Geopolymer material with both wave absorbing and electromagnetic shielding functions and preparation method thereof

Abstract

The present invention provides a geopolymer material having both wave absorption and electromagnetic shielding functions, comprising the following components by weight: 175-280 parts of a siliceous-aluminous mineral raw material, 100-130 parts of an alkali activator, 80-100 parts of a lightweight aggregate, 28-50 parts of a carbon material, and 2-8 parts of methylcellulose. The material preparation method comprises: mixing and stirring the components in the alkali activator until clarified, and allowing to stand; pouring the carbon material component and methylcellulose into the alkali activator solution, stirring and mixing, ultrasonically dispersing, and then adding the lightweight aggregate component thereto and stirring evenly; mixing and stirring the siliceous-aluminous minerals in proportion to obtain a geopolymer powder; and mixing the conductive alkali activator-lightweight aggregate mixture and the geopolymer powder evenly. The advantages of the present invention are that the components of the geopolymer material have good synergistic performance, fully utilizing the lightweight aggregate to construct a conductive network in the geopolymer, so that the lightweight and high-strength geopolymer material has both wave absorption and electromagnetic shielding functions, greatly broadening the application field of the geopolymer.

Description

Technical Field

[0001] The present invention belongs to the field of building materials, and in particular relates to a geopolymer material with both wave absorbing and electromagnetic shielding functions and a preparation method thereof. Background Art

[0002] Academician Qian Qihu, a renowned expert in protective engineering in my country, once stated, "The 21st century is the century of underground space." Research on explosion protection for underground projects has broad and far-reaching implications. On the one hand, as the penetration depth and explosive power of earth-penetrating weapons continue to increase, my country's underground projects and strategic energy storage projects face increasingly severe threats, necessitating an urgent need to enhance their explosion resistance. On the other hand, strategic facilities contain numerous electronic devices. Once exposed to electromagnetic radiation and impact, these devices can easily interfere with their normal operation and pose a significant threat to human health. Therefore, developing a lightweight, high-strength geopolymer material with both electromagnetic absorption and electromagnetic shielding capabilities is of paramount strategic importance.

[0003] Geopolymer is a new, green, and environmentally friendly building material with a network structure composed of AlO4 and SiO4 tetrahedral units. It exhibits excellent properties such as rapid hardening and early strength, high temperature resistance, sulfate resistance, and chemical stability, and has attracted considerable attention from researchers. Current research on the electromagnetic absorption and shielding capabilities of geopolymers focuses primarily on a single property. For example, patent CN111018414B incorporates a silicone-modified conductive filler to enhance the electromagnetic shielding function of geopolymers. Patent application CN106747631A utilizes hydrogen peroxide foaming and the addition of conductive carbon fibers to enhance the geopolymer's electromagnetic absorption. However, this geopolymer primarily absorbs electromagnetic waves, not blast waves. Current building materials are often developed towards multifunctionality and high performance. Therefore, leveraging the characteristics of geopolymers to develop lightweight, high-strength geopolymers with both electromagnetic absorption and electromagnetic shielding capabilities has become a critical issue that urgently needs to be addressed. Summary of the Invention

[0004] In view of the fact that the geopolymer materials in the prior art do not yet have the composite functions of absorbing explosion shock waves and electromagnetic shielding, the present invention provides a geopolymer material with both wave absorbing and electromagnetic shielding functions and a preparation method thereof.

[0005] The technical solution of the present invention is as follows: a geopolymer material with both wave absorbing and electromagnetic shielding functions comprises the following components by weight: 175-280 parts of siliceous and aluminous mineral raw materials, 100-130 parts of alkali activator, 80-100 parts of lightweight aggregate, 28-50 parts of carbon material, and 2-8 parts of methyl cellulose.

[0006] Furthermore, the silica-alumina mineral raw material comprises, by weight, 100-150 parts of granulated blast furnace slag powder, 20-40 parts of fly ash, 30-50 parts of silica fume, 3-8 parts of nano silicon oxide, and 2-5 parts of nano aluminum oxide.

[0007] Preferably, the silicon-alumina mineral raw material further comprises 10-15 parts by mass of nano-reduced iron powder and 10-15 parts by mass of nano-titanium dioxide.

[0008] Furthermore, the lightweight aggregate is at least one of polyurethane lightweight aggregate, clay ceramsite, expanded polystyrene, expanded perlite, and hollow glass microspheres, and the density of the lightweight aggregate is 0.1-0.8 g / cm 3 .

[0009] Furthermore, the carbon material comprises, by weight, 8-15 parts of graphene oxide, 10-20 parts of carbon fibers, 6-10 parts of graphite, and 4-6 parts of carbon nanotubes.

[0010] The present invention also provides a method for preparing a geopolymer material having both wave absorbing and electromagnetic shielding functions, which comprises the following steps:

[0011] S1. Prepare an alkaline activator solution: Mix the components of the alkaline activator in proportion and stir until clear, then let it stand;

[0012] S2. Preparing a conductive alkali activator-light aggregate mixture: Pour the carbon material component and 2-8 parts of methyl cellulose into the alkali activator solution obtained in step S1, stir and mix, and ultrasonically disperse to form a uniform conductive alkali activator solution, then add the lightweight aggregate component thereto and stir evenly to obtain a conductive alkali activator-light aggregate mixture;

[0013] S3. Preparing geopolymer powder: mixing, stirring and grinding silicon-aluminum minerals in proportion;

[0014] S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: uniformly mix the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3.

[0015] Preferably, the mixture is allowed to stand for 24 hours in step S1; and ultrasonic dispersion is performed at 40-50 Hz for 60-80 minutes in step S2.

[0016] Preferably, the method for preparing the geopolymer material comprises the following steps:

[0017] S1. Prepare an alkaline activator solution: mix 75 parts of liquid sodium silicate, 12 parts of sodium hydroxide, and 22 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours;

[0018] S2. Prepare a conductive base activator-light aggregate mixture: add 8 parts of graphene oxide, 10 parts of carbon fiber, 6 parts of graphite, 4 parts of carbon nanotubes, and 2 parts of methyl cellulose to the alkali activator solution obtained in step S1, stir and mix, and then disperse by ultrasonication at 40-50 Hz for 60-80 minutes to form a uniform conductive base activator solution, then add 80 parts of lightweight aggregate into the solution and stir evenly to obtain a conductive base activator-light aggregate mixture;

[0019] S3, preparing geopolymer powder: 110 parts of granulated blast furnace slag powder, 23 parts of fly ash, 32 parts of silica fume, 3 parts of nano silicon oxide, 2 parts of nano aluminum oxide, 10 parts of nano reduced iron powder and 10 parts of nano titanium dioxide are mixed, stirred and ground according to the proportions;

[0020] S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: uniformly mix the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3.

[0021] Preferably, the method for preparing the geopolymer material comprises the following steps:

[0022] S1. Prepare an alkaline activator solution: mix 80 parts of liquid sodium silicate, 12 parts of sodium hydroxide, and 25 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours;

[0023] S2. Prepare a conductive base activator-lightweight aggregate mixture: Pour 12 parts of graphene oxide, 13 parts of carbon fiber, 8 parts of graphite, 5 parts of carbon nanotubes, and 4 parts of methyl cellulose into the alkali activator solution obtained in step S1, stir and mix, and then disperse it by ultrasonication at 40-50 Hz for 60-80 minutes to form a uniform conductive base activator solution, then add 91 parts of lightweight aggregate into the solution and stir evenly to obtain a conductive base activator-lightweight aggregate mixture;

[0024] S3, preparing geopolymer powder: 132 parts of granulated blast furnace slag powder, 28 parts of fly ash, 39 parts of silica fume, 5 parts of nano silicon oxide, 4 parts of nano aluminum oxide, 12 parts of nano reduced iron powder and 13 parts of nano titanium dioxide are mixed, stirred and ground according to the proportions;

[0025] S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: uniformly mix the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3.

[0026] Preferably, the method for preparing the geopolymer material comprises the following steps:

[0027] S1. Prepare an alkaline activator solution: mix 88 parts of liquid sodium silicate, 14 parts of sodium hydroxide, and 28 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours;

[0028] S2. Prepare a conductive base activator-light aggregate mixture: add 15 parts of graphene oxide, 19 parts of carbon fiber, 10 parts of graphite, 6 parts of carbon nanotubes, and 8 parts of methyl cellulose to the alkali activator solution obtained in step S1, stir and mix, and then disperse by ultrasonication at 40-50 Hz for 60-80 minutes to form a uniform conductive base activator solution. Then, add 100 parts of lightweight aggregate and stir evenly to obtain a conductive base activator-light aggregate mixture;

[0029] S3, preparing geopolymer powder: 140 parts of granulated blast furnace slag powder, 35 parts of fly ash, 45 parts of silica fume, 7 parts of nano-silicon oxide, 4 parts of nano-aluminum oxide, 14 parts of nano-reduced iron powder and 13 parts of nano-titanium dioxide are mixed, stirred and ground in proportion;

[0030] S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3 are uniformly mixed to obtain the geopolymer material.

[0031] The advantages of the present invention are: the geopolymer material obtained from the various components of the present invention has good synergistic performance, fully utilizes the unique characteristics of the geopolymer system, and is significantly different from traditional cement-based materials; and fully utilizes lightweight aggregate to construct a conductive network in the geopolymer, so that the lightweight and high-strength geopolymer material has both wave absorption and electromagnetic shielding functions, greatly broadening the application field of the geopolymer. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] The geopolymer material with both wave absorbing and electromagnetic shielding functions provided by the present invention comprises the following components by weight: 175-280 parts of siliceous-aluminous minerals, 100-130 parts of alkali activator, 80-100 parts of lightweight aggregate, 28-50 parts of carbon material, and 2-8 parts of methyl cellulose.

[0034] The silica-alumina minerals include 100-150 parts of granulated blast furnace slag powder, 20-40 parts of fly ash, 30-50 parts of silica fume, 3-8 parts of nano silicon oxide, 2-5 parts of nano aluminum oxide, 10-15 parts of nano reduced iron powder (Fe3O4) and 10-15 parts of nano titanium dioxide.

[0035] The alkaline activator includes 70-90 parts of liquid sodium silicate, 10-15 parts of sodium hydroxide and 20-30 parts of deionized water.

[0036] The lightweight aggregate is at least one of polyurethane lightweight aggregate, clay ceramsite, expanded polystyrene, expanded perlite, and hollow glass microspheres, with a density of 0.1-0.8g / cm 3 .

[0037] The carbon material comprises 8-15 parts of graphene oxide, 10-20 parts of carbon fiber, 6-10 parts of graphite, and 4-6 parts of carbon nanotubes.

[0038] The granulated blast furnace slag powder in the above-mentioned siliceous and aluminous mineral components is rich in components such as silicon dioxide, aluminum oxide, iron oxide and calcium oxide. In addition to providing the required silicon and aluminum elements for the geopolymer reaction, the calcium oxide therein will form a stable three-dimensional silicate structure and CSH gel in the early polymerization reaction, thereby shortening the coagulation time of the geopolymer and improving the early strength of the geopolymer. Among them, the iron oxide has a good electromagnetic shielding effect and can adhere and disperse in the folds of graphene oxide-geopolymer gel, significantly enhancing the magnetic properties of graphene oxide in the geopolymer, and having a good electromagnetic shielding effect.

[0039] Fly ash is added to granulated blast furnace slag, which, on the one hand, provides more silicon and aluminum elements, and on the other hand, can improve the fluidity of geopolymer, reduce the macropores of geopolymer, and improve the density of gel; silica ash can quickly dissolve and release silicon element in geopolymer, improve the reaction ratio of the material, promote fluidity, and increase strength. At the same time, silica ash can improve the interface performance of geopolymer gel and lightweight aggregate, and has an important promoting effect on the construction and formation of conductive network; the high reactivity of nano-silicon oxide and nano-alumina increases nucleation sites for the formation of geopolymer gel, thereby improving the defects between gel and aggregate and enhancing the density of material; nano-reduced iron powder and nano-titanium dioxide, on the one hand, have the function of providing nucleation sites and promoting the density of gel structure, and on the other hand, after reduced iron powder is combined with conductive materials such as graphene oxide in the system, its magnetic properties can be significantly improved, and electromagnetic shielding performance can be fully exerted. Titanium dioxide, as an absorbing material, can cooperate with reduced iron powder to improve the electromagnetic absorbing performance of the system.

[0040] Therefore, the compounding of granulated blast furnace slag powder, fly ash, silica fume, nano-silicon oxide, nano-aluminum oxide, nano-reduced iron powder and nano-titanium dioxide not only provides the silicon and aluminum raw materials required for the geopolymer reaction, but also the components cooperate and react with each other, so that the geopolymer gel system has better density and strength, and exhibits good electromagnetic shielding and the ability to resist explosion shock waves.

[0041] Lightweight aggregates such as polyurethane lightweight aggregate, clay pellets, expanded polystyrene, expanded perlite, and hollow glass microspheres are based on the theory of dense aggregate packing and can be combined with a high-strength geopolymer matrix to make the material have high specific strength, low density, good working performance, and rapid strength development.

[0042] The method for preparing the geopolymer material of the present invention specifically comprises the following steps:

[0043] S1. Prepare an alkaline activator solution: Mix the components of the alkaline activator in proportion and stir until clear, and let it stand for 24 hours;

[0044] S2. Preparing a conductive alkali activator-lightweight aggregate mixture: Pour the carbon material component and 2-8 parts of methyl cellulose into the alkali activator solution obtained in step S1, stir and mix, and then disperse using 40-50 Hz ultrasound for 60-80 minutes to form a uniform conductive alkali activator solution, then add the lightweight aggregate component into the solution and stir evenly to obtain a conductive alkali activator-lightweight aggregate mixture;

[0045] S3. Preparing geopolymer powder: mixing, stirring and grinding silicon-aluminum minerals in proportion;

[0046] S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: The conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3 are uniformly mixed to obtain the geopolymer material of the present invention.

[0047] In the above step S2, the carbon material components, methyl cellulose, and lightweight aggregate are all added to the alkaline activator and mixed. This is because the functional groups such as hydroxyl and carboxyl in the graphene oxide in the carbon material can react with the methyl cellulose to make the nanomaterials such as carbon nanotubes, iron oxide, and titanium dioxide evenly dispersed in the geopolymer, thereby better exerting the promoting effect of fibers and nanomaterials on strength.

[0048] In addition to dispersing the carbon material, the alkaline activator, due to its strong alkalinity, can partially reduce graphene oxide, resulting in a two-dimensional structure with numerous wrinkles, folds, and grooves. Nanomaterials such as carbon nanotubes, iron oxide, and titanium dioxide are dispersed by the wrinkles and grooves. The geopolymer gel, relying on the nanomaterials, extends and expands on this two-dimensional structure, forming a regular, similar crystal structure. Together with the carbon fibers, it forms a unique three-dimensional gel system. This three-dimensional gel system not only significantly enhances the magnetic properties of the iron oxide in the reduced iron powder and granulated blast furnace slag, but also has good electrical conductivity, which can fully utilize the mechanisms of electrical and magnetic loss. In addition to its conductive function, the carbon fibers in the carbon material can bridge the lightweight aggregate and the gel matrix, inhibiting the formation of microcracks within the geopolymer.

[0049] Stirring the lightweight aggregate in the conductive alkali activator allows the alkali activator to partially soak into the aggregate. When reacting with the geopolymer powder, the nanomaterial's binding effect between the two is fully utilized, reducing interfacial defects, improving bonding properties and material strength, and enhancing the system's microwave absorption performance. Furthermore, because the alkali activator is conductive, soaking it in the alkali activator organically bonds the non-conductive lightweight aggregate, the alkali activator solution, and the carbon material. This allows conductive materials such as carbon fibers, reduced graphene oxide, and carbon nanotubes to adhere more easily. Together with the alkali activator solution within the aggregate, this forms a stable, continuous three-dimensional conductive network, thereby enhancing the system's electromagnetic shielding performance.

[0050] After the conductive base activator-lightweight aggregate mixture and the geopolymer powder are mixed in step S4, the densification effect of the silica fume and the nucleation effect of the nanomaterial can improve the interface properties between the carbon fiber and the geopolymer, wrap and anchor the carbon fiber in the gel, greatly improve the bonding strength between the fiber and the matrix, and significantly improve the strength and toughness of the material, so that it can withstand higher explosion shock waves.

[0051] The nucleation effect provided by carbon nanotubes, graphene, nano-alumina, silica and other nanofillers, the micro-aggregate effect of granulated blast furnace slag and the bridging effect of carbon fiber can fully fill and compact the defects and pores between the aggregate and the gel, thereby enhancing the material's ability to weaken shock waves by impedance matching, increasing its ability to elastically and plastically deform and consuming a large amount of energy in the deformation, and can better withstand the effects of instantaneous explosion loads.

[0052] The preparation process and technical effects of the present invention are described in detail below through several groups of examples.

[0053] Example 1

[0054] The method for preparing geopolymer material specifically comprises the following steps:

[0055] S1. Prepare an alkaline activator solution: mix 75 parts of liquid sodium silicate, 12 parts of sodium hydroxide, and 22 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours;

[0056] S2. Prepare a conductive base activator-light aggregate mixture: add 8 parts of graphene oxide, 10 parts of carbon fiber, 6 parts of graphite, 4 parts of carbon nanotubes, and 2 parts of methyl cellulose to the alkali activator solution obtained in step S1, stir and mix, and then disperse by ultrasonication at 40-50 Hz for 60-80 minutes to form a uniform conductive base activator solution, then add 80 parts of lightweight aggregate into the solution and stir evenly to obtain a conductive base activator-light aggregate mixture;

[0057] S3, preparing geopolymer powder: 110 parts of granulated blast furnace slag powder, 23 parts of fly ash, 32 parts of silica fume, 3 parts of nano silicon oxide, 2 parts of nano aluminum oxide, 10 parts of nano reduced iron powder and 10 parts of nano titanium dioxide are mixed, stirred and ground according to the proportions;

[0058] S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3 are uniformly mixed to obtain the geopolymer material.

[0059] Example 2

[0060] The method for preparing geopolymer material specifically comprises the following steps:

[0061] S1. Prepare an alkaline activator solution: mix 80 parts of liquid sodium silicate, 12 parts of sodium hydroxide, and 25 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours;

[0062] S2. Prepare a conductive base activator-lightweight aggregate mixture: Pour 12 parts of graphene oxide, 13 parts of carbon fiber, 8 parts of graphite, 5 parts of carbon nanotubes, and 4 parts of methyl cellulose into the alkali activator solution obtained in step S1, stir and mix, and then disperse it by ultrasonication at 40-50 Hz for 60-80 minutes to form a uniform conductive base activator solution, then add 91 parts of lightweight aggregate into the solution and stir evenly to obtain a conductive base activator-lightweight aggregate mixture;

[0063] S3, preparing geopolymer powder: 132 parts of granulated blast furnace slag powder, 28 parts of fly ash, 39 parts of silica fume, 5 parts of nano silicon oxide, 4 parts of nano aluminum oxide, 12 parts of nano reduced iron powder and 13 parts of nano titanium dioxide are mixed, stirred and ground according to the proportions;

[0064] S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3 are uniformly mixed to obtain the geopolymer material.

[0065] Example 3

[0066] The method for preparing geopolymer material specifically comprises the following steps:

[0067] S1. Prepare an alkaline activator solution: mix 88 parts of liquid sodium silicate, 14 parts of sodium hydroxide, and 28 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours;

[0068] S2. Prepare a conductive base activator-light aggregate mixture: add 15 parts of graphene oxide, 19 parts of carbon fiber, 10 parts of graphite, 6 parts of carbon nanotubes, and 8 parts of methyl cellulose to the alkali activator solution obtained in step S1, stir and mix, and then disperse by ultrasonication at 40-50 Hz for 60-80 minutes to form a uniform conductive base activator solution. Then, add 100 parts of lightweight aggregate and stir evenly to obtain a conductive base activator-light aggregate mixture;

[0069] S3, preparing geopolymer powder: 140 parts of granulated blast furnace slag powder, 35 parts of fly ash, 45 parts of silica fume, 7 parts of nano-silicon oxide, 4 parts of nano-aluminum oxide, 14 parts of nano-reduced iron powder and 13 parts of nano-titanium dioxide are mixed, stirred and ground in proportion;

[0070] S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3 are uniformly mixed to obtain the geopolymer material.

[0071] Comparative Example 1

[0072] The method for preparing geopolymer material specifically comprises the following steps:

[0073] S1. Prepare an alkaline activator solution: mix 73 parts of liquid sodium silicate, 11 parts of sodium hydroxide, and 22 parts of deionized water in proportion, stir until clear, and let stand for 24 hours;

[0074] S2. Preparing an alkali activator-lightweight aggregate mixture: Pour 92 parts of lightweight aggregate into the alkali activator solution obtained in step S1 and stir evenly to obtain an alkali activator-lightweight aggregate mixture;

[0075] S3. Preparation of geopolymer powder: 120 parts of granulated blast furnace slag powder, 22 parts of fly ash, 32 parts of silica fume, 4 parts of nano-silicon oxide, and 2 parts of nano-aluminum oxide are mixed, stirred, and ground in appropriate proportions;

[0076] S4. Preparation of a lightweight, high-strength geopolymer material having both wave-absorbing and electromagnetic shielding functions: uniformly mixing the alkali activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3 to obtain the geopolymer material.

[0077] Comparative Example 2

[0078] The method for preparing geopolymer material specifically comprises the following steps:

[0079] S1. Prepare an alkaline activator solution: mix 72 parts of liquid sodium silicate, 12 parts of sodium hydroxide, and 25 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours;

[0080] S2. Preparing an alkali activator-lightweight aggregate mixture: Pour 94 parts of lightweight aggregate into the alkali activator solution obtained in step S1 and stir evenly to obtain an alkali activator-lightweight aggregate mixture;

[0081] S3, preparing geopolymer powder: 132 parts of granulated blast furnace slag powder, 28 parts of fly ash, 39 parts of silica fume, 5 parts of nano silicon oxide, 4 parts of nano aluminum oxide, 12 parts of nano reduced iron powder and 13 parts of nano titanium dioxide are mixed, stirred and ground according to the proportions;

[0082] S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3 are uniformly mixed to obtain the geopolymer material.

[0083] Comparative Example 3

[0084] The method for preparing geopolymer material specifically comprises the following steps:

[0085] S1. Prepare an alkaline activator solution: mix 73 parts of liquid sodium silicate, 12 parts of sodium hydroxide, and 25 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours;

[0086] S2. Prepare a conductive base activator mixture: add 10 parts of graphene oxide, 11 parts of carbon fiber, 7 parts of graphite, 4 parts of carbon nanotubes, and 2 parts of methyl cellulose to the base activator solution obtained in step S1, stir and mix, and then disperse using 40-50 Hz ultrasound for 60-80 minutes to form a uniform conductive base activator solution;

[0087] S3, preparing geopolymer powder: 120 parts of granulated blast furnace slag powder, 30 parts of fly ash, 20 parts of silica fume, 4 parts of nano silicon oxide, 3 parts of nano aluminum oxide, 10 parts of nano reduced iron powder and 12 parts of nano titanium dioxide are mixed, stirred and ground according to the proportions;

[0088] S4. Preparation of a geopolymer material having both wave absorbing and electromagnetic shielding functions: the conductive base activator mixture obtained in step S2 and the geopolymer powder obtained in step S3 are uniformly mixed to obtain the geopolymer material.

[0089] The samples prepared in Examples 1-3 and Comparative Examples 1-3 were selected to conduct specific absorption energy based dynamic compression tests on an 80mm SHPB testing machine using a φ68×34mm 3 Cylindrical specimen, controlled strain rate 10s -1Six samples were tested for each mix ratio, and the specific absorption energy was calculated based on the stress-strain curve of the test results. The density is the dry apparent density, measured based on the "Test Method for Performance of Foam Concrete Products" JC / T2357-2016. The electromagnetic shielding performance test method refers to the "Measurement Method of Shielding Effectiveness of Electromagnetic Shielding Materials" GJB6190-2008, using the flange coaxial device method and a network vector analyzer in the 2-18 GHz frequency band. The results of the prepared geopolymer material with both wave absorption and electromagnetic shielding functions are shown in Table 1.

[0090] Table 1. Performance test results of geopolymer materials with both wave absorption and electromagnetic shielding functions

[0091] performance <![CDATA[Specific absorption energy (kJ / m 3 )]]> <![CDATA[Density (g / cm 3 )]]> Attenuation intensity (dB) Example 1 105 0.68 31.4 Example 2 120 0.56 33.8 Example 3 130 0.45 34.5 Comparative Example 1 72 0.54 5.3 Comparative Example 2 75 0.52 10.2 Comparative Example 3 58 1.89 25.3

[0092] As can be seen from the above table, the geopolymer materials of Examples 1 to 3 have high overall specific absorption energy, good explosion shock wave absorption performance, light density, high attenuation strength in the 2-18 GHz frequency band, and good electromagnetic shielding performance.

[0093] In Comparative Examples 1 and 2, since no carbon material and methyl cellulose are added in step S2, only lightweight aggregate is contained in the alkali activator, and there is no reduction of graphene oxide in the geopolymer to form two-dimensional structures such as wrinkles, folds and grooves. There is also no composite effect of graphene oxide and methyl cellulose, no conductive effect of carbon fiber, and no effect of inhibiting microcracks inside the geopolymer. As a result, the overall material has lower strength in the explosion shock wave and weaker electromagnetic shielding function. In Comparative Example 2, since more reduced iron powder and nano-titanium dioxide are added in step S3 than in Comparative Example 1, there are more nucleation sites than in Comparative Example 1, and the material strength is slightly better, but still relatively low.

[0094] In Comparative Example 3, since no lightweight aggregate is added in step S2, the nanomaterial cannot play a binding role in the conductive activator and the lightweight aggregate during the reaction of the geopolymer powder. There are defects in the interface, the material strength is insufficient, the explosion shock wave resistance is low; and the density is high.

[0095] Therefore, it can be explained that the various components of the present invention cooperate and react with each other, showing light weight, high strength, good electromagnetic shielding and the ability to resist explosion shock waves; and greatly broadening the application field of geopolymers.

[0096] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with this patent can make slight changes or modifications to equivalent embodiments using the above technical content without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the solution of the present invention.

Claims

1. A geopolymer material with both wave absorbing and electromagnetic shielding functions, characterized in that: The composition comprises the following components by weight: 175-280 parts of silicon-aluminum mineral raw material, 100-130 parts of alkali activator, 80-100 parts of lightweight aggregate, 28-50 parts of carbon material, and 2-8 parts of methyl cellulose; The silica-alumina mineral raw materials include, by weight, 100-150 parts of granulated blast furnace slag powder, 20-40 parts of fly ash, 30-50 parts of silica fume, 3-8 parts of nano silicon oxide, 2-5 parts of nano aluminum oxide, 10-15 parts of nano reduced iron powder and 10-15 parts of nano titanium dioxide; The carbon material comprises, by weight, 8-15 parts of graphene oxide, 10-20 parts of carbon fibers, 6-10 parts of graphite, and 4-6 parts of carbon nanotubes; The alkaline activator comprises 7090 parts of liquid sodium silicate, 1015 parts of sodium hydroxide and 2030 parts of deionized water in parts by weight.

2. The geopolymer material having both wave absorbing and electromagnetic shielding functions according to claim 1, characterized in that: The lightweight aggregate is at least one of polyurethane lightweight aggregate, clay ceramsite, expanded polystyrene, expanded perlite, and hollow glass microspheres, and the density of the lightweight aggregate is 0.1-0.8 g / cm 3 .

3. A method for preparing a geopolymer material, for preparing the geopolymer material having both wave absorbing and electromagnetic shielding functions according to claim 1 or 2, characterized in that: The steps include: S1. Prepare an alkaline activator solution: Mix the components of the alkaline activator in proportion and stir until clear, then let it stand; S2. Preparing a conductive alkali activator-light aggregate mixture: Pour the carbon material component and 2-8 parts of methyl cellulose into the alkali activator solution obtained in step S1, stir and mix, and ultrasonically disperse to form a uniform conductive alkali activator solution, then add the lightweight aggregate component thereto and stir evenly to obtain a conductive alkali activator-light aggregate mixture; S3. Preparing geopolymer powder: mixing, stirring and grinding silicon-aluminum minerals in proportion; S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: uniformly mix the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3.

4. The method for preparing a geopolymer material according to claim 3, wherein: In step S1, the mixture is allowed to stand for 24 hours; in step S2, ultrasonic dispersion is performed at 40-50 Hz for 60-80 minutes.

5. The method for preparing a geopolymer material according to claim 3 or 4, characterized in that: The steps include: S1. Prepare an alkaline activator solution: mix 75 parts of liquid sodium silicate, 12 parts of sodium hydroxide, and 22 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours; S2. Prepare a conductive base activator-light aggregate mixture: add 8 parts of graphene oxide, 10 parts of carbon fiber, 6 parts of graphite, 4 parts of carbon nanotubes, and 2 parts of methyl cellulose to the alkali activator solution obtained in step S1, stir and mix, and then disperse by ultrasonication at 40-50 Hz for 60-80 minutes to form a uniform conductive base activator solution, then add 80 parts of lightweight aggregate into the solution and stir evenly to obtain a conductive base activator-light aggregate mixture; S3, preparing geopolymer powder: 110 parts of granulated blast furnace slag powder, 23 parts of fly ash, 32 parts of silica fume, 3 parts of nano silicon oxide, 2 parts of nano aluminum oxide, 10 parts of nano reduced iron powder and 10 parts of nano titanium dioxide are mixed, stirred and ground according to the proportions; S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: uniformly mix the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3.

6. The method for preparing a geopolymer material according to claim 3 or 4, characterized in that: The steps include: S1. Prepare an alkaline activator solution: mix 80 parts of liquid sodium silicate, 12 parts of sodium hydroxide, and 25 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours; S2. Prepare a conductive base activator-lightweight aggregate mixture: Pour 12 parts of graphene oxide, 13 parts of carbon fiber, 8 parts of graphite, 5 parts of carbon nanotubes, and 4 parts of methyl cellulose into the alkali activator solution obtained in step S1, stir and mix, and then disperse it by ultrasonication at 40-50 Hz for 60-80 minutes to form a uniform conductive base activator solution, then add 91 parts of lightweight aggregate into the solution and stir evenly to obtain a conductive base activator-lightweight aggregate mixture; S3, preparing geopolymer powder: 132 parts of granulated blast furnace slag powder, 28 parts of fly ash, 39 parts of silica fume, 5 parts of nano silicon oxide, 4 parts of nano aluminum oxide, 12 parts of nano reduced iron powder and 13 parts of nano titanium dioxide are mixed, stirred and ground according to the proportions; S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: uniformly mix the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3.

7. The method for preparing a geopolymer material according to claim 3 or 4, characterized in that: The steps include: S1. Prepare an alkaline activator solution: mix 88 parts of liquid sodium silicate, 14 parts of sodium hydroxide, and 28 parts of deionized water in proportion, stir until clear, and let it stand for 24 hours; S2. Prepare a conductive base activator-light aggregate mixture: add 15 parts of graphene oxide, 19 parts of carbon fiber, 10 parts of graphite, 6 parts of carbon nanotubes, and 8 parts of methyl cellulose to the alkali activator solution obtained in step S1, stir and mix, and then disperse by ultrasonication at 40-50 Hz for 60-80 minutes to form a uniform conductive base activator solution. Then, add 100 parts of lightweight aggregate and stir evenly to obtain a conductive base activator-light aggregate mixture; S3, preparing geopolymer powder: 140 parts of granulated blast furnace slag powder, 35 parts of fly ash, 45 parts of silica fume, 7 parts of nano-silicon oxide, 4 parts of nano-aluminum oxide, 14 parts of nano-reduced iron powder and 13 parts of nano-titanium dioxide are mixed, stirred and ground in proportion; S4. Preparation of geopolymer material with both wave absorbing and electromagnetic shielding functions: the conductive base activator-lightweight aggregate mixture obtained in step S2 and the geopolymer powder obtained in step S3 are uniformly mixed to obtain the geopolymer material.