Magnetic induction oriented titanium carbide ferrite composite film and preparation method and application thereof

Abstract

The application discloses a kind of magnetically induced orientation titanium carbide ferrite composite film and its preparation method and application.The application solves the single mode of electromagnetic wave loss of MXene titanium carbide material and the low electromagnetic shielding efficiency, the developed magnetic induction orientation strategy can realize the same pole arrangement of the magnetic pole of introduced ferrite nanoparticles, control material structure in nanometer scale, rich the pore of MXene titanium carbide ferrite composite film, while inducing MXene titanium carbide sheet orientation in the same pole arrangement process of ferrite magnetic pole.In the preparation process of ferrite nanoparticles, by loading citric acid group on the surface of ferrite, the dispersibility of ferrite in MXene titanium carbide gel is improved, and the interaction between ferrite and MXene titanium carbide is enhanced.The prepared magnetically induced orientation MXene titanium carbide ferrite composite film shows an average electromagnetic shielding efficiency of 62.8 dB in the range of 2-18 GHz, and a highest Herman's orientation factor of 0.938.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of nanocomposites, and particularly relates to a magnetic induction oriented titanium carbide ferrite composite film and a preparation method and application thereof. BACKGROUND

[0002] Based on the development of current electronic technology and the improvement of integration, electromagnetic compatibility problems have become a key problem restricting the development of electronic technology. In order to better solve the compatibility problem of electronic components, materials with excellent electromagnetic shielding performance need to be developed. MXene titanium carbide material has relatively excellent mechanical properties and electrical properties, and has broad application prospects in the fields of sensing, catalysis and electromagnetic shielding. At present, MXene titanium carbide material has carried out in-depth research in the field of electromagnetic shielding, and different strategies are used to improve the shielding efficiency of MXene titanium carbide material for electromagnetic waves, such as thermal annealing (Science 2020, 369, 446-450), spatial confinement evaporation (ACS nano 2023, 17, 10628-10636), and introduction of magnetic particles (Small 2023, 19, 2300363.). Although increasing the porosity of the material and introducing magnetic nanoparticles can help improve the electromagnetic shielding performance of the material, the material also needs to maintain relatively excellent mechanical strength, and the previous electromagnetic shielding improvement strategies ignore the role of material orientation and do not well solve the problem of electromagnetic shielding under wide frequency electromagnetic waves.

[0003] MXene materials with layered structures are prepared through different assembly strategies, including vacuum-assisted filtration, scraping orientation, ice template and continuous centrifugal casting, but these methods can only control the layered structure of the sheet layer in the structure. Researchers have introduced hydrogen bonds, ionic bonds, covalent bonds and Π-Π interactions through interfacial crosslinking to improve the mechanical properties of the material. In addition, through the strategy of tensile induction, the orientation degree of the sheet layer of the two-dimensional material is improved, and the mechanical strength of the material is significantly improved. Controlling the structure and saturation magnetization of the material can significantly improve the electromagnetic shielding efficiency of the material, but the mechanical strength and interface orientation of the material cannot be considered.

[0004] The relevant research shows that the introduction of ferrite magnetic nanoparticles can significantly improve the magnetic hysteresis loss of the material, and the magnetic material has good shielding effect on low-frequency electromagnetic waves. The introduction of magnetic particles significantly improves the electromagnetic shielding efficiency of the material. In addition, the pore structure of the material greatly improves the absorption loss of electromagnetic waves. Researchers introduce a porous structure between the material layers through thermal annealing, which significantly improves the electromagnetic shielding efficiency of the material. Based on this, by studying the introduction of ferrite nanoparticles, a magnetic induction orientation strategy is developed to improve the orientation, porosity and saturation magnetization of two-dimensional MXene titanium carbide material, thereby improving the electromagnetic shielding efficiency of the material.

[0005] Currently, there are patents about MXene titanium carbide ferrite composite film materials: a ferrite manganese oxide MXene composite wave-absorbing particle, a preparation method and application thereof (CN114552231A), a MXene-based composite film, a preparation method and application thereof (CN117672621A), a manganese-zinc ferrite polyaniline titanium carbide composite wave-absorbing material and a preparation method thereof (CN112625441A), application of a multilayer MXene / aminozinc ferrite composite material as an adsorbent in enrichment of heavy metal mercury (CN116272871A), an amino spinel ferrite / MXene composite material, a preparation and application thereof (CN115990466A), a copper ferrite-MXene polymer composite antibacterial tracheal stent and a preparation method thereof (CN115252890A), MXene / zinc manganese ferrite / foamed silicone rubber wave-absorbing composite material, a preparation method and application thereof (CN114058186A), a sheet-like MXene loaded cobalt ferrite composite wave-absorbing material and a preparation method thereof (CN110290691A), a composite wave-absorbing material and a preparation method thereof (CN108251054A). Papers about titanium carbide MXene ferrite film materials: a) Small 2022, 18, 2201587.; b) ACS Appl. Mater. Interfaces 2021, 13, 21831-21843; c) Ceramics International 2023, 49, 27496-27505. The above patents and papers only discuss the influence of the introduction of ferrite on the electromagnetic shielding loss mode of the composite film, and do not discuss the innovation of the introduction of ferrite on the assembly mode of the composite film and the effective shielding of electromagnetic shielding in the wide frequency band. SUMMARY

[0006] The technical solutions of the present application: overcome the shortcomings of the prior art, provide a magnetic induction oriented titanium carbide ferrite composite film and a preparation method and application thereof, and the porous titanium carbide ferrite nanocomposite thin film material with high orientation and high electromagnetic shielding performance can be successfully prepared through the technical solutions provided by the present application.

[0007] The present application provides a magnetic induction blade coating orientation strategy, by introducing the hydrogen bond interaction between the magnetic functionalized ferrite particles and titanium carbide, under the shearing action of the applied magnetic field, the magnetic poles of the functionalized ferrite particles are deflected under the attraction of the applied magnetic field, at the same time, the orientation of the titanium carbide sheet is induced, the orientation degree of the material is improved, and the prepared titanium carbide ferrite composite film shows high orientation degree. When the ferrite content is 15 wt%, the prepared titanium carbide ferrite composite film shows a tensile strength of about 158.7 MPa and a Young's modulus of about 10.5 GPa, the saturation magnetization of the titanium carbide ferrite composite film after introducing the magnetic nanoparticles is 0.53 emu / g, the electrical conductivity is 2520±170 S / cm, the average electromagnetic shielding effectiveness of the material in the frequency range of 2-18 GHz is 62.8 dB, which is greatly improved compared with the electromagnetic shielding effectiveness of 38.8 dB of the titanium carbide thin film material, at this time, the thickness of the composite thin film material is about 15 μm. The improvement of the electromagnetic shielding effectiveness of the titanium carbide ferrite composite film is mainly due to the introduction of the magnetic ferrite material which brings about hysteresis loss and improves the shielding effectiveness of the composite thin film material under low frequency electromagnetic wave conditions, at the same time, after introducing the ferrite, a variety of pore structures are formed between the titanium carbide layers, which improves the loss of electromagnetic waves in space, finally, the magnetic induction orientation process makes the ferrite particles arrange in the same polarity while inducing the orientation of the titanium carbide sheet. The wide-angle X-ray diffraction characterization shows that after the magnetic induction orientation, the Herman's orientation factor f of the material reaches 0.938, at the same time, the electromagnetic shielding performance of the composite thin film material is tested by the vector network analyzer, and the electromagnetic shielding effectiveness of the titanium carbide ferrite thin film composite material is obviously improved.

[0008] In the present application, the orientation of the material is represented by Herman's orientation factor.

[0009] This invention is achieved through the following method: First, a single-piece titanium carbide nanosheet (with a diameter of 5-10 μm) aqueous dispersion is obtained by chemical etching and vortex oscillation. Then, the size of the ferrite particles is reduced by high-energy ball milling. The ball-milled ferrite is dissolved using N-methylpyrrolidone. Ferrite particles of suitable size are selected by differential centrifugation. Excess N-methylpyrrolidone is then washed away using ethanol and deionized water. Finally, citric acid is used to graft onto the ferrite surface to achieve ferrite functionalization. In the composite process of titanium carbide and functionalized ferrite, the titanium carbide aqueous dispersion was first concentrated to a concentration of 25 mg / mL. Simultaneously, a certain mass fraction of functionalized ferrite particles was added under stirring. Oriented titanium carbide-ferrite composite films (MAFs) were prepared using a magnetically induced orientation strategy. The optimal Herman's factor f of the prepared MAF was 0.938. With a functionalized ferrite content of 15 wt%, the film exhibited a saturation magnetization of 0.53 emu / g, a porosity of 19.2%, and an electromagnetic shielding effectiveness of 62.8 dB. It demonstrated excellent electromagnetic shielding effectiveness in the 2–18 GHz electromagnetic band.

[0010] The present invention discloses a method for preparing a magnetically oriented titanium carbide ferrite composite thin film, comprising the following steps:

[0011] Step 1: The raw material MAX phase is chemically etched using lithium fluoride (LiF) and concentrated hydrochloric acid (HCl), and reacted under heating conditions (reaction temperature 50℃, reaction time 30 h). After washing, shaking and exfoliation, and differential centrifugation, a single-layer titanium carbide nanosheet (sheet diameter 5-10 μm) aqueous dispersion is prepared. Preferably, the MAX phase includes Ti3AlC2, Ti3AlCN, Ti2AlC, etc.; preferably, the MXene includes Ti3C2T. x Ti3CNT x Ti2CT x wait;

[0012] Step 2: The ferrite raw material is ball-milled to reduce the size of the ferrite particles. A steel milling jar and steel milling balls are used to mill the ferrite, with a ball-to-ferrite mass ratio of 20:1. Additionally, 5% iron powder (by mass fraction of the ferrite) is added. The jar is then sealed and vacuumed. After ball milling, the ferrite size is reduced. Preferably, the ball milling process involves milling at 700 rpm for 12 hours, with alternating milling directions at 1-hour intervals.

[0013] Step three, the prepared ferrite powder is dissolved in N-methyl pyrrolidone solution, dispersed under ultrasonic cell crusher at 300 W for 30 min, and then separated by differential centrifugation at 3000-6000 rpm to obtain ferrite particles with a diameter of about 100-120 nm; preferably, the differential centrifugation is performed at 3000 rpm for 10 min to obtain supernatant, and at 6000 rpm for 10 min to obtain precipitate;

[0014] Step four, the ferrite particles obtained by differential centrifugation in step three are dispersed in an ethanol solution to wash away the N-methyl pyrrolidone solvent, and the washing is repeated three times with ethanol. After washing, the ferrite powder obtained is dried in an oven to remove excess ethanol solvent, and then the ferrite powder is added to deionized water to prepare a ferrite aqueous solution; preferably, the drying temperature of the oven is 50°C;

[0015] Step five, the ferrite aqueous solution prepared in step four is added to a citric acid solution to graft citric acid groups on the surface of the ferrite. After oscillation reaction for 24 h, the upper solution is poured off and deionized water is added again. The concentration of ferrite in the solution is calibrated by drying method, and the interaction between the ferrite and the functional groups on the surface of titanium carbide is enhanced by grafting citric acid on the surface of the ferrite; preferably, the molar ratio of citric acid to ferrite is 1:3;

[0016] Step six, the titanium carbide dispersion solution obtained in step one is concentrated by centrifugation to remove excess water, and a titanium carbide gel with a concentration of 25 mg / mL is obtained; preferably, the centrifugal concentration is performed at 8000 rpm for 10 min;

[0017] Step seven, the functionalized ferrite obtained in step five is added to the titanium carbide gel solution obtained in step six, and the titanium carbide and ferrite are fully stirred and uniformly dispersed at 400 rpm for 10 min; preferably, the amount of addition is between 0-45 wt% of the mass fraction of titanium carbide;

[0018] Step eight, the functionalized ferrite and titanium carbide hydrogel uniformly stirred in step seven is prepared on a flexible substrate using a film applicator with a magnetic scraper to obtain a magnetically induced oriented composite film. The prepared gel film has a thickness of 800 μm, and the optimal Herman's orientation factor of the magnetically induced oriented titanium carbide and ferrite composite film obtained after water evaporation is between 0.930-0.938; preferably, the flexible substrate is a hydrophilic polyvinylidene fluoride film;

[0019] Step nine, the functionalized ferrite titanium carbide hydrogel prepared in step seven is used to prepare titanium carbide ferrite composite films by non-magnetic induction orientation and non-orientation methods; preferably, a hydrophilic polyvinylidene fluoride film is used as a substrate during the preparation of the composite films by different methods.

[0020] Further, the specific steps for preparing a single-layer titanium carbide nanosheet aqueous dispersion in step one by oscillation and differential centrifugation are as follows: the MAX phase peeled off by hydrothermal reaction is dissolved in deionized water, and oscillation is performed under closed conditions for 2-5 min, then gradient centrifugation is performed, and titanium carbide between 1500-4500 rpm is selected. The titanium carbide layer obtained by centrifugation is dissolved in deionized water, and a certain volume of titanium carbide dispersion solution is dried to calibrate the concentration of titanium carbide in water; the specific chemical formula of the ferrite powder in step two includes MnZn(FeO2)4, ZnFe2O4, Fe3O4, etc. The ball milling tank is kept in a vacuum state during ball milling to prevent oxidation of the ferrite powder.

[0021] Further, during the crushing process using a cell sonicator, the ultrasonic container needs to be placed in an ice bath to prevent the temperature from being too high during the crushing process, and the temperature is always maintained at about 10°C. In step four, after the ferrite is washed with ethanol and dried, the obtained ferrite is ground using a mortar. During the process of grafting citric acid onto the ferrite, oscillation is turned on to allow the ferrite and citric acid to fully react. After 24 h of reaction, after the ferrite is naturally settled, the upper solution is removed and deionized water is added for dilution.

[0022] Further, in step seven, the mass fraction of the functionalized ferrite added is 5, 10, 15, 30, 45 wt%, and the substrate used in the process of using magnetic induction orientation to prepare titanium carbide ferrite composite films with high orientation is a polyvinylidene fluoride film with hydrophilic properties. Different ferrite mass fraction composite films are prepared.

[0023] Further, in step seven, the tabletop of the film coating machine is always kept in a heated state, and the film coating rate is controlled at 50 mm / s.

[0024] Further, the unoriented composite film prepared in step nine includes a composite film prepared by vacuum-assisted filtration and a composite film oriented but not subjected to magnetic induction orientation, wherein the Herman's orientation factor f of the composite film prepared by suction filtration is 0.574, and the orientation factor f of the composite film not subjected to magnetic induction orientation is 0.828; in step (9), the electromagnetic shielding efficiency of the composite film not subjected to magnetic induction orientation is 50.4 dB, and the electromagnetic shielding efficiency of the composite film subjected to magnetic induction orientation is 62.8 dB, in addition, the saturation magnetization after magnetic induction orientation is 0.53 emu / g, and the saturation magnetization of the titanium carbide ferrite composite film not subjected to magnetic induction orientation is 0.22 emu / g.

[0025] Further, the application includes that the composite film subjected to magnetic induction orientation in step seven has excellent performance in electrothermal conversion and excellent electromagnetic shielding efficiency for electromagnetic waves in S, C, X and Ku bands.

[0026] Principle of the application: the application first adopts in-situ reaction of lithium fluoride and concentrated hydrochloric acid to generate hydrogen fluoride to etch MAX phase, thereby preparing high-quality titanium carbide two-dimensional nanosheets (sheet diameter 5-10 μm), and reduces the size of the ferrite through high-energy ball milling, thereby obtaining ferrite particles with reduced size and grafted with citric acid groups on the surface, stirring the functionalized ferrite and titanium carbide at room temperature to make the titanium carbide and the functionalized ferrite interact through O-H-O hydrogen bonds, using a magnetic scraper to induce orientation of the ferrite to prepare a highly oriented titanium carbide ferrite composite film, and using a heating table to dry to obtain an independent flexible titanium carbide ferrite film. The titanium carbide ferrite composite film prepared through magnetic induction orientation exhibits porosity and magnetism, and due to the pore structure of the composite film and the orientation of the magnetic particles, the titanium carbide ferrite composite film exhibits high electromagnetic shielding performance.

[0027] Meanwhile, compared with the existing methods for preparing a titanium carbide ferrite composite film material, the application has the following advantages:

[0028] I. The strategy of magnetic induction orientation is developed, so that the magnetic poles of the ferrite particles are oriented and arranged, thereby improving the saturation magnetization of the prepared composite film and enhancing the electromagnetic shielding efficiency of the film.

[0029] II. The introduction of the ferrite particles effectively improves the shielding efficiency of the material for low-frequency electromagnetic waves, and widens the frequency band of the electromagnetic shielding of the material while improving the electromagnetic shielding efficiency of the material.

[0030] III. Under the induction of an applied magnetic field, the functionalized ferrite particles arrange themselves with the same magnetic poles, and at the same time, the titanium carbide nanosheets are induced to arrange regularly, obtaining a highly oriented composite film. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A preparation method of a titanium carbide ferrite composite film material and test results of performance improvement under the action of magnetic induction orientation are shown, including the changes in the internal structure of the composite film after magnetic induction orientation: a, the preparation process of the titanium carbide ferrite composite film includes mixing and stirring the functionalized ferrite and titanium carbide, then coating on a polyvinylidene fluoride substrate by a magnetic scraper, and drying under heating conditions to obtain a flexible and independent titanium carbide ferrite composite film; b, a schematic diagram of the structure of the titanium carbide ferrite composite film and a porous structure diagram of the titanium carbide ferrite composite film observed under a transmission electron microscope; c, test of unoriented titanium carbide ferrite composite film (UAF) and unoriented titanium carbide ferrite film (UMF) and oriented titanium carbide ferrite composite film (MAF) after magnetic induction, the Herman's orientation factor f of the composite film after magnetic induction is 0.938, which is significantly improved compared with 0.828 of the unoriented titanium carbide ferrite film and 0.574 of the unoriented titanium carbide ferrite composite film; d, after magnetic induction, the saturation magnetization of the material is significantly improved compared with the composite film without magnetic induction, and the saturation magnetization of the titanium carbide ferrite composite film after magnetic induction is 0.53 emu / g; e, test of the electromagnetic shielding performance shows that the titanium carbide ferrite composite film reaches an electromagnetic shielding efficiency of 62.8 dB after magnetic induction, which is significantly improved compared with the unoriented titanium carbide composite film and the titanium carbide composite film, and at the same time, the titanium carbide ferrite composite film has a rich pore structure, and the porosity of the material after magnetic induction reaches 19.2%.

[0032] Figure 2 The effect of the regulation of the ferrite mass fraction in the magnetic induction oriented titanium carbide ferrite composite film on the performance is shown: a, the effect of the increase of the content of ferrite in the titanium carbide ferrite composite film on the saturation magnetization; b, the effect of the change of the mass fraction of ferrite on the electromagnetic shielding efficiency; c, the effect of the increase of the ferrite on the conductivity of the composite film; d, under the optimal concentration of ferrite, the saturation magnetization, conductivity, tensile strength, Young's modulus, and electromagnetic shielding efficiency of the material are improved compared with the titanium carbide film.

[0033] Figure 3The method for preparing the titanium carbide ferrite thin film material and the evidence of the magnetic induction orientation process are shown: a, Raman characterization of the ferrite in the functionalization process and the interaction between the functionalized ferrite and titanium carbide; b, X-ray photoelectron spectroscopy characterization of the interaction between titanium carbide and functionalized ferrite; c, X-ray photoelectron spectroscopy characterization of the interaction between titanium carbide and functionalized ferrite; d, the movement state and structural change of the functionalized ferrite in the carbon titanium sheet layer in the magnetic induction orientation process; e, focused ion beam processing of the titanium carbide thin film material and focused ion beam processing of the titanium carbide ferrite thin film material.

[0034] Figure 4 The method for preparing the titanium carbide ferrite composite thin film material and its application in electromagnetic shielding and electric joule heat generation process are shown: a, the magnetic induction orientation titanium carbide ferrite composite film realizes high efficient electromagnetic shielding performance compared with the titanium carbide material in 2-18 GHz; b, the electromagnetic shielding principle of the titanium carbide ferrite thin film, the multi-stage reflection and absorption are formed between the composite film layers, and the magnetic hysteresis loss and dielectric loss are also included; c, the scanning electron microscope image of the macroscopic morphology of titanium carbide and the magnetic induction orientation titanium carbide ferrite composite film; d, the magnetic induction orientation titanium carbide ferrite composite film is bent under the action of the magnetic field and serves as the bridge of the conduction circuit; e, the temperature change of the joule heat generation of the magnetic induction orientation titanium carbide ferrite film under the application of different voltages, which has high heating efficiency and recycling effect; f, the infrared image of the titanium carbide ferrite composite film under the condition of power on. DETAILED DESCRIPTION

[0035] The application will be described in detail below with reference to the drawings and specific examples. However, the following examples are only used to explain the application, and the protection scope of the application should include the entire content of the claims, and through the description of the following examples, a person skilled in the art can fully realize the entire content of the claims of the application.

[0036] The method of the application is realized as follows: Figure 1 The process schematic diagram of the preparation method of the magnetic induction orientation titanium carbide ferrite composite thin film material is shown. First, the titanium carbide gel and the functionalized ferrite are fully mixed and stirred uniformly, the developed magnetic induction orientation strategy is used to prepare the titanium carbide ferrite composite film with high orientation, the film coating device is used for preparation, the composite titanium carbide ferrite gel film is obtained, the film is dried on the film coating machine, and finally the flexible independent titanium carbide ferrite composite film is obtained. The functionalized ferrite interacts with the titanium carbide through hydrogen bond, and the magnetic induction orientation titanium carbide ferrite composite film is prepared.

[0037] The two-dimensional titanium carbide nanosheet of the application is prepared by in-situ reaction of lithium fluoride and concentrated hydrochloric acid to generate hydrogen fluoride, and then the single sheet titanium carbide material is prepared by oscillation and centrifugal stripping, and the diameter of the single sheet titanium carbide material is between 5-10 μm; the ferrite material is a zinc-manganese ferrite material, which exhibits high saturation magnetization, and the functionalized ferrite nanoparticles loaded with citric acid groups are obtained by grafting citric acid on the surface of the ferrite; the specific process of the magnetic induction orientation is that by applying a magnetic scraper, the magnetic ferrite material is induced to have the same pole arrangement of magnetic poles, so that the magnetic induction oriented titanium carbide ferrite composite thin film material with enhanced saturation magnetization is obtained.

[0038] The prepared titanium carbide ferrite thin film material has a thickness of about 15 μm.

[0039] In the implementation process of the application, the following test methods are used:

[0040] A: The tensile strength test method includes the following steps: the prepared graphene titanium carbide MXene crosslinked composite thin film is cut into a test sample with a length of 1 cm and a width of 3 mm, and the sample is fixed on a paper test template with a span of 0.5 cm, a Shimadzu AGS-X tensile tester equipped with a 100 N sensor is used to test the tensile properties of the test sample at a tensile speed of 0.1 mm / min, and the stress-strain curve of the thin film can be obtained. The tensile strength is the tensile force at the time of fracture of the test sample / the cross-sectional area of the test sample.

[0041] B: The porosity test method includes the following steps: the porosity of the thin film = 1-the measured density of the thin film / the theoretical density of the thin film, wherein the measured density of the thin film = the mass of the thin film / the volume of the thin film, and the theoretical density of the thin film is calculated according to the content of each component of the composite thin film.

[0042] C: Young's modulus test method: Young's modulus is obtained by calculating the slope of the elastic region of the stress-strain curve.

[0043] D: The test method of electromagnetic shielding is to cut the sample into a disc with a diameter of 25 mm by using a vector network analyzer.

[0044] E: The test method of the saturation magnetization of the material is to test by a physical performance comprehensive test system, cut the thin film material into a square piece with a side length of 3 mm, and set the applied magnetic field range of the physical comprehensive test system to -5000-5000 Oe.

[0045] Example 1

[0046] Into a 200 mL Teflon reagent bottle, 10 mL of deionized water was added, 30 mL of concentrated hydrochloric acid (36 wt%) was added, and stirring was performed at 400 rpm for 5 min. While stirring, 3.2 g of LiF was slowly added, and stirring was performed for 5 min. While stirring, 2.0 g of Ti3AlC2 (Jilin Yi-Yi Technology Co., Ltd.) was slowly added, and stirring was performed for 5 min. The Teflon reagent bottle was tightly closed, and the sealing part was sealed with sealing film. The heating function of the water bath was turned on, the stirring speed was adjusted to 400 rpm, and the water bath was heated to 50 o C, and the reaction was performed for 30 h. The heating was turned off, the Teflon reagent bottle was taken out of the water bath, and the temperature was cooled to room temperature. The Teflon reagent bottle was opened in a fume hood, the reaction product was added with water, and centrifugation was performed at 3500 rpm for 5 min to a pH of about 6. Oscillation was performed for 5 min, centrifugation was performed at 1500 rpm for 30 min to collect the supernatant. Centrifugation was performed at 4500 rpm for 20 min to collect the supernatant, the precipitate was taken out, and the obtained precipitate was dispersed in water to prepare a gel with a concentration of 25 mg / mL. Thus, a large flake single-layer MXene dispersion liquid with a flake size of 5-10 μm was obtained.

[0047] Example 2

[0048] 10 g of ferrite was placed in a steel ball mill jar, 200 g of steel milling balls were added for ball milling, 0.5 g of iron powder was added, the ball mill jar was sealed, the ball mill jar was subjected to vacuum treatment, and then the ball mill jar was symmetrically placed on the ball mill according to requirements. The ball milling parameters were set as follows: ball milling speed, 700 rpm; ball milling time, 12 h; and after 1 h of forward rotation, 1 h of reverse rotation. After the ball milling was completed, the ferrite powder was poured into an N-methylpyrrolidone solvent for fractionation, and a cell ultrasonic crusher was used for dispersion under the condition of 300 W for 30 min. Then, the solution after ultrasonic treatment was subjected to differential centrifugation for screening of ferrite with a suitable size. Ferrite particles with a size of 3000-6000 rpm were selected, centrifugation was performed at 3000 rpm for 10 min, the upper solution was selected, and then centrifugation was performed at 6000 rpm for 10 min, to obtain ferrite particles with a suitable size. Then, the ferrite particles were washed with ethanol to wash away the excess N-methylpyrrolidone solution, and the washing with ethanol was repeated for three times. Finally, the washed ferrite dispersion liquid was placed in an oven for drying, to obtain dried ferrite powder.

[0049] Example 3

[0050] The dried ferrite powder obtained in Example 2 was taken into a quartz mortar, the ferrite block was ground thoroughly, and then the ferrite powder was placed in a 50 mL centrifuge tube, 20 mL of deionized water was added, and ultrasonic dispersion was performed in a 100 W ultrasonic cleaner for 10 min. The dispersed ferrite powder was filtered through a 400 mesh nylon filter screen to remove large particles of ferrite. The collected ferrite deionized dispersion was dried to calibrate the concentration of ferrite therein. The ferrite was functionalized using a prepared 20 mg / mL citric acid solution. The mass of ferrite in the solution was calculated to obtain its molar mass. The ferrite and citric acid were added in a molar ratio of 3:1. The ferrite was shaken in a shaker for 24 h to allow the citric acid to be fully grafted onto the ferrite. The functionalized ferrite was obtained and characterized by thermogravimetric method. The loading of citric acid on the ferrite was 2.968 wt%. The saturation magnetization of the functionalized ferrite, the ball-milled ferrite and the ferrite raw material was tested using a physical property comprehensive test system. The saturation magnetization of the ferrite after ball milling was higher than that of the ferrite raw material. In addition, the saturation magnetization of the functionalized ferrite was not much different from that of the functionalized ferrite.

[0051] Example 4

[0052] 30 mL of the titanium carbide water dispersion prepared in Example 1 was concentrated in a centrifuge at a speed of 8000 rpm for 10 min, and the excess upper solution was removed to obtain a titanium carbide gel dispersion of 25 mg / mL. The titanium carbide gel dispersion was stirred uniformly in a strong magnetic stirrer, and a calibrated functionalized ferrite water dispersion was added. The titanium carbide was added in a mass fraction of 5, 10, 15, 30 and 45 wt%. The obtained titanium carbide functionalized ferrite gel solution was stirred uniformly at a speed of 100 rpm for 10 min to obtain a titanium carbide ferrite gel dispersion. The gas bubbles generated during the gel stirring process were removed in a vacuum defoaming machine. Then, a scraper with magnetism was used to prepare a thin film by scraping. The scraper was scraped on a polyvinylidene fluoride substrate, the heating temperature was set to 35°C, the film coating speed was 50 mm / s, and the scraper with magnetism was used for coating. During the preparation of the thin film, the ferrite particles themselves have the physical property of being easily attracted by a magnetic field, which can induce the same pole arrangement of the functionalized ferrite during the movement of the magnetic scraper. Finally, a flexible and independent titanium carbide ferrite composite film was obtained by drying under heating.

[0053] Example 5

[0054] To verify the difference between the magnetic induction orientation and the non-magnetic induction orientation of the composite film, we designed a magnetic induction orientation strategy to prepare a titanium carbide ferrite composite film and introduced a ferrite film prepared by a non-magnetic induction orientation strategy. The preparation process of the non-magnetic induction orientation titanium carbide ferrite film material is as follows: a non-magnetic glass scraper is used for scraping orientation, a composite gel is prepared according to the preparation method of the functional ferrite of 15 wt% titanium carbide ferrite gel in Example 4, and the bubbles in the gel are removed, then a glass scraper is used for scraping to prepare a non-magnetic induction orientation titanium carbide ferrite composite film, and then a titanium carbide film is prepared by a general scraping method. In the scraping preparation process, the above preparation strategies all maintain the thickness of the scraped gel film to be 800 μm. The Herman's orientation factor f of the material is calculated by wide-angle X-ray diffraction test to obtain a magnetic induction orientation titanium carbide ferrite composite film of 0.938 and a non-magnetic induction orientation composite film of 0.828.

[0055] Example 6

[0056] The films prepared by different orientation methods are cut into 3 mm squares and tested by a physical performance comprehensive test system to obtain the saturation magnetization parameters of the material. The applied magnetic field range for the test is -5000-5000 Oe, the step length of the magnetic field application is 25 Oe / s, and the magnetic hysteresis loop of the material is tested. By comparing the saturation magnetization of the composite film hysteresis loop, it can be concluded that the material has a higher saturation magnetization after magnetic induction orientation. Compared with the composite film without magnetic induction orientation of 0.22 emu / g, the saturation magnetization of the material after magnetic induction orientation increases to 0.53 emu / g.

[0057] Example 7

[0058] According to the FTIR infrared spectrum of the prepared functional ferrite (Example 3), the material exhibits obvious hydroxyl and carboxyl peaks after functionalization. In addition, the Raman spectrum of the ferrite and the composite film is characterized to obtain (a part in the middle), the characteristic peaks of the functional ferrite in the oriented and non-oriented composite films show obvious red shift, indicating that the interaction between the functional ferrite and the titanium carbide material occurs. Figure 3

[0059] Example 8

[0060] ​The electromagnetic shielding test of the composite material is tested by using a vector network analyzer, the film is cut into a circular ring with a diameter of 25 mm, the wave band range of the tested electromagnetic wave is 2-18 GHz, and the test results show that with the increase of the content of the ferrite, the electromagnetic shielding effectiveness of the composite film shows the characteristics of first increasing and then decreasing, which is mainly due to the increase of the content of the ferrite, which causes the destruction of the structure between the titanium carbide layers, and the shielding effectiveness of the electromagnetic wave decreases, and the efficiency of the magnetic induction orientation of the ferrite magnetic pole to the same pole arrangement decreases due to the increase of the content of the ferrite, so that the overall saturation magnetization of the composite film decreases.

[0061] Example 9

[0062] It is found that the composite film prepared by magnetic induction orientation has the best electromagnetic shielding effectiveness and saturation magnetization when the content of the functionalized ferrite is 15 wt%, the electrical conductivity of the material is tested by a double probe method, and the electrical conductivity of the titanium carbide ferrite composite film is 2520±170 S / cm when the mass fraction of the ferrite is 15 wt%, the electrical conductivity of the other composite films is tested, and the electrical conductivity is similar, which shows that the electrical conductivity is not the key factor affecting the electromagnetic shielding effectiveness of the material, and then the electromagnetic shielding effectiveness of the composite film with a functionalized ferrite content of 15 wt% and the titanium carbide film in the range of 2-18 GHz is compared, the introduction of the ferrite and the design of the structure significantly improve the electromagnetic shielding effectiveness of the material, in the S wave band of 2-4 GHz, the electromagnetic shielding effectiveness of the magnetic induction orientation titanium carbide ferrite composite film is 60.8 dB, and the electromagnetic shielding effectiveness of the titanium carbide film is 35.0 dB, in the C wave band of 4-8 GHz, the magnetic induction orientation titanium carbide ferrite composite film shows an electromagnetic shielding effectiveness of 61.3 dB, and the titanium carbide film shows an electromagnetic shielding effectiveness of 36.2 dB, in the X wave band of 8-12 GHz, the magnetic induction orientation titanium carbide ferrite composite film shows an electromagnetic shielding effectiveness of 62.5 dB, and the electromagnetic shielding effectiveness of the titanium carbide film is 39.8 dB, in the Ku wave band of 12-18 GHz, the magnetic induction orientation titanium carbide ferrite composite film shows an electromagnetic shielding effectiveness of 64.4 dB, and the electromagnetic shielding effectiveness of the titanium carbide film is 40.4 dB. In addition, by testing the electrothermal performance of the magnetic induction orientation titanium carbide ferrite composite film, the material has a high heating efficiency when a voltage of 3 V is applied, reaches more than 110°C under the characterization of thermal imaging, and has a good cycle effect, which is mainly due to the introduction of the ferrite which hinders the conduction efficiency of the carriers between the titanium carbide layers, so that the material has a high heat generation temperature, and the introduction of the ferrite makes the material have magnetism, which can become a gate switch under the induction of the magnetic field.

[0063] It should be noted that according to the above-mentioned embodiments of the present application, the person skilled in the art can fully realize the scope of the independent claims and dependent claims of the present application, and the implementation process and method are the same as the above-mentioned embodiments; and the part not elaborated in the present application belongs to the known technology in the art.

[0064] The above is only part of the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for producing a magnetic induction oriented titanium carbide ferrite composite film, characterized by, Comprise the following steps: Step one, the Al layer in the MAX phase is etched by the way of generating hydrogen fluoride in situ reaction of lithium fluoride and concentrated hydrochloric acid to prepare MXene titanium carbide material, the preparation process includes stirring under heating condition, washing after reaction, oscillation stripping and differential centrifugal separation, and single-layer MXene titanium carbide nanosheet water dispersion is obtained; Step two, the size of the ferrite raw material particles is reduced by using a planetary ball mill through a ball milling strategy to obtain small-size ferrite particles, the ball-milled ferrite powder is dissolved in N-methyl pyrrolidone solvent, and after ultrasonic, differential centrifugal separation and ethanol washing and drying, small-size ferrite particles with a size of 100-120 nm are obtained; Step three, the small-size ferrite in step two is dissolved in deionized water, a citric acid solution is added, and the reaction is carried out under oscillation to graft citric acid groups on the surface of the ferrite to obtain a functionalized ferrite water dispersion; Step four, the MXene titanium carbide nanosheet water dispersion in step one and the functionalized ferrite water dispersion in step three are stirred and blended to obtain a MXene titanium carbide ferrite composite gel; Step five, the MXene titanium carbide ferrite composite gel in step four is prepared into a MXene titanium carbide ferrite composite film by a magnetic induction orientation preparation strategy; In step five, the magnetic induction orientation is achieved by using a magnetic scraper, during the movement of the magnetic scraper following the automatic film coating machine, the ferrite magnetic particles are attracted by the magnetic scraper, so that the magnetic poles of the ferrite particles are rearranged, and in the process of rearranging the magnetic poles, the functional groups on the surface of the ferrite improve the orientation of the MXene titanium carbide nanosheet, and at the same time, a porous structure is created between the MXene titanium carbide layers, the substrate material used in the magnetic induction orientation process is a polyvinylidene fluoride film with hydrophilicity, the film coating rate is 50 mm / s, the heating temperature of the scraping platform is 35℃, and after water evaporation, an independent flexible magnetic induction oriented MXene titanium carbide ferrite composite film is obtained.

2. The method of claim 1, wherein the method is characterized by: In step one, the temperature for etching the MAX phase under heating condition is 50℃, the stirring rate is 500 rpm, and the reaction time is 30 h, the accordion-shaped MXene titanium carbide obtained by etching is dispersed in deionized water, and the final solution is repeatedly washed with deionized water to present a dark green color, and then oscillated for 10-30 min and subjected to differential centrifugal separation, and the water dispersion of single-layer MXene titanium carbide nanosheet is collected.

3. The method of claim 1, wherein the method further comprises the step of: 3-1) applying a magnetic field to the substrate to induce the orientation of the titanium carbide particles. In the second step, the process of reducing the ferrite size by the planetary ball mill is as follows: the mass ratio of the steel ball mill jar and the ball mill ball is 20:1, the ball mill ball and the ferrite are mixed and added into the ball mill jar, then the iron powder with the mass fraction of 5% is added to prevent the ferrite from being further oxidized during the ball milling process, and at the same time, the ball mill jar is kept in a vacuum state, the parameters of the planetary ball mill are set, the ball milling speed is 700 rpm, the ball milling time is 12 h, and the ball milling direction is changed every 1 h; after the ball milling is completed, the powder is dissolved in N-methyl pyrrolidone solvent and ultrasonic dispersion is performed on the powder by using a cell crusher, the ultrasonic power is 300 W, the ultrasonic time is 30 min, the solution with the ferrite dispersed therein is collected by differential centrifugation, the parameters of the differential centrifugation are 3000 rpm for 10 min to take the upper solution of the solution, and then 6000 rpm for 10 min to obtain the ferrite particles with appropriate size, the N-methyl pyrrolidone solvent in the ferrite is removed by using ethanol washing, the washing is repeated three times, drying is performed in an oven, and the ferrite with the ferrite size distribution of 100-120 nm is obtained.

4. The method of claim 1, wherein the method further comprises the step of: 4-1) applying a magnetic field to the substrate to induce the orientation of the titanium carbide particles. In the third step, the molar ratio of citric acid and ferrite is 1:3, the oscillation reaction is performed at a temperature of 25°C for 24 h, the rotation speed of the shaking table is set to 100 rpm, after the reaction is completed, the upper solution is removed, deionized water is added again, and the functionalized ferrite with the surface grafted citric acid groups is obtained.

5. The method of claim 1, wherein the method further comprises the step of: 5.

1. applying a magnetic field to the substrate to induce a magnetic orientation of the TiC ferromagnetic layer. In the fourth step, the rotation speed of the stirring is 400 rpm, and the stirring time is 10 min.

6. The magnetically induced oriented titanium carbide ferrite composite film obtained by the preparation method in any one of claims 1-5.

7. The magnetically induced oriented titanium carbide ferrite composite film according to claim 6, wherein: The composite film has an optimal Herman's factor of 0.

938. f 0.

938.

8. The magnetically induced oriented titanium carbide ferrite composite film according to claim 6, wherein: The functionalized ferrite content of the composite film is 15 wt%, the tensile strength is 158.7 MPa, the Young's modulus is 10.5 GPa, the saturation magnetization is 0.53 emu / g, the electrical conductivity is 2520±170 S / cm, the average electromagnetic shielding effectiveness in the frequency range of 2-18 GHz is 62.8 dB, and the thickness is 15 μm.

9. The application of the magnetically induced oriented titanium carbide ferrite composite film in the electromagnetic shielding field according to claim 6.

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