CN109049883B

CN109049883B - Wave-absorbing composite board and application thereof

Info

Publication number: CN109049883B
Application number: CN201811000908.7A
Authority: CN
Inventors: 赵若红; 梅超; 徐安; 傅继阳; 刘爱荣; 吴玖荣
Original assignee: Guangzhou University
Current assignee: Guangzhou University
Priority date: 2018-08-29
Filing date: 2018-08-29
Publication date: 2020-12-08
Anticipated expiration: 2038-08-29
Also published as: CN109049883A

Abstract

The invention discloses a wave-absorbing composite board and application thereof. The electromagnetic wave transmission layer has high electromagnetic wave transmittance, so that electromagnetic waves are easy to enter the wave-absorbing composite board and are absorbed by the electromagnetic wave loss layer in a consumed mode, and residual electromagnetic waves penetrating through the electromagnetic wave loss layer are reflected on the surface of the electromagnetic wave reflection layer and are absorbed by the electromagnetic wave loss layer in a consumed mode again. The wave-absorbing composite board has excellent electromagnetic wave absorption loss performance and mechanical property, can meet the requirements of building structures, is used in the field of electromagnetic shielding, can achieve good electromagnetic shielding effect, effectively prevents local electromagnetic leakage and electromagnetic intrusion interference outside the area, and has good application prospect in places such as MRI system scanning rooms.

Description

Wave-absorbing composite board and application thereof

Technical Field

The invention relates to an electromagnetic wave absorbing structure, in particular to a wave absorbing composite plate and application thereof.

Background

With the development of science and technology and the improvement of the human cognition level, the application of electromagnetic waves has more and more ways and wider range. Nowadays, electromagnetic waves are widely used in the fields of communication, medical care and health, and food hygiene. However, research shows that the long-term work and life under the electromagnetic radiation condition can cause harm to physical and psychological health of people. In addition, electromagnetic radiation can interfere with an electronic machine, so that the electronic machine is misoperated, the normal work of the machine is influenced, even serious accidents and harm occur, the receiving of broadcasting and television is also influenced, information leakage is generated, and serious information safety problems occur. Therefore, in some building structures, the problem of shielding electromagnetic waves needs to be considered. For example, the electromagnetic shielding of the MRI system scanning room in a hospital plays an important role in ensuring the normal operation of the device and protecting the surrounding environment, and the position of the MRI system device must ensure that the uniformity and normal operation of the magnetic field are not affected by external interference during operation, and also ensure that the safety of related personnel and the functions of other sensitive devices are not affected by the magnetic field. However, most of the general electromagnetic wave absorbing materials cannot be used in a large scale in practical construction engineering due to high price, poor mechanical properties, low strength, and the like. For this reason, studies on cement-based wave-absorbing materials have been started. The cement-based wave-absorbing material is generally prepared by directly adding materials with an electromagnetic wave absorption function into cement-based common concrete, but the absorption rate of the cement-based wave-absorbing material to electromagnetic waves is low because the cement-based wave-absorbing material has a compact structure and low porosity, and is easy to cause impedance matching imbalance with a free space, so that most of the electromagnetic waves are reflected on the surface of the cement-based wave-absorbing material, and the cement-based wave-absorbing material has a single structural design in a building structure and is generally only of a single-layer structure. Therefore, there is a need to develop an electromagnetic wave absorbing material suitable for building structures and having better electromagnetic wave absorbing performance.

In order to improve the wave absorbing performance of the electromagnetic wave absorbing material, the material with good wave absorbing performance is selected, and the wave absorbing effect of the material can be obviously improved by adopting a multi-layer structure mode for the structural design of the material. The multiple layers are made of different materials, so that the functions of the layers are different, and the wave-absorbing performance of the wave-absorbing material can be improved to the greatest extent under the combined action of all the layers.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention aims to provide the wave-absorbing composite plate which is suitable for building structures and has good electromagnetic wave absorption performance. The wave-absorbing composite plate is sequentially provided with an electromagnetic wave transmission layer, an electromagnetic wave loss layer and an electromagnetic wave reflection layer from the surface to the inside, wherein the electromagnetic wave transmission layer has high electromagnetic wave transmittance, so that electromagnetic waves can be incident into the electromagnetic wave loss layer and then consumed and absorbed, and residual electromagnetic waves can be reflected back into the electromagnetic wave loss layer by the electromagnetic wave reflection layer and consumed and absorbed again. The wave-absorbing composite board has excellent electromagnetic wave absorption loss performance, low preparation cost, high strength and excellent mechanical property, and can meet the requirements of building structures.

In order to solve the technical problem, the technical scheme adopted by the invention is as follows:

the wave-absorbing composite plate comprises an electromagnetic wave transmission layer, an electromagnetic wave loss layer and an electromagnetic wave reflection layer which are sequentially arranged from the surface to the inside, wherein the electromagnetic wave transmission layer comprises an electromagnetic wave transmission composite material, and the electromagnetic wave loss layer comprises an electromagnetic wave loss composite material.

The preparation method of the electromagnetic wave transmission composite material comprises the following steps: firstly, adding sodium bicarbonate into epoxy resin glue, and uniformly mixing to obtain a mixture A; adding a silane coupling agent into the mixture A, uniformly mixing, then adding expanded polystyrene particles, uniformly mixing, adding an alkali-activated slag cementing material after the surfaces of the expanded polystyrene particles are completely wetted, and uniformly mixing to obtain a mixture B; thirdly, before the mixture B is initially solidified, vibrating the mixture B to separate particles, heating the particles in a water bath, and then standing to obtain modified expanded polystyrene particles; uniformly mixing the alkali-activated slag cementing material with the modified expanded polystyrene particles, then sequentially adding the foam stabilizer and the foaming agent, uniformly mixing, then quickly filling into a mold, and removing the mold after shaping to obtain a test block; fifthly, steaming and curing the test block to obtain the electromagnetic wave transmission composite material.

The inventor finds in research that the expanded polystyrene particles have hydrophobicity, are difficult to disperse uniformly in water, are difficult to be tightly connected with a cementing material, have low strength and small volume weight, and are easy to float upwards in the stirring process for preparing the electromagnetic wave transmission composite material. Therefore, the invention pretreats the expanded polystyrene particles, utilizes the silane coupling agent to modify the expanded polystyrene particles to change the original hydrophobicity into hydrophilicity, and simultaneously uses the epoxy resin glue and the alkali-activated slag cementing material which are added with the sodium bicarbonate powder in advance to form a shell on the surfaces of the expanded polystyrene particles, thereby overcoming the problem that the expanded polystyrene particles are easy to float in stirring due to small volume weight and improving the strength of the expanded polystyrene particles. Before the initial setting and curing of the cementing material, the invention also carries out water bath heating on the pretreated expanded polystyrene particles, so that the sodium bicarbonate in the particles can generate carbon dioxide gas due to thermal decomposition, thereby enabling the particles to form a porous structure and being more beneficial to the transmission of electromagnetic waves. Compared with the expanded polystyrene particles, the modified expanded polystyrene particles prepared by the invention not only increase the volume weight, can not float upwards in stirring, but also have hydrophilic surface, are easy to disperse uniformly in water, can be easily and tightly connected with a cementing material, have porous structure as a whole, and have good electromagnetic wave transmission performance and high strength. The invention adds the modified expanded polystyrene particles into the alkali-activated slag cementing material, and adds the foam stabilizer and the foaming agent to prepare the electromagnetic wave transmission composite material. A series of independent, disconnected and closed bubbles generated by the foaming agent can enable the composite material to form a porous structure. Meanwhile, the foam stabilizer can enable bubbles generated by the foaming agent to be more stable, so that the prepared composite material is stable in porosity and stronger in electromagnetic wave transmission performance.

The preparation method of the electromagnetic wave loss composite material comprises the following steps: uniformly mixing nickel-coated copper powder and sodium bicarbonate, adding the mixture into epoxy resin glue, and uniformly mixing to obtain a mixed colloid; dropping the mixed colloid into glycerin drop by drop, standing and curing to obtain hardened colloid particles; thirdly, heating the colloidal particles in a water bath, and then standing to obtain porous colloidal particles; and fourthly, uniformly mixing the alkali-activated slag cementing material and the porous colloidal particles, then loading the mixture into a mold, and then vibrating, curing, demolding and curing again to obtain the electromagnetic wave loss composite material.

The inventors have found that, although nickel-coated copper powder has excellent conductivity and electromagnetic wave loss properties, the nickel-coated copper powder has small particles and high density, and is not uniformly dispersed when directly added to a material. Therefore, the nickel-coated copper powder is pretreated by the method. Firstly, mixing nickel-coated copper powder and sodium bicarbonate powder, then adding the mixture into epoxy resin glue, uniformly stirring to prepare mixed glue, and then dropping the mixed glue into glycerol. Then, the colloid particles are heated in a water bath, the epoxy resin glue on the colloid particles can be softened into a sticky state when being heated, the sodium bicarbonate can be decomposed to generate carbon dioxide gas when being heated, and the carbon dioxide gas and the sodium bicarbonate can act together to enable the colloid particles to form a porous structure, so that the porous colloid particles are prepared. Therefore, the technical problem that the nickel-coated copper powder is unevenly dispersed in the material due to small particles and high density is solved, and the prepared porous colloidal particles have stronger electromagnetic wave loss performance. The porous colloidal particles are added into the alkali-activated slag cementing material to prepare the electromagnetic wave loss composite material, so that the electromagnetic wave loss performance of the electromagnetic wave loss composite material can be enhanced, and the mechanical property of the electromagnetic wave loss composite material can also be enhanced.

As a preferred embodiment of the wave-absorbing composite plate, the preparation method of the alkali-activated slag cementing material comprises the following steps: uniformly mixing the fly ash and the slag to obtain a mixed ash body, then adding an alkali activator into the mixed ash body, and uniformly mixing to obtain the alkali-activated slag cementing material.

The invention adopts fly ash, slag and alkali activator to react to prepare alkali-activated slag cementing material which is used as a substrate material of an electromagnetic wave transmission composite material and an electromagnetic wave loss composite material. Therefore, the industrial wastes such as the slag and the fly ash are effectively utilized, the resource waste and the harm of the industrial wastes to the environment are reduced, the preparation cost of the wave-absorbing composite plate is greatly reduced, and the electromagnetic wave transmission composite material and the electromagnetic wave loss composite material which are prepared by taking the alkali-activated slag cementing material as a base material have the advantages of excellent mechanical property, good structural compactness, high compressive strength, good freezing resistance and corrosion resistance, difficult collapse, stable porosity, environment-friendly and pollution-free preparation process, and capability of meeting the requirements of building structures. Further, the slag contains a component having a loss function of electromagnetic waves such as a metal, so that the alkali-activated slag-binding material as a base material can consume an absorption part of electromagnetic waves.

As a preferred embodiment of the method for producing the alkali-activated slag-binding material according to the present invention, fly ash-slag (7:5) to (10:3) are used in a mass ratio. The inventor finds that the cementing material prepared from the fly ash and the slag according to the proportion has better comprehensive performance through a series of experimental researches. As the most preferable embodiment of the method for producing the alkali-activated slag-binding material of the present invention, fly ash/slag is 7:3 in terms of mass ratio. The inventor finds out through series of experimental researches that the comprehensive performance of the cementing material prepared from the fly ash and the slag in the proportion is optimal.

In a preferred embodiment of the method for preparing the alkali-activated slag cement, the ash is mixed with an alkali activator, wherein the alkali activator is 1 (0.3-0.5) by mass ratio.

In a more preferred embodiment of the method for producing an alkali-activated slag cement of the present invention, the ash is mixed with an alkali activator in a mass ratio of 1 (0.4 to 0.5).

In a more preferred embodiment of the method for producing an alkali-activated slag cement of the present invention, the ash is mixed with an alkali activator in a mass ratio of 1 (0.3 to 0.35).

As a preferred embodiment of the method for producing the alkali-activated slag-binding material of the present invention, the method for producing the alkali-activating agent is: and uniformly mixing water, water glass and sodium hydroxide, and standing for 24 hours to obtain the alkali activator.

In a preferred embodiment of the method for producing an alkali activator of the present invention, the ratio by mass of water to water glass to sodium hydroxide is (45 to 55):1: 2. The inventor finds that the alkali activator prepared from the raw materials in the proportion has good performance and excellent excitation effect on excited materials through series of experimental researches.

As the most preferable embodiment of the method for producing the alkali-activator of the present invention, water/water glass/sodium hydroxide is 50:1:2 by mass ratio. The inventor finds out through a series of experimental researches that the alkali activator prepared from the raw materials with the mixture ratio has the best performance and the best excitation effect on the excited material.

As a preferred embodiment of the wave-absorbing composite plate, in the step of the preparation method of the electromagnetic wave transmission composite material, according to the mass-to-volume ratio, 2-3 g of sodium bicarbonate and 20-30 mL of epoxy resin adhesive are added; the inventor finds that the mixture A prepared from the sodium bicarbonate and the epoxy resin adhesive in the proportion has better performance and better wrapping effect on the surface of the expanded polystyrene particles through series of experimental researches, so that the prepared modified expanded polystyrene particles have better performance. Preferably, in the step (i) of the preparation method of the electromagnetic wave transmission composite material, the mass-to-volume ratio of sodium bicarbonate to epoxy resin adhesive is 2.5g to 25 mL; the inventor finds out through a series of experimental researches that the mixture A prepared from the sodium bicarbonate and the epoxy resin adhesive in the proportion has the best performance and the best wrapping effect on the surface of the expanded polystyrene particles, so that the performance of the prepared modified expanded polystyrene particles is the best.

In the step (II) of the preparation method of the wave-absorbing composite plate, the silane coupling agent, the mixture A, the foamed polystyrene particles and the alkali-activated slag cementing material are mixed in a ratio of 1-1.5 mL of the silane coupling agent, 10-12 mL of the foamed polystyrene particles and 10-11 mL of the alkali-activated slag cementing material, and 18-22 g of the alkali-activated slag cementing material. The inventor has made extensive studies to find that when modified expanded polystyrene particles are prepared from the silane coupling agent, the mixture A, the expanded polystyrene particles and the alkali-activated slag cement in the above proportions, the modified expanded polystyrene particles can form an ideal shell. Too large a proportion of the expanded polystyrene particles or too small a proportion of the alkali-activated slag binder may result in failure to form an ideal shell on the surface of the expanded polystyrene particles.

In the most preferred embodiment of the wave-absorbing composite plate, in the step (ii) of the preparation method of the electromagnetic wave transmission composite material, the silane coupling agent, the mixture a, the foamed polystyrene particles and the alkali-activated slag binding material are mixed in a ratio of 1mL of the silane coupling agent to 1mL of the foamed polystyrene particles to 10mL of the alkali-activated slag binding material to 20g of the alkali-activated slag binding material.

As a preferred embodiment of the wave-absorbing composite plate of the present invention, in the step (ii) of the method for preparing the electromagnetic wave transmission composite material, before use, the expanded polystyrene particles are washed with deionized water and dried. As a preferred embodiment of the wave-absorbing composite plate, the preparation method of the electromagnetic wave transmission composite material comprises the second step of washing the expanded polystyrene particles with deionized water for 2-3 times before use, and then drying the particles in an oven. Preferably, the drying temperature is 60-70 ℃, and the drying time is 12 h.

In the step III of the preparation method of the wave-absorbing composite plate, the particles are heated in a water bath at 65-75 ℃ for 10-15 min and then are kept stand for 24h to obtain the modified expanded polystyrene particles. The inventors have made extensive studies and have found that when the vibration-separated particles are heated in a water bath under the water bath condition, modified expanded polystyrene particles having a good porous structure can be obtained.

As a preferred embodiment of the wave-absorbing composite plate, the method for preparing the electromagnetic wave transmission composite material has the specific operations in the step (iv): mixing the alkali-activated slag cementing material and the modified expanded polystyrene particles, uniformly stirring, sequentially adding the foam stabilizer and the foaming agent, uniformly stirring, quickly filling into a mold, cutting off the bread heads after the mixed material is molded in the mold, and then removing the mold to obtain the test block. Preferably, the agitation is performed in a neat paste blender.

In the step (iv) of the preparation method of the electromagnetic wave transmission composite material, the alkali-activated slag cementing material, namely the modified expanded polystyrene particles (4-6): 1 is calculated according to the mass ratio. The inventor obtains through a series of deep researches that when the alkali-activated slag cementing material and the modified expanded polystyrene particles are mixed according to the proportion, the obtained composite material has excellent electromagnetic wave transmission performance and excellent mechanical property. If the dosage of the alkali-activated slag cementing material is too large, the electromagnetic wave transmission performance of the composite material is influenced; if the proportion of the modified expanded polystyrene particles is too large, the mechanical properties such as strength of the composite material can be affected.

As the most preferred embodiment of the wave-absorbing composite plate, in the step (iv) of the preparation method of the electromagnetic wave transmission composite material, the alkali-activated slag cement and the modified expanded polystyrene particles are 5:1 by mass ratio. The inventor obtains through a series of deep researches that when the alkali-activated slag cementing material and the modified expanded polystyrene particles are mixed according to the proportion, the comprehensive performance of the obtained composite material is optimal.

In the step (iv) of the preparation method of the wave-absorbing composite plate, the foam stabilizer, the foaming agent and the modified expanded polystyrene particles are mixed in a ratio of 2-4 g of the foaming agent to 5-7 mL of the modified expanded polystyrene particles to 40-50 g of the foam stabilizer.

As the most preferable embodiment of the wave-absorbing composite plate, in the step (iv) of the method for preparing an electromagnetic wave transmission composite material, the mixture ratio of the foam stabilizer, the foaming agent and the modified expanded polystyrene particles is 2g, 5mL and 44 g.

In the step (iv) of the method for preparing the electromagnetic wave transmission composite material, the foam stabilizer is gum arabic powder.

In the step (iv) of the method for preparing the electromagnetic wave transmission composite material, the foaming agent is an FP-180 animal foaming agent. The FP-180 animal foaming agent used in the present invention is obtained from Hiantoin Yike building New technology application Co., Ltd, and the practice of the present invention is within the scope of the present invention without limitation.

As a preferred embodiment of the wave-absorbing composite plate, in the fifth step of the preparation method of the electromagnetic wave transmission composite material, the test block is placed in an autoclave, autoclaved at 175-185 ℃ for 8 hours, and then placed in a curing box for curing for 3 days, so as to obtain the electromagnetic wave transmission composite material. Preferably, the temperature of the curing box is 20 ℃ and the humidity is 95%. The inventor has made a series of intensive studies, and when the test block is autoclaved under the autoclaving condition, the obtained composite material has a good porous structure.

As a preferred embodiment of the wave-absorbing composite plate, in the step (i) of the preparation method of the electromagnetic wave loss composite material, the mass-to-volume ratio of nickel-coated copper powder, sodium bicarbonate and epoxy resin adhesive is 8-12 g, 2-3 g, and 18-22 mL. The inventor obtains through a series of intensive researches that when the nickel-coated copper powder, the sodium bicarbonate and the epoxy resin adhesive are mixed according to the proportion to prepare the mixed colloid, the porous structure of the obtained porous colloid particles is good.

As the most preferable embodiment of the wave-absorbing composite plate, in the step (i) of the preparation method of the electromagnetic wave loss composite material, the mass-to-volume ratio of nickel-coated copper powder, sodium bicarbonate and epoxy resin adhesive is 10g, 2.5g and 20 mL. The inventor has made extensive studies, and when the nickel-coated copper powder, the sodium bicarbonate and the epoxy resin adhesive are mixed according to the proportion to prepare the mixed colloid, the porous structure of the obtained porous colloid particles is the best.

In the step III of the preparation method of the wave-absorbing composite plate, the colloid particles are heated in a water bath at 65-75 ℃ for 10-15 min and then are kept stand for 24h to obtain the porous colloid particles. The inventors have made extensive studies and found that when the hardened colloidal particles are heated in a water bath under the water bath condition, porous colloidal particles having a good porous structure can be obtained.

As a preferred embodiment of the wave-absorbing composite plate, the method for preparing the electromagnetic wave loss composite material comprises the following specific operations in step (iv): and uniformly mixing the alkali-activated slag cementing material and the porous colloidal particles, then loading into a mold, vibrating for 15-20 s, then placing into a curing box, curing for 24h, removing the mold, and continuously curing the material after mold removal for 3 days to obtain the electromagnetic wave loss composite material. Preferably, the curing is performed under an environmental condition of 20 ℃ and 95% humidity.

In the step (iv) of the preparation method of the electromagnetic wave loss composite material, according to the mass ratio, the porous colloidal particles as the alkali-activated slag gelling material are 8: 1-10: 1. The inventor obtains through a series of deep researches that the composite material prepared by mixing the alkali-activated slag gelled material and the porous colloidal particles according to the proportion has excellent electromagnetic wave absorption loss function and excellent mechanical property. If the proportion of the porous colloidal particles is too small, the electromagnetic wave loss function of the resulting composite material cannot be maximized, and if the proportion of the porous colloidal particles is too large, the electromagnetic wave loss function of the resulting composite material is decreased.

As a preferred embodiment of the wave-absorbing composite plate of the present invention, the electromagnetic wave reflecting layer includes a metal plate.

In addition, the invention also aims to provide application of the wave-absorbing composite plate, and particularly application of the wave-absorbing composite plate in the field of wave-absorbing materials for buildings. In addition, the invention also aims to provide the application of the wave-absorbing composite plate, and particularly relates to the application of the wave-absorbing composite plate in nuclear magnetic resonance chamber electromagnetic shielding.

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

1. the electromagnetic wave transmission layer is an electromagnetic wave transmission composite material with a porous structure, the electromagnetic wave transmission composite material has high electromagnetic wave transmission rate, excellent mechanical property, high compressive strength, good frost resistance and corrosion resistance, stable porosity, low preparation cost, environmental protection and no pollution, can effectively improve the impedance characteristic of the surface of the electromagnetic wave transmission layer, enables more electromagnetic waves to be incident into the wave-absorbing composite plate, and greatly reduces the reflectivity of the surface of the electromagnetic wave transmission layer to the electromagnetic waves.

2. The electromagnetic wave loss layer is an electromagnetic wave loss composite material, and the electromagnetic wave loss composite material has the advantages of excellent electromagnetic wave absorption loss function and mechanical property, high compressive strength, good structural compactness, difficulty in leaking electromagnetic waves, great reduction in the overall thickness and weight of the wave-absorbing structure, light and thin overall wave-absorbing structure and improvement in the use safety.

3. The wave-absorbing composite plate is sequentially provided with an electromagnetic wave transmission layer, an electromagnetic wave loss layer and an electromagnetic wave reflection layer from the surface to the inside, wherein the electromagnetic wave transmission layer has high electromagnetic wave transmittance, so that electromagnetic waves are easy to enter the inside of the wave-absorbing composite plate and are consumed and absorbed by the electromagnetic wave loss layer, and residual electromagnetic waves penetrating through the electromagnetic wave loss layer are reflected on the surface of the electromagnetic wave reflection layer and are consumed and absorbed again by the electromagnetic wave loss layer. The wave-absorbing composite board has excellent electromagnetic wave absorption loss performance, is used in the field of electromagnetic shielding, can achieve good electromagnetic shielding effect, and effectively prevents local electromagnetic leakage and electromagnetic intrusion interference outside the area. The wave-absorbing composite board also has excellent mechanical property, can meet the requirement of building structures, and has good application prospect in places needing electromagnetic shielding, such as MRI system scanning rooms and the like.

Drawings

FIG. 1 is a schematic structural view of the wave-absorbing composite plate of the present invention;

FIG. 2 is a graph showing the variation of the reflection loss of electromagnetic waves with frequency for the materials of example 1, comparative example 1 and comparative example 2;

FIG. 3 is a graph showing the change in the absorption loss of electromagnetic waves with frequency for the materials of example 5, comparative example 3 and comparative example 4;

fig. 4 is a graph of the absorption loss of electromagnetic waves with frequency of the wave-absorbing composite plate of example 10 and the electromagnetic wave loss composite material of example 5.

Detailed Description

To illustrate the technical solutions of the present invention more clearly, the following embodiments are further described, but the present invention is not limited thereto, and only some embodiments of the present invention are given. Unless otherwise specified, the methods used in the examples of the present invention are all conventional methods. The raw materials used in the present invention are commercially available, and the present invention is not limited thereto.

The embodiment of the invention provides a wave-absorbing composite plate, as shown in figure 1, the wave-absorbing composite plate is sequentially provided with an electromagnetic wave transmission layer 1, an electromagnetic wave loss layer 2 and an electromagnetic wave reflection layer 3 from the surface to the inside, wherein the electromagnetic wave transmission layer 1 is made of an electromagnetic wave transmission composite material, the electromagnetic wave loss layer 2 is made of an electromagnetic wave loss composite material, and the electromagnetic wave reflection layer 3 is made of a metal plate.

The preparation method of the electromagnetic wave transmission composite material comprises the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring uniformly, and standing for 24h to obtain an alkali activator; according to the mass ratio, water glass and sodium hydroxide (45-55) to 1: 2;

(2) preparation of a first alkali-activated slag cement: adding the fly ash and the slag into a clean slurry stirrer, uniformly stirring to obtain a mixed ash body, then adding an alkali activator, and uniformly stirring to obtain a first alkali-activated slag cementing material; according to the mass ratio, the fly ash and the slag are (7:5) - (10:3), the mixed ash and the alkali activator are (1), (0.4-0.5);

(3) adding sodium bicarbonate into the epoxy resin adhesive, and uniformly stirring to obtain a mixture A; according to the mass volume ratio, the sodium bicarbonate and the epoxy resin adhesive are 2-3 g and 20-30 mL;

(4) washing the expanded polystyrene particles with deionized water for 2-3 times, and then drying in an oven at 60-70 ℃ for 12 hours;

(5) adding a silane coupling agent into the mixture A, uniformly mixing, then adding the expanded polystyrene particles treated in the step (4), uniformly stirring by using a stirrer, adding a first alkali-activated slag cementing material after the surfaces of the expanded polystyrene particles are completely wetted, and uniformly stirring in a slurry mixer to obtain a mixture B; the silane coupling agent, the mixture A, the foamed polystyrene particles and the first alkali-activated slag cementing material are mixed according to a ratio, wherein the silane coupling agent is the mixture A, the foamed polystyrene particles are 1-1.5 mL, the first alkali-activated slag cementing material is 10-12 mL, the first alkali-activated slag cementing material is 10-11 mL, and the first alkali-activated slag cementing material is 18-22 g;

(6) before the mixture B is initially set, pouring the mixture B into a plastic tray, then placing the plastic tray on a vibration table to vibrate and separate particles, heating the vibrated particles in a water bath at 65-75 ℃ for 10-15 min, and then standing for 24h to obtain modified expanded polystyrene particles;

(7) preparation of a second alkali-activated slag cement: adding the fly ash and the slag into a clean slurry stirrer, uniformly stirring to obtain a mixed ash body, then adding an alkali activator, and uniformly stirring to obtain a second alkali-activated slag cementing material; according to the mass ratio, the fly ash and the slag are (7:5) - (10: 3); according to the mass ratio, mixing ash bodies and alkali excitant, wherein the alkali excitant is 1 (0.3-0.35);

(8) adding the second alkali-activated slag cementing material and the modified expanded polystyrene particles into a paste mixer, uniformly stirring, then sequentially adding the foam stabilizer and the foaming agent, uniformly stirring, then quickly filling into a mold, cutting off the bread heads after the mixed material is molded in the mold, and then removing the mold to obtain a test block; according to the mass ratio, the second alkali-activated slag cementing material is modified expanded polystyrene particles (4-6): 1; the foam stabilizer comprises a foaming agent, a foaming agent and modified expanded polystyrene particles, wherein the foaming agent is 2-4 g of modified expanded polystyrene particles, 5-7 mL of modified expanded polystyrene particles and 40-50 g of modified expanded polystyrene particles; the foam stabilizer is Arabic gum powder, and the foaming agent is FP-180 animal foaming agent;

(9) and (3) placing the test block into an autoclave, autoclaving for 8 hours at 175-185 ℃, and then placing into a curing box with the temperature of 20 ℃ and the humidity of 95% for curing for 3 days to obtain the electromagnetic wave transmission composite material.

The preparation method of the electromagnetic wave loss composite material comprises the following steps:

(2) preparing the alkali-activated slag cementing material: adding the fly ash and the slag into a clean slurry stirrer, uniformly stirring to obtain a mixed ash body, then adding an alkali activator, and uniformly stirring to obtain an alkali-activated slag cementing material; according to the mass ratio, the fly ash and the slag are (7:5) - (10:3), the mixed ash and the alkali activator are (1), (0.3-0.35);

(3) mixing the nickel-coated copper powder and sodium bicarbonate, uniformly stirring in a slurry mixer, adding into epoxy resin glue, and uniformly stirring by using a high-speed stirrer to obtain a mixed colloid; according to the mass volume ratio, 8-12 g of nickel-coated copper powder, 2-3 g of sodium bicarbonate and 18-22 mL of epoxy resin adhesive;

(4) dropwise adding the mixed colloid into glycerol by using a 25mL common burette, and standing for 24 hours to obtain hardened colloid particles; the amount of each drop of the mixed colloid is about 0.05 mL;

(5) heating the colloidal particles in a water bath at 65-75 ℃ for 10-15 min, and then standing for 24h to obtain porous colloidal particles;

(6) mixing the alkali-activated slag cementing material and the porous colloidal particles, uniformly stirring in a slurry mixer, then placing into a mold, vibrating for 15-20 s on a vibrating table, then placing into a curing box, curing for 24h under the environmental conditions of 20 ℃ and 95% of humidity, removing the mold, and continuously curing the material after mold removal for 3 days under the same environmental conditions to obtain the electromagnetic wave loss composite material; according to the mass ratio, the porous colloidal particles are 8: 1-10: 1.

Example 1

This example 1 provides an electromagnetic wave transmission composite material, and the preparation method thereof includes the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring for 8-10 min, and standing for 24h to obtain an alkali activator; according to the mass ratio, water glass and sodium hydroxide are 50:1: 2;

(2) preparation of a first alkali-activated slag cement: adding the fly ash and the slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding an alkali activator, and stirring for 4-5 min to obtain a first alkali-activated slag cementing material; according to the mass ratio, the fly ash and the slag are 7:3, and the mixed ash and the alkali activator are 1: 0.4;

(3) adding sodium bicarbonate into the epoxy resin adhesive, and stirring for 3-5 min to obtain a mixture A; according to the mass volume ratio, the sodium bicarbonate and the epoxy resin adhesive are 1g to 10 mL;

(4) washing the expanded polystyrene particles with deionized water for 2-3 times, and then drying in a drying oven at 65 ℃ for 12 hours;

(5) adding 10mL of silane coupling agent into 100mL of the mixture A, uniformly mixing, then adding 100mL of the expanded polystyrene particles treated in the step (4), stirring for 4-5 min by using a stirrer, adding 200g of first alkali-activated slag cementing material after the surfaces of the expanded polystyrene particles are completely wetted, and stirring for 30-35 s in a slurry mixer to obtain a mixture B;

(6) before the mixture B is initially set, pouring the mixture B into a plastic tray with the diameter of 30cm, then placing the plastic tray on a vibration table to vibrate for 30-45 s so as to separate particles, heating the vibrated particles in a water bath at 70 ℃ for 10-15 min, and then standing for 24h to obtain modified expanded polystyrene particles;

(7) preparation of a second alkali-activated slag cement: adding 140g of fly ash and 60g of slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding 64g of alkali activator, and stirring for 4-5 min to obtain a second alkali-activated slag cementing material;

(8) adding 200g of second alkali-activated slag cementing material and 40g of modified expanded polystyrene particles into a paste mixer, stirring for 4-5 min to uniformly mix the materials, then sequentially adding 2g of Arabic gum powder and 5mL of FP-180 animal foaming agent, stirring for 20-25 s, then quickly filling the stirred materials into a mold and standing for 3h, cutting off the bread heads after molding, and then removing the mold to obtain a test block;

(9) and (3) placing the test block into an autoclave, autoclaving for 8 hours at 180 ℃, and then placing into a curing box with the temperature of 20 ℃ and the humidity of 95% for curing for 3 days to obtain the electromagnetic wave transmission composite material.

Example 2

This embodiment 2 provides an electromagnetic wave transmission composite material, and the preparation method thereof includes the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring for 8-10 min, and standing for 24h to obtain an alkali activator; according to the mass ratio, the ratio of water to water glass to sodium hydroxide is 45:1: 2;

(2) preparation of a first alkali-activated slag cement: adding the fly ash and the slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding an alkali activator, and stirring for 4-5 min to obtain a first alkali-activated slag cementing material; according to the mass ratio, the fly ash and the slag are 7:5, and the mixed ash and the alkali activator are 1: 0.45;

(3) adding sodium bicarbonate into the epoxy resin adhesive, and stirring for 3-5 min to obtain a mixture A; according to the mass volume ratio, the sodium bicarbonate and the epoxy resin adhesive are 2g and 30 mL;

(4) washing the expanded polystyrene particles with deionized water for 2-3 times, and then drying in an oven at 60 ℃ for 12 hours;

(5) adding 12mL of silane coupling agent into 110mL of the mixture A, uniformly mixing, then adding 105mL of the expanded polystyrene particles treated in the step (4), stirring for 4-5 min by using a stirrer, adding 180g of first alkali-activated slag cementing material after the surfaces of the expanded polystyrene particles are completely wetted, and stirring for 30-35 s in a slurry mixer to obtain a mixture B;

(6) before the mixture B is initially set, pouring the mixture B into a plastic tray with the diameter of 30cm, then placing the plastic tray on a vibration table to vibrate for 30-45 s so as to separate particles, heating the vibrated particles in a water bath at 65 ℃ for 10-15 min, and then standing for 24h to obtain modified expanded polystyrene particles;

(7) preparation of a second alkali-activated slag cement: adding 140g of fly ash and 100g of slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding 72g of alkali activator, and stirring for 4-5 min to obtain a second alkali-activated slag cementing material;

(8) adding 200g of second alkali-activated slag cementing material and 50g of modified expanded polystyrene particles into a paste mixer, stirring for 4-5 min to mix uniformly, then sequentially adding 3g of Arabic gum powder and 6mL of FP-180 animal foaming agent, stirring for 20-25 s, then quickly filling the stirred material into a mold and standing for 3h, cutting off the bread head after molding, and then removing the mold to obtain a test block;

(9) and (3) placing the test block into an autoclave, autoclaving for 8 hours at 175 ℃, and then placing into a curing box with the temperature of 20 ℃ and the humidity of 95% for curing for 3 days to obtain the electromagnetic wave transmission composite material.

Example 3

This embodiment 3 provides an electromagnetic wave transmission composite material, and the preparation method thereof includes the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring for 8-10 min, and standing for 24h to obtain an alkali activator; according to the mass ratio, the ratio of water to water glass to sodium hydroxide is 55:1: 2;

(2) preparation of a first alkali-activated slag cement: adding the fly ash and the slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding an alkali activator, and stirring for 4-5 min to obtain a first alkali-activated slag cementing material; according to the mass ratio, the fly ash and the slag are 10:3, and the mixed ash and the alkali activator are 1: 0.5;

(3) adding sodium bicarbonate into the epoxy resin adhesive, and stirring for 3-5 min to obtain a mixture A; according to the mass volume ratio, 3g of sodium bicarbonate and 20mL of epoxy resin glue;

(4) washing the expanded polystyrene particles with deionized water for 2-3 times, and then drying in an oven at 70 ℃ for 12 hours;

(5) adding 15mL of silane coupling agent into 120mL of the mixture A, uniformly mixing, then adding 110mL of the expanded polystyrene particles treated in the step (4), stirring for 4-5 min by using a stirrer, adding 220g of first alkali-activated slag cementing material after the surfaces of the expanded polystyrene particles are completely wetted, and stirring for 30-35 s in a slurry mixer to obtain a mixture B;

(6) before the mixture B is initially set, pouring the mixture B into a plastic tray with the diameter of 30cm, then placing the plastic tray on a vibration table to vibrate for 30-45 s so as to separate particles, heating the vibrated particles in a water bath at the temperature of 75 ℃ for 10-15 min, and then standing for 24h to obtain modified expanded polystyrene particles;

(7) preparation of a second alkali-activated slag cement: adding 200g of fly ash and 60g of slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding 91g of alkali activator, and stirring for 4-5 min to obtain a second alkali-activated slag cementing material;

(8) adding 240g of second alkali-activated slag cementing material and 40g of modified expanded polystyrene particles into a paste mixer, stirring for 4-5 min to mix uniformly, then sequentially adding 4g of Arabic gum powder and 7mL of FP-180 animal foaming agent, stirring for 20-25 s, then quickly filling the stirred material into a mold and standing for 3h, cutting off the bread head after molding, and then removing the mold to obtain a test block;

(9) and (3) putting the test block into an autoclave, autoclaving for 8 hours at 185 ℃, and then putting the test block into a curing box with the temperature of 20 ℃ and the humidity of 95% for curing for 3 days to obtain the electromagnetic wave transmission composite material.

Example 4

This embodiment 4 provides an electromagnetic wave transmission composite material, and the preparation method thereof includes the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring for 8-10 min, and standing for 24h to obtain an alkali activator; according to the mass ratio, water glass and sodium hydroxide are 48:1: 2;

(2) preparation of a first alkali-activated slag cement: adding the fly ash and the slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding an alkali activator, and stirring for 4-5 min to obtain a first alkali-activated slag cementing material; according to the mass ratio, the fly ash and the slag are 8:3, and the mixed ash and the alkali activator are 1: 0.4;

(5) adding 13mL of silane coupling agent into 110mL of the mixture A, uniformly mixing, then adding 108mL of the expanded polystyrene particles treated in the step (4), stirring for 4-5 min by using a stirrer, adding 210g of the first alkali-activated slag cementing material after the surfaces of the expanded polystyrene particles are completely wetted, and stirring for 30-35 s in a slurry mixer to obtain a mixture B;

(7) preparation of a second alkali-activated slag cement: adding 170g of fly ash and 80g of slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding 80g of alkali activator, and stirring for 4-5 min to obtain a second alkali-activated slag cementing material;

(8) adding 220g of second alkali-activated slag cementing material and 40g of modified expanded polystyrene particles into a clean slurry stirrer, stirring for 4-5 min to uniformly mix, then sequentially adding 3.5g of gum arabic powder and 6.5mL of FP-180 animal foaming agent, stirring for 20-25 s, then quickly filling the stirred material into a mold and standing for 3h, cutting off the bread head after molding, and then removing the mold to obtain a test block;

Example 5

This embodiment 5 provides an electromagnetic wave loss composite material, and the preparation method thereof includes the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring for 10-15 min to uniformly mix, and standing for 24h to obtain an alkali activator; according to the mass ratio, water glass and sodium hydroxide are 50:1: 2;

(2) preparing the alkali-activated slag cementing material: adding 700g of fly ash and 300g of slag into a clean slurry stirrer, stirring for 120-150 s, uniformly mixing to obtain a mixed ash body, then adding 320g of alkali activator, stirring for 4-5 min, and uniformly mixing to obtain an alkali activated slag cementing material;

(3) mixing 100g of nickel-coated copper powder and 25g of sodium bicarbonate, stirring in a slurry mixer for 15-20 s to mix uniformly, adding into 200mL of epoxy resin adhesive, and stirring for 3-4 min by using a high-speed stirrer to mix uniformly to obtain a mixed colloid;

(4) dropwise adding the mixed colloid into glycerol (each drop is about 0.05mL) by using a 25mL common burette, and standing for 24h to obtain hardened colloid particles;

(5) taking out the solidified and hardened colloidal particles in the glycerol, heating the colloidal particles in a water bath at 70 ℃ for 10-15 min, and standing for 24h to obtain porous colloidal particles;

(6) mixing 1000g of alkali-activated slag cementing material and 125g of porous colloidal particles, stirring for 4-5 min in a slurry mixer to uniformly mix the materials, then loading the mixture into a mold, vibrating the mixture on a vibrating table for 15-20 s, then placing the mixture into a curing box, curing the mixture for 24h under the environmental conditions of temperature of 20 ℃ and humidity of 95%, removing the mold, and continuously curing the removed material for 3 days under the same environmental conditions to obtain the electromagnetic wave loss composite material.

Example 6

This embodiment 6 provides an electromagnetic wave loss composite material, and the preparation method thereof includes the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring for 10-15 min to uniformly mix, and standing for 24h to obtain an alkali activator; according to the mass ratio, the ratio of water to water glass to sodium hydroxide is 45:1: 2;

(2) preparing the alkali-activated slag cementing material: adding 700g of fly ash and 500g of slag into a clean slurry stirrer, stirring for 120-150 s, uniformly mixing to obtain a mixed ash body, then adding 360g of alkali activator, stirring for 4-5 min, and uniformly mixing to obtain an alkali activated slag cementing material;

(3) mixing 100g of nickel-coated copper powder and 20g of sodium bicarbonate, stirring in a slurry mixer for 15-20 s to mix uniformly, adding into 180mL of epoxy resin adhesive, and stirring for 3-4 min by using a high-speed stirrer to mix uniformly to obtain a mixed colloid;

(5) taking out the solidified and hardened colloidal particles in the glycerol, heating the colloidal particles in a water bath at 65 ℃ for 10-15 min, and standing for 24h to obtain porous colloidal particles;

(6) mixing 1100g of alkali-activated slag cementing material and 120g of porous colloidal particles, stirring for 4-5 min in a slurry mixer to uniformly mix the materials, then loading the mixture into a mold, vibrating the mixture on a vibrating table for 15-20 s, then placing the mixture into a curing box, curing the mixture for 24h under the environmental conditions that the temperature is 20 ℃ and the humidity is 95%, removing the mold, and continuously curing the removed material for 3 days under the same environmental conditions to obtain the electromagnetic wave loss composite material.

Example 7

This embodiment 7 provides an electromagnetic wave loss composite material, and the preparation method thereof includes the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring for 10-15 min to uniformly mix, and standing for 24h to obtain an alkali activator; according to the mass ratio, the ratio of water to water glass to sodium hydroxide is 55:1: 2;

(2) preparing the alkali-activated slag cementing material: adding 1000g of fly ash and 300g of slag into a clean slurry stirrer, stirring for 120-150 s, uniformly mixing to obtain a mixed ash body, then adding 455g of alkali activator, stirring for 4-5 min, and uniformly mixing to obtain an alkali activated slag cementing material;

(3) mixing 120g of nickel-coated copper powder and 30g of sodium bicarbonate, stirring for 15-20 s in a slurry mixer to uniformly mix the nickel-coated copper powder and the sodium bicarbonate, adding the mixture into 220mL of epoxy resin adhesive, and stirring for 3-4 min by using a high-speed mixer to uniformly mix the epoxy resin adhesive and the sodium bicarbonate to obtain a mixed colloid;

(5) taking out the solidified and hardened colloidal particles in the glycerol, heating the colloidal particles in a water bath at 75 ℃ for 10-15 min, and standing for 24h to obtain porous colloidal particles;

(6) mixing 1200g of alkali-activated slag cementing material and 120g of porous colloidal particles, stirring for 4-5 min in a slurry mixer to uniformly mix the materials, then loading the mixture into a mold, vibrating the mixture on a vibrating table for 15-20 s, then placing the mixture into a curing box, curing the mixture for 24h under the environmental conditions that the temperature is 20 ℃ and the humidity is 95%, removing the mold, and continuously curing the removed material for 3 days under the same environmental conditions to obtain the electromagnetic wave loss composite material.

Example 8

This embodiment 8 provides an electromagnetic wave loss composite material, and the preparation method thereof includes the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring for 10-15 min to uniformly mix, and standing for 24h to obtain an alkali activator; according to the mass ratio, the ratio of water to water glass to sodium hydroxide is 52:1: 2;

(2) preparing the alkali-activated slag cementing material: adding 900g of fly ash and 400g of slag into a clean slurry stirrer, stirring for 120-150 s, uniformly mixing to obtain a mixed ash body, then adding 416g of alkali activator, stirring for 4-5 min, and uniformly mixing to obtain an alkali-activated slag cementing material;

(3) mixing 96g of nickel-coated copper powder and 24g of sodium bicarbonate, stirring in a slurry mixer for 15-20 s to mix uniformly, adding into 216mL of epoxy resin adhesive, and stirring for 3-4 min by using a high-speed stirrer to mix uniformly to obtain a mixed colloid;

(6) mixing 1000g of alkali-activated slag cementing material and 120g of porous colloidal particles, stirring for 4-5 min in a slurry mixer to uniformly mix the materials, then loading the mixture into a mold, vibrating the mixture on a vibrating table for 15-20 s, then placing the mixture into a curing box, curing the mixture for 24h under the environmental conditions that the temperature is 20 ℃ and the humidity is 95%, removing the mold, and continuously curing the removed material for 3 days under the same environmental conditions to obtain the electromagnetic wave loss composite material.

Example 9

This embodiment 9 provides an electromagnetic wave loss composite material, and the preparation method thereof includes the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring for 10-15 min to uniformly mix, and standing for 24h to obtain an alkali activator; according to the mass ratio, water glass and sodium hydroxide are 48:1: 2;

(2) preparing the alkali-activated slag cementing material: adding 800g of fly ash and 350g of slag into a clean slurry stirrer, stirring for 120-150 s, uniformly mixing to obtain a mixed ash body, then adding 345g of alkali activator, stirring for 4-5 min, and uniformly mixing to obtain an alkali activated slag cementing material;

(3) mixing 80g of nickel-coated copper powder and 20g of sodium bicarbonate, stirring in a slurry mixer for 15-20 s to mix uniformly, adding into 200mL of epoxy resin adhesive, and stirring for 3-4 min by using a high-speed stirrer to mix uniformly to obtain a mixed colloid;

Example 10

This embodiment 10 provides a wave-absorbing composite plate, as shown in fig. 1, the wave-absorbing composite plate is sequentially provided with an electromagnetic wave transmission layer 1, an electromagnetic wave loss layer 2, and an electromagnetic wave reflection layer 3 from the front to the inside, where the electromagnetic wave transmission layer 1 is made of the electromagnetic wave transmission composite material of embodiment 1, the electromagnetic wave loss layer 2 is made of the electromagnetic wave loss composite material of embodiment 5, and the electromagnetic wave reflection layer 3 is made of a metal plate.

Example 11

This embodiment 11 provides a wave-absorbing composite plate, as shown in fig. 1, the wave-absorbing composite plate is sequentially provided with an electromagnetic wave transmission layer 1, an electromagnetic wave loss layer 2, and an electromagnetic wave reflection layer 3 from the front to the inside, where the electromagnetic wave transmission layer 1 is made of the electromagnetic wave transmission composite material of embodiment 2, the electromagnetic wave loss layer 2 is made of the electromagnetic wave loss composite material of embodiment 6, and the electromagnetic wave reflection layer 3 is made of a metal plate.

Example 12

This embodiment 12 provides a wave-absorbing composite plate, as shown in fig. 1, the wave-absorbing composite plate is sequentially provided with an electromagnetic wave transmission layer 1, an electromagnetic wave loss layer 2, and an electromagnetic wave reflection layer 3 from the front to the inside, where the electromagnetic wave transmission layer 1 is composed of the electromagnetic wave transmission composite material of embodiment 3, the electromagnetic wave loss layer 2 is composed of the electromagnetic wave loss composite material of embodiment 7, and the electromagnetic wave reflection layer 3 is composed of a metal plate.

Example 13

This embodiment 13 provides a wave-absorbing composite plate, as shown in fig. 1, the wave-absorbing composite plate is sequentially provided with an electromagnetic wave transmission layer 1, an electromagnetic wave loss layer 2, and an electromagnetic wave reflection layer 3 from the front to the inside, where the electromagnetic wave transmission layer 1 is composed of the electromagnetic wave transmission composite material of embodiment 4, the electromagnetic wave loss layer 2 is composed of the electromagnetic wave loss composite material of embodiment 8, and the electromagnetic wave reflection layer 3 is composed of a metal plate.

Example 14

This embodiment 14 provides a wave-absorbing composite plate, as shown in fig. 1, the wave-absorbing composite plate is sequentially provided with an electromagnetic wave transmission layer 1, an electromagnetic wave loss layer 2, and an electromagnetic wave reflection layer 3 from the front to the inside, where the electromagnetic wave transmission layer 1 is made of the electromagnetic wave transmission composite material of embodiment 1, the electromagnetic wave loss layer 2 is made of the electromagnetic wave loss composite material of embodiment 9, and the electromagnetic wave reflection layer 3 is made of a metal plate.

Comparative example 1

An alkali-activated slag cementing material is prepared by the following steps:

(2) preparing the alkali-activated slag cementing material: adding 140g of fly ash and 60g of slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding 64g of alkali activator, and stirring for 4-5 min to obtain the alkali-activated slag cementing material.

Comparative example 2

A composite material is prepared by the following steps:

(2) preparing the alkali-activated slag cementing material: adding 140g of fly ash and 60g of slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding 64g of alkali activator, and stirring for 4-5 min to obtain an alkali-activated slag cementing material;

(3) adding 200g of alkali-activated slag cementing material and 40g of expanded polystyrene particles into a paste mixer, stirring for 4-5 min to uniformly mix the materials, then sequentially adding 2g of gum arabic powder and 5mLFP-180 animal foaming agent, stirring for 20-25 s, then quickly filling the stirred materials into a mold and standing for 3h, cutting off the bread heads after molding, and then removing the mold to obtain a test block;

(4) and (3) placing the test block into an autoclave, autoclaving for 8 hours at 180 ℃, and then placing into a curing box with the temperature of 20 ℃ and the humidity of 95% for curing for 3 days to obtain the composite material.

The expanded polystyrene particles used in comparative example 2 were commercially available ordinary expanded polystyrene particles, and were not subjected to any pretreatment before use.

Comparative example 3

An alkali-activated slag cementing material is prepared by the following steps:

(1) preparing an alkali activator: mixing water, water glass and sodium hydroxide, stirring for 10-15 min, and standing for 24h to obtain an alkali activator; according to the mass ratio, water glass and sodium hydroxide are 50:1: 2;

(2) preparing the alkali-activated slag cementing material: adding 700g of fly ash and 300g of slag into a clean slurry stirrer, stirring for 120-150 s to obtain a mixed ash body, then adding 320g of alkali activator, and stirring for 4-5 min to obtain the alkali-activated slag cementing material.

Comparative example 4

A composite material is prepared by the following steps:

(3) mixing 1000g of alkali-activated slag cementing material and 125g of nickel-coated copper powder, stirring for 4-5 min in a slurry mixer, then loading into a mold, vibrating for 15-20 s on a vibrating table, then placing into a curing box, curing for 24h under the environmental conditions of 20 ℃ and 95% of humidity, demolding, and continuously curing the demolded material for 3 days under the same environmental conditions to obtain the composite material.

The nickel-coated copper powder used in comparative example 4 was not subjected to any pretreatment.

Examples of effects

First, electromagnetic wave transmission performance test

The electromagnetic wave transmission composite material of example 1, the alkali-activated slag-binding material of comparative example 1, and the composite material of comparative example 2 were prepared into samples of the same specification, and subjected to an electromagnetic wave transmission performance test.

Test method (bow method): in a microwave anechoic chamber, the power of the electromagnetic wave which passes through a reference metal plate from a transmitting antenna and then reaches a receiving antenna is P1, the power which reaches the receiving antenna after the reference metal plate is changed into a sample plate is P2, and the wave-absorbing reflectivity of the wave-absorbing material is as follows: l-u-s-10 ㏒ (P1/P2).

As shown in fig. 2, a1 is a graph showing a change in electromagnetic wave reflection loss with frequency of a sample plate made of the alkali-activated slag-binding material of comparative example 1, a2 is a graph showing a change in electromagnetic wave reflection loss with frequency of a sample plate made of the composite material of comparative example 2, and A3 is a graph showing a change in electromagnetic wave reflection loss with frequency of a sample plate made of the electromagnetic wave-transmitting composite material of example 1.

And (4) analyzing results: as can be seen from fig. 2, the sample plate made of the electromagnetic wave transmission composite material of example 1 has the best electromagnetic wave transmission performance, and it can also be seen that the electromagnetic wave transmission composite material of the present invention has significantly more excellent electromagnetic transmission performance compared to the gel material, which also indicates that the modified expanded polystyrene particles prepared by the present invention can effectively improve the electromagnetic transmission performance of the composite material.

Second, electromagnetic wave loss performance test

The electromagnetic wave loss composite material of example 5, the alkali-activated slag-binding material of comparative example 3, and the composite material of comparative example 4 were prepared into samples of the same specification, and subjected to an electromagnetic wave loss performance test.

Test method (bow method): in the microwave anechoic chamber, the power of the electromagnetic wave from the transmitting antenna to the receiving antenna through the reference metal plate is P1, the power reaching the receiving antenna after the reference metal plate is changed into a sample plate is P2, and the wave-absorbing reflectivity of the wave-absorbing material is as follows: l-u-s-10 ㏒ (P1/P2).

The results of the tests are shown in FIG. 3, in which B is the electromagnetic wave absorption loss versus frequency curve of the sample plate made of the alkali-activated slag-gelling material of comparative example 3, C is the electromagnetic wave absorption loss versus frequency curve of the sample plate made of the composite material of comparative example 4, and D is the electromagnetic wave absorption loss versus frequency curve of the sample plate made of the electromagnetic wave loss composite material of example 5.

And (4) analyzing results: as can be seen from fig. 3, the sample plate made of the electromagnetic wave loss composite material of example 5 has the best effect on the electromagnetic wave absorption loss, and it can also be seen that the electromagnetic wave loss composite material of the present invention has significantly more excellent electromagnetic absorption loss properties compared to the gel material, which also shows that the porous colloidal particles containing nickel-coated copper powder prepared by the present invention can effectively improve the electromagnetic absorption loss properties of the composite material.

Third, electromagnetic wave absorption loss performance test

The wave-absorbing composite plate of the embodiment 10 and the electromagnetic wave loss composite material of the embodiment 5 are made into sample plates with the same specification, and an electromagnetic wave absorption loss performance test is carried out.

The test results are shown in fig. 4, wherein a in fig. 4 is a curve of the variation of the electromagnetic wave absorption loss with frequency of the sample plate made of the electromagnetic wave loss composite material of example 5, and B is a curve of the variation of the electromagnetic wave absorption loss with frequency of the sample plate made of the wave-absorbing composite plate of example 10.

And (4) analyzing results: as can be seen from fig. 4, compared with the electromagnetic wave loss composite material with a single-layer structure, the wave-absorbing composite plate with three different functional layers has a better function of absorbing the electromagnetic wave loss.

The inventor also carries out the same electromagnetic wave absorption loss performance test on the wave-absorbing composite plate of the embodiment 11-14, and the test result shows that: the electromagnetic wave absorption loss performance of the wave-absorbing composite plates of the embodiments 11 to 14 is close to that of the embodiment 10, which shows that the wave-absorbing composite plate prepared by the invention has excellent electromagnetic wave absorption loss performance and is suitable for electromagnetic shielding building structures.

Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims

1. The wave-absorbing composite board is characterized by comprising an electromagnetic wave transmission layer, an electromagnetic wave loss layer and an electromagnetic wave reflection layer which are sequentially arranged from the surface to the inside, wherein the electromagnetic wave transmission layer comprises an electromagnetic wave transmission composite material, and the electromagnetic wave loss layer comprises an electromagnetic wave loss composite material;

the preparation method of the electromagnetic wave transmission composite material comprises the following steps: firstly, adding sodium bicarbonate into epoxy resin glue, and uniformly mixing to obtain a mixture A; adding a silane coupling agent into the mixture A, uniformly mixing, then adding expanded polystyrene particles, uniformly mixing, adding an alkali-activated slag cementing material after the surfaces of the expanded polystyrene particles are completely wetted, and uniformly mixing to obtain a mixture B; thirdly, before the mixture B is initially solidified, vibrating the mixture B to separate particles, heating the particles in a water bath, and then standing to obtain modified expanded polystyrene particles; uniformly mixing the alkali-activated slag cementing material with the modified expanded polystyrene particles, then sequentially adding the foam stabilizer and the foaming agent, uniformly mixing, then quickly filling into a mold, and removing the mold after shaping to obtain a test block; steaming and curing the test block to obtain the electromagnetic wave transmission composite material;

2. The wave-absorbing composite plate of claim 1, wherein the alkali-activated slag cement is prepared by a method comprising the following steps: uniformly mixing the fly ash and the slag to obtain a mixed ash body, then adding an alkali activator into the mixed ash body, and uniformly mixing to obtain the alkali-activated slag cementing material.

3. The wave-absorbing composite plate according to claim 2, wherein in the preparation method of the alkali-activated slag cementing material, the mass ratio of fly ash to slag is (7:5) - (10: 3).

4. The wave-absorbing composite plate according to claim 2, wherein in the preparation method of the alkali-activated slag cementing material, the mass ratio of fly ash to slag is 7: 3.

5. The wave-absorbing composite plate according to claim 2, wherein in the preparation method of the alkali-activated slag cementing material, the mixed ash and alkali activator are (0.3-0.5) in mass ratio.

6. The wave-absorbing composite plate according to claim 2, wherein in the preparation method of the alkali-activated slag cementing material, the mixed ash and alkali activator are (0.4-0.5) in mass ratio.

7. The wave-absorbing composite plate according to claim 2, wherein in the preparation method of the alkali-activated slag cementing material, the mixed ash and alkali activator are (0.3-0.35) 1 in mass ratio.

8. The wave-absorbing composite plate of claim 2, wherein the alkali-activator is prepared by a method comprising: and uniformly mixing water, water glass and sodium hydroxide, and standing for 24 hours to obtain the alkali activator.

9. The wave-absorbing composite plate according to claim 8, wherein in the preparation method of the alkali activator, the mass ratio of water, water glass and sodium hydroxide is (45-55): 1: 2.

10. The wave-absorbing composite plate according to claim 8, wherein in the preparation method of the alkali activator, the mass ratio of water to water glass to sodium hydroxide is 50:1: 2.

11. The wave-absorbing composite plate according to claim 1, wherein in the step (i) of the preparation method of the electromagnetic wave transmission composite material, in terms of mass-to-volume ratio, 2-3 g of sodium bicarbonate and 20-30 mL of epoxy resin adhesive are added;

in the preparation method of the electromagnetic wave transmission composite material, the silane coupling agent, the mixture A, the foamed polystyrene particles and the alkali-activated slag cementing material are mixed according to a ratio of 1-1.5 mL of the silane coupling agent to 1-12 mL of the foamed polystyrene particles to 10-11 mL of the alkali-activated slag cementing material to 18-22 g of the alkali-activated slag cementing material.

12. The wave-absorbing composite plate according to claim 1, wherein in the step (i) of the preparation method of the electromagnetic wave transmission composite material, the mass-to-volume ratio of sodium bicarbonate to epoxy resin adhesive is 2.5g to 25 mL.

13. The wave-absorbing composite plate according to claim 1, wherein in the step of the preparation method of the electromagnetic wave transmission composite material, the silane coupling agent, the mixture A, the foamed polystyrene particles and the alkali-activated slag binding material are mixed in a ratio of 1mL to 10mL to 20 g.

14. The wave-absorbing composite plate according to claim 1, wherein the preparation method of the electromagnetic wave transmission composite material comprises the following steps of (1) washing and drying the expanded polystyrene particles with deionized water before use;

in the step III of the preparation method of the electromagnetic wave transmission composite material, the particles are heated in a water bath at the temperature of 65-75 ℃ for 10-15 min and then are kept stand for 24h to obtain the modified expanded polystyrene particles.

15. The wave-absorbing composite plate according to claim 1, wherein in the step (r) of the preparation method of the electromagnetic wave transmission composite material, the alkali-activated slag cementing material is modified expanded polystyrene particles (4-6): 1; in the fourth step of the preparation method of the electromagnetic wave transmission composite material, the foam stabilizer, the foaming agent and the modified expanded polystyrene particles are mixed according to the ratio of 2-4 g of the foaming agent to 5-7 mL of the modified expanded polystyrene particles to 40-50 g of the foam stabilizer.

16. The wave-absorbing composite plate according to claim 1, wherein in the step (r) of the preparation method of the electromagnetic wave transmission composite material, the alkali-activated slag cement material, namely, the modified expanded polystyrene particles, is 5: 1; in the step (iv) of the preparation method of the electromagnetic wave transmission composite material, the mixture ratio of the foam stabilizer, the foaming agent and the modified expanded polystyrene particles is that the foam stabilizer is foaming agent, and the modified expanded polystyrene particles are 2g, 5mL and 44 g.

17. The wave-absorbing composite plate according to claim 1, wherein in the step (r) of the preparation method of the electromagnetic wave transmission composite material, the foam stabilizer is gum arabic powder.

18. The wave-absorbing composite plate according to claim 1, wherein in the step (r) of the preparation method of the electromagnetic wave transmission composite material, the foaming agent is an FP-180 animal foaming agent.

19. The wave-absorbing composite plate according to claim 1, wherein in the fifth step of the preparation method of the electromagnetic wave transmission composite material, the test block is placed in an autoclave, autoclaved at 175-185 ℃ for 8 hours, and then placed in a curing oven for curing for 3 days, so as to obtain the electromagnetic wave transmission composite material.

20. The wave absorbing composite panel of claim 19, wherein the curing box has a temperature of 20 ℃ and a humidity of 95%.

21. The wave-absorbing composite plate according to claim 1, wherein in the step (i) of the preparation method of the electromagnetic wave loss composite material, the nickel-coated copper powder, the sodium bicarbonate and the epoxy resin adhesive are 8-12 g, 2-3 g, 18-22 mL; in the fourth step of the preparation method of the electromagnetic wave loss composite material, the alkali-activated slag cementing material and the porous colloidal particles are 8: 1-10: 1 by mass ratio.

22. The wave-absorbing composite plate according to claim 1, wherein in the step (i) of the preparation method of the electromagnetic wave loss composite material, the weight-to-volume ratio of nickel-coated copper powder, sodium bicarbonate and epoxy resin adhesive is 10g, 2.5g and 20 mL.

23. The wave-absorbing composite plate according to claim 1, wherein the preparation method of the electromagnetic wave loss composite material comprises the third step of heating the colloidal particles in a water bath at a temperature of 65-75 ℃ for 10-15 min, and then standing for 24h to obtain porous colloidal particles;

the preparation method of the electromagnetic wave loss composite material comprises the following specific operations: and uniformly mixing the alkali-activated slag cementing material and the porous colloidal particles, then loading into a mold, vibrating for 15-20 s, then placing into a curing box, curing for 24h, removing the mold, and continuously curing the material after mold removal for 3 days to obtain the electromagnetic wave loss composite material.

24. The wave absorbing composite panel of claim 23, wherein the curing is performed at an ambient temperature of 20 ℃ and a humidity of 95%.

25. The wave-absorbing composite plate of any one of claims 1 to 24, wherein the electromagnetic wave reflecting layer comprises a metal plate.

26. The wave-absorbing composite plate of any one of claims 1 to 25 for use in the field of wave-absorbing materials for construction.