阅读说明：本技术 一种多功能隐身材料及其制备方法 (Multifunctional stealth material and preparation method thereof ) 是由 叶伟 张杏 孙启龙 龙啸云 高强 季涛 于 2021-08-26 设计创作，主要内容包括：本发明提供一种多功能隐身材料的制备方法,步骤包括：S1.以DMF为溶剂,配备PVDF溶液并等分为A、B、C三份,其中溶液C额外加入TPU；S2.将纳米四氧化三铁改性后加入至溶液A中；S3.将纳米级氧化石墨烯分散后与溶液B混合；S4.将纳米掺锡氧化铟改性后加入至溶液C中；S5.将溶液C通过静电纺丝工艺进行纺丝,即远红外隐身层；S6.将溶液A通过静电纺丝工艺进行纺丝,即第一电磁波隐身层；S7.将溶液B通过静电纺丝工艺进行纺丝,即第二电磁波隐身层；S8.将颜料喷涂在第二电磁波隐身层上,即可见光隐身层。本发明还公开了上述制备方法制备得到的产品。本发明提供的隐身材料对电磁波、远红外和可见光均具有隐身功能,表现出了良好的隐身效果。(The invention provides a preparation method of a multifunctional stealth material, which comprises the following steps: s1, taking DMF as a solvent, preparing a PVDF solution, equally dividing into A, B, C parts, wherein the solution C is additionally added with TPU; s2, adding modified nano ferroferric oxide into the solution A; s3, dispersing the nano-scale graphene oxide and mixing with the solution B; s4, adding the modified nano tin-doped indium oxide into the solution C; s5, spinning the solution C through an electrostatic spinning process to obtain a far infrared stealth layer; s6, spinning the solution A through an electrostatic spinning process to obtain a first electromagnetic wave stealth layer; s7, spinning the solution B through an electrostatic spinning process to obtain a second electromagnetic wave stealth layer; s8, spraying the pigment on the second electromagnetic wave stealth layer to obtain the visible light stealth layer. The invention also discloses a product prepared by the preparation method. The stealth material provided by the invention has stealth functions on electromagnetic waves, far infrared rays and visible light, and shows a good stealth effect.)

1. A preparation method of a multifunctional stealth material is characterized by comprising the following steps: the method comprises the following steps:

s1, preparing a PVDF solution with the concentration of 15-20wt% by taking DMF as a solvent, and equally dividing the obtained solution into A, B, C parts, wherein the solution C is additionally added with 30wt% of TPU;

s2, ball-milling the nano ferroferric oxide, the ball, the ethanol and the hydroxy cellulose according to the mass ratio of 3-4:1:1:0.05, taking out and drying after the ball-milling is finished to obtain modified ferroferric oxide powder, adding the modified ferroferric oxide powder into the solution A, and performing ultrasonic dispersion for 30-60min, wherein the addition amount of the modified ferroferric oxide is 5-10 wt%;

s3, dispersing the nanoscale graphene oxide into DMF (dimethyl formamide) to prepare 2-5wt% of graphene dispersion liquid, mixing the graphene dispersion liquid with the solution B according to the volume ratio of 1:1, and performing ultrasonic dispersion for 30-60 min;

s4, ball-milling the nano tin-doped indium oxide, balls, ethanol and hydroxyl cellulose according to the mass ratio of 3-4:1:1:0.05, taking out and drying after the ball-milling is finished, obtaining modified nano tin-doped indium oxide powder, adding the modified nano tin-doped indium oxide powder into the solution C, and performing ultrasonic dispersion for 30-60min, wherein the addition amount of the modified nano tin-doped indium oxide powder is 5-10 wt%;

s5, spinning the solution C through an electrostatic spinning process, and drying to obtain a fiber layer with the area density of 40-60 g/square meter, namely a far infrared stealth layer;

s6, taking the fiber layer obtained in the step S5 as a base layer, spinning the solution A through an electrostatic spinning process, and drying to obtain the fiber layer with the surface density of 20-50g/m²A fiber layer, namely a first electromagnetic wave stealth layer;

s7, taking the fiber layer obtained in the step S6 as a base layer, spinning the solution B through an electrostatic spinning process, and drying to obtain the fiber layer with the surface density of 20-50g/m²A fiber layer, namely a second electromagnetic wave stealth layer;

s8, adding the pigment into the waterborne polyurethane, stirring, uniformly dispersing, spraying on the second electromagnetic wave stealth layer, and drying to obtain the visible light stealth layer.

2. The method for preparing the multifunctional camouflage material according to claim 1, wherein the method comprises the following steps: the ball milling time in step S2 or step S4 was 12 hours.

3. The method for preparing the multifunctional camouflage material according to claim 2, wherein the method comprises the following steps: and step S2 or step S4, adding the modified ferroferric oxide powder or the modified nano tin-doped indium oxide powder into the solution A or the solution C in a high-pressure spraying mode, wherein the pressure during high-pressure spraying is 0.4 MPa.

4. The method for preparing the multifunctional camouflage material according to claim 1, wherein the method comprises the following steps: the electrostatic spinning process uses a multi-nozzle electrostatic spinning process.

5. The method for preparing the multifunctional camouflage material according to claim 1, wherein the method comprises the following steps: repeating the steps S5-S7 to prepare the multifunctional stealth material with a plurality of layers.

6. The multifunctional stealth material prepared by the preparation method of claim 1 is characterized in that: the material comprises a far infrared stealth layer, an electromagnetic wave first stealth layer, an electromagnetic wave second stealth layer and a visible light stealth layer from bottom to top.

Technical Field

The invention belongs to the technical field of stealth materials, and particularly relates to a multifunctional stealth material and a preparation method thereof.

Background

The stealth material is used as an important component of stealth technology, and is a material basis for realizing the stealth technology on the premise that the equipment shape cannot be changed. At present, the detection is often combined with comprehensive technologies such as visible light, infrared and radar, and the existing multifunctional stealth material with visible light, infrared and radar stealth is deficient, so that the development of the multifunctional stealth material has wide market prospect.

Multifunctional stealth needs to integrate color camouflage of visible light wave band, low emissivity of far infrared and high absorption of radar, and is essentially selective reflection, absorption, radiation and the like of materials, and powder materials such as nanofiber materials, nano ferroferric oxide and the like, a multilayer functional structure and the like are important means for realizing multifunctional stealth.

Most of the prior art has one or two stealths of visible light, far infrared and radar, and lacks materials with stealth effect under three conditions. In addition, the existing multifunctional stealth material has the defects of heavy weight and hardness, and is inconvenient to apply.

At present, researchers achieve compatibility of visible light stealth and infrared stealth through a nano film system structure (CN 110703369B), but radar stealth is not covered, and meanwhile, preparation modes are greatly different. In the aspect of multilayer structure, researchers have proposed multifunctional stealth materials (CN 110356054A and CN 203876323U), but the products lack visible light stealth, and in addition, the functional powder is loaded by coating, which results in heavy fabrics and easy agglomeration of the powder. In addition, an infrared-visible light compatible stealth composite fiber membrane and a preparation method thereof, "CN 104018295B", disclose SiO₂@Bi₂O₃Although the preparation of the composite fiber membrane has infrared and radar stealth functions, the preparation lacks the visible light stealth function, and simultaneously, the fiber membrane obtained by high-temperature sintering treatment has the defects of insufficient flexibility and strength. CN101871136A discloses an infrared stealth fiber and a preparation method thereof, and the fiber is prepared by melting, blending and spinning low-infrared-emissivity powder and a high-molecular matrix material. The method can solve the defects of thick coating, high density, poor bonding fastness with fabrics and the like, but lacks radar and visible light stealth, and in addition, the nanofiber disclosed by the invention can play a greater role.

Disclosure of Invention

In order to solve the problem that materials capable of hiding in visible light, far infrared and radar simultaneously are lacked in the prior art, the invention provides a multifunctional hiding material and a preparation method thereof.

The invention adopts the following technical scheme:

a preparation method of the multifunctional stealth material comprises the following steps:

s1, preparing a PVDF solution with the concentration of 15-20wt% by taking DMF as a solvent, and equally dividing the obtained solution into A, B, C parts, wherein the solution C is additionally added with 30wt% of TPU;

s2, ball-milling the nano ferroferric oxide, the ball, the ethanol and the hydroxy cellulose according to the mass ratio of 3-4:1:1:0.05, taking out and drying after the ball-milling is finished to obtain modified ferroferric oxide powder, adding the modified ferroferric oxide powder into the solution A, and performing ultrasonic dispersion for 30-60min, wherein the addition amount of the modified ferroferric oxide is 5-10%;

s3, dispersing the nanoscale graphene oxide into DMF (dimethyl formamide) to prepare 2-5wt% of graphene dispersion liquid, mixing the graphene dispersion liquid with the solution B according to the volume ratio of 1:1, and performing ultrasonic dispersion for 30-60 min;

s4, ball-milling the nano tin-doped indium oxide, balls, ethanol and hydroxyl cellulose according to the mass ratio of 3-4:1:1:0.05, taking out and drying after the ball-milling is finished to obtain modified nano tin-doped indium oxide powder, adding the modified nano tin-doped indium oxide powder into the solution C, and performing ultrasonic dispersion for 30-60min, wherein the addition amount of the modified nano tin-doped indium oxide powder is 5-10%;

s5, spinning the solution C through an electrostatic spinning process, and drying to obtain a fiber layer with the area density of 40-60 g/square meter, namely a far infrared stealth layer;

s6, taking the fiber layer obtained in the step S5 as a base layer, spinning the solution A through an electrostatic spinning process, and drying to obtain the fiber layer with the surface density of 20-50g/m²A fiber layer, namely a first electromagnetic wave stealth layer;

s7, taking the fiber layer obtained in the step S6 as a base layer, spinning the solution B through an electrostatic spinning process, and drying to obtain the fiber layer with the surface density of 20-50g/m²A fiber layer, namely a second electromagnetic wave stealth layer;

s8, adding the pigment into the waterborne polyurethane, stirring, uniformly dispersing, spraying on the second electromagnetic wave stealth layer, and drying to obtain the visible light stealth layer.

Further, the ball milling time in step S2 or step S4 is 12 hours.

Further, in step S2 or step S4, the modified ferroferric oxide powder or the modified nano tin-doped indium oxide powder is added into the solution a or the solution C by high-pressure spraying, wherein the pressure during high-pressure spraying is 0.4 MPa.

Further, the electrospinning process uses a multi-nozzle electrospinning process.

Further, the steps S5-S7 are repeated to prepare the multifunctional camouflage material having a plurality of layers.

The multifunctional stealth material prepared by the preparation method comprises a far infrared stealth layer, an electromagnetic wave first stealth layer, an electromagnetic wave second stealth layer and a visible light stealth layer from bottom to top.

Compared with the prior art, the invention has the following beneficial effects:

(1) in the prior art, a stealth material with a stealth function on electromagnetic waves, far infrared rays and visible light is rare, the stealth material provided by the invention has the stealth function of three scenes, has a dark green or khaki camouflage effect by using different pigments, has the lowest camouflage effect of 0.41 in an infrared emissivity test, has a wave band less than-10 dB of 6-9GHz in an electromagnetic wave reflection loss test, and shows good stealth effect in three scenes;

(2) the traditional materials with comprehensive camouflage performances of electromagnetic waves, infrared rays, visible light and the like are heavy and are hard composite plates, and the materials prepared by the method of the invention by a powder dispersion technology and a mode of combining electrostatic spinning have the characteristics of flexibility and light weight;

(3) the invention relates to the dispersibility of ferroferric oxide and tin-doped indium oxide powder, which is characterized in that the ball milling technology is utilized for secondary processing and refining, and meanwhile, hydroxycellulose is added for surface modification, so that the hydroxycellulose can be loaded on the surface of particles in the ball milling process, and the hydroxycellulose is an effective dispersant, so that the dispersibility of the powder in a solution is improved.

Drawings

FIG. 1 is a schematic structural view of a stealth material;

fig. 2 is a cross-sectional SEM image of the resulting stealth material.

Detailed Description

The present invention is further described with reference to the following examples, which are provided for illustration only and are not to be construed as limiting the scope of the claims, and other alternatives which may occur to those skilled in the art are also within the scope of the claims.

The multifunctional stealth material provided by the invention comprises a far infrared stealth layer, an electromagnetic wave first stealth layer, an electromagnetic wave second stealth layer and a visible light stealth layer from bottom to top as shown in figure 1; the main component of the far infrared stealth layer is tin-doped indium oxide, the main component of the first stealth layer of the electromagnetic wave is ferroferric oxide, and the main component of the second stealth layer of the electromagnetic wave is graphene oxide.

Example 1

A preparation method of the multifunctional stealth material comprises the following steps:

s1, preparing a PVDF solution with the concentration of 20wt% by taking DMF as a solvent, and equally dividing the obtained solution into A, B, C parts, wherein the solution C is additionally added with 30wt% of TPU;

s2, ball-milling the nano ferroferric oxide, the ball, the ethanol and the hydroxy cellulose for 12 hours according to the mass ratio of 3:1:1:0.05, taking out and drying after the ball-milling is finished to obtain modified ferroferric oxide powder, adding the modified ferroferric oxide powder into the solution A in a high-pressure spraying mode, and performing ultrasonic dispersion for 60 minutes, wherein the adding amount of the modified ferroferric oxide is 10 percent, and the high-pressure spraying pressure is 0.4 MPa;

s3, dispersing the nanoscale graphene oxide into DMF (dimethyl formamide) to prepare 5wt% of graphene dispersion liquid, mixing the graphene dispersion liquid with the solution B according to the volume ratio of 1:1, and performing ultrasonic dispersion for 60 min;

s4, ball-milling the nano tin-doped indium oxide, balls, ethanol and hydroxyl cellulose for 12 hours according to the mass ratio of 3:1:1:0.05, taking out and drying after ball-milling is finished to obtain modified nano tin-doped indium oxide powder, adding the modified nano tin-doped indium oxide powder into the solution C in a high-pressure spraying mode, and performing ultrasonic dispersion for 60 minutes, wherein the addition amount of the modified nano tin-doped indium oxide powder is 10%, and the high-pressure spraying pressure is 0.4 MPa;

s5, spinning the solution C through an electrostatic spinning process, and drying to obtain a fiber layer with the area density of 60 g/square meter, namely a far infrared stealth layer;

s6, taking the fiber layer obtained in the step S5 as a base layer, spinning the solution A through an electrostatic spinning process, and drying to obtain the fiber layer with the surface density of 50g/m²A fiber layer, namely a first electromagnetic wave stealth layer;

S7.taking the fiber layer obtained in the step S6 as a base layer, spinning the solution B through an electrostatic spinning process, and drying to obtain the fiber layer with the surface density of 50g/m²A fiber layer, namely a second electromagnetic wave stealth layer;

and S8, adding the dark green pigment into the waterborne polyurethane, stirring, uniformly dispersing, spraying on the second electromagnetic wave stealth layer, and drying to obtain the visible light stealth layer.

According to the nanofiber multilayer structure film stealth material prepared by the preparation method, the outermost layer achieves visible light stealth through dark green adjustment matched with the environment, the electromagnetic wave absorption material in the middle layer achieves radar stealth, the low-emissivity material in the innermost layer is added to achieve infrared stealth, and the screened materials are not mutually interfered in spectrum, so that the optimal stealth effect can be achieved. Adopting an infrared emissivity test standard: GB 30127-2013; electromagnetic wave reflection loss test standard: testing GJB 2038A-2011, wherein the performance is shown in Table 1, and the surface of the material has the camouflage performance of a jungle; the infrared emissivity reaches 0.45, and the low infrared emissivity can reduce the possibility of infrared detection; at 8-18GHz, the electromagnetic wave loss < -10dB wave band of the material is 8GHz, and the electromagnetic wave stealth performance of the material is excellent.

TABLE 1 Properties of the materials

Example 2

A preparation method of the multifunctional stealth material comprises the following steps:

s1, preparing a PVDF solution with the concentration of 20wt% by taking DMF as a solvent, and equally dividing the obtained solution into A, B, C parts, wherein the solution C is additionally added with 30wt% of TPU;

s2, ball-milling the nano ferroferric oxide, the ball, the ethanol and the hydroxy cellulose for 12 hours according to the mass ratio of 4:1:1:0.05, taking out and drying after the ball-milling is finished to obtain modified ferroferric oxide powder, adding the modified ferroferric oxide powder into the solution A in a high-pressure spraying mode, and performing ultrasonic dispersion for 30 minutes, wherein the addition amount of the modified ferroferric oxide is 5%, and the high-pressure spraying pressure is 0.4 MPa;

s3, dispersing the nanoscale graphene oxide into DMF (dimethyl formamide) to obtain 2wt% graphene dispersion liquid, mixing the graphene dispersion liquid with the solution B according to the volume ratio of 1:1, and performing ultrasonic dispersion for 30 min;

s4, ball-milling the nano tin-doped indium oxide, balls, ethanol and hydroxyl cellulose for 12 hours according to the mass ratio of 4:1:1:0.05, taking out and drying after ball-milling to obtain modified nano tin-doped indium oxide powder, adding the modified nano tin-doped indium oxide powder into the solution C in a high-pressure spraying mode, and performing ultrasonic dispersion for 30 minutes, wherein the addition amount of the modified nano tin-doped indium oxide powder is 5%, and the high-pressure spraying pressure is 0.4 MPa;

s5, spinning the solution C through an electrostatic spinning process, and drying to obtain a fiber layer with the area density of 40 g/square meter, namely a far infrared stealth layer;

s6, taking the fiber layer obtained in the step S5 as a base layer, spinning the solution A through an electrostatic spinning process, and drying to obtain the fiber layer with the surface density of 30g/m²A fiber layer, namely a first electromagnetic wave stealth layer;

s7, taking the fiber layer obtained in the step S6 as a base layer, spinning the solution B through an electrostatic spinning process, and drying to obtain the fiber layer with the surface density of 30g/m²A fiber layer, namely a second electromagnetic wave stealth layer;

and S8, adding the dark green pigment into the waterborne polyurethane, stirring, uniformly dispersing, spraying on the second electromagnetic wave stealth layer, and drying to obtain the visible light stealth layer.

According to the nanofiber multilayer structure film stealth material prepared by the preparation method, the outermost layer achieves visible light stealth through dark green adjustment matched with the environment, the electromagnetic wave absorption material in the middle layer achieves radar stealth, the low-emissivity material in the innermost layer is added to achieve infrared stealth, and the screened materials are not mutually interfered in spectrum, so that the optimal stealth effect can be achieved. Adopting an infrared emissivity test standard: GB 30127-2013; electromagnetic wave reflection loss test standard: testing GJB 2038A-2011, wherein the performance is shown in Table 2, and the surface of the material has the camouflage performance of a jungle; the infrared emissivity reaches 0.47, and the low infrared emissivity can reduce the possibility of infrared detection; at 8-18GHz, the electromagnetic wave loss < -10dB band of the material is 6GHz, and the electromagnetic wave of the material has good stealth performance.

TABLE 2 Properties of the materials

Example 3

A preparation method of the multifunctional stealth material comprises the following steps:

s1, preparing a PVDF solution with the concentration of 20wt% by taking DMF as a solvent, and equally dividing the obtained solution into A, B, C parts, wherein the solution C is additionally added with 30wt% of TPU;

s2, ball-milling the nano ferroferric oxide, the ball, the ethanol and the hydroxy cellulose for 12 hours according to the mass ratio of 3:1:1:0.05, taking out and drying after the ball-milling is finished to obtain modified ferroferric oxide powder, adding the modified ferroferric oxide powder into the solution A in a high-pressure spraying mode, and performing ultrasonic dispersion for 60 minutes, wherein the adding amount of the modified ferroferric oxide is 10 percent, and the high-pressure spraying pressure is 0.4 MPa;

s3, dispersing the nanoscale graphene oxide into DMF (dimethyl formamide) to prepare 4wt% graphene dispersion liquid, mixing the graphene dispersion liquid with the solution B according to the volume ratio of 1:1, and performing ultrasonic dispersion for 60 min;

s4, ball-milling the nano tin-doped indium oxide, balls, ethanol and hydroxyl cellulose for 12 hours according to the mass ratio of 3:1:1:0.05, taking out and drying after ball-milling is finished to obtain modified nano tin-doped indium oxide powder, adding the modified nano tin-doped indium oxide powder into the solution C in a high-pressure spraying mode, and performing ultrasonic dispersion for 30 minutes, wherein the addition amount of the modified nano tin-doped indium oxide powder is 10%, and the high-pressure spraying pressure is 0.4 MPa;

s5, spinning the solution C through an electrostatic spinning process, and drying to obtain a fiber layer with the area density of 60 g/square meter, namely a far infrared stealth layer;

s6, taking the fiber layer obtained in the step S5 as a base layer, spinning the solution A through an electrostatic spinning process, and drying to obtain the fiber layer with the surface density of 50g/m²Fibrous layers, i.e. first electromagnetic waves being invisibleA body layer;

s7, taking the fiber layer obtained in the step S6 as a base layer, spinning the solution B through an electrostatic spinning process, and drying to obtain the fiber layer with the surface density of 40g/m²A fiber layer, namely a second electromagnetic wave stealth layer;

s8, adding the yellow-earth pigment into the waterborne polyurethane, stirring, uniformly dispersing, spraying on the second electromagnetic wave stealth layer, and drying to obtain the visible light stealth layer.

According to the nanofiber multilayer structure film stealth material prepared by the preparation method, the outermost layer is adjusted to achieve visible light stealth through the earthy yellow matched with the environment, the electromagnetic wave absorbing material in the middle layer achieves radar stealth, the low emissivity material in the innermost layer is added to achieve infrared stealth, and the screened materials are not mutually interfered in spectrum, so that the optimal stealth effect can be achieved. Adopting an infrared emissivity test standard: GB 30127-2013; electromagnetic wave reflection loss test standard: testing GJB 2038A-2011, wherein the performance is shown in Table 3, and the surface of the material has the camouflage performance of a jungle; the infrared emissivity reaches 0.41, and the low infrared emissivity can reduce the possibility of infrared detection; at 8-18GHz, the electromagnetic wave loss < -10dB wave band of the material is 9GHz, and the material has excellent electromagnetic wave stealth performance.

TABLE 3 Properties of the materials

Test items	Test results
		Visual effect of visible light	Earthy yellow
Infrared emissivity (8-14 mu m)	0.41
		Less-10 dB of effective frequency band of electromagnetic wave reflection loss (8-18 GHz)	9GHz

In addition, by repeating the steps of S5 to S7, the multifunctional stealth material having a plurality of layers is prepared, and the number of layers of the infrared stealth layer or the electromagnetic wave stealth layer can be adjusted according to the demand for the far infrared or electromagnetic wave stealth effect.

The experimental results show that the material provided by the invention has the invisible functions of visible light, infrared and electromagnetic waves, and is greatly improved compared with the traditional bifunctional material, and the traditional material has poor dispersion effect when ferroferric oxide and tin-doped indium oxide powder are used simultaneously.

Materials with comprehensive camouflage performances of electromagnetic waves, infrared light, visible light and the like on the market are often heavy in weight and are hard composite boards, while materials prepared by a powder dispersion technology and a mode of combining electrostatic spinning have the characteristics of flexibility and light weight, as shown in a prepared stealth material interface diagram shown in figure 2, a fiber structure obtained by electrostatic spinning can be obviously observed, the weight of the stealth material is greatly reduced, and the stealth material is of a layered structure, so that the electromagnetic waves, infrared light and visible light stealth performances are comprehensively utilized, and a synergistic effect is achieved.

It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.