阅读说明：本技术 一种具有可谐调吸波性能的材料及其制备方法 (Material with tunable wave absorption performance and preparation method thereof ) 是由 王广胜 高珊 于 2019-11-05 设计创作，主要内容包括：本发明涉及一种具有可谐调吸波性能的材料,所述材料为二维碳基负载镧系稀土氧化物(CN-REOs)纳米材料与聚偏氟乙烯(PVDF)的复合材料(CN-REOs/PVDF),其包括少量氮掺杂的具有部分类石墨相氮化碳(g-C<Sub>3</Sub>N<Sub>4</Sub>)结构的二维碳基和纳米尺度的镧系稀土氧化物。本发明还涉及所述吸波材料的制备方法。本发明的吸波材料具有优异的吸波性能和可谐调性。(The invention relates to a material with tunable wave absorption performance, which is a composite material (CN-REOs/PVDF) of a two-dimensional carbon-based load lanthanide rare earth oxide (CN-REOs) nano material and polyvinylidene fluoride (PVDF), and comprises a small amount of nitrogen-doped carbon nitride (g-C) with a partial graphite-like phase 3 N 4 ) Two-dimensional carbon-based and nanoscale lanthanide rare earth oxides of structure. The invention also relates to a preparation method of the wave-absorbing material. The wave-absorbing material has excellent wave-absorbing performance and tunability.)

1. The material with the tunable wave absorption performance is characterized in that the wave absorption material is a composite material (CN-REOs/PVDF) of a two-dimensional carbon-based lanthanide rare earth oxide (CN-REOs) nano material and polyvinylidene fluoride (PVDF), and the composite material comprises a small amount of nitrogen-doped carbon nitride (g-C) with a partial graphite-like phase₃N₄) Two-dimensional carbon-based and nanoscale lanthanide rare earth oxides of structure.

2. The material according to claim 1, characterized in that said lanthanide rare earth oxide is selected from the group consisting of lanthanum oxide (La)₂O₃) Cerium oxide (CeO)₂) Praseodymium oxide (Pr)₆O₁₁) Neodymium oxide (Nd)₂O₃) Samarium oxide (Sm)₂O₃) Europium oxide (Eu)₂O₃) Gadolinium oxide (Gd)₂O₃) Terbium oxide (TbO)_1.81) Dysprosium oxide (Dy)₂O₃) Erbium oxide (Er)₂O₃) Thulium oxide (Tm)₂O₃) Ytterbium oxide (Yb)₂O₃) And lutetium oxide (Lu)₂O₃)。

3. The material according to claim 1 or 2, characterized in that the two-dimensional carbon-based supported lanthanide rare earth oxide (CN-REOs) is prepared by feeding a carbon source of melamine to a hydrated rare earth nitrate in a molar mass ratio of 32: 7.

4. Material according to any one of claims 1 to 3, characterized in that the hydrated rare earth nitrate is chosen from lanthanum nitrate hexahydrate (La (NO)₃)₃·6H₂O), cerium nitrate hexahydrate (Ce (NO)₃)₃·6H₂O), praseodymium nitrate hexahydrate (Pr (NO)₃)₃·6H₂O), neodymium nitrate hexahydrate (Nd (NO)₃)₃·6H₂O), samarium nitrate hexahydrate (Sm (NO)₃)₃·6H₂O), europium nitrate hexahydrate (Eu (NO)₃)₃·6H₂O), gadolinium nitrate hexahydrate (Gd (NO)₃)₃·6H₂O), terbium nitrate hexahydrate (Tb (NO)₃)₃·6H₂O), dysprosium nitrate hexahydrate (Dy (NO)₃)₃·6H₂O), erbium nitrate hexahydrate (Er (NO)₃)₃·6H₂O), thulium nitrate hexahydrate (Tm (NO)₃)₃·6H₂O), ytterbium nitrate pentahydrate (Yb (NO)₃)₃·5H₂O) and lanthanum nitrate hexahydrate (Lu (NO)₃)₃·6H₂O)。

5. The material according to any one of claims 1 to 4, which has use of increasing the wave absorption amount and widening the effective absorption frequency width.

6. The material according to any one of claims 1 to 5, wherein the tunable wave absorbing property is controllable in absorption peak position, effective absorption frequency range and width.

7. A method of making the material of any one of claims 1-6, comprising the steps of:

step one, preparing a two-dimensional carbon-based lanthanide rare earth oxide-loaded nanocomposite material:

(1) adding 1.0g F127 into 40mL of water, placing the water in a water bath at 40 ℃, stirring for 1h, adding 0.7mmol of hydrated rare earth nitrate, and stirring for 2 h;

(2) dissolving 3.2mmol of melamine in 100mL of water at 80 ℃;

(3) mixing the two solutions, stirring in a water bath at 60 ℃ until the solution is evaporated to dryness, placing the evaporated solid in a tubular furnace, and sintering under the protection of nitrogen, wherein the sintering procedure is as follows: heating from 20 ℃ to 350 ℃ at a heating rate of 1 ℃/min, and then preserving heat for 3 h; then heating from 350 ℃ to 850 ℃ at the heating rate of 2 ℃/min, and then preserving heat for 2 h; naturally cooling to room temperature to obtain black solid powder, namely the two-dimensional carbon-based lanthanide rare earth oxide-loaded nano composite material;

secondly, preparing a composite material of a two-dimensional carbon-based lanthanide rare earth oxide-loaded nano composite material and polyvinylidene fluoride (PVDF):

(1) weighing the two-dimensional carbon-based supported lanthanide rare earth oxide nanocomposite and PVDF according to the mass ratio of 3: 37-3: 7, wherein the total mass is 0.15 g;

(2) dissolving weighed PVDF in 15mL of N, N-dimethylformamide, performing ultrasonic treatment until a transparent mixed solution is obtained, dissolving weighed two-dimensional carbon-based lanthanide rare earth oxide-loaded nano composite particles in the mixed solution, and mechanically stirring to obtain a black suspension;

(3) and transferring the prepared mixed solution into an evaporating dish, and placing the evaporating dish in an oven at 70 ℃ for 4h to evaporate the solvent to obtain the two-dimensional carbon-based composite film loaded with the lanthanide rare earth oxide and the PVDF.

The technical field is as follows:

the invention relates to a material with tunable wave absorption performance, which is a composite material (CN-REOs/PVDF) of a two-dimensional carbon-based load lanthanide rare earth oxide (CN-REOs) nano material and polyvinylidene fluoride (PVDF), and belongs to the technical field of nano materials. The invention also relates to a preparation method of the material.

Technical background:

in recent years, with the rapid development of electronic technology, the wide application of wireless communication devices, computers, household appliances and the like brings convenience to people and brings electromagnetic radiation hazard. With the increasing demand of people for green life, the electromagnetic radiation hazard has gradually attracted people's attention, and after water pollution, atmospheric pollution and noise pollution, the electromagnetic radiation pollution has been recognized as the fourth pollution by the world. In order to reduce the harm caused by electromagnetic radiation, the preparation of the high-performance wave-absorbing material is very important.

The wave absorbing material can introduce electromagnetic waves into its interior and attenuate and dissipate electromagnetic energy in two ways, one is to convert the electromagnetic energy into other energy such as heat energy, and the other is to cancel the amplitudes of the electromagnetic waves by utilizing the destructive interference between the electromagnetic waves.

Impedance matching and attenuation theory are two important factors determining the electromagnetic wave absorption performance of the material. The complex dielectric constant epsilon '-j epsilon' and the complex permeability mu '-j mu' of the material directly influence the wave absorbing performance of the material. The interface impedance is reduced by adjusting the dielectric-magnetic parameters of the material, and the microwave loss is increased, so that an effective way for obtaining an ideal wave absorber is provided. At present, the first problem of the wave-absorbing material is to solve the problems of light weight, broadband absorption, and controllable absorption position and bandwidth. In recent years, graphene, which is a non-negligible member of two-dimensional carbon materials, has been widely used in the fields of photocatalysis, hydrogen storage, biology, wave absorption, etc. due to its high theoretical surface area, high electrical conductivity, high electron mobility, high stability and other good physicochemical properties. However, with the progress of research, researchers find that the application of graphene in the field of wave absorption is limited by the defects of ultrahigh dielectric property, high energy consumption, easiness in agglomeration, difficulty in impedance matching and the like in the preparation process of the graphene. Therefore, it is urgent to find a novel two-dimensional carbon-based wave-absorbing material and a preparation method thereof.

The method aims to overcome the defects of complicated preparation process, single property and uncontrollable wave absorption performance of a two-dimensional carbon-based material represented by graphene, and provides a method for preparing a two-dimensional carbon-based supported lanthanide rare earth oxide nanocomposite by adopting a simple solvothermal-sintering method, so that a wave-absorbing material with excellent and tunable performance is obtained.

The invention content is as follows:

the invention relates to a material with tunable wave absorption performance, which is characterized in thatThe material is a composite material (CN-REOs/PVDF) of a two-dimensional carbon-based load lanthanide rare earth oxide (CN-REOs) nano material and polyvinylidene fluoride (PVDF), and comprises a small amount of nitrogen-doped carbon nitride (g-C) with a partial graphite-like phase₃N₄) Two-dimensional carbon-based and nanoscale lanthanide rare earth oxides of structure. Taking two-dimensional carbon-based rare earth cerium oxide (CN-Ce) as an example, the two-dimensional carbon-based rare earth cerium oxide comprises a small amount of nitrogen-doped carbon nitride (g-C) with a partial graphite-like phase₃N₄) Two-dimensional carbon based and nano-scale cerium oxide of structure. The invention also relates to a preparation method of the material.

Preferably, the lanthanide rare earth oxide is selected from lanthanum oxide (La)₂O₃) Cerium oxide (CeO)₂) Praseodymium oxide (Pr)₆O₁₁) Neodymium oxide (Nd)₂O₃) Samarium oxide (Sm)₂O₃) Europium oxide (Eu)₂O₃) Gadolinium oxide (Gd)₂O₃) Terbium oxide (TbO)_1.81) Dysprosium oxide (Dy)₂O₃) Erbium oxide (Er)₂O₃) Thulium oxide (Tm)₂O₃) Ytterbium oxide (Yb)₂O₃) And lutetium oxide (Lu)₂O₃)。

Preferably, the two-dimensional carbon-based supported lanthanide rare earth oxide (CN-REOs) refers to the charging molar mass ratio of carbon source melamine to hydrated rare earth nitrate in preparation is 32: 7.

Preferably, the hydrated rare earth nitrate is selected from lanthanum nitrate hexahydrate (La (NO)₃)₃·6H₂O), cerium nitrate hexahydrate (Ce (NO)₃)₃·6H₂O), praseodymium nitrate hexahydrate (Pr (NO)₃)₃·6H₂O), neodymium nitrate hexahydrate (Nd (NO)₃)₃·6H₂O), samarium nitrate hexahydrate (Sm (NO)₃)₃·6H₂O), europium nitrate hexahydrate (Eu (NO)₃)₃·6H₂O), gadolinium nitrate hexahydrate (Gd (NO)₃)₃·6H₂O), terbium nitrate hexahydrate (Tb (NO)₃)₃·6H₂O), dysprosium nitrate hexahydrate (Dy (NO)₃)₃·6H₂O), erbium nitrate hexahydrate (Er (NO)₃)₃·6H₂O), thulium nitrate hexahydrate (Tm (NO)₃)₃·6H₂O), ytterbium nitrate pentahydrate (Yb (NO)₃)₃·5H₂O) and lanthanum nitrate hexahydrate (Lu (NO)₃)₃·6H₂O)。

Preferably, the material of the present invention has a use for increasing the wave absorption amount and widening the effective absorption frequency width.

Preferably, the tunable wave-absorbing performance is realized by changing the feed ratio of melamine to hydrated rare earth nitrate and the types of the added hydrated rare earth nitrate in the preparation process of the two-dimensional carbon-based supported lanthanide rare earth oxide.

The tunable wave-absorbing property means that the position of an absorption peak, the effective absorption frequency range and the width are controllable.

The invention also relates to a method for preparing the material with tunable wave absorption performance, which comprises the following steps:

step one, preparing a two-dimensional carbon-based lanthanide rare earth oxide-loaded nanocomposite material:

(1) adding 1.0g of surfactant F127 (poloxamer) into 40mL of water, placing the water in a water bath at 40 ℃, stirring for 1h, adding 0.7mmol of hydrated rare earth nitrate, and stirring for 2 h;

(2) dissolving 3.2mmol of melamine in 100mL of water at 80 ℃;

(3) mixing the two solutions, stirring in a water bath at 60 ℃ until the solution is evaporated to dryness, placing the evaporated solid in a tubular furnace, and sintering under the protection of nitrogen, wherein the sintering procedure is as follows: heating from 20 ℃ to 350 ℃ at a heating rate of 1 ℃/min, and then preserving heat for 3 h; then heating from 350 ℃ to 850 ℃ at the heating rate of 2 ℃/min, and then preserving heat for 2 h; naturally cooling to room temperature to obtain black solid powder, namely the two-dimensional carbon-based lanthanide rare earth oxide-loaded nano composite material.

Secondly, preparing a composite material of a two-dimensional carbon-based lanthanide rare earth oxide-loaded nano composite material and polyvinylidene fluoride (PVDF):

(1) weighing the two-dimensional carbon-based supported lanthanide rare earth oxide nanocomposite and PVDF according to the mass ratio of 3: 37-3: 7, wherein the total mass is 0.15 g;

(2) dissolving weighed PVDF in 15mL of N, N-dimethylformamide, performing ultrasonic treatment until a transparent mixed solution is obtained, dissolving weighed two-dimensional carbon-based lanthanide rare earth oxide-loaded nano composite particles in the mixed solution, and mechanically stirring to obtain a black suspension;

(3) and transferring the prepared mixed solution into an evaporating dish, and placing the evaporating dish in an oven at 70 ℃ for 4h to evaporate the solvent to obtain the two-dimensional carbon-based composite film loaded with the lanthanide rare earth oxide and the PVDF.

And tabletting the obtained composite film by adopting a hot pressing method, and carrying out wave absorption test by using a coaxial method.

Compared with the existing material, the material has the following advantages:

(1) the preparation method of the material is simple and convenient, the two-dimensional carbon base and the supported lanthanide rare earth oxide are simultaneously prepared by a solution-sintering method, doping treatment is not needed, the sample performance is stable, and mass production can be realized.

(2) The material is uniformly loaded, and the lanthanide rare earth oxide is uniformly loaded on the two-dimensional carbon-based material in the crystallization process due to the dispersion effect of the surfactant F127. See fig. 1a to 1 m.

(3) After the nano composite wave-absorbing material prepared by the invention is mixed with PVDF, compared with the wave-absorbing effect of the pure two-dimensional carbon-based material and the PVDF, the wave-absorbing amount of the material is greatly improved, and the frequency absorbing section is widened, so that the wave-absorbing performance of the material is improved. See fig. 2a to 2 n.

(4) The invention adjusts the position of the material on the electromagnetic wave absorption peak and the frequency range and the width of effective absorption by changing the loading amount of cerium oxide and the type of the loaded lanthanide rare earth oxide. See fig. 3 and 4.

(5) The preparation process of the composite material is mostly a physical method, and the composite material is simple and convenient to operate, consumes less time and energy and is environment-friendly.

Description of the drawings:

fig. 1a to 1 m: TEM image of the microscopic morphology of two-dimensional carbon-based supported lanthanide rare earth (CN-La to CN-Lu) oxide nanocomposites.

Fig. 2a to 2 m: reflection loss curve diagram of two-dimensional carbon-based lanthanide rare earth (CN-La to CN-Lu) oxide-loaded and PVDF composite material.

FIG. 2 n: reflection loss profile of two-dimensional Carbon Nanoparticles (CN) with PVDF composites.

FIG. 3: the curve of the influence of the addition of the cerium nitrate hexahydrate on the effective wave-absorbing frequency bandwidth of the (CN-Ce)/PVDF composite material is marked as S1 when the addition is 0.05 g; the label is S2 when the addition amount is 0.10 g; the addition amount is 0.20g and is marked as S3; the label is S4 when the addition amount is 0.30 g; the label is S5 when the addition amount is 0.50 g; the label is S6 when the addition amount is 0.70 g; the addition amount of 0.90g was designated as S7.

FIG. 4: and the type of the supported lanthanide rare earth oxide is used for regulating and controlling the position and the effective absorption frequency range of the electromagnetic wave absorption peak of the CN-REOs/PVDF composite material.

Detailed Description