A biomass charcoal-based composite material and a preparation method and application thereof
By preparing biomass carbon-based composite materials and combining loofah sponge with polyacid solution to form porous composite materials, the problems of high density and narrow frequency of existing electromagnetic wave absorbing materials are solved, and a thin and efficient electromagnetic wave absorption effect is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANTONG UNIV
- Filing Date
- 2024-04-18
- Publication Date
- 2026-07-24
Smart Images
Figure CN118439583B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of functional materials technology, specifically relating to a biomass carbon-based composite material, its preparation method, and its application. Background Technology
[0002] With the continuous development of electromagnetic technology, more and more electromagnetic devices are entering daily life and military applications. While these devices bring many conveniences to humanity, they also pose significant risks. Scientific research has shown that prolonged exposure to a strong electromagnetic radiation environment can severely damage bodily functions. In the military field, technological advancements have led to the development of successive generations of high-precision detection equipment, posing a serious threat to the stealth capabilities of military equipment such as missiles and tanks. Therefore, improving stealth technology is the most effective way to mitigate this threat, and the key to improving stealth technology lies in developing excellent electromagnetic wave absorbing materials. Currently, absorbing materials mainly include ferrites, ceramics, nanomaterials, and conductive polymers. However, current absorbing materials suffer from problems such as high density, narrow absorption frequency bands, and poor impedance matching in single-component absorption performance. Therefore, developing lightweight, thin, and stable composite materials is an important direction for research on absorption performance.
[0003] Biomass carbon is environmentally friendly, inexpensive, and has stable performance. Its surface and spatial structure contain a large number of residual functional groups, and its internal spatial structure has spatial defects, which are beneficial to electromagnetic wave absorption performance and electromagnetic loss. Summary of the Invention
[0004] In view of this, the purpose of this invention is to provide a biomass carbon-based composite material, its preparation method and application, which has both magnetic loss and dielectric loss, superior wave absorption performance, and a simple preparation method.
[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:
[0006] A method for preparing a biomass carbon-based composite material includes the following steps:
[0007] S1. Mix loofah sponge, N,N-dimethylformamide and epichlorohydrin, and react at 80℃-100℃ for 0.5h-1.5h with stirring. Add ethylenediamine and continue the reaction for 0.5h-1.5h. Add triethylamine and continue the reaction for 1.5h-3h. Wash and dry the reaction product to obtain cationic modified loofah sponge.
[0008] S2. The cationic modified loofah sponge is soaked in a polyacid solution, dried, and then calcined at high temperature under an inert atmosphere to obtain a biomass carbon-based composite material.
[0009] On the one hand, loofah sponge has abundant functional groups and unique micro-nano structures. High temperatures can preserve the cavities of biomass materials and transform them into conductive carbon materials, which is conducive to the formation of conductive networks and spatial defects in microwave absorbing materials. On the other hand, polyoxometalates in polyacid solutions have a clear crystal structure and excellent redox properties as metal clusters. The cation-modified loofah sponge combines with polyacids through electrostatic attraction, which helps to form heterojunctions and improve the interfacial polarization effect.
[0010] Furthermore, in step S1, the loofah sponge is a loofah sponge that has undergone alkali treatment. The alkali treatment specifically involves immersing the loofah sponge in NaOH solution for 10-24 hours, washing it with pure water until neutral, and then drying it at 60°C.
[0011] Furthermore, in step S1, the mass ratio of the loofah sponge, N,N-dimethylformamide, epichlorohydrin, ethylenediamine, and triethylamine is 0.5:100-150:50-100:5-10:5-10.
[0012] Further, step S1 specifically involves: mixing the cationic modified loofah sponge, N,N-dimethylformamide and epichlorohydrin, reacting at 85°C for 1 hour with stirring, adding ethylenediamine, continuing the reaction for 1 hour, adding triethylamine, and continuing the reaction for 2 hours.
[0013] Furthermore, the polyacid solution is K5[FeW] 12 O 40 ]·10H2O、KH4[CoW 12 O 40 ]·18H2O and K[BW 12 O 40 A solution prepared from 11.4H2O.
[0014] Furthermore, in step S2, the concentration of the polyacid solution is 1-10 g / L, and the ratio of the amount of loofah sponge to the polyacid solution is 3 g: 500 mL.
[0015] Furthermore, in step S2, the soaking time is 8 to 24 hours.
[0016] Furthermore, in step S2, the high-temperature calcination under an inert atmosphere specifically involves: placing the material in a ceramic boat and then in a tube furnace, introducing nitrogen gas into the tube furnace for protection, heating at 2-5℃ / min to 600-900℃ for high-temperature calcination and holding for 2 hours to obtain a biomass carbon-based composite material.
[0017] The present invention also provides a biomass carbon-based composite material prepared by the above-described preparation method.
[0018] The present invention also provides an application of the above-mentioned biomass carbon-based composite material in the preparation of microwave absorbing materials.
[0019] Compared with existing technologies, the raw material used in this invention, biomass loofah sponge, is inexpensive, renewable, and abundant, and has a unique three-dimensional network. The excellent electromagnetic properties of polyacids, combined with the high-temperature calcination of the two to form a porous composite material, promote the repeated absorption of electromagnetic waves and improve the wave absorption performance of the material. Attached Figure Description
[0020] Figure 1 Electromagnetic wave absorption performance of the biomass char-based composite material prepared in Example 7. Detailed Implementation
[0021] Example 1
[0022] (1) Immerse the loofah sponge sample in a 10% NaOH solution for 12 hours, then wash it with pure water until it is neutral, and dry it at 60°C to remove the grease and other byproducts on the surface of the loofah sponge. Then make it into a 1cm*1cm sample.
[0023] (2) 0.5g of alkali-treated loofah sponge, 113g of N,N-dimethylformamide and 70g of epichlorohydrin were placed in a three-necked flask at 85℃ and stirred for 1h. 7.2g of ethylenediamine was added and the reaction was continued for 1h. Then 7.3g of triethylamine was added and the reaction was carried out. After 2h of reaction, the mixture was quickly poured out, washed with distilled water and dried in an oven at 60℃ to obtain cationic modified loofah sponge.
[0024] (3) Place 0.3g of cationic modified loofah sponge into 50mL of 2g / L K5[FeW] solution. 12 O 40 Soak in a polyacid solution of 10H2O for 24 hours, then remove and dry in an oven at 60℃.
[0025] (4) Place the above-mentioned loofah sponge in a ceramic boat and place it in a tube furnace. Introduce nitrogen into the tube furnace for protection, heat it at 3℃ / min to 650℃ for high-temperature calcination and hold for 2 hours to obtain biomass carbon-based composite material.
[0026] Example 2
[0027] (1) Immerse the loofah sponge sample in a 10% NaOH solution for 12 hours, then wash it with pure water until it is neutral, and dry it at 60°C to remove the grease and other byproducts on the surface of the loofah sponge. Then make it into a 1cm*1cm sample.
[0028] (2) 0.5g of alkali-treated loofah sponge, 113g of N,N-dimethylformamide and 70g of epichlorohydrin were placed in a three-necked flask at 85℃ and stirred for 1h. 7.2g of ethylenediamine was added and the reaction was continued for 1h. Then 7.3g of triethylamine was added and the reaction was carried out. After 2h of reaction, the mixture was quickly poured out, washed with distilled water and dried in an oven at 60℃ to obtain cationic modified loofah sponge.
[0029] (3) Place 0.3g of cationic modified loofah sponge into 50mL of 2g / L KH4[CoW] 12 O 40 Soak in a polyacid solution of 18H2O for 24 hours, then remove and dry in an oven at 60℃.
[0030] (4) Place the above-mentioned loofah sponge in a ceramic boat and place it in a tube furnace. Introduce nitrogen into the tube furnace for protection, heat it at 3℃ / min to 650℃ for high-temperature calcination and hold for 2 hours to obtain biomass carbon-based composite material.
[0031] Example 3
[0032] (1) Immerse the loofah sponge sample in a 10% NaOH solution for 12 hours, then wash it with pure water until it is neutral, and dry it at 60°C to remove the grease and other byproducts on the surface of the loofah sponge. Then make it into a 1cm*1cm sample.
[0033] (2) 0.5g of alkali-treated loofah sponge, 113g of N,N-dimethylformamide and 70g of epichlorohydrin were placed in a three-necked flask at 85℃ and stirred for 1h. 7.2g of ethylenediamine was added and the reaction was continued for 1h. Then 7.3g of triethylamine was added and the reaction was carried out. After 2h of reaction, the mixture was quickly poured out, washed with distilled water and dried in an oven at 60℃ to obtain cationic modified loofah sponge.
[0034] (3) Place 0.3g of cationic modified loofah sponge into 50mL of 2g / L K[BW] solution. 12 O 40 Soak in 11.4H2O polyacid solution for 24 hours, then remove and dry in an oven at 60℃.
[0035] (4) Place the above-mentioned loofah sponge in a ceramic boat and place it in a tube furnace. Introduce nitrogen into the tube furnace for protection, heat it at 3℃ / min to 650℃ for high-temperature calcination and hold for 2 hours to obtain biomass carbon-based composite material.
[0036] Example 4
[0037] (1) Immerse the loofah sponge sample in a 10% NaOH solution for 12 hours, then wash it with pure water until it is neutral, and dry it at 60°C to remove the grease and other byproducts on the surface of the loofah sponge. Then make it into a 1cm*1cm sample.
[0038] (2) 0.5g of alkali-treated loofah sponge, 113g of N,N-dimethylformamide and 70g of epichlorohydrin were placed in a three-necked flask at 85℃ and stirred for 1h. 7.2g of ethylenediamine was added and the reaction was continued for 1h. Then 7.3g of triethylamine was added and the reaction was carried out. After 2h of reaction, the mixture was quickly poured out, washed with distilled water and dried in an oven at 60℃ to obtain cationic modified loofah sponge.
[0039] (3) Place 0.3g of cationic modified loofah sponge into 50mL of 2g / L K5[FeW] solution. 12 O 40 Soak in a polyacid solution of 10H2O for 24 hours, then remove and dry in an oven at 60℃.
[0040] (4) Place the above-mentioned loofah sponge in a ceramic boat and place it in a tube furnace. Introduce nitrogen into the tube furnace for protection, heat it at 3℃ / min to 700℃ for high-temperature calcination and hold for 2 hours to obtain biomass carbon-based composite material.
[0041] Example 5
[0042] (1) Immerse the loofah sponge sample in a 10% NaOH solution for 12 hours, then wash it with pure water until it is neutral, and dry it at 60°C to remove the grease and other byproducts on the surface of the loofah sponge. Then make it into a 1cm*1cm sample.
[0043] (2) 0.5g of alkali-treated loofah sponge, 113g of N,N-dimethylformamide and 70g of epichlorohydrin were placed in a three-necked flask at 85℃ and stirred for 1h. 7.2g of ethylenediamine was added and the reaction was continued for 1h. Then 7.3g of triethylamine was added and the reaction was carried out. After 2h of reaction, the mixture was quickly poured out, washed with distilled water and dried in an oven at 60℃ to obtain cationic modified loofah sponge.
[0044] (3) Place 0.3g of cationic modified loofah sponge into 50mL of 2g / L KH4[CoW] 12 O 40 Soak in a polyacid solution of 18H2O for 24 hours, then remove and dry in an oven at 60℃.
[0045] (4) Place the above-mentioned loofah sponge in a ceramic boat and place it in a tube furnace. Introduce nitrogen into the tube furnace for protection, heat it at 3℃ / min to 700℃ for high-temperature calcination and hold for 2 hours to obtain biomass carbon-based composite material.
[0046] Example 6
[0047] (1) Immerse the loofah sponge sample in a 10% NaOH solution for 12 hours, then wash it with pure water until it is neutral, and dry it at 60°C to remove the grease and other byproducts on the surface of the loofah sponge. Then make it into a 1cm*1cm sample.
[0048] (2) 0.5g of alkali-treated loofah sponge, 113g of N,N-dimethylformamide and 70g of epichlorohydrin were placed in a three-necked flask at 85℃ and stirred for 1h. 7.2g of ethylenediamine was added and the reaction was continued for 1h. Then 7.3g of triethylamine was added and the reaction was carried out. After 2h of reaction, the mixture was quickly poured out, washed with distilled water and dried in an oven at 60℃ to obtain cationic modified loofah sponge.
[0049] (3) Place 0.3g of cationic modified loofah sponge into 50mL of 2g / L K[BW] solution. 12 O 40 Soak in 11.4H2O polyacid solution for 24 hours, then remove and dry in an oven at 60℃.
[0050] (4) Place the above-mentioned loofah sponge in a ceramic boat and place it in a tube furnace. Introduce nitrogen into the tube furnace for protection, heat it at 3℃ / min to 700℃ for high-temperature calcination and hold for 2 hours to obtain biomass carbon-based composite material.
[0051] Example 7
[0052] (1) Immerse the loofah sponge sample in a 10% NaOH solution for 12 hours, then wash it with pure water until it is neutral, and dry it at 60°C to remove the grease and other byproducts on the surface of the loofah sponge. Then make it into a 1cm*1cm sample.
[0053] (2) 0.5g of alkali-treated loofah sponge, 113g of N,N-dimethylformamide and 70g of epichlorohydrin were placed in a three-necked flask at 85℃ and stirred for 1h. 7.2g of ethylenediamine was added and the reaction was continued for 1h. Then 7.3g of triethylamine was added and the reaction was carried out. After 2h of reaction, the mixture was quickly poured out, washed with distilled water and dried in an oven at 60℃ to obtain cationic modified loofah sponge.
[0054] (3) Place 0.3g of cationic modified loofah sponge into 50mL of 2g / L K5[FeW] solution. 12 O 40 Soak in a polyacid solution of 10H2O for 24 hours, then remove and dry in an oven at 60℃.
[0055] (4) Place the above-mentioned loofah sponge in a ceramic boat and place it in a tube furnace. Introduce nitrogen into the tube furnace for protection, heat it at 3℃ / min to 750℃ for high-temperature calcination and hold for 2 hours to obtain biomass carbon-based composite material.
[0056] Example 8
[0057] (1) Immerse the loofah sponge sample in a 10% NaOH solution for 12 hours, then wash it with pure water until it is neutral, and dry it at 60°C to remove the grease and other byproducts on the surface of the loofah sponge. Then make it into a 1cm*1cm sample.
[0058] (2) 0.5g of alkali-treated loofah sponge, 113g of N,N-dimethylformamide and 70g of epichlorohydrin were placed in a three-necked flask at 85℃ and stirred for 1h. 7.2g of ethylenediamine was added and the reaction was continued for 1h. Then 7.3g of triethylamine was added and the reaction was carried out. After 2h of reaction, the mixture was quickly poured out, washed with distilled water and dried in an oven at 60℃ to obtain cationic modified loofah sponge.
[0059] (3) Place 0.3g of cationic modified loofah sponge into 50mL of 2g / L KH4[CoW] 12 O 40 Soak in a polyacid solution of 18H2O for 24 hours, then remove and dry in an oven at 60℃.
[0060] (4) Place the above-mentioned loofah sponge in a ceramic boat and place it in a tube furnace. Introduce nitrogen into the tube furnace for protection, heat it at 3℃ / min to 750℃ for high-temperature calcination and hold for 2 hours to obtain biomass carbon-based composite material.
[0061] Example 9
[0062] (1) Immerse the loofah sponge sample in a 10% NaOH solution for 12 hours, then wash it with pure water until it is neutral, and dry it at 60°C to remove the grease and other byproducts on the surface of the loofah sponge. Then make it into a 1cm*1cm sample.
[0063] (2) 0.5g of alkali-treated loofah sponge, 113g of N,N-dimethylformamide and 70g of epichlorohydrin were placed in a three-necked flask at 85℃ and stirred for 1h. 7.2g of ethylenediamine was added and the reaction was continued for 1h. Then 7.3g of triethylamine was added and the reaction was carried out. After 2h of reaction, the mixture was quickly poured out, washed with distilled water and dried in an oven at 60℃ to obtain cationic modified loofah sponge.
[0064] (3) Place 0.3g of cationic modified loofah sponge into 50mL of 2g / L K[BW] solution. 12 O 40 Soak in 11.4H2O polyacid solution for 24 hours, then remove and dry in an oven at 60℃.
[0065] (4) Place the above-mentioned loofah sponge in a ceramic boat and place it in a tube furnace. Introduce nitrogen into the tube furnace for protection, heat it at 3℃ / min to 750℃ for high-temperature calcination and hold for 2 hours to obtain biomass carbon-based composite material.
[0066] Experimental Example 1
[0067] The microwave absorbing materials prepared in Examples 1-9 were mixed with paraffin at a mass ratio of 2:8 and pressed into ring-shaped absorber samples. Based on the coaxial reflection method, the absorption effects of the microwave absorbing materials in Examples 1-9 are shown in the table. The reflection loss of the ring-shaped sample prepared from the biomass carbon-based composite material obtained in Example 7 was analyzed using a vector network analyzer in the electromagnetic wave frequency range of 1-18 GHz as a function of electromagnetic wave frequency. Figure 1 As shown. The results indicate that the composite material prepared in Example 7 has a more efficient bandwidth and superior absorption performance compared to the other examples, with an absorption bandwidth ranging from 8 to 12 GHz.
[0068] Table 1
[0069]
Claims
1. A method for preparing a biomass char-based composite material, characterized in that, Includes the following steps: S1. Mix loofah sponge, N,N-dimethylformamide and epichlorohydrin, and react at 80℃-100℃ for 0.5h-1.5h with stirring. Add ethylenediamine and continue the reaction for 0.5h-1.5h. Add triethylamine and continue the reaction for 1.5h-3h. Wash and dry the reaction product to obtain cationic modified loofah sponge. S2. The cationic modified loofah sponge is soaked in a polyacid solution, taken out and dried, and then calcined at high temperature under an inert atmosphere to obtain a biomass carbon-based composite material. The concentration of the polyacid solution is 1~10 g / L, and the ratio of the cationic modified loofah sponge to the polyacid solution is 3 g:500mL. The polyacid solution is K5[FeW] 12 O 40 ]·10H2O、KH4[CoW 12 O 40 ]·18H2O and K[BW 12 O 40 A solution prepared from 11.4H2O.
2. The preparation method according to claim 1, characterized in that, In step S1, the loofah sponge is a loofah sponge that has undergone alkali treatment. The alkali treatment specifically involves immersing the loofah sponge in NaOH solution for 10-24 hours, washing it with pure water until it is neutral, and then drying it at 60°C.
3. The preparation method according to claim 1, characterized in that, In step S1, the mass ratio of the loofah sponge, N,N-dimethylformamide, epichlorohydrin, ethylenediamine and triethylamine is 0.5 : 100~150 : 50~100 : 5~10 : 5~10.
4. The preparation method according to claim 3, characterized in that, Step S1 specifically involves mixing the loofah sponge, N,N-dimethylformamide, and epichlorohydrin, reacting at 85°C with stirring for 1 hour, adding ethylenediamine, continuing the reaction for 1 hour, adding triethylamine, and continuing the reaction for 2 hours.
5. The preparation method according to claim 1, characterized in that, In step S2, the soaking time is 8 to 24 hours.
6. The preparation method according to claim 1, characterized in that, In step S2, the high-temperature calcination under an inert atmosphere specifically involves placing the material in a ceramic boat and then placing it in a tube furnace. Nitrogen gas is introduced into the tube furnace for protection, and the temperature is raised to 600~900 ℃ at a rate of 2-5 ℃ / min for high-temperature calcination and held for 2 h to obtain the biomass carbon-based composite material.
7. The biomass-based composite material prepared by the preparation method according to any one of claims 1-6.
8. The application of the biomass carbon-based composite material according to claim 7 in the preparation of microwave absorbing materials.