CN118419900B - A preparation method and material of biomass carbon/silver composite electromagnetic shielding material - Google Patents
A preparation method and material of biomass carbon/silver composite electromagnetic shielding material Download PDFInfo
- Publication number
- CN118419900B CN118419900B CN202410510400.0A CN202410510400A CN118419900B CN 118419900 B CN118419900 B CN 118419900B CN 202410510400 A CN202410510400 A CN 202410510400A CN 118419900 B CN118419900 B CN 118419900B
- Authority
- CN
- China
- Prior art keywords
- solution
- biomass carbon
- silver
- electromagnetic shielding
- shielding material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000002028 Biomass Substances 0.000 title claims abstract description 175
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 171
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 171
- 239000000463 material Substances 0.000 title claims abstract description 154
- 229910052709 silver Inorganic materials 0.000 title claims abstract description 94
- 239000004332 silver Substances 0.000 title claims abstract description 94
- 239000002131 composite material Substances 0.000 title claims abstract description 79
- 238000002360 preparation method Methods 0.000 title claims abstract description 40
- VYFYYTLLBUKUHU-UHFFFAOYSA-N dopamine Chemical compound NCCC1=CC=C(O)C(O)=C1 VYFYYTLLBUKUHU-UHFFFAOYSA-N 0.000 claims abstract description 90
- 239000002023 wood Substances 0.000 claims abstract description 76
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims abstract description 56
- 229960003638 dopamine Drugs 0.000 claims abstract description 45
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims abstract description 44
- 235000011114 ammonium hydroxide Nutrition 0.000 claims abstract description 44
- 239000000178 monomer Substances 0.000 claims abstract description 43
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims abstract description 41
- 238000002791 soaking Methods 0.000 claims abstract description 37
- PLKATZNSTYDYJW-UHFFFAOYSA-N azane silver Chemical compound N.[Ag] PLKATZNSTYDYJW-UHFFFAOYSA-N 0.000 claims abstract description 33
- LENZDBCJOHFCAS-UHFFFAOYSA-N tris Chemical compound OCC(N)(CO)CO LENZDBCJOHFCAS-UHFFFAOYSA-N 0.000 claims abstract description 28
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 claims abstract description 26
- CTENFNNZBMHDDG-UHFFFAOYSA-N Dopamine hydrochloride Chemical compound Cl.NCCC1=CC=C(O)C(O)=C1 CTENFNNZBMHDDG-UHFFFAOYSA-N 0.000 claims abstract description 20
- 229960001149 dopamine hydrochloride Drugs 0.000 claims abstract description 20
- 238000006243 chemical reaction Methods 0.000 claims abstract description 18
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims abstract description 15
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 claims abstract description 13
- 239000008103 glucose Substances 0.000 claims abstract description 13
- 229910001961 silver nitrate Inorganic materials 0.000 claims abstract description 13
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000000243 solution Substances 0.000 claims description 140
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 24
- 238000010438 heat treatment Methods 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 12
- 238000001816 cooling Methods 0.000 claims description 8
- 239000008367 deionised water Substances 0.000 claims description 8
- 229910021641 deionized water Inorganic materials 0.000 claims description 8
- 238000003756 stirring Methods 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 7
- 238000003763 carbonization Methods 0.000 claims description 6
- 238000005406 washing Methods 0.000 claims 1
- 229920001690 polydopamine Polymers 0.000 abstract description 42
- 238000010000 carbonizing Methods 0.000 abstract description 8
- FOIXSVOLVBLSDH-UHFFFAOYSA-N Silver ion Chemical compound [Ag+] FOIXSVOLVBLSDH-UHFFFAOYSA-N 0.000 abstract description 5
- 239000011148 porous material Substances 0.000 abstract description 5
- 230000009977 dual effect Effects 0.000 abstract 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 82
- 239000002245 particle Substances 0.000 description 16
- 238000010586 diagram Methods 0.000 description 12
- 230000000694 effects Effects 0.000 description 8
- 238000004140 cleaning Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 239000003575 carbonaceous material Substances 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 239000007769 metal material Substances 0.000 description 4
- 229920002522 Wood fibre Polymers 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000002025 wood fiber Substances 0.000 description 3
- 241000894006 Bacteria Species 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000005539 carbonized material Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 125000000524 functional group Chemical group 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 1
- 238000003915 air pollution Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000005670 electromagnetic radiation Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000003911 water pollution Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0073—Shielding materials
- H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/16—Making metallic powder or suspensions thereof using chemical processes
- B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
- B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Nanotechnology (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Composite Materials (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Electromagnetism (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Carbon And Carbon Compounds (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Abstract
The invention relates to the technical field of shielding materials, in particular to a preparation method of a biomass carbon/silver composite electromagnetic shielding material and a material thereof, comprising the steps of adopting cetyltrimethylammonium bromide solution to perform active treatment on wood materials, and carbonizing the wood materials after the active treatment to prepare biomass carbon; preparing dopamine monomer solution by using hydrochloric acid solution, trimethylol aminomethane solution and dopamine hydrochloride, modifying biomass carbon by using hydrogen peroxide solution and the prepared dopamine monomer solution to prepare polydopamine modified biomass carbon, preparing silver ammonia solution by using silver nitrate solution and ammonia solution, soaking polydopamine modified biomass carbon into the silver ammonia solution, adjusting the pH value of the silver ammonia solution, adding glucose solution, and performing ultrasonic reaction to prepare the biomass carbon/silver composite electromagnetic shielding material. According to the invention, silver nano particles can be deposited in the surface and internal pores of the polydopamine modified biomass carbon, and the polydopamine modified biomass carbon has excellent electromagnetic shielding capability in dual wave bands.
Description
Technical Field
The invention relates to the technical field of shielding materials, in particular to a preparation method of a biomass carbon/silver composite electromagnetic shielding material and the material thereof.
Background
With the continuous development of science and technology, electromagnetic pollution is considered as the fourth biggest pollution after air pollution, water pollution and noise pollution. Electromagnetic radiation not only affects the normal operation of precision electronics, but also threatens human health. Meanwhile, the rapid popularization of modern telecommunication technologies represented by 5G has prompted improvements in electromagnetic shielding (EMI) materials and equipment.
The electromagnetic shielding material mainly comprises metals, filling materials, surface coating materials and conductive coatings. The traditional metal-based material shows excellent electromagnetic interference shielding effect due to high conductivity, but the defects of high price, ultra-high density, poor environmental resistance and the like are gradually replaced by other materials, so that the exploration of the electromagnetic shielding material with lighter weight and lower cost becomes more important. The biomass carbon electromagnetic shielding material has wide sources and low cost, and in recent years, wood resources are widely researched due to the characteristics of good sustainability, light weight, porous layered structure, rich resources and the like, but the wood materials belong to insulating materials, have poor conductivity and cannot realize the electromagnetic shielding interference effect. In the prior art, when wood materials and metal materials are compounded, the problems that a metal material coating is unstable and is not uniformly distributed, the advantages of the wood materials and the metal materials cannot be fully exerted, the electromagnetic shielding effect of a plurality of wave bands cannot be simultaneously realized and the like are easy to occur.
Therefore, how to effectively compound the wood-based material with other conductive materials, fully exert the advantages of each component of the composite material, achieve excellent electromagnetic shielding effect in a plurality of wave bands, ensure the maximization of electromagnetic shielding efficiency, and become a technical problem to be solved urgently.
Disclosure of Invention
In view of the above, the invention provides a preparation method of a biomass carbon/silver composite electromagnetic shielding material and a material thereof, which aims to overcome the defects of the prior art.
In one aspect, the invention provides a preparation method of a biomass carbon/silver composite electromagnetic shielding material, which comprises the following steps:
step one, biomass carbon preparation
Performing active treatment on the wood material by adopting a cetyl trimethyl ammonium bromide solution, and carbonizing the wood material subjected to the active treatment to obtain biomass carbon;
Step two, preparing polydopamine modified biomass carbon
Preparing a dopamine monomer solution by adopting a hydrochloric acid solution, a tris (hydroxymethyl) aminomethane solution and dopamine hydrochloride according to a proportion, and modifying biomass carbon by adopting a hydrogen peroxide solution and the prepared dopamine monomer solution according to a proportion to prepare polydopamine modified biomass carbon;
step three, preparation of biomass carbon/silver composite electromagnetic shielding material
Preparing silver ammonia solution by adopting silver nitrate solution and ammonia solution according to the proportion, soaking polydopamine modified biomass carbon into the prepared silver ammonia solution, adjusting the pH value of the silver ammonia solution, adding glucose solution, and carrying out ultrasonic reaction to obtain the biomass carbon/silver composite electromagnetic shielding material.
Preferably, the preparation method of the biomass carbon/silver composite electromagnetic shielding material comprises the steps of firstly, adopting a cetyltrimethylammonium bromide solution to perform active treatment on a wood material, wherein the cetyltrimethylammonium bromide solution with the concentration of 0.03-0.1mol/L is adopted to perform ultrasonic soaking on the wood material for 30min, deionized water is adopted to clean the wood material after ultrasonic soaking, and the cleaned wood material is dried at the temperature of 60 ℃ for 24h.
Preferably, in the preparation method of the biomass carbon/silver composite electromagnetic shielding material, in the first step, carbonization treatment comprises the steps of heating to 700-900 ℃ at a heating rate of 5 ℃ per minute, preserving heat for 3 hours, and naturally cooling to room temperature.
The preparation method of the biomass carbon/silver composite electromagnetic shielding material comprises the steps of sequentially adding a hydrochloric acid solution and dopamine hydrochloride into the tris (hydroxymethyl) aminomethane solution, wherein the concentration of the hydrochloric acid solution is 1mol/L, the concentration of the tris (hydroxymethyl) aminomethane solution is 0.4mol/L, the molar ratio of the hydrochloric acid solution to the tris (hydroxymethyl) aminomethane solution to the dopamine hydrochloride is 1:1.2:0.0316, and magnetically stirring for 10min at room temperature to obtain the dopamine monomer solution.
In the preparation method of the biomass carbon/silver composite electromagnetic shielding material, the biomass carbon is modified by adopting the hydrogen peroxide solution and the prepared dopamine monomer solution according to the proportion, and the preparation method comprises the steps of immersing the biomass carbon into the dopamine monomer solution, and dropwise adding the hydrogen peroxide solution into the dopamine monomer solution at the dropwise speed of 0.02ml/s, wherein the concentration of the hydrogen peroxide solution is 0.043mol/L, and the volume ratio of the hydrogen peroxide solution to the dopamine monomer solution is 1:35.
In the second step, after the dropwise adding of the hydrogen peroxide solution is completed, the biomass carbon is soaked for 24 hours, and the biomass carbon is turned over every 4 hours.
The preparation method of the biomass carbon/silver composite electromagnetic shielding material comprises the steps of adding 0.1mol/L silver nitrate solution into 5% wt ammonia solution according to a volume ratio of 5:2 to prepare silver ammonia solution, soaking polydopamine modified biomass carbon into the prepared silver ammonia solution, adjusting the pH value of the silver ammonia solution soaked with polydopamine modified biomass carbon to 10 by adopting 0.1mol/L citric acid solution, adding 0.2mol/L glucose solution, and carrying out ultrasonic reaction for 30-60min to prepare the biomass carbon/silver composite electromagnetic shielding material.
Preferably, in the preparation method of the biomass carbon/silver composite electromagnetic shielding material, in the third step, the volume ratio of the glucose solution to the silver nitrate solution is 1:1.
In the third step, in the ultrasonic reaction process, the polydopamine modified biomass carbon is turned over every 5 minutes.
In another aspect, the invention provides a biomass carbon/silver composite electromagnetic shielding material, which is prepared according to the method.
The preparation method of the biomass carbon/silver composite electromagnetic shielding material and the material thereof have the following beneficial effects:
1. The cetyl trimethyl ammonium bromide solution is used for carrying out the activity treatment on the wood material before carbonization treatment, more favorable functional group inheritance can be obtained before carbonization treatment, the defect caused by the inertia of the surface of the carbonized material is avoided, the surface of the carbonized biomass carbon material is positively charged, and the effective combination of the biomass carbon material and dopamine is promoted due to the electrostatic adsorption effect of the positive charge;
2. The dopamine monomer is adhered to the cell channels of carbonized wood to form a polydopamine layer, hydrogen peroxide is added in the forming process, so that the time for forming the polydopamine layer is shortened, and the polydopamine film layer with uniform thickness is ensured to be obtained in a short time;
3. The silver nano particles are deposited in the pores on the surface and in the inside of the polydopamine modified biomass carbon, so that the effective combination of the wood material and the conductive silver particles is realized, wherein the electromagnetic shielding performance of the vertically cut wood blocks carbonized at 800 ℃ for 3 hours is 59.6-64.7dB in an X wave band, the electromagnetic shielding performance of the vertically cut wood blocks is 83.9-104.9dB in a Ka wave band, the excellent electromagnetic shielding capacity is possessed in both wave bands, the application requirements of the electromagnetic shielding material in both wave bands can be met, and the shielding efficiency is 99.99%;
4. the preparation method of the biomass carbon/silver composite electromagnetic shielding material has the advantages of safety, reliability and no pollution, and the prepared biomass carbon/silver composite electromagnetic shielding material has the characteristics of corrosion resistance, moisture resistance, bacteria resistance, high-efficiency electromagnetic shielding performance and the like, and is suitable for mass production.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is an SEM morphology diagram of a cross section of a biomass carbon/silver composite electromagnetic shielding material prepared in example 1 of the present invention;
Fig. 2 is an SEM morphology diagram of a cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 2 of the present invention;
fig. 3 is an SEM morphology diagram of a cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 3 of the present invention;
Fig. 4 is an SEM morphology diagram of a cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 4 of the present invention;
Fig. 5 is an SEM morphology diagram of a cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 5 of the present invention;
fig. 6 is an SEM morphology diagram of a cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 6 of the present invention;
FIG. 7 is an electromagnetic shielding performance diagram of the biomass carbon/silver composite electromagnetic shielding material prepared in the embodiment 3 of the present invention in the X-band;
FIG. 8 is an electromagnetic shielding performance diagram of the biomass carbon/silver composite electromagnetic shielding material prepared in example 4 of the present invention in the X-band;
FIG. 9 is an electromagnetic shielding performance diagram of the biomass carbon/silver composite electromagnetic shielding material prepared in example 5 of the present invention in the X-band;
FIG. 10 is a graph showing electromagnetic shielding performance of the biomass carbon/silver composite electromagnetic shielding material prepared in example 3 in Ka band;
fig. 11 is an electromagnetic shielding performance diagram of the biomass carbon/silver composite electromagnetic shielding material prepared in example 4 of the present invention in Ka band.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
It is noted that the following embodiments and features of the embodiments may be combined with each other without conflict, and that all other embodiments obtained by persons of ordinary skill in the art without creative efforts based on the embodiments in the present disclosure are within the scope of protection of the present disclosure.
It is noted that various aspects of the embodiments are described below within the scope of the following claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the present disclosure, one skilled in the art will appreciate that one aspect described herein may be implemented independently of any other aspect, and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method practiced using any number of the aspects set forth herein. In addition, such apparatus may be implemented and/or such methods practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.
Example 1
Preparation of biomass carbon/silver composite electromagnetic shielding material:
step one, biomass carbon preparation
Carrying out ultrasonic soaking on the wood material cut perpendicular to the wood growth direction for 30min by adopting a hexadecyl trimethyl ammonium bromide solution with the concentration of 0.03mol/L, cleaning the wood material subjected to ultrasonic soaking by adopting deionized water, and drying the cleaned wood material at the temperature of 60 ℃ for 24h;
Carbonizing the activated wood material, specifically, heating to 700 ℃ at a heating rate of 5 ℃ per min, preserving heat for 3 hours, and naturally cooling to room temperature to obtain biomass carbon;
Step two, preparing polydopamine modified biomass carbon
Sequentially adding hydrochloric acid solution and dopamine hydrochloride into the tris (hydroxymethyl) aminomethane solution, wherein the concentration of the hydrochloric acid solution is 1mol/L, the concentration of the tris (hydroxymethyl) aminomethane solution is 0.4mol/L, the molar ratio of the hydrochloric acid solution to the tris (hydroxymethyl) aminomethane solution to the dopamine hydrochloride is 1:1.2:0.0316, and magnetically stirring the mixture at room temperature for 10min to prepare a dopamine monomer solution;
Soaking biomass carbon into a dopamine monomer solution, dropwise adding a hydrogen peroxide solution into the dopamine monomer solution at a dropwise adding speed of 0.02ml/s, wherein the concentration of the hydrogen peroxide solution is 0.043mol/L, the volume ratio of the hydrogen peroxide solution to the dopamine monomer solution is 1:35, soaking the biomass carbon for 24 hours after the dropwise adding of the hydrogen peroxide solution is completed, and turning over the biomass carbon every 4 hours;
step three, preparation of biomass carbon/silver composite electromagnetic shielding material
Adding 0.1mol/L silver nitrate solution into 5%wt ammonia solution according to the volume ratio of 5:2 to prepare silver ammonia solution, soaking polydopamine modified biomass carbon into the prepared silver ammonia solution, adopting 0.1mol/L citric acid solution to adjust the pH value of the silver ammonia solution soaked with polydopamine modified biomass carbon to 10, adding 0.2mol/L glucose solution, carrying out ultrasonic reaction for 30min, and turning over polydopamine modified biomass carbon every 5 min in the ultrasonic reaction process to prepare the biomass carbon/silver composite electromagnetic shielding material.
Example 2
Preparation of biomass carbon/silver composite electromagnetic shielding material:
step one, biomass carbon preparation
Carrying out ultrasonic soaking on the wood material cut in parallel to the wood growth direction for 30min by adopting a hexadecyl trimethyl ammonium bromide solution with the concentration of 0.06mol/L, cleaning the wood material subjected to ultrasonic soaking by adopting deionized water, and drying the cleaned wood material at the temperature of 60 ℃ for 24h;
Carbonizing the activated wood material, specifically, heating to 700 ℃ at a heating rate of 5 ℃ per min, preserving heat for 3 hours, and naturally cooling to room temperature to obtain biomass carbon;
Step two, preparing polydopamine modified biomass carbon
Sequentially adding hydrochloric acid solution and dopamine hydrochloride into the tris (hydroxymethyl) aminomethane solution, wherein the concentration of the hydrochloric acid solution is 1mol/L, the concentration of the tris (hydroxymethyl) aminomethane solution is 0.4mol/L, the molar ratio of the hydrochloric acid solution to the tris (hydroxymethyl) aminomethane solution to the dopamine hydrochloride is 1:1.2:0.0316, and magnetically stirring the mixture at room temperature for 10min to prepare a dopamine monomer solution;
Soaking biomass carbon into a dopamine monomer solution, dropwise adding a hydrogen peroxide solution into the dopamine monomer solution at a dropwise adding speed of 0.02ml/s, wherein the concentration of the hydrogen peroxide solution is 0.043mol/L, the volume ratio of the hydrogen peroxide solution to the dopamine monomer solution is 1:35, soaking the biomass carbon for 24 hours after the dropwise adding of the hydrogen peroxide solution is completed, and turning over the biomass carbon every 4 hours;
step three, preparation of biomass carbon/silver composite electromagnetic shielding material
Adding 0.1mol/L silver nitrate solution into 5%wt ammonia solution according to the volume ratio of 5:2 to prepare silver ammonia solution, soaking polydopamine modified biomass carbon into the prepared silver ammonia solution, adopting 0.1mol/L citric acid solution to adjust the pH value of the silver ammonia solution soaked with polydopamine modified biomass carbon to 10, adding 0.2mol/L glucose solution, carrying out ultrasonic reaction for 30min, and turning over polydopamine modified biomass carbon every 5 min in the ultrasonic reaction process to prepare the biomass carbon/silver composite electromagnetic shielding material.
Example 3
Preparation of biomass carbon/silver composite electromagnetic shielding material:
step one, biomass carbon preparation
Carrying out ultrasonic soaking on the wood material cut perpendicular to the wood growth direction for 30min by adopting a hexadecyl trimethyl ammonium bromide solution with the concentration of 0.1mol/L, cleaning the wood material subjected to ultrasonic soaking by adopting deionized water, and drying the cleaned wood material at the temperature of 60 ℃ for 24h;
Carbonizing the activated wood material, specifically, heating to 800 ℃ at a heating rate of 5 ℃ per min, preserving heat for 3 hours, and naturally cooling to room temperature to obtain biomass carbon;
Step two, preparing polydopamine modified biomass carbon
Sequentially adding hydrochloric acid solution and dopamine hydrochloride into the tris (hydroxymethyl) aminomethane solution, wherein the concentration of the hydrochloric acid solution is 1mol/L, the concentration of the tris (hydroxymethyl) aminomethane solution is 0.4mol/L, the molar ratio of the hydrochloric acid solution to the tris (hydroxymethyl) aminomethane solution to the dopamine hydrochloride is 1:1.2:0.0316, and magnetically stirring the mixture at room temperature for 10min to prepare a dopamine monomer solution;
Soaking biomass carbon into a dopamine monomer solution, dropwise adding a hydrogen peroxide solution into the dopamine monomer solution at a dropwise adding speed of 0.02ml/s, wherein the concentration of the hydrogen peroxide solution is 0.043mol/L, the volume ratio of the hydrogen peroxide solution to the dopamine monomer solution is 1:35, soaking the biomass carbon for 24 hours after the dropwise adding of the hydrogen peroxide solution is completed, and turning over the biomass carbon every 4 hours;
step three, preparation of biomass carbon/silver composite electromagnetic shielding material
Adding 0.1mol/L silver nitrate solution into 5%wt ammonia solution according to the volume ratio of 5:2 to prepare silver ammonia solution, soaking polydopamine modified biomass carbon into the prepared silver ammonia solution, adopting 0.1mol/L citric acid solution to adjust the pH value of the silver ammonia solution soaked with polydopamine modified biomass carbon to 10, adding 0.2mol/L glucose solution, carrying out ultrasonic reaction for 60min, and turning over polydopamine modified biomass carbon every 5 min in the ultrasonic reaction process to prepare the biomass carbon/silver composite electromagnetic shielding material.
Example 4
Preparation of biomass carbon/silver composite electromagnetic shielding material:
step one, biomass carbon preparation
Carrying out ultrasonic soaking on the wood material cut in parallel to the wood growth direction for 30min by adopting a hexadecyl trimethyl ammonium bromide solution with the concentration of 0.1mol/L, cleaning the wood material subjected to ultrasonic soaking by adopting deionized water, and drying the cleaned wood material at the temperature of 60 ℃ for 24h;
Carbonizing the activated wood material, specifically, heating to 800 ℃ at a heating rate of 5 ℃ per min, preserving heat for 3 hours, and naturally cooling to room temperature to obtain biomass carbon;
Step two, preparing polydopamine modified biomass carbon
Sequentially adding hydrochloric acid solution and dopamine hydrochloride into the tris (hydroxymethyl) aminomethane solution, wherein the concentration of the hydrochloric acid solution is 1mol/L, the concentration of the tris (hydroxymethyl) aminomethane solution is 0.4mol/L, the molar ratio of the hydrochloric acid solution to the tris (hydroxymethyl) aminomethane solution to the dopamine hydrochloride is 1:1.2:0.0316, and magnetically stirring the mixture at room temperature for 10min to prepare a dopamine monomer solution;
Soaking biomass carbon into a dopamine monomer solution, dropwise adding a hydrogen peroxide solution into the dopamine monomer solution at a dropwise adding speed of 0.02ml/s, wherein the concentration of the hydrogen peroxide solution is 0.043mol/L, the volume ratio of the hydrogen peroxide solution to the dopamine monomer solution is 1:35, soaking the biomass carbon for 24 hours after the dropwise adding of the hydrogen peroxide solution is completed, and turning over the biomass carbon every 4 hours;
step three, preparation of biomass carbon/silver composite electromagnetic shielding material
Adding 0.1mol/L silver nitrate solution into 5%wt ammonia solution according to the volume ratio of 5:2 to prepare silver ammonia solution, soaking polydopamine modified biomass carbon into the prepared silver ammonia solution, adopting 0.1mol/L citric acid solution to adjust the pH value of the silver ammonia solution soaked with polydopamine modified biomass carbon to 10, adding 0.2mol/L glucose solution, carrying out ultrasonic reaction for 60min, and turning over polydopamine modified biomass carbon every 5 min in the ultrasonic reaction process to prepare the biomass carbon/silver composite electromagnetic shielding material.
Example 5
Preparation of biomass carbon/silver composite electromagnetic shielding material:
step one, biomass carbon preparation
Carrying out ultrasonic soaking on the wood material cut perpendicular to the wood growth direction for 30min by adopting a hexadecyl trimethyl ammonium bromide solution with the concentration of 0.06mol/L, cleaning the wood material subjected to ultrasonic soaking by adopting deionized water, and drying the cleaned wood material at the temperature of 60 ℃ for 24h;
Carbonizing the activated wood material, specifically, heating to 900 ℃ at a heating rate of 5 ℃ per min, preserving heat for 3 hours, and naturally cooling to room temperature to obtain biomass carbon;
Step two, preparing polydopamine modified biomass carbon
Sequentially adding hydrochloric acid solution and dopamine hydrochloride into the tris (hydroxymethyl) aminomethane solution, wherein the concentration of the hydrochloric acid solution is 1mol/L, the concentration of the tris (hydroxymethyl) aminomethane solution is 0.4mol/L, the molar ratio of the hydrochloric acid solution to the tris (hydroxymethyl) aminomethane solution to the dopamine hydrochloride is 1:1.2:0.0316, and magnetically stirring the mixture at room temperature for 10min to prepare a dopamine monomer solution;
Soaking biomass carbon into a dopamine monomer solution, dropwise adding a hydrogen peroxide solution into the dopamine monomer solution at a dropwise adding speed of 0.02ml/s, wherein the concentration of the hydrogen peroxide solution is 0.043mol/L, the volume ratio of the hydrogen peroxide solution to the dopamine monomer solution is 1:35, soaking the biomass carbon for 24 hours after the dropwise adding of the hydrogen peroxide solution is completed, and turning over the biomass carbon every 4 hours;
step three, preparation of biomass carbon/silver composite electromagnetic shielding material
Adding 0.1mol/L silver nitrate solution into 5%wt ammonia solution according to the volume ratio of 5:2 to prepare silver ammonia solution, soaking polydopamine modified biomass carbon into the prepared silver ammonia solution, adopting 0.1mol/L citric acid solution to adjust the pH value of the silver ammonia solution soaked with polydopamine modified biomass carbon to 10, adding 0.2mol/L glucose solution, carrying out ultrasonic reaction for 60min, and turning over polydopamine modified biomass carbon every 5 min in the ultrasonic reaction process to prepare the biomass carbon/silver composite electromagnetic shielding material.
Example 6
Preparation of biomass carbon/silver composite electromagnetic shielding material:
step one, biomass carbon preparation
Carrying out ultrasonic soaking on the wood material cut in parallel to the wood growth direction for 30min by adopting a hexadecyl trimethyl ammonium bromide solution with the concentration of 0.03mol/L, cleaning the wood material subjected to ultrasonic soaking by adopting deionized water, and drying the cleaned wood material at the temperature of 60 ℃ for 24h;
Carbonizing the activated wood material, specifically, heating to 900 ℃ at a heating rate of 5 ℃ per min, preserving heat for 3 hours, and naturally cooling to room temperature to obtain biomass carbon;
Step two, preparing polydopamine modified biomass carbon
Sequentially adding hydrochloric acid solution and dopamine hydrochloride into the tris (hydroxymethyl) aminomethane solution, wherein the concentration of the hydrochloric acid solution is 1mol/L, the concentration of the tris (hydroxymethyl) aminomethane solution is 0.4mol/L, the molar ratio of the hydrochloric acid solution to the tris (hydroxymethyl) aminomethane solution to the dopamine hydrochloride is 1:1.2:0.0316, and magnetically stirring the mixture at room temperature for 10min to prepare a dopamine monomer solution;
Soaking biomass carbon into a dopamine monomer solution, dropwise adding a hydrogen peroxide solution into the dopamine monomer solution at a dropwise adding speed of 0.02ml/s, wherein the concentration of the hydrogen peroxide solution is 0.043mol/L, the volume ratio of the hydrogen peroxide solution to the dopamine monomer solution is 1:35, soaking the biomass carbon for 24 hours after the dropwise adding of the hydrogen peroxide solution is completed, and turning over the biomass carbon every 4 hours;
step three, preparation of biomass carbon/silver composite electromagnetic shielding material
Adding 0.1mol/L silver nitrate solution into 5%wt ammonia solution according to the volume ratio of 5:2 to prepare silver ammonia solution, soaking polydopamine modified biomass carbon into the prepared silver ammonia solution, adopting 0.1mol/L citric acid solution to adjust the pH value of the silver ammonia solution soaked with polydopamine modified biomass carbon to 10, adding 0.2mol/L glucose solution, carrying out ultrasonic reaction for 30min, and turning over polydopamine modified biomass carbon every 5 min in the ultrasonic reaction process to prepare the biomass carbon/silver composite electromagnetic shielding material.
Example 7
Microscopic morphologies of cross sections of the biomass carbon/silver composite electromagnetic shielding materials prepared in examples 1, 2,3,4, 5 and 6 were observed by using a cold field emission scanning electron microscope of model Hitachi S4800, and acceleration voltages of 5kV were used, and scanning electron microscope photographs of cross sections of the biomass carbon/silver composite electromagnetic shielding materials prepared in examples 1, 2,3,4, 5 and 6 are shown in fig. 1, 2,3,4, 5 and 6, respectively.
As shown in fig. 1, the cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 1, for the wood material cut perpendicular to the wood growth direction, silver particles were deposited along the wood fibers and distributed uniformly.
As shown in fig. 2, in the cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 2, for the wood material cut parallel to the wood growth direction, silver particles are deposited along the pores of the wood material, and the particles can enter the pores, so that effective combination between biomass carbon and silver particles is realized.
As shown in fig. 3, the cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 3, for the wood material cut perpendicular to the wood growth direction, a large number of silver particles are deposited along the wood fiber, the particles are closely distributed, and the silver particles can fully cover the wood cross section. As the deposition time increases, the silver particle content increases significantly.
As shown in fig. 4, in the cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 4, silver particles are deposited along the honeycomb porous structure of the wood material for the wood material cut parallel to the growth direction of the wood, and a dense silver layer is formed on the surface and inside of the wood channel, so that a good conductive path can be formed.
As shown in fig. 5, the cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 5 has uniform silver particle size for wood materials cut perpendicular to the wood growth direction, and the silver layer is compact and uniformly distributed on the surface of wood fiber.
As shown in fig. 6, in the cross section of the biomass carbon/silver composite electromagnetic shielding material prepared in example 6, for the wood material cut parallel to the wood growth direction, silver particles enter the porous channels, and effective bonding between biomass carbon and silver particles can be achieved.
The electromagnetic shielding performance of the biomass carbon/silver composite electromagnetic shielding materials prepared in example 3, example 4 and example 5 was tested by using a vector network analyzer with model number N523OC PNA-L in a waveguide method, the tested wave bands were an X wave band (8-12 GHz) and a Ka wave band (26.5-40 GHz), the number of scanning points was 400, and the electromagnetic shielding performance diagrams of the biomass carbon/silver composite electromagnetic shielding materials prepared in example 3, example 4 and example 5 in the X wave band were sequentially shown in fig. 7, fig. 8 and fig. 9, and the electromagnetic shielding performance diagrams of the biomass carbon/silver composite electromagnetic shielding materials prepared in example 3 and example 4 in the Ka wave band were shown in fig. 10 and fig. 11.
As shown in fig. 7, the electromagnetic shielding performance of the biomass carbon/silver composite electromagnetic shielding material prepared in example 3 is 55.1-60dB in the X-band, and in combination with the illustration in fig. 3, it is demonstrated that the silver nanoparticles are successfully plated on the surface of the biomass carbon, and the electromagnetic shielding performance can be improved by effectively combining the two materials.
As shown in fig. 8, the electromagnetic shielding performance of the biomass carbon/silver composite electromagnetic shielding material prepared in example 4 is 59.6-64.7dB in the X-band, and in combination with fig. 4, as silver nanoparticles can be plated into the channel to form various interfaces, multiple reflections are caused in the channel, thereby improving the electromagnetic shielding performance and better realizing the synergistic effect between biomass carbon and conductive silver particles.
As shown in fig. 9, the electromagnetic shielding performance of the biomass carbon/silver composite electromagnetic shielding material prepared in example 5 is 56.7-62.5dB in the X-band, and in combination with fig. 5, silver particles are uniformly and densely deposited on the surface of the wood material, so that an excellent conductive network can be formed, and an excellent electromagnetic shielding performance can be realized.
As shown in fig. 10, the electromagnetic shielding performance of the biomass carbon/silver composite electromagnetic shielding material prepared in the embodiment 3 is 58.2-67.8dB in Ka band, which is equivalent to the performance of the X band, and has excellent electromagnetic shielding capability in both the X band and the Ka band, so that the application requirements of the dual-band electromagnetic shielding material can be satisfied.
As shown in fig. 11, the electromagnetic shielding performance of the biomass carbon/silver composite electromagnetic shielding material prepared in the embodiment 4 is 83.9-104.9dB in Ka band, and compared with the performance of the X band, the electromagnetic shielding performance is improved by about 40dB, and the biomass carbon/silver composite electromagnetic shielding material has excellent electromagnetic shielding capability in both the X band and the Ka band, so that the application requirements of the dual-band electromagnetic shielding material can be satisfied simultaneously.
The preparation method of the biomass carbon/silver composite electromagnetic shielding material and the material thereof have the following beneficial effects:
1. The cetyl trimethyl ammonium bromide solution is used for carrying out the activity treatment on the wood material before carbonization treatment, more favorable functional group inheritance can be obtained before carbonization treatment, the defect caused by the inertia of the surface of the carbonized material is avoided, the surface of the carbonized biomass carbon material is positively charged, and the effective combination of the biomass carbon material and dopamine is promoted due to the electrostatic adsorption effect of the positive charge;
2. The dopamine monomer is adhered to the cell channels of carbonized wood to form a polydopamine layer, hydrogen peroxide is added in the forming process, so that the time for forming the polydopamine layer is shortened, and the polydopamine film layer with uniform thickness is ensured to be obtained in a short time;
3. The silver nano particles are deposited in the pores on the surface and in the inside of the polydopamine modified biomass carbon, so that the effective combination of the wood material and the conductive silver particles is realized, wherein the electromagnetic shielding performance of the vertically cut wood blocks carbonized at 800 ℃ for 3 hours is 59.6-64.7dB in an X wave band, the electromagnetic shielding performance of the vertically cut wood blocks is 83.9-104.9dB in a Ka wave band, the excellent electromagnetic shielding capacity is possessed in both wave bands, the application requirements of the electromagnetic shielding material in both wave bands can be met, and the shielding efficiency is 99.99%;
4. the preparation method of the biomass carbon/silver composite electromagnetic shielding material has the advantages of safety, reliability and no pollution, and the prepared biomass carbon/silver composite electromagnetic shielding material has the characteristics of corrosion resistance, moisture resistance, bacteria resistance, high-efficiency electromagnetic shielding performance and the like, and is suitable for mass production.
The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present invention should be included in the present invention. Therefore, the protection scope of the invention is subject to the protection scope of the claims.
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410510400.0A CN118419900B (en) | 2024-04-26 | 2024-04-26 | A preparation method and material of biomass carbon/silver composite electromagnetic shielding material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410510400.0A CN118419900B (en) | 2024-04-26 | 2024-04-26 | A preparation method and material of biomass carbon/silver composite electromagnetic shielding material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN118419900A CN118419900A (en) | 2024-08-02 |
| CN118419900B true CN118419900B (en) | 2025-03-18 |
Family
ID=92315664
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410510400.0A Active CN118419900B (en) | 2024-04-26 | 2024-04-26 | A preparation method and material of biomass carbon/silver composite electromagnetic shielding material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118419900B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119162679B (en) * | 2024-09-29 | 2025-07-11 | 四川大学 | A method for preparing bamboo charcoal/regenerated cellulose composite fiber |
| CN119263258A (en) * | 2024-10-08 | 2025-01-07 | 合肥工业大学 | A method for preparing carbon nanotube/silver-doped biomass carbon material with electromagnetic shielding performance |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107265440A (en) * | 2017-06-29 | 2017-10-20 | 南京开钰安全科技有限责任公司 | Improve nano material of commercial graphites alkene film layer electric conductivity and preparation method thereof |
| CN111935965A (en) * | 2020-07-14 | 2020-11-13 | 西安工程大学 | Preparation method of silver/biomass porous carbon electromagnetic wave absorption composite material |
| CN112892486A (en) * | 2021-01-19 | 2021-06-04 | 西南科技大学 | Preparation method of inorganic heavy metal waste liquid adsorption material, adsorption material and application |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BR102014012295A2 (en) * | 2014-05-21 | 2018-08-07 | Univ Minas Gerais | photochemical method for obtaining hybrid nanostructures of carbon metals and nanomaterials and their applications and uses |
| CN106732358B (en) * | 2016-12-21 | 2019-06-28 | 中南大学 | A kind of biomass carbonization microballoon loading iron oxide and its preparation and application |
| CN107858160B (en) * | 2017-12-07 | 2020-05-12 | 王凯 | A kind of biomass raw material processing method and product thereof |
| CN115948169A (en) * | 2022-11-24 | 2023-04-11 | 生态环境部土壤与农业农村生态环境监管技术中心 | Preparation method and application of a biochar-loaded modified nano-zero-valent iron material |
| CN116355360A (en) * | 2022-12-29 | 2023-06-30 | 宁夏清研高分子新材料有限公司 | Conductive COC material with electromagnetic shielding function and preparation method thereof |
| CN116947037A (en) * | 2023-07-19 | 2023-10-27 | 北京化工大学 | A method for preparing a fir-based activated carbon hydrovoltaic power generation device |
-
2024
- 2024-04-26 CN CN202410510400.0A patent/CN118419900B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107265440A (en) * | 2017-06-29 | 2017-10-20 | 南京开钰安全科技有限责任公司 | Improve nano material of commercial graphites alkene film layer electric conductivity and preparation method thereof |
| CN111935965A (en) * | 2020-07-14 | 2020-11-13 | 西安工程大学 | Preparation method of silver/biomass porous carbon electromagnetic wave absorption composite material |
| CN112892486A (en) * | 2021-01-19 | 2021-06-04 | 西南科技大学 | Preparation method of inorganic heavy metal waste liquid adsorption material, adsorption material and application |
Also Published As
| Publication number | Publication date |
|---|---|
| CN118419900A (en) | 2024-08-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN118419900B (en) | A preparation method and material of biomass carbon/silver composite electromagnetic shielding material | |
| CN101649477B (en) | Preparation method of metal carbon aerogel composite material | |
| JP2020526029A (en) | Nickel-plated carbon fiber film, its manufacturing method, shield structure and its manufacturing method | |
| CN111410194B (en) | Composite electromagnetic wave-absorbing foam prepared from ZIF-67/melamine and preparation method thereof | |
| CN113271758B (en) | Electromagnetic wave shielding breathable porous carbon composite material and preparation method and application thereof | |
| CN108570163A (en) | A kind of preparation method of the high-efficiency electromagnetic shielding porous material based on nano-cellulose | |
| CN116404128A (en) | Porous hard carbon anode material and preparation method and application thereof | |
| CN111171482B (en) | Preparation method of carbon fiber felt/silver nanowire/polyvinylidene fluoride composite material | |
| CN116005451A (en) | A kind of preparation method of electromagnetic shielding material and electromagnetic shielding material | |
| CN116041780B (en) | Preparation method of heterostructure-adjustable multilayer porous electromagnetic shielding composite foam material | |
| CN110241611A (en) | A kind of high temperature resistant carbon fiber magnetic wave-absorbing composite material and its preparation method | |
| CN112250063A (en) | A kind of method for promoting the graphitization of woody bio-carbon at low temperature | |
| CN113388254A (en) | MoCo bimetal sulfide/carbon fiber composite material and preparation method thereof | |
| CN114804218B (en) | A kind of multilevel heterostructure microwave absorbing material and its preparation method | |
| CN116656001A (en) | Functional fiber-based composite foam material and preparation method thereof | |
| CN115700310B (en) | Nickel metal alkene modified composite carbon fiber and preparation method thereof | |
| CN115584540B (en) | Diamond wire saw with composite coating and preparation process thereof | |
| CN114980715B (en) | A composite porous microsphere material and its preparation method and application | |
| CN112501596B (en) | Fluorine-free and palladium-silver-free activation method before chemical nickel plating on titanium surface | |
| CN116103016A (en) | Preparation and application of MOF-derived one-dimensional rod-like nitrogen-doped porous carbon matrix coated CoNi nanoparticles composites | |
| CN102912323B (en) | Preparation method of carbon fiber surface nano CoFeB microwave-absorbing coating | |
| CN118714830A (en) | A preparation method and material of biomass carbon-based porous copper-clad high-impedance electromagnetic shielding material | |
| CN118164485B (en) | A layered high-absorption electromagnetic shielding composite material and its preparation method | |
| CN108914150B (en) | Preparation method of ultrathin Ni-P composite electrode material with ordered micro-nano-pore array structure | |
| CN110129777A (en) | A kind of short flow process of the anticorrosion timber of surface chemistry plating Ni-W-P ternary alloy layer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |