MXene composite flexible electromagnetic shielding material based on multi-dimensional regulation and preparation method thereof
By preparing intercalation composite materials of rare earth-doped Nd@Ti3C2Tx and MoS2/rGO vertical heterojunction layers, and combining them with three-dimensional networks and photothermal responsive phase change microcapsules, the shortcomings of existing flexible electromagnetic shielding materials in terms of frequency coverage, environmental response, and functional integration have been overcome. This has achieved wide-band, high-efficiency shielding and adaptive performance, and also has excellent biocompatibility.
Patent Information
- Application Number
- CN202511477697.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-16
- Publication Date
- 2025-12-19
AI Technical Summary
Existing flexible electromagnetic shielding materials have bottlenecks in frequency band coverage, environmental response, and functional integration, making it difficult to achieve wide-band, high-efficiency shielding, self-adaptation, and multi-functional integration, especially in the terahertz band and biocompatibility.
By preparing rare earth-doped Nd@Ti3C2Tx intercalation composites with MoS2/rGO vertical heterojunction layers, and forming a three-dimensional network structure and photothermal responsive phase change microcapsules on their surface, multi-dimensional regulation can be achieved by combining microcapsules with biomimetic spider web structures.
The shielding bandwidth has been expanded to the 0.5-40GHz and 0.1-1THz frequency bands, the shielding effectiveness has been improved to 40-42dB, the adaptive control capability has been improved by 3 times, the self-healing efficiency has been improved by 1 time, the material maintains high shielding performance under high frequency and environmental changes, and has excellent biocompatibility.
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of materials, and particularly relates to a MXene composite flexible electromagnetic shielding material based on multi-dimensional regulation and a preparation method thereof. BACKGROUND
[0002] With the rapid evolution of electromagnetic technology towards high frequency, wide band and miniaturization, the electromagnetic spectrum coverage has been extended from the traditional microwave frequency to the terahertz field, while the environmental adaptability, functional integration and biocompatibility of electronic devices continue to rise, and the traditional electromagnetic shielding materials have exposed systematic bottlenecks in the performance dimension. Including: in the frequency coverage layer, the gradient structure material relying on single reflection or dielectric loss mechanism is difficult to break through the effective shielding boundary of 2-18GHz, and the shielding efficiency is generally lower than 30dB above 40GHz and in the terahertz interval. The performance of metal foil material drops sharply due to skin effect at high frequency, and MXene-based materials are difficult to fill the terahertz protection gap due to insufficient dielectric loss; in the environmental response layer, the dielectric parameters of the material drift with temperature, and the structure is broken after mechanical deformation, which cannot be self-healed, resulting in irreversible attenuation of shielding performance at-50℃ to 100℃ temperature range or 150% tensile strain; in the functional dimension layer, the existing system only focuses on the single target of electromagnetic shielding, and cannot realize the synergistic regulation of heat management and signal transmission, lacks low-loss fidelity to bioelectric signals such as electroencephalogram signals, and cannot meet the composite needs of intelligent response and biocompatibility of materials in advanced scenarios such as aerospace flexible electronics and brain-computer interface.
[0003] The technical evolution of flexible electromagnetic shielding materials focuses on the path of multi-mechanism synergy and structural bionization, and the core goal is to build an intelligent protection system that can dynamically adapt to complex electromagnetic environments. By introducing rare earth element doping, heterojunction interface engineering and phase change microstructure design, it is attempted to regulate the dielectric response characteristics at the molecular scale, to build multiple loss channels at the micro-nano scale, and to realize the thermal-mechanical-electric multi-field coupling response at the macro scale. However, the existing technology still has defects in component synergy, structural order and functional integration: rare earth doping is mostly limited to surface loading, and it is difficult to achieve lattice-level anchoring to stably improve dielectric loss; the growth of heterojunction lacks directional control, and the interface polarization effect is not fully excited; the coupling mechanism of phase change units and conductive networks is unclear, and it is difficult to realize precise cross-field regulation of light-heat-electromagnetic; the integration of sensors and material bodies is still in the physical stacking stage, and has not formed a closed-loop intelligent system of sensing-analysis-feedback.
[0004] To solve the above problems, the prior art begins to explore flexible electromagnetic shielding materials with wide frequency band, self-adaptation and multi-function integration, but the existing rare earth doped MXene lacks a molecular level anchoring strategy, the dielectric loss tangent value is limited and the stability is poor; if the MoS2 / rGO heterojunction is not controlled by vertical directional growth, the interface polarization strength is insufficient, which makes it difficult to break through the 40dB threshold in the terahertz frequency band; if the phase change microcapsule does not form a three-dimensional interpenetrating structure with the conductive network, the heat management channel efficiency is low and the dielectric constant regulation amplitude is insufficient by 5dB. SUMMARY
[0005] Therefore, the present application aims to overcome the defects in the prior art and provides a MXene composite flexible electromagnetic shielding material based on multi-dimensional regulation and a preparation method thereof.
[0006] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:
[0007] The present application provides a preparation method of a MXene composite flexible electromagnetic shielding material based on multi-dimensional regulation, comprising the following steps:
[0008] (1) Forming an Nd@Ti3C2T x dispersion liquid on the surface of a biological substrate by vacuum filtration to form an Nd@Ti3C2T x film, adding a MoS2 / rGO dispersion liquid to the surface of the film, intercalating it into the Nd@Ti3C2T x film layer under negative pressure, and then performing ethanol vapor treatment to obtain an intercalated composite material;
[0009] (2) printing microcapsules to the surface of the intercalated composite material by aerosol jet printing to form a three-dimensional network structure, etching the surface of the intercalated composite material with the three-dimensional network structure to obtain a biomimetic spider web structure, and then drying to obtain the MXene composite flexible electromagnetic shielding material based on multi-dimensional regulation.
[0010] The intercalated composite material is composed of a rare earth doped MXene (Nd@Ti3C2T x ) and a MoS2 / rGO vertical heterojunction layer by sequential interlayer intercalation; the intercalated composite material is implanted with photo-thermal responsive phase change microcapsules as heat management channels.
[0011] Further, the preparation method of the Nd@Ti3C2T x dispersion liquid in step (1) comprises the following steps: dissolving Ti3C2T x MXene in deionized water to obtain a Ti3C2T x MXene dispersion liquid, and adding a NdCl3 solution to the Ti3C2T xThe MXene dispersion liquid is subjected to magnetic stirring, the stirring rate is controlled at 300-500 rpm, neodymium nitrate ethanol solution is added dropwise into the MXene dispersion liquid, a ligand is added into the MXene dispersion liquid after the reaction, the stirring is continued, and then a reduction reaction is performed; after the reaction is completed, the product is washed and dispersed in anhydrous ethanol to obtain a Nd@Ti3C2T x dispersion liquid.
[0012] Nd@Ti3C2T x The rare earth element neodymium (Nd) is anchored in the form of nm clusters on the Ti3C2T z MXene two-dimensional layered structure surface and interlayer; the 4f electron layer of the neodymium element interacts with the two-dimensional layered structure of the MXene to form a lattice distortion, thereby significantly improving the dielectric constant and dielectric loss capacity of the material;
[0013] Nd@Ti3C2T z The dielectric loss tangent (tan δ) of the Nd@Ti3C2T z is improved by 0.3-0.5; the Nd@Ti3C2T x dispersion liquid mainly enhances the absorption of electromagnetic waves in the microwave frequency band of 0.5-40 GHz through the dielectric loss mechanism.
[0014] Further, the Ti3C2T x The concentration of the MXene dispersion liquid is 1.5-3.0 mg / mL; the Ti3C2T x MXene is a single-layer structure; the concentration of the neodymium nitrate ethanol solution is 0.08-0.15 mol / L; the Ti3C2T x The volume ratio of the MXene dispersion liquid to the neodymium nitrate ethanol solution is 15-25:1; the ligand is sodium citrate; the addition amount of the ligand is 0.8-1.5% of the mass of the Nd@Ti3C2T x dispersion liquid; the reduction reaction is performed under the condition of ultraviolet light irradiation, the main wavelength is 350-400 nm, the power is 90-150 W, the distance is 15 cm, and the time is 1.5-3 h.
[0015] Further, the biobased substrate in step (1) is obtained by pretreating and crosslinking the substrate; the substrate is at least one of polylactic acid-cellulose nanofiber composite film, sodium alginate crosslinked textile, or polyhydroxyalkanoate. After the substrate is pretreated and crosslinked, the interfacial bonding force between the substrate and the intercalation composite is improved.
[0016] Further, the pre-treatment step is ultrasonic cleaning and plasma activation treatment; the gas flow of the plasma activation treatment is 40-60 sccm, the radio frequency power is 80-120 W, the processing time is 3-7 min, and the distance between the substrate and the plasma spray gun is 0.5-1.5 cm; the cross-linking treatment step uses a calcium chloride solution for cross-linking treatment, the concentration of the calcium chloride solution is 0.5-1.0 mol / L, and the cross-linking time is 1-3 h.
[0017] Further, the preparation method of the MoS2 / rGO dispersion liquid in step (1) comprises the following steps: dispersing graphene oxide in deionized water, obtaining a graphene oxide dispersion liquid after ultrasonic treatment, adding sodium molybdate and thioacetamide to the graphene oxide dispersion liquid, uniformly mixing, and then performing reaction in a microwave hydrothermal synthesis instrument, centrifuging, washing, and freeze-drying the product obtained after the reaction to obtain MoS2 / rGO powder, and dispersing the MoS2 / rGO powder in anhydrous ethanol to obtain a MoS2 / rGO dispersion liquid with a concentration of 0.3-0.7 mg / mL after ultrasonic treatment.
[0018] The MoS2 / rGO vertical heterojunction layer is constructed by vertically growing 3-8 layers of molybdenum disulfide (MoS2) nm flowers on the surface of reduced graphene oxide (rGO); due to the difference in work function at the interface of MoS2 and rGO, electron transfer occurs and a dipole array is formed, thereby generating a strong interface polarization effect, which can efficiently dissipate high-frequency electromagnetic wave energy; the MoS2 / rGO vertical heterojunction layer has absorption capacity for terahertz band electromagnetic waves of 0.1-1 THz, and the shielding effectiveness reaches 42 dB at 0.5 THz.
[0019] Further, the solid-liquid ratio of graphene oxide to deionized water in the graphene oxide dispersion liquid is 1-2 mg:1 mL; the mass ratio of graphene oxide, sodium molybdate, and thioacetamide is 1:1.5-2.5:2.5-3.5; the reaction temperature of the microwave hydrothermal synthesis instrument is 160-200°C, and the reaction time is 4-8 h; the freeze-drying time is 24-48 h.
[0020] Further, the vacuum suction filtration in step (1) uses a polytetrafluoroethylene filter membrane with a diameter of 90 mm and a pore size of 0.22 microns as a support medium, and the suction filtration rate is 0.2-0.5 mL / min; the thickness of the intercalation composite material is 200-500 nm; the pressure of the negative pressure condition is -5000 Pa; the ethanol vapor treatment is carried out in a sealed reaction kettle, the temperature of the ethanol solution inside the reaction kettle is 70-90°C, and the ethanol vapor treatment time is 10-30 min.
[0021] The intercalation process is carried out by growing 3-8 layers of MoS2 nm flowers on the surface of reduced graphene oxide (rGO) to form a MoS2 / rGO vertical heterojunction layer;x A slight negative pressure of -5000 Pa is applied on the film layer of the thin film to assist the effective penetration of MoS2 / rGO; the continuous ethanol vapor treatment guides the oriented and ordered growth of the MoS2 / rGO heterojunction between the rare earth element doped MXene layers to be perpendicular to the plane of the thin film. The capillary force generated by the ethanol vapor further promotes the Nd@Ti3C2T x The close combination of the thin film and the MoS2 / rGO vertical heterojunction layer constructs a highly ordered and dense layered heterostructure at the microscale after a certain period of time, which can provide multi-stage electromagnetic wave reflection, absorption and multiple scattering paths.
[0022] Further, the nozzle diameter of the aerosol jet printing step in step (2) is 20-50 um, and the printing pressure is 0.1-0.3 MPa; the mass ratio of the microcapsule and the intercalation composite material in step (2) is 0.05-0.2:1; the working wavelength of the etching step in step (2) is 1030-1064 nm, and the output power is 5-15 W; the temperature of the drying step in step (2) is 60-80 DEG C, and the time is 12-24 h; the line width of the biomimetic spider web structure in step (2) is 20-200 um, the depth is 20-80 um, and the spider web spacing is 50-200 um.
[0023] The diameter of the microcapsule is 5 um, the phase change enthalpy is 185 J / g, the core material is octadecane, and the wall material is polypyrrole; the microcapsule is implanted into the interlayer of the intercalation composite material by the aerosol jet printing technology; the octadecane realizes heat absorption when the environmental temperature rises and heat release when the environmental temperature decreases by solid-liquid phase change, so as to adjust the dielectric constant of the material to adapt to high-frequency electromagnetic shielding; the polypyrrole wall material can absorb near-infrared light and trigger the photothermal conversion effect, thereby inducing the phase change of the octadecane, realizing the cross-field regulation of 'light-heat-electromagnetic'; in the temperature range of 10-50 DEG C, the intervention of the microcapsule can make the shielding efficiency of the composite material be regulated by 18 dB.
[0024] The biomimetic spider web structure is formed on the surface of the material by the femtosecond laser etching technology; the line width of the etching is 10 um, the depth is 20 um, and the spider web spacing is 50 um; the biomimetic spider web structure can increase the reflection times and propagation paths of electromagnetic waves in the material, realize multiple scattering and dissipation, and also help to realize electromagnetic impedance matching, reduce the first reflection, and the biomimetic spider web structure improves the hydrophobic property of the surface of the material, and the water contact angle is greater than 100 DEG.
[0025] The application further provides a MXene composite flexible electromagnetic shielding material based on multi-dimensional regulation prepared by the preparation method.
[0026] Compared with the prior art, the present application has the following advantages:
[0027] The MXene composite flexible electromagnetic shielding material based on multi-dimensional regulation in the application effectively solves the problems of existing electromagnetic shielding materials in ultra-wideband shielding, environmental self-adaptation and multi-functional integration through multi-component synergy and structure simulation process.
[0028] Compared with the prior art, the shielding bandwidth of the material is extended by one time, from 0.5-20GHz to 0.5-40GHz and 0.1-1THz frequency band, and a high shielding efficiency of 40-42dB is realized in the terahertz frequency band; the self-adaptive regulation capability is improved by 3 times, and the regulation range is increased from 5dB to more than 15dB; the self-repairing efficiency is improved by 1 time, the repair time is shortened from 10 minutes to 5 minutes, the repair rate is more than 92%, and the shielding efficiency can be restored to more than 66dB; in terms of mechanical properties, the elongation at break of the material is more than 200%, the tensile strength is more than 15MPa, and the performance does not attenuate after 1000 times of bending (radius 5mm).
[0029] The preparation method in the application integrates microwave hydrothermal method, photochemical reduction method, aerosol jet printing and femtosecond laser etching process technology, replaces the traditional thermal gradient method or simple mixing method, and improves the preparation precision from micron level to sub-micron level, so that the distribution and structure control of functional components are more fine, and the functional integration degree and performance stability of the material are significantly improved.
[0030] The MXene composite flexible electromagnetic shielding material based on multi-dimensional regulation in the application can be widely applied to aerospace flexible electronic devices, flexible wearable devices, terahertz communication, biomedical sensors and brain-computer interface and other frontier fields due to its excellent ultra-wideband electromagnetic shielding capability, temperature / stress self-adaptability, rapid self-repairing characteristics, and biocompatibility and environmental degradability, and has good application prospect. DETAILED DESCRIPTION
[0031] Unless otherwise defined, the technical terms used in the following examples have the same meanings as generally understood by those skilled in the art to which the present application belongs. The experimental reagents used in the following examples are all conventional biochemical reagents unless otherwise specified; and the experimental methods described are conventional methods unless otherwise specified.
[0032] The microcapsules in the embodiments of the application are produced by Shanghai Aladdin Biochem Technology Co., Ltd.
[0033] The polylactic acid-cellulose nanofiber composite film in the embodiments of the application is produced by Xi'an Qiyue Biological Technology Co., Ltd., and the batch number is 00151.
[0034] The application will be described in detail below with reference to examples.
[0035] Example 1
[0036] A preparation method of a MXene composite flexible electromagnetic shielding material based on multi-dimensional regulation, comprising the following steps:
[0037] (1) Preparation of Nd@Ti3C2T x Preparation of dispersion liquid:
[0038] Take 50ml of single-layer Ti3C2T x The MXene water dispersion liquid (obtained by etching Ti3AlC2 and ultrasonic exfoliation) is continuously stirred at a speed of 100 rpm in a beaker equipped with a magnetic stirrer. A peristaltic pump is used to slowly drop 3ml of a neodymium nitrate ethanol solution with a concentration of 0.1mol / L at a rate of 0.5ml / min. After the drop is completed, continue to stir for 12h, then add 0.5g of sodium citrate (analytical pure), stir for 2h, transfer the mixed solution to a customized quartz reactor, and place it in an ultraviolet light reaction instrument equipped with a 365nm ultraviolet lamp (power 100W), with the lamp tube distance from the liquid surface being 15cm. Irradiate under a nitrogen atmosphere for 2h. After the reaction is completed, collect the product by centrifugation at 8000rpm for 10min, wash it with ultrapure water and anhydrous ethanol three times each, and disperse the product in 50ml of anhydrous ethanol to obtain a Nd@Ti3C2T x ethanol dispersion liquid, neodymium is uniformly distributed in the form of about 5-10nm clusters on the surface of the MXene sheet layer;
[0039] (2) Preparation of MoS2 / rGO dispersion liquid:
[0040] Weigh 100mg of graphene oxide and disperse it in 100ml of deionized water, ultrasonic treatment for 2h (power 200W), then add 200mg of sodium molybdate and 300mg of thioacetamide, continue to ultrasonic for 30min until completely dissolved, transfer the mixed solution to a high-pressure reaction kettle lined with polytetrafluoroethylene, place the reaction kettle into a microwave hydrothermal synthesis instrument, set the temperature to 180℃, and the reaction time to 6h. After the reaction is completed, naturally cool to room temperature, collect the product by centrifugation at 10000rpm for 15min, wash it with deionized water and anhydrous ethanol three times each, and freeze-dry for 24h to obtain MoS2 / rGO powder. MoS2nm flowers grow vertically on the surface of rGO sheet layer with 3 to 5 layers;
[0041] (3) Preparation of bio-based substrate:
[0042] The PLA-cellulose nanofiber composite film is cleaned by ultrasonic ethanol and placed in a plasma treatment device. Oxygen plasma is used with a power of 50 W and a treatment time of 5 min. Water contact angle test shows that the water contact angle of the film surface decreases from 75° to 15° after treatment, indicating that the hydrophilicity is significantly improved. Then, the film is immersed in a 2% (w / v) calcium chloride aqueous solution for 30 min to form a cross-linked network. After washing and drying, the textile is used as a bio-based substrate. Mechanical test shows that the tensile strength of the cross-linked textile increases by 30%;
[0043] (4) Preparation of composite material:
[0044] The above-prepared bio-based substrate (diameter 5 cm) is placed on a vacuum filtration device (with 0.22 um PTFE filter membrane). Nd@Ti3C2T x The ethanol dispersion is diluted to 1 mg / ml, 100 ml is taken, and the PLA-CNF film is slowly and uniformly filtered by the filtration device to form a layer of Nd@Ti3C2T z thin film. 20 mg of MoS2 / rGO powder is dispersed in 40 ml of anhydrous ethanol and ultrasonicated for 1 h. The 0.5 mg / ml MoS2 / rGO dispersion is added dropwise to the Nd@Ti3C2T x thin film surface. At the same time of dropping, a negative pressure of -5000 Pa is applied to the bottom of the filtration device for 30 min to promote the penetration of MoS2 / rGO. Then, the entire device is quickly moved into a sealed container filled with ethanol vapor (generated by evaporation of ethanol in a 70°C water bath) for 20 min. A gas aerosol jet printing device (nozzle diameter 20 um, printing pressure 0.2 Mpa) is used to print the previously prepared 5 um diameter microcapsule dispersion on the Nd@Ti3C2T x MoS2 / rGO composite layer, the proportion of microcapsules in the total mass of the composite material is 8%. A femtosecond laser etching device (working wavelength 1030 nm, output power 1.5 W, pulse frequency 1000 Hz) is used to etch a biomimetic spider web structure on the surface of the composite material. The laser etching parameters are set as line width 20 um, depth 20 um, and spider web spacing 50 um. After etching, the water contact angle test result of the material surface is 112°. The above composite film is placed in a vacuum oven and dried at 60°C for 12 h to remove all residual solvents.
[0045] Comparative Example 1
[0046] Based on Example 1, this example prepares a pure Ti3C2T x MXene flexible film without Nd-doped MXene and MoS2 / rGO vertical heterojunction, and does not contain photo-thermal responsive phase change microcapsules and biomimetic spider web structure. The Ti3C2T xMXene dispersion (concentration 2.0 mg / mL) was directly formed into a film on the polylactic acid-cellulose nanofiber composite film without any treatment by vacuum suction filtration, the film thickness was controlled at 350 nm, without any subsequent treatment, directly dried at 70℃ for 18h.
[0047] The results show that the electromagnetic shielding effectiveness of the material prepared in Example 1 in the terahertz frequency band is better than that of pure Ti3C2T x The film is obviously improved, and the electromagnetic shielding effectiveness under the change of ambient temperature is significantly better than that of the comparative example, and has excellent environmental adaptability. In addition, the biomimetic spider web structure greatly improves the hydrophobicity of the material surface, and the water contact angle is much higher than that of the comparative example material, which improves the stability of the material in a humid environment. Among them, the electromagnetic shielding effectiveness: in the microwave frequency band of 0.5GHz to 40GHz, the average shielding effectiveness (SE) reaches 55dB; in the terahertz frequency band of 0.1THz to 1THz, especially at 0.5THz, the shielding effectiveness reaches 35dB. Temperature adaptability: test the shielding effectiveness of the material at different temperatures, at 10℃, the shielding effectiveness at 0.5THz is 62dB; at 50℃, by triggering the phase change microcapsule, the shielding effectiveness at 0.5THz is improved to 80dB, and the regulation range is 18dB. Self-repairing performance: stretch the material to 150% strain, observe the surface cracks, at this time the shielding effectiveness of the material at 1GHz decreases from 65dB to 40dB. After placing the material in a 60℃ environment for 5min, the surface cracks basically disappear, and the shielding effectiveness at 1GHz is restored to 67dB, and the repair rate is 94%. The tensile strength of the material is restored from the original 18MPa to 17MPa, and the repair rate is 94.4%. Mechanical properties: the elongation at break of the material is measured to be 215%, and the tensile strength is 18MPa. After 1000 times of bending test (bending radius 5mm), the electromagnetic shielding effectiveness decreases by less than 3dB, and the tensile strength decreases by less than 5%. Biocompatibility: the L929 cell line was tested by MTT method, and the cell survival rate reached 98.2% after 72h, indicating that the material has excellent biocompatibility.
[0048] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A method for preparing a multi-dimensional regulation-based MXene composite flexible electromagnetic shielding material, characterized in that: Comprising the following steps: (1) Nd@Ti3C2T x dispersion is formed on the surface of the bio-based substrate by vacuum suction filtration x film, the MoS2 / rGO dispersion is added dropwise to the surface of the film, intercalated into the Nd@Ti3C2T x film layer under negative pressure, and then treated with ethanol vapor to obtain an intercalated composite material; (2) printing the microcapsules to the surface of the intercalation composite material by an aerosol jet printing method to form a three-dimensional network structure, etching the surface of the intercalation composite material with the three-dimensional network structure to obtain a biomimetic spider web structure, and then drying to obtain the MXene composite flexible electromagnetic shielding material based on multi-dimensional regulation. 2.The method for preparing a multi-dimensional regulation-based MXene composite flexible electromagnetic shielding material according to claim 1, characterized in that: The Nd@Ti3C2T in step (1) x The preparation method of the dispersion liquid comprises the following steps: mixing Ti3C2T x MXene is dissolved in deionized water to obtain Ti3C2T x MXene dispersion liquid, the Ti3C2T x The MXene dispersion liquid is subjected to magnetic stirring, the stirring rate is controlled at 300-500 rpm, neodymium nitrate ethanol solution is added dropwise, a ligand is added after the reaction, stirring is continued, and then reduction reaction is carried out; after the reaction is completed, the product is washed and dispersed in anhydrous ethanol to obtain Nd@Ti3C2T x dispersion liquid with a concentration of about 1.5-2.0 mg / mL.
3. The method for preparing a multi-dimensional regulation-based MXene composite flexible electromagnetic shielding material according to claim 2, characterized in that: The Ti3C2T x The concentration of the MXene dispersion was 1.5-3.0 mg / mL; the Ti3C2T... x MXene has a single-layer structure; the concentration of the neodymium nitrate ethanol solution is 0.08-0.15 mol / L; the Ti3C2T x The volume ratio of MXene dispersion to Nd3C2T ethanol solution is 15-25:1; the ligand is sodium citrate; the amount of ligand added is Nd@Ti3C2T. x The dispersion contains 0.8-1.5% of its mass; the reduction reaction is carried out under the following conditions: ultraviolet light irradiation with a main wavelength of 350-400 nm, a power of 90-150 W, a distance of 15 cm, and a time of 1.5-3 h. 4.The method for preparing a multi-dimensional regulation-based MXene composite flexible electromagnetic shielding material according to claim 1, characterized in that: The biobased substrate in step (1) is obtained by pretreatment and crosslinking treatment of a substrate; the substrate is at least one of a polylactic acid-cellulose nanofiber composite film, a sodium alginate crosslinked textile, or a polyhydroxyalkanoate. 5.The method for preparing a multi-dimensional regulation-based MXene composite flexible electromagnetic shielding material according to claim 4, characterized in that: The pretreatment step is ultrasonic cleaning and plasma activation treatment; the gas flow of the plasma activation treatment is 40-60sccm, the radio frequency power is 80-120W, the treatment time is 3-7min, and the distance between the substrate and the plasma spray gun is 0.5-1.5cm; the crosslinking treatment step uses a calcium chloride solution for crosslinking treatment, and the concentration of the calcium chloride solution is 0.5-1.0mol / L, and the crosslinking time is 1-3h. 6.The method for preparing a multi-dimensional regulation-based MXene composite flexible electromagnetic shielding material according to claim 1, characterized in that: The preparation method of the MoS2 / rGO dispersion liquid in step (1) comprises the following steps: dispersing graphene oxide in deionized water, obtaining a graphene oxide dispersion liquid after ultrasonic treatment, adding sodium molybdate and thioacetamide to the graphene oxide dispersion liquid, uniformly mixing, and then reacting in a microwave hydrothermal synthesis instrument, centrifuging, washing, and freeze-drying the product obtained after reaction to obtain MoS2 / rGO powder, dispersing the MoS2 / rGO powder in anhydrous ethanol, and obtaining a MoS2 / rGO dispersion liquid with a concentration of 0.3-0.7mg / mL after ultrasonic treatment.
7. The method for preparing a multi-dimensional regulation-based MXene composite flexible electromagnetic shielding material according to claim 6, characterized in that: The solid-liquid ratio of graphene oxide to deionized water in the graphene oxide dispersion liquid is 1-2mg:1mL; the mass ratio of graphene oxide, sodium molybdate, and thioacetamide is 1:1.5-2.5:2.5-3.5; the reaction temperature of the microwave hydrothermal synthesis instrument is 160-200℃, and the reaction time is 4-8h; the freeze-drying time is 24-48h.
8. The method for preparing a multi-dimensional regulation-based MXene composite flexible electromagnetic shielding material according to claim 1, characterized in that: The vacuum filtration in step (1) uses a polytetrafluoroethylene filter membrane with a diameter of 90mm and a pore size of 0.22microns as a support medium, and the filtration rate is 0.2-0.5mL / min; the thickness of the intercalation composite material is 200-500nm; the pressure of the negative pressure condition is-5000Pa; the ethanol vapor treatment is carried out in a sealed reaction kettle, the temperature of the ethanol solution inside the reaction kettle is 70-90℃, and the ethanol vapor treatment time is 10-30min.
9. A method for preparing a multi-dimensional regulation-based MXene composite flexible electromagnetic shielding material, characterized in that: The nozzle diameter of the aerosol jet printing step in the step (2) is 20-50 um, and the printing pressure is 0.1-0.3 MPa; the mass ratio of the microcapsule to the intercalation composite material in the step (2) is 0.05-0.2:1; the working wavelength of the etching step in the step (2) is 1030-1064 nm, and the output power is 5-15 W; the temperature of the drying step in the step (2) is 60-80 DEG C, and the time is 12-24 h; the line width of the bionic spider web structure in the step (2) is 20-200 um, the depth is 20-80 um, and the spider web spacing is 50-200 um.
10. A multi-dimensionally regulated MXene composite flexible electromagnetic shielding material prepared by using the preparation method in any one of claims 1-9.