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CN-115867013-B - Preparation method of porous carbon-based composite electromagnetic shielding material with high-communication network structure

CN115867013BCN 115867013 BCN115867013 BCN 115867013BCN-115867013-B

Abstract

The invention relates to a porous carbon-based composite electromagnetic shielding material with a high communication network structure and a preparation method thereof, belonging to the technical field of electromagnetic shielding. The composite electromagnetic shielding material is composed of a porous carbon matrix, co 3 O 4 nano particles and CNTs composite reinforcement, wherein the Co 3 O 4 nano particles and the CNTs are uniformly dispersed on a three-dimensional network structure of the porous carbon, the porous carbon after hydrophilic treatment is immersed in a cobalt source solution containing the CNTs and added with a NaOH aqueous solution, and then Co 3 O 4 nano particles can be formed on the three-dimensional network structure of the porous carbon in situ through solvothermal reaction, and meanwhile, the CNTs and the generated Co 3 O 4 nano particles are mutually wound, so that the composite electromagnetic shielding material is prepared. According to the invention, co 3 O 4 nano particles and CNTs are simultaneously introduced into the porous carbon, so that the electromagnetic shielding performance of the porous carbon can be obviously improved to meet the requirements of commercial standards, the preparation process is simple, the operation is easy, the large-scale production is easy, and the preparation method has good application prospects in the field of electromagnetic shielding materials.

Inventors

  • Jing Ruixuan
  • GU LIMIN
  • LIU HEGUANG
  • DAI LINA
  • Wang Ningqiang

Assignees

  • 西安超码科技有限公司

Dates

Publication Date
20260508
Application Date
20221130

Claims (6)

  1. 1. A preparation method of a porous carbon-based composite electromagnetic shielding material with a high-communication network structure is characterized in that the composite electromagnetic shielding material is composed of a porous carbon matrix, co 3 O 4 nano-particles and composite reinforcements of CNTs, and the Co 3 O 4 nano-particles and the CNTs are uniformly dispersed on a three-dimensional network structure of the porous carbon; The preparation method comprises the following steps: (1) Performing hydrophilic treatment on the porous carbon; (2) Immersing the porous carbon after hydrophilic treatment in cobalt source solution containing CNTs, simultaneously adding NaOH aqueous solution, and uniformly mixing to form reaction solution; (3) Transferring the reaction solution into a reaction kettle for solvothermal reaction, so that a cobalt source grows in situ on a three-dimensional network structure of the porous carbon to form Co 3 O 4 nano-particles, and simultaneously, the CNTs and the generated Co 3 O 4 nano-particles are intertwined, thereby realizing uniform distribution of the Co 3 O 4 nano-particles and the CNTs on the three-dimensional network structure of the porous carbon; (4) After the solvothermal reaction is finished, collecting a reaction product, washing and drying to obtain a Co 3 O 4 nano-particle/CNTs/porous carbon composite material, namely a porous carbon-based composite electromagnetic shielding material with a high-communication network structure; wherein, the cobalt source solution containing CNTs in the step (2) is prepared from Co (NO 3 ) 2 ·6H 2 O, CNTs and ethanol).
  2. 2. The method for preparing the porous carbon-based composite electromagnetic shielding material with the high-communication network structure, as claimed in claim 1, is characterized in that the porous carbon in the step (1) is prepared by carbonizing melamine foam; The carbonization process comprises the following steps of heating to 350-450 ℃ and preserving heat for 1-2 hours under the protection of nitrogen or inert gas, then continuously heating to 700-1000 ℃ and preserving heat for 1-2 hours, and then cooling, wherein the heating rate and the cooling rate are 5-15 ℃ per minute.
  3. 3. The preparation method of the high-communication network structure porous carbon-based composite electromagnetic shielding material is characterized by comprising the following steps of performing hydrophilic treatment on porous carbon by adopting a nitric acid solution in the step (1), wherein the porous carbon is placed into a nitric acid solution with the concentration of 2-3 mol/L, heated to 100-130 ℃ and kept for 1-3 hours, and then taken out for cleaning and drying, so that the hydrophilic treatment of the porous carbon is completed.
  4. 4. The method for preparing the porous carbon-based composite electromagnetic shielding material with the high-communication network structure according to claim 1, wherein in the cobalt source solution containing CNTs in the step (2), co (NO 3 ) 2 ·6H 2 O) is 0.1-0.3 mol/L, and CNTs is 0.1-0.5 mg/mL.
  5. 5. The method for preparing a porous carbon-based composite electromagnetic shielding material with a high communication network structure according to claim 4, wherein in the step (2), the volume ratio of the cobalt source solution containing CNTs to the porous carbon after hydrophilic treatment is (6~3) 1, the volume ratio of the cobalt source solution containing CNTs to the NaOH aqueous solution is (12-13:1), and the concentration of the NaOH aqueous solution is 0.1-0.3 mol/L.
  6. 6. The preparation method of the high-communication network structure porous carbon-based composite electromagnetic shielding material is characterized in that in the step (3), the temperature of solvothermal reaction is 160-200 ℃ and the time is 8-18 h.

Description

Preparation method of porous carbon-based composite electromagnetic shielding material with high-communication network structure Technical Field The invention relates to a porous carbon-based composite electromagnetic shielding material with a high communication network structure and a preparation method thereof, belonging to the technical field of electromagnetic shielding. Background Along with the continuous development of social economy, information technology also enters into the rapid development age, and various integrated and intelligent electronic and electric equipment gradually enter into the fields of communication, traffic, medical equipment, household appliances and the like from the mobile communication 1G age to the 5G age of the information revolution nowadays. Electromagnetic waves have been found to provide great convenience to people's lives, and also to provide a large amount of electromagnetic radiation, causing electromagnetic pollution (EMI). Electromagnetic pollution can cause great threat to the environment and human body, and along with the gradual upgrade of electronic equipment, the requirements on sensitivity and precision are higher and higher, and the electronic equipment is also more sensitive to electromagnetic interference signals. Shielding is one of the most effective methods for resisting electromagnetic interference, and excellent conductivity and perfect conductive network structure are the preconditions for the electromagnetic shielding composite material to obtain high shielding efficiency, and effective multiple interface reflection absorption and the characteristics of the material are important factors for realizing high performance and controllable shielding performance of the electromagnetic shielding composite material. Therefore, the development of novel electromagnetic shielding materials with light weight, high efficiency, flexibility, corrosion resistance and low cost has become an important development direction in the field of electromagnetic shielding materials. The porous carbon with the high-communication network structure is novel porous carbon with a three-dimensional structure, belongs to a difficult-graphitization carbon material, can keep higher flexibility after high-temperature treatment, has certain strength, has the advantages of low density, high strength, good conductivity, corrosion resistance, easiness in processing and forming and the like, and is considered as one of ideal candidate materials of next-generation electromagnetic shielding materials. However, the electromagnetic shielding performance of the porous carbon is general and has a certain gap from the performance requirement of the electromagnetic shielding material. The porous carbon composite material is prepared by compounding a proper second phase material with porous carbon, and is a main means for improving the electromagnetic shielding performance of the porous carbon. The metal and alloy materials have the greatest advantages that the high conductivity of the metal and alloy materials shows good electromagnetic wave attenuation capability, and the metal and alloy materials are usually compounded with porous carbon in the form of a coating, but the metal density is high, the corrosion resistance is low, the manufacturing process is complex, the cost is high, and the wear resistance of the metal coating is poor. The transition metal oxide has wide application prospect in the electromagnetic shielding field due to the characteristics of high magnetic permeability, low cost, good biocompatibility, high saturation magnetization and the like. Since the factors determining the electromagnetic shielding performance of the material are dielectric loss and magnetic loss, and the dielectric constant of the porous carbon is not high, most of magnetic materials such as ferric oxide and cobalt oxide are adopted as reinforcing bodies at present. The electromagnetic shielding performance of the porous carbon-based corrosion and aversion composite material can not reach commercial standards, and the electromagnetic shielding performance of the porous carbon-based corrosion and aversion composite material needs to be further improved to meet the requirements of commercial application. Disclosure of Invention Aiming at the defects of the prior porous carbon-based composite electromagnetic shielding material, the invention provides the porous carbon-based composite electromagnetic shielding material with a high communication network structure and the preparation method thereof, wherein Co 3O4 nano particles and CNTs are simultaneously introduced into porous carbon, so that the electromagnetic shielding performance can be obviously improved to reach commercial standards, and in the preparation process, co 3O4 nano particles can grow in situ on the porous carbon network structure by carrying out hydrophilic treatment on the porous carbon and the auxiliary effect of the CNTs, and the continuou