g / L-2 g / L (e.g., 1 g / L, 1.6 g / L, or 2 g / L), respectively.

[0068] The mass ratio of MAX phase material to polyvinylpyrrolidone is 1:10;

[0069] The volume ratio of hydrazine hydrate to nickel chloride hexahydrate is 8-12 mL: 3 g (e.g., 8 mL: 3 g, 10 mL: 3 g, or 12 mL: 3 g).

[0070] In a preferred embodiment of the present invention, the concentrations of nickel chloride hexahydrate, polyvinylpyrrolidone, and sodium hydroxide in ethylene glycol are 12 g / L, 20 g / L, and 1.6 g / L, respectively.

[0071] If the concentration of polyvinylpyrrolidone is too high, it will hinder the movement of the MAX phase material to the vicinity of the generated Ni chain, so that the resulting composite material does not have quasi-one-dimensional structural characteristics.

[0072] In a preferred embodiment of the present invention, the stirring time T1 in step (2) is 30-60 min (e.g., 30 min, 40 min, 50 min or 60 min); the ultrasonic treatment time T2 is 10-20 min (e.g., 10 min, 15 min or 20 min); the stirring time T3 is 10-20 min (e.g., 10 min, 15 min or 20 min); and the stirring time T4 is 10-20 min (e.g., 10 min, 15 min or 20 min).

[0073] In a preferred embodiment of the present invention, the applied magnetic field strength in step (3) is 40-80 mT (e.g., 40 mT, 46 mT, 50 mT, 55 mT, 62 mT or 80 mT), the reaction time T5 is 0.5-1.5 h (e.g., 0.5 h, 1 h or 1.5 h), and the reaction temperature is 70-90 °C (e.g., 70 °C, 80 °C or 90 °C).

[0074] In a preferred embodiment of the present invention, the applied magnetic field strength in step (3) is 46mT, the reaction time T5 is 1h, and the reaction temperature is 80℃.

[0075] In a preferred embodiment of the present invention, in step (3), when half of the reaction time T5 has elapsed under the induction of an external magnetic field, the direction of the magnetic field is changed by 90° and the reaction continues.

[0076] The addition of an external magnetic field induces the formation of a one-dimensional Ni chain structure; at the same time, changing the direction of the magnetic field allows more MAX phase material to be interwoven onto the Ni chain.

[0077] In a preferred embodiment of the present invention, step (3) involves rinsing with deionized water until the pH of the supernatant is 7, then rinsing twice with an alcohol solution, and finally drying in a vacuum drying oven at 60°C for 12 hours.

[0078] This invention provides a quasi-one-dimensional chain-like MAX phase composite material, which is prepared using the aforementioned preparation method.

[0079] The following detailed description of a quasi-one-dimensional chain-like MAX phase composite material and its preparation method according to specific embodiments of the present invention is provided below.

[0080] Example 1

[0081] This embodiment provides a method for preparing a quasi-one-dimensional chain-like MAX phase composite material, characterized by comprising the following steps:

[0082] (1)Cr 1.5 V 0.5 Preparation and pretreatment of AlC materials:

[0083] Four powders, Cr, V, Al, and C, were mixed evenly in a mixer in a molar ratio of Cr:V:Al:C = 1.5:0.5:1.1:1 (wherein, Al will volatilize during sintering, so the Al content is slightly higher than the atomic ratio). Then, the mixture was sintered at 1400℃ for 2 hours in a vacuum tube furnace under argon atmosphere protection.

[0084] After sintering, the material was ground and passed through a 500-mesh sieve; subsequently, it was ball-milled for 8 hours at 300 rpm / min using a planetary ball mill with a ball-to-material ratio of 15:1 to obtain Cr. 1.5 V 0.5 AlC material.

[0085] Among them, Cr after ball milling 1.5 V 0.5 Microscopic morphology images of AlC materials obtained by scanning electron microscopy are shown below. Figure 1 As shown, the particle size distribution map is as follows: Figure 2 As shown. According to Figure 1 and Figure 2 It can be seen that after ball milling, the material has D10 = 0.37 μm, D50 = 0.62 μm, and D90 = 1.4 μm. The Cr... 1.5 V 0.5 The smaller particle size and larger specific surface area of ​​AlC materials make it more favorable for Ni particle nucleation and growth on Cr. 1.5 V 0.5 AlC material powder surface.

[0086] (2) Preparation of the reaction solution:

[0087] 0.6 g of nickel chloride hexahydrate, 1 g of polyvinylpyrrolidone, and 0.08 g of NaOH were slowly added sequentially to 50 mL of ethylene glycol, and stirred for 30 min. After complete dissolution, 0.1 g of Cr was slowly added. 1.5 V 0.5 AlC material was sonicated for 10 min and then stirred on a magnetic stirrer for 10 min. Finally, 2 mL of hydrazine hydrate solution (wt≥80%) was slowly added and stirred for 10 min to obtain the reaction solution.

[0088] (3) Preparation of quasi-one-dimensional chain-like MAX phase composite materials:

[0089] First, place the reaction solution in a 100mL reaction vessel, then place the reaction vessel in an 80℃ oven, and place the N and N poles of the rubidium magnet parallel to each other on both sides of the reaction vessel. The magnetic field strength at the middle position of the rubidium magnet is 46mT.

[0090] Under the induction of an external magnetic field, after the reaction proceeds for 30 minutes, the reaction vessel is rotated 90° in the horizontal direction. At this time, the direction of the magnetic field is rotated 90° relative to the reaction vessel, and the reaction continues for another 30 minutes.

[0091] After the reaction, turn off the oven power, remove the magnetic field, and wait for it to cool to room temperature. Then, rinse with deionized water until the pH of the supernatant is 7. Finally, rinse twice with alcohol and dry in a vacuum drying oven at 60°C for 12 hours to obtain the product.

[0092] Among them, the obtained Cr 1.5 V 0.5 The scanning electron microscope images of the AlC-Ni composite material are as follows: Figure 3 As shown ( Figure 3 (The lengths of the scale bars in (a) and (b) are different), the mapping maps are as follows: Figure 4 As shown. According to Figure 3 As shown in Figure 4, the composite material obtained in Example 1 exhibits quasi-one-dimensional structural characteristics. Cr 1.5 V 0.5 AlC powder is linked together by Ni chains grown under a specific magnetic field to form a quasi-one-dimensional chain-like Cr. 1.5 V 0.5AlC-Ni composite material.

[0093] The obtained Cr 1.5 V 0.5 The XRD pattern of the AlC-Ni composite material is as follows: Figure 5 As shown, the composite material obtained in Example 1 has high purity.

[0094] For Cr 1.5 V 0.5 AlC-Ni composite materials and Cr 1.5 V 0.5 AlC material (Cr obtained in step (1) above) 1.5 V 0.5 The electromagnetic parameters and electromagnetic wave absorption performance of AlC MAX phase materials were measured.

[0095] The obtained Cr 1.5 V 0.5 AlC-Ni composite materials and Cr 1.5 V 0.5 The electromagnetic parameter diagram of the AlC MAX phase is shown below. Figure 14 As shown. It can be seen that Cr 1.5 V 0.5 The real part of the dielectric constant of AlC-Ni composite material increases, and according to the free electron theory, the conductivity of the material increases. Therefore, the quasi-one-dimensional structure formed increases the overall conductivity of the material.

[0096] The obtained Cr 1.5 V 0.5 AlC-Ni composite materials and Cr 1.5 V 0.5 The attenuation constant and minimum reflection loss of the AlC MAX phase are shown in the figure below. Figure 15 As shown, the introduction of Ni chains gives the composite material a magnetic property lacking in MAX phase materials, promoting its development and application in the fields of electromagnetic shielding and absorption.

[0097] Example 2

[0098] This embodiment provides a method for preparing a quasi-one-dimensional chain-like MAX phase composite material, which differs from Example 1 in that the MAX phase material prepared in step (1) is different.

[0099] Step (1) in this embodiment is the preparation of Ti3AlC2 material, wherein the molar ratio of Ti, Al and C is 3:1.2:2, and the other steps and parameters are the same as in Example 1.

[0100] The scanning electron microscope images and mapping patterns of the obtained Ti3AlC2-Ni composite material are shown below. Figure 6As shown, the composite material obtained in Example 2 has quasi-one-dimensional structural characteristics. Ti3AlC2 powder is linked together by Ni chains grown under a specific magnetic field to form a quasi-one-dimensional chain-like Ti3AlC2-Ni composite material.

[0101] The XRD pattern of the obtained Ti3AlC2-Ni composite material is as follows: Figure 7 As shown, the composite material obtained in Example 2 has high purity.

[0102] Example 3

[0103] This embodiment provides a method for preparing a quasi-one-dimensional chain-like MAX phase composite material, which differs from Embodiment 1 in that the intensity of the external magnetic field induced in step (3) is different.

[0104] In this embodiment, the external magnetic field induced intensity is 62mT, and the other steps and parameters are the same as in Embodiment 1.

[0105] Among them, the obtained Cr 1.5 V 0.5 Scanning electron microscopy images and mapping patterns of AlC-Ni composite materials are shown below. Figure 8 As shown, the composite material obtained in Example 3 exhibits quasi-one-dimensional structural characteristics. Cr 1.5 V 0.5 AlC powder is linked together by Ni chains grown under a specific magnetic field to form a quasi-one-dimensional chain-like Cr. 1.5 V 0.5 AlC-Ni composite material.

[0106] Comparative Example 1

[0107] This comparative example provides a method for preparing a MAX phase composite material, which differs from Example 1 in that step (1) is not ball-milled.

[0108] This comparative example directly uses Cr after passing through a 500-mesh sieve. 1.5 V 0.5 The AlC material was used for subsequent experiments, and other steps and parameters were the same as in Example 1.

[0109] Among them, the obtained Cr 1.5 V 0.5 The scanning electron microscope images of the AlC-Ni composite material are as follows: Figure 9 As shown, the composite material obtained in Comparative Example 1 does not possess quasi-one-dimensional structural characteristics. The reason may be that Cr... 1.5 V 0.5 The AlC powder particles are too large.

[0110] Comparative Example 2

[0111] This comparative example provides a method for preparing a MAX phase composite material, which differs from Example 1 in that the hydrothermal reaction time in step (3) is different.

[0112] The hydrothermal reaction time in this comparative example was 2 hours. After 1 hour of reaction, the magnetic field was rotated 90° and the reaction continued for another hour. Other steps and parameters were the same as in Example 1.

[0113] Among them, the obtained Cr 1.5 V 0.5 The scanning electron microscope images of the AlC-Ni composite material are as follows: Figure 10 As shown, the composite material obtained in Comparative Example 2 does not possess quasi-one-dimensional structural characteristics. This may be because the reaction time is relatively long, and the magnetic field direction is not switched in time.

[0114] Comparative Example 3

[0115] This comparative example provides a method for preparing a MAX phase composite material, which differs from Example 1 in that the amount of polyvinylpyrrolidone used in step (2) is different.

[0116] The amount of polyvinylpyrrolidone used in this comparative example was 2g; other steps and parameters were the same as in Example 1.

[0117] Among them, the obtained Cr 1.5 V 0.5 The scanning electron microscope images of the AlC-Ni composite material are as follows: Figure 11 As shown, the composite material obtained in Comparative Example 3 does not possess quasi-one-dimensional structural characteristics. This may be because the high concentration of polyvinylpyrrolidone hinders the growth of Cr... 1.5 V 0.5 AlC powder moves toward the vicinity of the generated Ni chains.

[0118] Comparative Example 4

[0119] This comparative example provides a method for preparing a MAX phase composite material. The difference between this method and Example 1 is that step (3) does not involve external magnetic field induction, while the other steps and parameters are the same as in Example 1.

[0120] Among them, the obtained Cr 1.5 V 0.5 The scanning electron microscope images of the AlC-Ni composite material are as follows: Figure 12 As shown, the composite material obtained in Comparative Example 4 does not possess quasi-one-dimensional structural characteristics. This may be because no external magnetic field was added to induce the formation of a one-dimensional Ni chain structure.

[0121] Comparative Example 5

[0122] This comparative example provides a method for preparing a MAX phase composite material. The difference between this method and Example 1 is that the magnetic field added in step (3) is a constant magnetic field, and the direction of the magnetic field is not changed. Other steps and parameters are the same as in Example 1.

[0123] Among them, the obtained Cr 1.5 V 0.5 The scanning electron microscope images of the AlC-Ni composite material are as follows: Figure 13 As shown, the composite material obtained in Comparative Example 5 does not possess quasi-one-dimensional structural characteristics. This may be because the direction of the external magnetic field was not reversed, and Cr... 1.5 V 0.5 AlC particles cannot adhere well to the grown Ni chains.

[0124] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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 a quasi-one-dimensional chain-like MAX phase composite material, characterized in that, Includes the following steps: (1) Preparation and pretreatment of MAX phase materials: Preparation of MAX phase materials, wherein the molecular formula of the MAX phase materials is M n+1 AX n Wherein, M is any one or two or more of Cr, Ti, V, Nb or Mo, A is Al, Si or Ga, X is C and / or N, and n is 1, 2, 3 or 4; the MAX phase material is ground, sieved and ball-milled, and the median particle size D50 is 0.5-0.8 μm; (2) Preparation of the reaction solution: Nickel chloride hexahydrate, polyvinylpyrrolidone, and sodium hydroxide were sequentially added to ethylene glycol and stirred until dissolved. The stirring time was 30-60 minutes. The concentration of polyvinylpyrrolidone in ethylene glycol was 15-25 g / L. Add the MAX phase material pretreated in step (1), first sonicate for 10-20 min, then stir for 10-20 min; Add hydrazine hydrate and stir for 10-20 minutes to obtain the reaction solution; The mass ratio of nickel chloride hexahydrate to polyvinylpyrrolidone is 3:5, and the mass ratio of MAX phase material to polyvinylpyrrolidone is 1:

10. (3) Preparation of quasi-one-dimensional chain-like MAX phase composite materials: The reaction solution obtained in step (2) is placed in a reaction vessel and reacted at 70-90℃ for 0.5-1.5h under an external magnetic field of 40-80mT. When the reaction is halfway through, the magnetic field direction is reversed by 90° and the reaction continues. After the reaction is completed, the product is washed and dried to obtain the quasi-one-dimensional chain MAX phase composite material.

2. The preparation method according to claim 1, characterized in that, The preparation method of the MAX phase material is as follows: the elements involved in the MAX phase material are mixed in a molar ratio and sintered at 1400℃ for 2 hours in a vacuum tube furnace under argon atmosphere protection.

3. The preparation method according to claim 1, characterized in that, The sieving in step (1) is to pass through a 500-mesh sieve; the ball milling is to ball mill at a speed of 300 rpm / min for 8 hours, with a ball-to-material ratio of 15:

1.

4. The preparation method according to claim 1, characterized in that, In step (2), the concentrations of nickel chloride hexahydrate and sodium hydroxide in ethylene glycol are 10-15 g / L and 1-2 g / L, respectively; the volume ratio of hydrazine hydrate to the mass ratio of nickel chloride hexahydrate is 8-12 mL:3 g, and the mass percentage concentration of hydrazine hydrate is ≥80%.

5. The preparation method according to claim 1, characterized in that, Step (3) Rinse with deionized water until the pH of the supernatant is 7, then rinse twice with alcohol solution, and then dry in a vacuum drying oven at 60°C for 12 hours.

6. A quasi-one-dimensional chain-like MAX phase composite material, characterized in that, The quasi-one-dimensional chain-like MAX phase composite material was prepared using the preparation method described in any one of claims 1-5.

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