Method for constructing microwave absorption material by loading metal phthalocyanine on MXene
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIHANG UNIV
- Filing Date
- 2024-12-11
- Publication Date
- 2026-07-14
Smart Images
Figure CN119560802B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a self-assembly method for preparing MXene-loaded phthalocyanine composite materials and their application in the field of microwave absorption. Background Technology
[0002] 5G technology, as the latest advancement in wireless communication, has achieved rapid development in various fields such as the Internet of Things, smart cities, and aerospace. It has greatly improved people's lives, providing greater efficiency and convenience. However, in addition to the numerous potential advantages of 5G technology, the accompanying electromagnetic radiation and electromagnetic pollution issues also require continued attention and research. Numerous studies have shown that long-term exposure to electronic warfare pollution can easily lead to catastrophic diseases such as leukemia and tumors, posing a serious threat to human health; electronic devices are also likely to be subject to electromagnetic interference from other devices, severely affecting the accuracy and stability of data and signals. Therefore, both human health and the stable operation of electronic devices necessitate mitigating electromagnetic hazards, and the design and development of electromagnetic wave absorbing materials (i.e., microwave absorbing materials) offer solutions to this problem.
[0003] As a novel two-dimensional material, MXene has shown promising applications in wireless communication, energy storage and conversion, electromagnetic wave absorption, and electromagnetic interference shielding. MXene possesses abundant hydrophilic functional groups (-O and -OH), excellent mechanical properties, good electrical properties, and a chemically active surface, thus exhibiting significant value in the field of electromagnetic wave absorption and making it a candidate material for preparing "thin, lightweight, wide, and strong" absorbing materials. However, the original MXene absorbers suffer from a series of problems, such as self-agglomeration, easy oxidation, a single loss mechanism, and susceptibility to impedance mismatch, which greatly limit their absorption performance and practical applications.
[0004] To further improve the microwave absorption performance and environmental adaptability of MXene, MXene-based microwave absorbing materials obtained through composition and structural design have been widely used. Reasonable composition optimization can lead to richer synergistic loss mechanisms, stronger polarization loss capabilities, and impedance matching of MXene-based microwave absorbing materials. Utilizing the synergistic advantages between the components of composite materials, multifunctionality of MXene-based materials can also be achieved, such as thermal insulation, hydrophobicity, and corrosion resistance, greatly expanding their application range in practical environments. Furthermore, constructing three-dimensional hierarchical structures through structural design and expanding the coupling scale of multi-dimensional units can enhance attenuation capabilities, providing a feasible approach for preparing ultra-lightweight, ultra-low filler content MXene-based microwave absorbing materials. However, how to select suitable filler materials to composite with the MXene matrix, ensuring microwave absorption performance while also being easy to prepare and low-cost, remains a pressing problem to be solved. Summary of the Invention
[0005] This invention is based on the inventors' discoveries regarding the following facts and problems:
[0006] Phthalocyanines are synthetic compounds with a unique 18-electron extended conjugated system. The central hydrogen atom can be replaced by a metal element, chelating with the metal within the cavity through two covalent bonds and two coordinate bonds to form a metal phthalocyanine. The electronic structure of phthalocyanines determines their exceptional stability; the strong internal coupling makes their benzene ring structure resistant to deformation, resulting in significant thermal and chemical stability. The presence of the central metal atom further contributes to their stability. This stable conjugated structure leads to very strong absorption in the 300–400 nm (Soret band) and 700 nm (Q band), facilitating the construction of multi-band absorption systems. However, through π-π supramolecular interactions, these planar and highly conjugated aromatic macrocycles tend to spontaneously organize into stacks.
[0007] Furthermore, through in-depth research, the inventors discovered that metallic phthalocyanines readily coordinate axially with other substances through a central metal, effectively preventing phthalocyanine stacking. MXene possesses abundant surface functional groups; through further functionalization, its surface groups can be axially coordinated with the central metal of metallic phthalocyanines, mitigating the stacking problem and simultaneously constructing numerous heterogeneous interfaces, facilitating electron hopping and enhancing electron transport. Therefore, functionalizing MXene and axially coordinating it with metallic phthalocyanines represents one of the future development directions for high-performance electromagnetic wave absorbing materials.
[0008] In view of this, in one aspect of the present invention, the technical problem solved by the present invention is to address the shortcomings of the prior art by introducing metal phthalocyanine into the MXene-based absorbing material system, and providing a self-assembly method for preparing MXene-metal phthalocyanine composite materials and their applications in the field of microwave absorption. This method has a simple and reproducible process, and the materials used are easy to synthesize, inexpensive, and readily mass-producible, which is beneficial for the realization of material and commercial applications. By using this method, unique metal phthalocyanine can be introduced into the interlayer and surface of MXene, bringing about multiple loss mechanisms, effectively optimizing the impedance matching of MXene, and thus enabling the preparation of high-performance composite materials for application in the field of microwave absorption, especially for constructing frequency-tunable absorbing materials.
[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for constructing electromagnetic wave absorbing materials by loading MXene with metal phthalocyanine and its application, wherein the method is as follows:
[0010] S1. Functionalization of MXene with alkaline solution
[0011] Preferably, a few layers of MXene are mixed with an alkaline solution to obtain an alkaline solution of MXene; the alkaline solution of MXene is stirred under an argon atmosphere, and then separated to obtain the functionalized MXene;
[0012] S2. Mix the metal phthalocyanine powder with the first solvent and disperse it to obtain a dispersed metal phthalocyanine solution; mix the dispersed metal phthalocyanine solution with the functionalized MXene dispersion to obtain a homogeneous solution of MXene and metal phthalocyanine.
[0013] S3. The homogeneous solution of MXene and metal phthalocyanine is ultrasonically mixed under an argon atmosphere, and the reaction is carried out by magnetic stirring to obtain an MXene-metal phthalocyanine composite solution;
[0014] S4. The MXene-metal phthalocyanine composite solution is filtered, washed, and dried to obtain the composite material.
[0015] Preferably, the alkaline solution in S1 is at least one of potassium hydroxide or sodium hydroxide; the concentration is 0.125-1.000 mol / L, preferably 0.5 mol / L, and the functionalization time is 2-12 h;
[0016] Preferably, the first solvent mentioned in S2 is selected from DMF; the functionalized MXene dispersion solution uses the first solvent as the dispersion solvent;
[0017] Preferably, the metal phthalocyanine center metal in S2 is one or more of Fe, Co, Ni, Cu, Zn, Mn, and Pb;
[0018] Preferably, in S2, the metal phthalocyanine solution is dispersed using ultrasound or a cell disruptor for a dispersion time of 10–60 min.
[0019] Preferably, the mass ratio of MXene to metal phthalocyanine in S2 is 1:1 to 1:9;
[0020] Preferably, in step S3, the metal phthalocyanine solution is mixed with the MXene solution by dropwise addition, the reaction is carried out at room temperature, the magnetic stirring speed is 300-600 r / min, and the stirring time is 10-30 h;
[0021] Preferably, in the MXene-metal phthalocyanine composite solution in S3, MXene accounts for 5% to 50% of the mass percentage of the composite solution;
[0022] Preferably, centrifugal washing is used in S4, with a rotation speed of 3000 to 10000 rpm;
[0023] Preferably, MXene-metal phthalocyanine composite materials are used in the field of microwave absorption.
[0024] Microwave-absorbing composite materials were prepared by combining MXene-metal phthalocyanine composite materials and a matrix, with a mass ratio of MXene-metal phthalocyanine composite materials to the matrix of (0.1-0.4):1.
[0025] The matrix is selected from at least one of paraffin, resin, and polyvinylidene fluoride;
[0026] The preparation method of microwave absorbing composite material includes the following steps:
[0027] (1) The MXene-metal phthalocyanine composite material and the matrix are mixed in a predetermined ratio and dispersed in an organic solvent, and ultrasonically mixed to obtain a homogeneous solution; the organic solvent is at least one of N,N-dimethylformamide (DMF) or n-hexane;
[0028] (2) The mixed solution is transferred to a glass evaporating dish and dried (preferably at 80°C) to remove the solvent to obtain a uniformly dispersed composite film. The film is then placed in a mold and hot-pressed to obtain the microwave absorbing composite material. The thickness of the resulting composite film is in the mm range, such as 1-5 mm.
[0029] The MXene-phthalocyanine composite material obtained in this invention is used to prepare microwave absorbing composite materials by combining it with a matrix. The absorption frequency range can be controlled by adjusting the ratio of MXene-phthalocyanine content, the ratio of MXene-phthalocyanine composite material to matrix content, and the film thickness (generally, the adjustable absorption frequency range is 2-18 GHz). In this experiment, the effective absorption bandwidth of the MXene-phthalocyanine composite microwave absorbing material based on a PVDF substrate is 0-4 GHz, and the reflection loss value is -10 to -60 dB.
[0030] In another aspect of the invention, a metal phthalocyanine-MXene composite material for electromagnetic wave absorption is proposed. According to an embodiment of the invention, this metal phthalocyanine-MXene composite absorbing material is prepared by the method described above for preparing metal phthalocyanine-MXene composite materials. Thus, in this metal phthalocyanine-MXene composite material, the metal phthalocyanine is axially coordinated with MXene through a central metal, and the skin effect is eliminated by the coupling between highly conductive and low-conductivity materials, improving the impedance matching of the composite material and facilitating the incidence of more electromagnetic waves. Simultaneously, a large number of heterogeneous interfaces are generated, leading to charge redistribution, generating a macroscopic electric moment, and inducing interface polarization. Furthermore, due to the different work functions of the metal phthalocyanine and MXene, a potential barrier is easily formed at the interface after coordination. The presence of this barrier results in a large interface resistance, which is conducive to charge accumulation in this region. When an external electromagnetic field is applied to the material, the positive and negative charges at the interface are driven to form local dipoles, causing a change in charge density and the appearance of an electric dipole moment. Through polarization behavior, electromagnetic wave energy is converted into heat energy and dissipated. When this composite material is used as an electromagnetic wave absorbing material, it exhibits good reflection loss capability. Experimental results show that the metal phthalocyanine-MXene composite material can be used for future high-performance electromagnetic wave absorbing materials.
[0031] Compared with the prior art, the present invention has the following advantages:
[0032] This invention prepares an MXene-metal phthalocyanine composite material by axially coordinating functionalized few-layer MXene with metal phthalocyanine through self-assembly. By combining these two different materials, the impedance matching of the composite material is improved, and a large number of heterogeneous interfaces are formed. The potential barriers formed at these interfaces induce polarization behavior, enhancing the electromagnetic wave attenuation capability of the composite material. This allows for the preparation of high-performance composite materials for application in microwave absorption, particularly for constructing frequency-tunable absorbing materials. The method is simple and reproducible, and the materials used are easy to synthesize, inexpensive, and readily mass-producible, facilitating the commercialization of the materials and devices. Attached Figure Description
[0033] Figure 1 This is a SEM image of the functionalized few-layer MXene in an embodiment of the present invention.
[0034] Figure 2 These are SEM images of few-layer MXene-loaded metal phthalocyanines in an embodiment of the present invention (a is CoPc, b is FePc, and c is CuPc).
[0035] Figure 3 This is a microwave absorption performance diagram of the MXene / CoPc (MXene to CoPc mass ratio of 1:4) composite material based on PVDF polymer matrix prepared in Example 1 of the present invention.
[0036] Figure 4 This is a microwave absorption performance diagram of the MXene / CoPc (MXene to CoPc mass ratio of 1:2) composite material based on PVDF polymer matrix prepared in Example 1 of the present invention.
[0037] Figure 5 This is a microwave absorption performance diagram of the MXene / FePc (MXene to FePc mass ratio of 1:4) composite material based on PVDF polymer matrix prepared in Example 2 of the present invention.
[0038] Figure 6 This is a microwave absorption performance diagram of the MXene / FePc composite material (MXene to FePc mass ratio of 1:2) based on the PVDF polymer matrix prepared in Example 2 of the present invention.
[0039] Figure 7 This is a microwave absorption performance diagram of the MXene / CuPc (MXene to CuPc mass ratio of 1:4) composite material based on PVDF polymer matrix prepared in Example 3 of the present invention.
[0040] Figure 8 This is a microwave absorption performance diagram of the MXene / CuPc (MXene to CuPc mass ratio of 1:2) composite material based on PVDF polymer matrix prepared in Example 3 of the present invention. Detailed Implementation
[0041] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.
[0042] Example 1
[0043] This embodiment describes a method for preparing MXene-loaded CoPc composite materials based on self-assembly.
[0044] The method is as follows:
[0045] S1. Dissolve 0.4g of MXene powder in 200mL of deionized water, add 0.5M NaOH solution, stir magnetically for 4h to functionalize MXene, and then separate the solid and liquid.
[0046] S2. When the mass ratio of MXene to CoPc is 1:4, dissolve 0.24g of CoPc in 240mL of DMF and disperse it using ultrasound or a cell disruptor to obtain a CoPc solution; when the mass ratio of MXene to CoPc is 1:2, dissolve 0.28g of CoPc in 280mL of DMF and disperse it using ultrasound or a cell disruptor to obtain a CoPc solution.
[0047] S3. When the mass ratio of MXene to CoPc is 1:4, 0.06g of functionalized MXene is dissolved in 60mL of DMF, and the CoPc solution obtained in S2 is added dropwise to the MXene solution. After ultrasonic dispersion, the solution is magnetically stirred for 20h under an argon atmosphere to obtain a homogeneous solution. When the mass ratio of MXene to CoPc is 1:2, 0.14g of functionalized MXene is dissolved in 140mL of DMF, and the CoPc solution obtained in S2 is added dropwise to the MXene solution. After ultrasonic dispersion, the solution is magnetically stirred for 20h under an argon atmosphere to obtain a homogeneous solution.
[0048] S4. The S3 solution is washed with DMF and deionized water, and then freeze-dried to obtain the composite material.
[0049] The SEM image of the functionalized MXene prepared in step S1 of this embodiment is shown below. Figure 1 As shown, after MXene is modified, the nanosheets curl and wrinkle to form a three-dimensional petal-like structure. Due to their stacking, the size further increases. Both curling and stacking are beneficial to the construction of conductive networks.
[0050] The SEM image of the composite material prepared in step S4 of this embodiment is shown below. Figure 2 As shown in Figure a, MXene retains the functionalized wrinkled morphology and large size, and CoPc was successfully loaded onto MXene.
[0051] This embodiment also provides the MXene-loaded CoPc and polymer matrix composite material prepared above. The resulting MXene-phthalocyanine composite material is used in microwave absorbing materials: the MXene-phthalocyanine composite material and the matrix are mixed in a predetermined ratio and dispersed in an organic solvent, and ultrasonically mixed to obtain a homogeneous solution; the mixed solution is transferred to a glass evaporating dish, dried (preferably at 80°C) to remove the solvent to obtain a uniformly dispersed composite film, and then the film is placed in a mold and hot-pressed to obtain the microwave absorbing composite material. Its microwave absorption performance is shown in the figure below. Figure 3 and Figure 4 As shown.
[0052] For composite materials using MXene-CoPc material (MXene to CoPc mass ratio of 1:4) as filler and PVDF as matrix:
[0053] (1) When the filler content is 10wt% (the filler content is the mass ratio of MXene-metal phthalocyanine composite material to matrix), corresponding to a thickness of 5.00mm, the minimum reflection loss of -12.24dB is achieved at 17.21GHz, and the effective absorption bandwidth is 1.22GHz; Figure 3It can be seen that its performance changes with the thickness;
[0054] (2) When the filler content is 15wt% and the corresponding thickness is 5.00mm, the minimum reflection loss of -21.43dB is achieved at 14.96GHz, and the effective absorption bandwidth is 1.76GHz; Figure 3 It can be seen that its performance changes with the thickness;
[0055] (3) When the filler content is 20wt% and the corresponding thickness is 3.00mm, the minimum reflection loss of -23.57dB is achieved at 7.28GHz, and the effective absorption bandwidth is 2.08GHz; from Figure 3 It can be seen that its performance changes with the thickness.
[0056] For composite materials using MXene-CoPc material (MXene to CoPc mass ratio of 1:2) as filler and PVDF as matrix:
[0057] (1) When the filler content is 10wt%, corresponding to a thickness of 5.00mm, the minimum reflection loss of -22.30dB is achieved at 3.76GHz, and the effective absorption bandwidth is 1.52GHz; Figure 4 It can be seen that its performance changes with the thickness.
[0058] (2) When the filler content is 15wt%, the corresponding thickness is 2.95mm, and the minimum reflection loss of -53.16dB is achieved at 6.08GHz, with an effective absorption bandwidth of 1.52GHz; from Figure 4 It can be seen that its performance changes with the thickness.
[0059] (3) When the filler content is 20wt% and the corresponding thickness is 2.00mm, the minimum reflection loss of -20.49dB is achieved at 7.94GHz, and the effective absorption bandwidth is 1.13GHz; from Figure 4 It can be seen that its performance changes with the thickness.
[0060] Example 2
[0061] This embodiment describes a method for preparing MXene-loaded FePc composite materials based on self-assembly.
[0062] The method is as follows:
[0063] S1. Dissolve 0.4g of MXene powder in 200mL of deionized water, add 0.5M NaOH solution, stir magnetically for 4h to functionalize MXene, and then separate the solid and liquid.
[0064] S2. When the mass ratio of MXene to FePc is 1:4, dissolve 0.24g of FePc in 240mL of DMF and disperse it using ultrasound or a cell disruptor to obtain a FePc solution; when the mass ratio of MXene to FePc is 1:2, dissolve 0.28g of FePc in 280mL of DMF and disperse it using ultrasound or a cell disruptor to obtain a FePc solution.
[0065] S3. When the mass ratio of MXene to FePc is 1:4, 0.06g of functionalized MXene is dissolved in 60mL of DMF, and the FePc solution obtained in S2 is added dropwise to the MXene solution. After ultrasonic dispersion, the solution is magnetically stirred for 20h under an argon atmosphere to obtain a homogeneous solution. When the mass ratio of MXene to FePc is 1:2, 0.14g of functionalized MXene is dissolved in 140mL of DMF, and the FePc solution obtained in S2 is added dropwise to the MXene solution. After ultrasonic dispersion, the solution is magnetically stirred for 20h under an argon atmosphere to obtain a homogeneous solution.
[0066] S4. The S3 solution is washed with DMF and deionized water, and then freeze-dried to obtain the composite material.
[0067] The SEM image of the functionalized MXene prepared in step S1 of this embodiment is shown below. Figure 1 As shown, after MXene is modified, the nanosheets curl and wrinkle to form a three-dimensional petal-like structure. Due to their stacking, the size further increases. Both curling and stacking are beneficial to the construction of conductive networks.
[0068] The SEM image of the composite material prepared in step S4 of this embodiment is shown below. Figure 2 As shown in Figure b, MXene retains the functionalized folded morphology and large size, and FePc was successfully loaded onto MXene.
[0069] This embodiment also provides the MXene-loaded FePc composite material and polymer matrix prepared above. The resulting MXene-phthalocyanine composite material is used in microwave absorbing materials: the MXene-phthalocyanine composite material and the matrix are mixed in a predetermined ratio and dispersed in an organic solvent, and ultrasonically mixed to obtain a homogeneous solution; the mixed solution is transferred to a glass evaporating dish, dried (preferably at 80°C) to remove the solvent to obtain a uniformly dispersed composite film, and then the film is placed in a mold and hot-pressed to obtain the microwave absorbing composite material. Its microwave absorption performance is shown in the figure. Figure 5 and Figure 6 As shown.
[0070] For composite materials using MXene-FePc material (MXene to FePc mass ratio of 1:4) as filler and PVDF as matrix:
[0071] (1) When the filler content is 10wt% and the corresponding thickness is 2.00mm, the minimum reflection loss of -8.57dB is achieved at 17.20GHz, and the effective absorption bandwidth is 0.00GHz; Figure 5 It can be seen that its performance changes with the thickness;
[0072] (2) When the filler content is 15wt% and the corresponding thickness is 3.00mm, the minimum reflection loss of -12.61dB is achieved at 11.92GHz, and the effective absorption bandwidth is 1.92GHz; from Figure 5 It can be seen that its performance changes with the thickness;
[0073] (3) When the filler content is 20wt% and the corresponding thickness is 5.00mm, the minimum reflection loss of -21.06dB is achieved at 15.84GHz, and the effective absorption bandwidth is 2.72GHz; from Figure 5 It can be seen that its performance changes with the thickness.
[0074] For composite materials using MXene-FePc material (MXene to FePc mass ratio of 1:2) as filler and PVDF as matrix:
[0075] (1) When the filler content is 10wt%, corresponding to a thickness of 4.50mm, the minimum reflection loss of -39.66dB is achieved at 17.36GHz, and the effective absorption bandwidth is 1.60GHz; Figure 6 It can be seen that its performance changes with the thickness.
[0076] (2) When the filler content is 15wt%, the corresponding thickness is 4.50mm, and the minimum reflection loss of -36.64dB is achieved at 16.08GHz, with an effective absorption bandwidth of 1.76GHz; from Figure 6 It can be seen that its performance changes with the thickness.
[0077] (3) When the filler content is 20wt% and the corresponding thickness is 4.00mm, the minimum reflection loss of -27.71dB is achieved at 15.84GHz, and the effective absorption bandwidth is 1.84GHz; from Figure 6 It can be seen that its performance changes with the thickness.
[0078] Example 3
[0079] This embodiment describes a method for preparing MXene-loaded CuPc composite materials based on self-assembly.
[0080] The method is as follows:
[0081] S1. Dissolve 0.4g of MXene powder in 200mL of deionized water, add 0.5M NaOH solution, stir magnetically for 4h to functionalize MXene, and then separate the solid and liquid.
[0082] S2. When the mass ratio of MXene to CuPc is 1:4, dissolve 0.24g of CuPc in 240mL of DMF and disperse it using ultrasound or a cell disruptor to obtain a CuPc solution; when the mass ratio of MXene to CuPc is 1:2, dissolve 0.28g of CuPc in 280mL of DMF and disperse it using ultrasound or a cell disruptor to obtain a CuPc solution.
[0083] S3. When the mass ratio of MXene to CuPc is 1:4, 0.06g of functionalized MXene is dissolved in 60mL of DMF, and the CuPc solution obtained in S2 is added dropwise to the MXene solution. After ultrasonic dispersion, the solution is magnetically stirred for 20h under an argon atmosphere to obtain a homogeneous solution. When the mass ratio of MXene to CuPc is 1:2, 0.14g of functionalized MXene is dissolved in 140mL of DMF, and the CuPc solution obtained in S2 is added dropwise to the MXene solution. After ultrasonic dispersion, the solution is magnetically stirred for 20h under an argon atmosphere to obtain a homogeneous solution.
[0084] S4. The S3 solution is washed with DMF and deionized water, and then freeze-dried to obtain the composite material.
[0085] The SEM image of the functionalized MXene prepared in step S1 of this embodiment is shown below. Figure 1 As shown, after MXene is modified, the nanosheets curl and wrinkle to form a three-dimensional petal-like structure. Due to their stacking, the size further increases. Both curling and stacking are beneficial to the construction of conductive networks.
[0086] The SEM image of the composite material prepared in step S4 of this embodiment is shown below. Figure 2 As shown in Figure c, MXene retains the functionalized folded morphology and large size, and CuPc was successfully loaded onto MXene.
[0087] This embodiment also provides the MXene-supported CuPc and polymer matrix composite material prepared above. The resulting MXene-phthalocyanine composite material is used in microwave absorbing materials: the MXene-phthalocyanine composite material and the matrix are mixed in a predetermined ratio and dispersed in an organic solvent, and ultrasonically mixed to obtain a homogeneous solution; the mixed solution is transferred to a glass evaporating dish, dried (preferably at 80°C) to remove the solvent to obtain a uniformly dispersed composite film, and then the film is placed in a mold and hot-pressed to obtain the microwave absorbing composite material. Its microwave absorption performance is shown in the figure. Figure 7 and Figure 8 As shown.
[0088] For composite materials using MXene-CuPc material (MXene to CuPc mass ratio of 1:4) as filler and PVDF as substrate:
[0089] (1) When the filler content is 10wt% and the corresponding thickness is 4.50mm, the minimum reflection loss of -35.57dB is achieved at 5.12GHz, and the effective absorption bandwidth is 2.80GHz; Figure 7 It can be seen that its performance changes with the thickness;
[0090] (2) When the filler content is 15wt% and the corresponding thickness is 5.00mm, the minimum reflection loss of -22.79dB is achieved at 4.32GHz, and the effective absorption bandwidth is 2.00GHz; from Figure 7 It can be seen that its performance changes with the thickness;
[0091] (3) When the filler content is 20wt% and the corresponding thickness is 1.75mm, the minimum reflection loss of -29.96dB is achieved at 10.48GHz, and the effective absorption bandwidth is 2.24GHz; from Figure 7 It can be seen that its performance changes with the thickness.
[0092] For composite materials using MXene-CuPc material (MXene to CuPc mass ratio of 1:2) as filler and PVDF as substrate:
[0093] (1) When the filler content is 10wt%, corresponding to a thickness of 3.50mm, the minimum reflection loss of -39.98dB is achieved at 5.68GHz, and the effective absorption bandwidth is 1.28GHz; Figure 8 It can be seen that its performance changes with the thickness.
[0094] (2) When the filler content is 15wt%, the corresponding thickness is 1.27mm, and the minimum reflection loss of -42.96dB is achieved at 12.56GHz, with an effective absorption bandwidth of 2.40GHz; from Figure 8It can be seen that its performance changes with the thickness.
[0095] (3) When the filler content is 20wt% and the corresponding thickness is 1.50mm, the minimum reflection loss of -14.00dB is achieved at 8.16GHz, and the effective absorption bandwidth is 1.04GHz; from Figure 8 It can be seen that its performance changes with the thickness.
[0096] The above description is merely illustrative of embodiments of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.
Claims
1. An application of an MXene-supported metal phthalocyanine composite material, characterized in that, In the field of microwave absorption, the preparation method of MXene-supported metal phthalocyanine composite material includes the following steps: S1. Functionalizing MXene with an alkaline solution; mixing a few-layer MXene with an alkaline solution to obtain an alkaline solution of MXene; stirring the alkaline solution of MXene under an argon atmosphere, and then separating to obtain the functionalized MXene; the alkali is at least one of potassium hydroxide or sodium hydroxide; the concentration of the alkaline solution is 0.125-1.000 mol / L, and the functionalization time is 2-12 h; S2. Mix the metal phthalocyanine powder with the first solvent and disperse it to obtain a dispersed metal phthalocyanine solution; mix the dispersed metal phthalocyanine solution with the functionalized MXene dispersion to obtain a homogeneous solution of MXene and metal phthalocyanine; the first solvent is selected from DMF; the functionalized MXene dispersion uses the first solvent as the dispersion solvent; disperse the metal phthalocyanine solution using ultrasound or a cell disruptor for 10-60 min; the mass ratio of MXene to metal phthalocyanine is 1:1 to 1:9; S3. The homogeneous solution of MXene and metal phthalocyanine is ultrasonically mixed under an argon atmosphere, and the reaction is carried out by magnetic stirring to obtain an MXene-metal phthalocyanine composite solution; the metal phthalocyanine solution is added dropwise to the MXene solution, the reaction is carried out at room temperature, the magnetic stirring speed is 300~600 r / min, and the stirring time is 10-30 h; in the MXene-metal phthalocyanine composite solution, MXene accounts for 5%~50% of the mass percentage of the composite solution; S4. The MXene-metal phthalocyanine composite solution is filtered, washed, and dried to obtain the composite material; In MXene-loaded metal phthalocyanine composites, the metal phthalocyanine is axially coordinated with MXene through a central metal. The coupling between the highly conductive and low-conductivity materials eliminates the skin effect, improves the impedance matching of the composite material, and facilitates the incidence of more electromagnetic waves. At the same time, a large number of heterogeneous interfaces are generated, leading to charge redistribution, generating macroscopic electric moments, and inducing interface polarization. Meanwhile, due to the different work functions of metal phthalocyanine and MXene, a potential barrier is easily formed at the interface after coordination. The presence of the barrier leads to interface resistance, which is conducive to charge accumulation in this region. When an external electromagnetic field is applied to the material, the positive and negative charges at the interface are driven to form local dipoles, resulting in changes in charge density and the appearance of electric dipole moments.
2. The application according to claim 1, characterized in that, The concentration of the alkaline solution in S1 is 0.5 mol / L.
3. The application according to claim 1, characterized in that, The metal phthalocyanine center metal mentioned in S2 is one or more of Fe, Co, Ni, Cu, Zn, Mn, and Pb.
4. The application according to claim 1, characterized in that, In S4, centrifugal washing is used, with a rotation speed of 3000~10000 rpm.
5. The application according to claim 1, characterized in that, Microwave-absorbing composite materials were prepared by combining MXene-metal phthalocyanine composite materials and a matrix, with a mass ratio of MXene-metal phthalocyanine composite materials to the matrix of (0.1-0.4):
1. The matrix is selected from at least one of paraffin, resin, and polyvinylidene fluoride.
6. The application according to claim 5, characterized in that, The preparation method of microwave absorbing composite material includes the following steps: (1) The MXene-metal phthalocyanine composite material and the matrix are mixed in a predetermined ratio and dispersed in an organic solvent, and ultrasonically mixed to obtain a homogeneous solution; the organic solvent is at least one of N,N-dimethylformamide (DMF) or n-hexane; (2) The mixed solution is transferred to a glass evaporating dish, dried to remove the solvent and obtain a uniformly dispersed composite film. The film is then placed in a mold and hot-pressed to obtain the microwave absorbing composite material. The thickness of the resulting composite film is on the order of mm. The absorption frequency band was controlled by adjusting the ratio of MXene and metal phthalocyanine, the ratio of MXene-metal phthalocyanine composite material to matrix, and the film thickness. The controlled absorption frequency band range was 2-18 GHz.