3D printing radio frequency band dielectric near-zero material and preparation method and application thereof

Abstract

The invention relates to the technical field of dielectric near-zero materials, in particular to a 3D printing radio frequency band dielectric near-zero material and a preparation method and application thereof, and the material comprises at least one of a 3D printing PDMS / CNTs film, a PDMS / Ni-coated CNTs film, a PDMS / CoNi-coated CNTs film and a PDMS / FeCoNi-coated CNTs film. Ni (at) CNTs powder, CoNi (at) CNTs powder or FeCoNi (at) CNTs powder is synthesized on the inner wall of the carbon nano tube in situ, and then polydimethylsiloxane is used for 3D printing. Wherein the dielectric constant of the PDMS / FeCoNi-coated CNTs thin film is converted from negative to positive, and the radio frequency ENZ performance is achieved at the frequency of 53 MHz.

Description

Technical Field

[0001] The present invention relates to the technical field of dielectric near-zero materials, and specifically to a 3D-printed radio-frequency band dielectric near-zero material, a preparation method and an application thereof. Background Art

[0002] Dielectric near-zero (ENZ) materials, due to the real part of their dielectric constant changing from negative to positive or from positive to negative at the plasma frequency, thus having an extremely small dielectric constant, have attracted extensive interest from researchers in the fields of materials science and physics. These exotic ENZ materials exhibit unique properties such as enhanced optical nonlinearity, enhanced electric field, phase tunneling, pulse shaping, photon traps, etc. Therefore, ENZ materials have made great progress in many emerging fields, such as geometry-independent antennas, impedance matchers, integrated waveguide devices, electromagnetic perfect fluids, radio-frequency superconducting quantum interference devices, etc. Among the various mechanisms for realizing ENZ materials, widely used plasma materials such as conductive oxides are mainly used to achieve ENZ in the terahertz band, photon doping is mainly applied in the millimeter wave and terahertz bands, and the plasma frequency of doped semiconductors is mainly in the infrared wavelength.

[0003] However, the research on ENZ materials in the low-frequency, especially radio-frequency band, is indeed of great significance and crucial. With the development of radio-frequency electronic devices, radio-frequency ENZ materials can be combined with electronic devices to improve the performance of electronic devices. Currently, there are relatively few reports on radio-frequency ENZ materials, mainly because the plasma frequencies of most plasma materials appear in the high-frequency band, and it is difficult to reduce the plasma frequency of single-phase materials to the low-frequency. According to the effective medium theory, it is expected to reduce the plasma frequency to the radio-frequency band by preparing plasma materials and dielectric materials into a stacked structure or a composite material. This strategy essentially reduces the plasma frequency by reducing the carrier concentration of the composite material.

[0004] Currently, the strategies or mechanisms for realizing radio-frequency ENZ materials are relatively simple, and no other mechanisms for realizing radio-frequency ENZ materials have been reported. On the other hand, the currently reported radio-frequency ENZ materials are mainly thin-film materials or ceramic materials, which are difficult to adapt to applications in complex environments or scenarios. Therefore, it is urgent to explore new mechanisms and develop advanced processes to prepare radio-frequency ENZ materials in this field to meet the applications in complex scenarios, which is of great significance for promoting basic research and practical applications. Summary of the Invention

[0005] The purpose of the present invention is to provide a 3D-printed radio-frequency band dielectric near-zero material, a preparation method and an application thereof.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A 3D printed radio frequency band dielectric near-zero material, including at least one of 3D printed PDMS / CNTs film, PDMS / Ni@CNTs film, PDMS / CoNi@CNTs film and PDMS / FeCoNi@CNTs film.

[0008] The preparation method of the 3D printed radio frequency band dielectric near-zero material described in the present invention: Ni@CNTs powder, CoNi@CNTs powder or FeCoNi@CNTs powder is in-situ synthesized on the inner wall of carbon nanotubes, and then any one of CNTs powder, Ni@CNTs powder, CoNi@CNTs powder or FeCoNi@CNTs powder is mixed with polydimethylsiloxane and 3D printed.

[0009] Among them, the preparation method of the FeCoNi@CNTs powder is to dissolve cyanamide, cobalt chloride hexahydrate, nickel chloride hexahydrate and ferric chloride hexahydrate in deionized water and stir at 120 °C; then put the mixture into an oven and dry at 80 °C; after drying, put the product into a tube furnace and heat, first keep at 500 °C, then heat to 900 °C and keep; when the tube furnace cools to room temperature, take out the powder and soak it in sulfuric acid, then centrifuge and wash until the pH is neutral; finally, put the powder into a dryer and dry to obtain FeCoNi@CNTs powder.

[0010] Among them, the preparation method of the CoNi@CNTs powder is to dissolve cyanamide, cobalt chloride hexahydrate and nickel chloride hexahydrate in deionized water and stir at 120 °C; then put the mixture into an oven and dry at 80 °C; after drying, put the product into a tube furnace and heat, first keep at 500 °C, then heat to 900 °C and keep; when the tube furnace cools to room temperature, take out the powder and soak it in acid, then centrifuge and wash until the pH is neutral; finally, put the powder into a dryer and dry to obtain CoNi@CNTs powder.

[0011] Among them, the preparation method of the Ni@CNTs powder is to dissolve cyanamide and nickel chloride hexahydrate in deionized water and stir at 120 °C; then put the mixture into an oven and dry at 80 °C; after drying, put the product into a tube furnace and heat, first keep at 500 °C, then heat to 900 °C and keep; when the tube furnace cools to room temperature, take out the powder and soak it in sulfuric acid for 24 hours, then centrifuge and wash until the pH is neutral; finally, put the powder into a dryer and dry to obtain Ni@CNTs powder.

[0012] Further, use a planetary mixer to mix any one of FeCoNi@CNTs, CoNi@CNTs powder, Ni@CNTs powder, and CNTs powder with PDMS and a curing agent to prepare a 3D printing ink; use a 3D printer to print a thin film structure; cure the obtained thin film structure at 55°C to obtain a 3D printed radio frequency band dielectric near-zero material.

[0013] Further, the weight ratio of PDMS to the curing agent is 10:1.

[0014] Further, the printer is a direct ink writing 3D printer with a 1.1 mm nozzle.

[0015] The 3D printed radio frequency band dielectric near-zero material prepared by the present invention can be used in fields such as magnetic drive actuators and implantable magnetic drive electronic devices.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] The present invention designs a 3D printed radio frequency ENZ material for the first time, and studies the dielectric properties of 3D printed PDMS / CNTs, PDMS / Ni@CNTs, PDMS / CoNi@CNTs, and PDMS / FeCoNi@CNTs thin films from 1 MHz to 110 MHz. PDMS / CNTs, PDMS / Ni@CNTs, and PDMS / CoNi@CNTs all exhibit negative dielectric constants from 1 MHz to 110 MHz, and the absolute values of the negative dielectric constants decrease in turn, indicating that the plasma frequencies are all higher than 110 MHz. For PDMS / FeCoNi@CNTs, the real part of the dielectric constant changes from negative to positive, and ENZ is achieved at 53 MHz. Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the preparation process of FeCoNi@CNTs powder and 3D printed thin film.

[0019] Figure 2 Among them, (a) is the SEM image of Ni@CNTs powder. (b) is the TEM image of Ni@CNTs powder. (c) is the content of each element in Ni@CNTs characterized by SEM-EDS.

[0020] Figure 3 Among them, (a) is the SEM image of CoNi@CNTs powder. (b) is the TEM image of CoNi@CNTs powder. (c) is the content of each element in CoNi@CNTs characterized by SEM-EDS.

[0021] Figure 4 Among them, (a) is the SEM image of CNTs, and (b) is the TEM image of CNTs, and a tubular structure is observed.

[0022] Figure 5 Among them, (a) is the SEM image of FeCoNi@CNTs powder. (b) is the TEM image of FeCoNi@CNTs powder. (c) is the SEM-EDS data of FeCoNi@CNTs.

[0023] Figure 6 Among them, (a)-(f) are the TEM images and mapping images of FeCoNi@CNTs.

[0024] Figure 7 It is a physical image of the 3D-printed PDMS / FeCoNi@CNTs film.

[0025] Figure 8 Among them, (a)-(d) are the SEM images of the cross-sections of the 3D-printed PDMS / CNTs film, PDMS / Ni@CNTs film, PDMS / CoNi@CNTs film, and PDMS / FeCoNi@CNTs film, respectively.

[0026] Figure 9 It is the real part of the dielectric constant performance of the 3D-printed PDMS / CNTs film, PDMS / Ni@CNTs film, and PDMS / CoNi@CNTs film at 1 MHz - 110 MHz.

[0027] Figure 10 It is the real part of the dielectric constant performance of the 3D-printed PDMS / FeCoNi@CNTs film at 1 MHz - 110 MHz. Specific implementation manners

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] Example 1 Preparation of Ni@CNTs powder

[0030] Dissolve cyanamide (6 g) and nickel chloride hexahydrate (1.14 g) in deionized water (100 mL), and stir for 3 hours at 120 °C. Then put the mixture into an oven and dry at 80 °C for 24 hours. After drying, heat the product in a tube furnace, first hold at 500 °C for 2 hours, then heat to 900 °C and hold for 2 hours, with a heating rate of 3 °C / minute and an argon atmosphere. When the tube furnace cools to room temperature, take out the powder and soak it in 0.5 M sulfuric acid for 24 hours, then centrifuge and wash until the pH is neutral. Finally, dry the powder in a dryer at 80 °C to obtain Ni@CNTs powder.

[0031] As Figure 2 , (a) is the SEM image of Ni@CNTs powder, and a tubular structure is observed. (b) is the TEM image of Ni@CNTs powder, and it can be seen that Ni metal particles are encapsulated within the carbon nanotube structure. (c) is the content of each element in Ni@CNTs characterized by SEM-EDS, and the atomic ratio of C, N, Ni is 89.3%, 6%, 4.7%.

[0032] Preparation of CoNi@CNTs powder in Example 2

[0033] Dissolve cyanamide (6 g), cobalt chloride hexahydrate (0.57 g) and nickel chloride hexahydrate (0.57 g) in deionized water (100 mL), and stir for 3 hours at 120 °C. Then put the mixture into an oven and dry at 80 °C for 24 hours. After drying, heat the product in a tube furnace, first hold at 500 °C for 2 hours, then heat to 900 °C and hold for 2 hours, with a heating rate of 3 °C / minute and an argon atmosphere. When the tube furnace cools to room temperature, take out the powder and soak it in 0.5 M sulfuric acid for 24 hours, then centrifuge and wash until the pH is neutral. Finally, dry the powder in a dryer at 80 °C to obtain CoNi@CNTs powder.

[0034] As Figure 3 , (a) is the SEM image of CoNi@CNTs powder, and a tubular structure is observed. (b) is the TEM image of CoNi@CNTs powder, and it can be seen that CoNi alloy particles are encapsulated within the carbon nanotube structure. (c) is the content of each element in CoNi@CNTs characterized by SEM-EDS, and the atomic ratio of C, N, Co, Ni is 82.7%, 12.3%, 2.2%, 2.8%.

[0035] Preparation of FeCoNi@CNTs powder in Example 3

[0036] As Figure 1As shown, cyanamide (6 g), cobalt chloride hexahydrate (0.38 g), nickel chloride hexahydrate (0.38 g), and iron chloride hexahydrate (0.43 g) were dissolved in deionized water (100 mL) and stirred at 120 °C for 3 hours. Then the mixture was placed in an oven and dried at 80 °C for 24 hours. After drying, the product was placed in a tube furnace and heated. First, it was maintained at 500 °C for 2 hours, then heated to 900 °C and maintained for 2 hours, with a heating rate of 3 °C / minute and an argon atmosphere. When the tube furnace cooled to room temperature, the powder was taken out and soaked in 0.5 M sulfuric acid for 24 hours, then centrifuged and washed until the pH was neutral. Finally, the powder was dried in a dryer at 80 °C to obtain FeCoNi@CNTs powder.

[0037] As Figure 5 , (a) is the SEM image of FeCoNi@CNTs powder, and a tubular structure was observed. (b) is the TEM image of FeCoNi@CNTs powder, and the FeCoNi alloy particles are wrapped inside the carbon nanotube structure. (c) is the SEM-EDS data of FeCoNi@CNTs, and the atomic contents of the tested elements are 84.5% carbon, 10.3% nitrogen, 1.6% Fe, 1.6% Co, and 2% Ni.

[0038] As Figure 6 , (a)-(f) are the TEM images and mapping images of FeCoNi@CNTs. Obviously, carbon and nitrogen elements are distributed on the tubular structure, and iron, cobalt, and nickel elements are distributed on the particles.

[0039] Example 4 Preparation of 3D Printed Radio Frequency Band Dielectric Near-Zero Materials

[0040] As Figure 1 shown, FeCoNi@CNTs (or CoNi@CNTs powder, Ni@CNTs powder, CNTs powder) was mixed with PDMS and a curing agent at a rotation speed of 2000 rpm using a planetary mixer (ARE-310, Thinky) for 2 minutes to prepare 3D printing ink. The weight ratio of PDMS to the curing agent is 10:1. A direct ink writing 3D printer (Regenovo Biotechnology Co., Ltd.) with a 1.1 mm nozzle was used to print a thin film structure. The obtained thin film structure was placed at 55 °C for 24 hours to cure. The filler content of the 3D printed PDMS / CNTs, PDMS / Ni@CNTs, PDMS / CoNi@CNTs, and PDMS / FeCoNi@CNTs thin films is 30 wt%.

[0041] Among them, as Figure 4 , (a) is the SEM image of CNTs, and (b) is the TEM image of CNTs, and a tubular structure was observed.

[0042] Figure 7 Figure of the physical object of the 3D-printed PDMS / FeCoNi@CNTs film, showing good flexibility and can be folded, wound, stretched, twisted, etc.

[0043] Figure 8 Among them, (a)-(d) are SEM images of the cross-sections of the 3D-printed PDMS / CNTs film, PDMS / Ni@CNTs film, PDMS / CoNi@CNTs film, and PDMS / FeCoNi@CNTs film, respectively.

[0044] Figure 9 Figure of the real part of the dielectric constant of the 3D-printed PDMS / CNTs film, PDMS / Ni@CNTs film, and PDMS / CoNi@CNTs film at 1 MHz - 110 MHz. This performance was measured by an impedance analyzer (Agilent, 4294A). Obviously, the real part data of the dielectric constant of these three films are all negative in the frequency range of 1 MHz to 110 MHz, showing negative dielectric properties.

[0045] Figure 10 Figure of the real part of the dielectric constant of the 3D-printed PDMS / FeCoNi@CNTs film at 1 MHz - 110 MHz. This performance was measured by an impedance analyzer (Agilent, 4294A). The real part of the dielectric constant of this film changes from negative to positive at 53 MHz, achieving near-zero dielectric performance in the radio frequency band.

[0046] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A 3D printed radio frequency band dielectric near-zero material, characterized by: It includes at least one of 3D printed PDMS / CNTs film, PDMS / Ni@CNTs film, PDMS / CoNi@CNTs film and PDMS / FeCoNi@CNTs film.

2. The method for preparing 3D printed radio frequency band dielectric near-zero material according to claim 1, characterized in that: Ni@CNTs powder, CoNi@CNTs powder or FeCoNi@CNTs powder is in situ synthesized on the inner wall of the carbon nanotube, and then any one of the CNTs powder, Ni@CNTs powder, CoNi@CNTs powder or FeCoNi@CNTs powder is mixed with polydimethylsiloxane for 3D printing.

3. The method for preparing 3D printed radio frequency band dielectric near-zero material according to claim 2, characterized in that: The preparation method of the FeCoNi@CNTs powder is as follows: dissolving cyanamide, cobalt chloride hexahydrate, nickel chloride hexahydrate and ferric chloride hexahydrate in deionized water and stirring at 120°C; then putting the mixture into an oven and drying it at 80°C; after drying, putting the product into a tube furnace for heating, first keeping it at 500°C, then heating it to 900°C and keeping it; when the tube furnace is cooled to room temperature, taking out the powder and soaking it in sulfuric acid, then centrifuging and washing it until the pH is neutral; finally putting the powder into a dryer for drying, and obtaining the FeCoNi@CNTs powder.

4. The method for preparing 3D printed radio frequency band dielectric near-zero material according to claim 2, characterized in that: The preparation method of the CoNi@CNTs powder is as follows: dissolving cyanamide, cobalt chloride hexahydrate and nickel chloride hexahydrate in deionized water and stirring at 120°C; then putting the mixture into an oven and drying it at 80°C; after drying, putting the product into a tube furnace for heating, first keeping it at 500°C, then heating it to 900°C and keeping it; when the tube furnace is cooled to room temperature, taking out the powder and soaking it in acid, then centrifuging and washing it until the pH is neutral; finally putting the powder into a dryer for drying, and obtaining the CoNi@CNTs powder.

5. The method for preparing 3D printed radio frequency band dielectric near-zero material according to claim 2, characterized in that: The preparation method of the Ni@CNTs powder is as follows: dissolving cyanamide and nickel chloride hexahydrate in deionized water and stirring at 120°C; then putting the mixture into an oven and drying it at 80°C; after drying, putting the product into a tube furnace for heating, first maintaining it at 500°C, then heating it to 900°C and maintaining it; when the tube furnace is cooled to room temperature, taking out the powder and soaking it in sulfuric acid for 24 hours, then centrifuging and washing it until the pH is neutral; finally putting the powder into a dryer for drying, and thus obtaining the Ni@CNTs powder.

6. The method for preparing 3D printed radio frequency band dielectric near-zero material according to claim 2, characterized in that: Use a planetary mixer to mix any one of FeCoNi@CNTs, CoNi@CNTs powder, Ni@CNTs powder, and CNTs powder with PDMS and a curing agent to prepare a 3D printing ink; use a 3D printer to print a thin film structure; and place the obtained thin film structure at 55°C for curing to obtain a 3D printed radio frequency band dielectric near-zero material.

7. The method for preparing 3D printed radio frequency band dielectric near-zero material according to claim 6, characterized in that: The weight ratio of PDMS to curing agent was 10:

1.

8. The method for preparing 3D printed radio frequency band dielectric near-zero material according to claim 7, characterized in that: The printer is a direct ink writing 3D printer with a 1.1 mm nozzle.

9. Application of the 3D printed radio frequency band dielectric near-zero material according to claim 1 in magnetically driven actuators and implantable magnetically driven electronic devices.

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