Preparation method of a dielectrically adjustable three-dimensional hierarchical nanocapsule absorbing material

Abstract

The invention discloses a preparation method of a dielectrically adjustable three-dimensional hierarchical nanocapsule wave-absorbing material. A three-dimensional hierarchical nanostructure formed by randomly intersecting nickel (Ni) nanosheets is prepared by reducing a nickel salt through a one-step polyol solvothermal method. Then, in situ polymerization is used to coat a polystyrene (PS) shell layer modified by graphene quantum dots (GQDs) on the surface of the magnetically graded Ni core, thereby obtaining a Ni / GQDs / PS three-dimensional hierarchical nanocapsule absorbing material. . The invention improves the multiple scattering and microwave permeability of the easily magnetized surface through the geometric effect and anisotropy of the Ni hierarchical structure, and realizes three-dimensional magnetic loss enhancement; the graded Ni core is coated with the GQDs / PS shell, and the polarity Combined with non-polar materials, the microwave dielectric constant can be adjusted, and the dielectric loss, impedance matching, and absorption frequency band can be modulated. At the same time, it can effectively prevent the oxidation of the Ni core and realize the adjustable microwave absorption performance of the material.

Description

technical field

[0001] The invention relates to a method for preparing a composite wave-absorbing material with adjustable performance, in particular to a method for preparing a dielectrically adjustable three-dimensional graded nanocapsule wave-absorbing material, which belongs to the field of wave-absorbing functional materials. Background technique

[0002] With the miniaturization and high-frequency development of electronic devices, electromagnetic interference and electromagnetic radiation have seriously affected social production and human health. Electromagnetic shielding and electromagnetic absorption have therefore become hot issues in civilian and military related fields. In the past ten years, ferromagnetic metals and alloys have become a research hotspot in the field of microwave-absorbing materials due to their high saturation magnetization, small hysteresis coefficient, and high microwave permeability. However, with the improvement of electromagnetic compatibi...

Examples

Embodiment 1

[0049] 1. Dissolve 3 mmol of nickel acetate tetrahydrate and 1 g of polyethylene glycol 4000 in 20 mL of ethylene glycol, and stir magnetically at 80 ° C for 20 min until completely dissolved to obtain a clear solution 1;

[0050] 2. Add 0.045mol of sodium hydroxide to 10mL of ethylene glycol, and stir with magnetic force at 80°C for 20min until completely dissolved to obtain a clear solution 2;

[0051] 3. Fully mix solution 1 and solution 2 and stir evenly, transfer to a 50ml polytetrafluoroethylene reactor lining, and put it into a stainless steel shell, react at 200°C for 8 hours, take it out after cooling to room temperature, and remove the product Use a magnetic field to separate out, and use distilled water and absolute ethanol to wash 3 times respectively, obtain the Ni hierarchical nano core;

[0052] 4. Redisperse the graded nano-Ni obtained in step 3 into deionized water, add 1g of polyvinylpyrrolidone (PVP) for ultrasonication and disperse evenly;

[0053] 5. Use ...

Embodiment 2

[0059] 1. Dissolve 3 mmol of nickel acetate tetrahydrate and 1 g of polyethylene glycol 4000 in 20 mL of ethylene glycol, and stir magnetically at 80 ° C for 20 min until completely dissolved to obtain a clear solution 1;

[0060] 2. Add 0.045mol flaky sodium hydroxide to 10mL ethylene glycol, and stir magnetically at 80°C for 20min until it is completely dissolved to obtain a clear solution 2;

[0061] 3. Fully mix solution 1 and solution 2 and stir evenly, transfer to a 50ml polytetrafluoroethylene reactor lining, and put it into a stainless steel shell, react at 200°C for 8 hours, take it out after cooling to room temperature, and remove the product Use a magnetic field to separate out, and use distilled water and absolute ethanol to wash 3 times respectively, obtain the Ni hierarchical nano core;

[0062] 4. Redisperse the graded nano-Ni obtained in step 3 into deionized water, add 1g of polyvinylpyrrolidone (PVP) for ultrasonication and disperse evenly;

[0063] 5. Use a...

Embodiment 3

[0069] 1. Dissolve 3 mmol of nickel acetate tetrahydrate and 1 g of polyethylene glycol 4000 in 20 mL of ethylene glycol, and stir magnetically at 80 ° C for 20 min until completely dissolved to obtain a clear solution 1;

[0070] 2. Add 0.045mol flaky sodium hydroxide to 10mL ethylene glycol, and stir magnetically at 80°C for 20min until it is completely dissolved to obtain a clear solution 2;

[0071] 3. Fully mix solution 1 and solution 2 and stir evenly, transfer to a 50ml polytetrafluoroethylene reactor lining, and put it into a stainless steel shell, react at 200°C for 8 hours, take it out after cooling to room temperature, and remove the product Use a magnetic field to separate out, and use distilled water and absolute ethanol to wash 3 times respectively, obtain the Ni hierarchical nano core;

[0072] 4. Redisperse the graded nano-Ni obtained in step 3 into deionized water, add 1g of polyvinylpyrrolidone (PVP) for ultrasonication and disperse evenly;

[0073] 5. Use a...

technical field

[0001] The invention relates to a method for preparing a composite wave-absorbing material with adjustable performance, in particular to a method for preparing a dielectrically adjustable three-dimensional graded nanocapsule wave-absorbing material, which belongs to the field of wave-absorbing functional materials. Background technique

[0002] With the miniaturization and high-frequency development of electronic devices, electromagnetic interference and electromagnetic radiation have seriously affected social production and human health. Electromagnetic shielding and electromagnetic absorption have therefore become hot issues in civilian and military related fields. In the past ten years, ferromagnetic metals and alloys have become a research hotspot in the field of microwave-absorbing materials due to their high saturation magnetization, small hysteresis coefficient, and high microwave permeability. However, with the improvement of electromagnetic compatibi...

Examples

Embodiment 1

[0049] 1. Dissolve 3 mmol of nickel acetate tetrahydrate and 1 g of polyethylene glycol 4000 in 20 mL of ethylene glycol, and stir magnetically at 80 ° C for 20 min until completely dissolved to obtain a clear solution 1;

[0050] 2. Add 0.045mol of sodium hydroxide to 10mL of ethylene glycol, and stir with magnetic force at 80°C for 20min until completely dissolved to obtain a clear solution 2;

[0051] 3. Fully mix solution 1 and solution 2 and stir evenly, transfer to a 50ml polytetrafluoroethylene reactor lining, and put it into a stainless steel shell, react at 200°C for 8 hours, take it out after cooling to room temperature, and remove the product Use a magnetic field to separate out, and use distilled water and absolute ethanol to wash 3 times respectively, obtain the Ni hierarchical nano core;

[0052] 4. Redisperse the graded nano-Ni obtained in step 3 into deionized water, add 1g of polyvinylpyrrolidone (PVP) for ultrasonication and disperse evenly;

[0053] 5. Use ...

Embodiment 2

[0059] 1. Dissolve 3 mmol of nickel acetate tetrahydrate and 1 g of polyethylene glycol 4000 in 20 mL of ethylene glycol, and stir magnetically at 80 ° C for 20 min until completely dissolved to obtain a clear solution 1;

[0060] 2. Add 0.045mol flaky sodium hydroxide to 10mL ethylene glycol, and stir magnetically at 80°C for 20min until it is completely dissolved to obtain a clear solution 2;

[0061] 3. Fully mix solution 1 and solution 2 and stir evenly, transfer to a 50ml polytetrafluoroethylene reactor lining, and put it into a stainless steel shell, react at 200°C for 8 hours, take it out after cooling to room temperature, and remove the product Use a magnetic field to separate out, and use distilled water and absolute ethanol to wash 3 times respectively, obtain the Ni hierarchical nano core;

[0062] 4. Redisperse the graded nano-Ni obtained in step 3 into deionized water, add 1g of polyvinylpyrrolidone (PVP) for ultrasonication and disperse evenly;

[0063] 5. Use a...

Embodiment 3

[0069] 1. Dissolve 3 mmol of nickel acetate tetrahydrate and 1 g of polyethylene glycol 4000 in 20 mL of ethylene glycol, and stir magnetically at 80 ° C for 20 min until completely dissolved to obtain a clear solution 1;

[0070] 2. Add 0.045mol flaky sodium hydroxide to 10mL ethylene glycol, and stir magnetically at 80°C for 20min until it is completely dissolved to obtain a clear solution 2;

[0071] 3. Fully mix solution 1 and solution 2 and stir evenly, transfer to a 50ml polytetrafluoroethylene reactor lining, and put it into a stainless steel shell, react at 200°C for 8 hours, take it out after cooling to room temperature, and remove the product Use a magnetic field to separate out, and use distilled water and absolute ethanol to wash 3 times respectively, obtain the Ni hierarchical nano core;

[0072] 4. Redisperse the graded nano-Ni obtained in step 3 into deionized water, add 1g of polyvinylpyrrolidone (PVP) for ultrasonication and disperse evenly;

[0073] 5. Use a...

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