CN-118561271-B - Preparation method of high-efficiency heat-insulation wave-absorbing integrated light carbon-based nano aerogel

Abstract

The invention discloses a preparation method of high-efficiency heat-insulating and wave-absorbing integrated light carbon-based nano aerogel, which comprises the steps of uniformly dispersing a certain amount of graphene oxide in a solution containing a chitosan crosslinking agent, obtaining the chitosan crosslinking agent modified graphene oxide aerogel through liquid phase self-assembly reaction and freeze drying, growing a series of two-dimensional Metal Organic Frameworks (MOFs) nano arrays with different metal proportions in situ in the modified graphene oxide aerogel through liquid phase reaction to obtain MOFs and graphene oxide composite aerogel, and then performing high-temperature pyrolysis on the composite aerogel at a certain temperature to obtain the light wave-absorbing and heat-insulating integrated carbon-based nano aerogel material. The carbon-based nano aerogel material provided by the invention has the advantages of simple preparation process, short preparation period, easiness in industrial production, low density, wide absorption frequency band, strong absorption capacity and good heat insulation performance.

Inventors

• XU XUEQING
• MU QIYUN
• LI DESHUN
• YANG XIAORONG
• YANG ZHIWANG

Assignees

• 西北师范大学

Dates

Publication Date

20260505

Application Date

20240613

Claims (5)

1. 1. The preparation method of the high-efficiency heat-insulating wave-absorbing integrated light carbon-based nano aerogel is characterized by comprising the following steps of: 1) Uniformly mixing the graphene oxide dispersion liquid and a chitosan solution, reacting for 2-24 hours at 20-80 ℃, and freeze-drying to obtain chitosan modified graphene oxide aerogel; 2) Immersing the chitosan modified graphene oxide aerogel into a mixed solution of metal salt and an organic ligand, stirring for 10-12 hours at room temperature, centrifuging to obtain precipitate, washing and drying to obtain graphene oxide composite aerogel loaded with MOFs nano-sheet arrays; The metal salt is a combination of cobalt nitrate and zinc nitrate, and the organic ligand is 2-methylimidazole, wherein the molar ratio of the cobalt nitrate to the zinc nitrate is more than 1:3 and not more than 3:1 based on the molar ratio of Co 2+ /Zn 2+ ; 3) And heating the graphene oxide composite aerogel loaded with the MOFs nano-sheet array to 500-1000 ℃ at a speed of 1-10 ℃ per minute under an inert atmosphere to perform high-temperature pyrolysis, so as to obtain the heat-insulating and wave-absorbing integrated light carbon-based nano aerogel material.
2. 2. The method for preparing the high-efficiency heat-insulating and wave-absorbing integrated light carbon-based nano aerogel is characterized in that in the step 1), the mass ratio of graphene oxide to chitosan is 1:4-4:1.
3. 3. The method for preparing the high-efficiency heat-insulating-wave-absorbing integrated light carbon-based nano aerogel according to claim 1, wherein in the step 2), the mass ratio of the metal salt to the organic ligand is 2:1-1:6.
4. 4. The method for preparing the high-efficiency heat-insulating-wave-absorbing integrated light carbon-based nano aerogel is characterized in that in the step 2), the mass ratio of the chitosan modified graphene oxide aerogel to the metal salt is 1:20-1:15.
5. 5. The method for preparing the high-efficiency heat-insulating and wave-absorbing integrated light carbon-based nano aerogel according to claim 1, wherein in the step 3), the inert atmosphere is a nitrogen atmosphere or an argon atmosphere.

Description

Preparation method of high-efficiency heat-insulation wave-absorbing integrated light carbon-based nano aerogel Technical Field The invention belongs to the technical field of composite wave-absorbing materials, and particularly relates to a preparation method of a light high-efficiency heat-insulating and wave-absorbing integrated carbon-based nano aerogel material. Background The rapid development of flexible electronic equipment makes the problems of electromagnetic radiation, electromagnetic interference and the like increasingly prominent, seriously influences the normal operation of the equipment and the safe transmission of information, and brings potential threat to human health. Especially, the continuous upgrading of the 5G communication technology and the Internet of things technology and the development of electronic equipment to portability, integration, intellectualization, refinement and the like are realized, the stability requirement of information transmission is enhanced, and higher requirements are also provided for the electromagnetic interference resistance of the electronic equipment. In the field of military, with the continuous development of radar detection systems, electronic countermeasure technologies and accurate guided weapons, the survival ability of various military equipment and the sudden prevention ability of weapon systems are extremely threatened, so that the improvement of the stealth ability of the weapon equipment has important significance for enhancing the defending ability of sea, land and air weapon equipment. The electromagnetic wave absorbing or shielding material, especially flexible electromagnetic wave absorbing material, can convert electromagnetic wave energy into other energy, weaken electromagnetic wave strength, prevent electromagnetic information leakage, cut off electromagnetic wave propagation, inhibit the radiation and interference of harmful electromagnetic wave, and lower the target signal of military equipment, such as aircraft, ship, etc. to reach stealth aim. Therefore, the method has important technological and application values for the research and the design of the flexible electromagnetic wave-absorbing material. In addition, the integrated high-speed operation of portable electronic devices, thermal runaway caused by the long-term operation of electronic equipment has a fire risk, and if a human body is exposed to such an environment for a long period of time, serious health hazards may be caused. The wave absorbing material shows a certain thermal effect after absorbing electromagnetic waves, and can cause a certain trouble to the operation of electronic equipment, and is not beneficial to the infrared stealth of military equipment. The heat insulation design is needed to prevent the heating elements such as a microprocessor and the like from damaging other elements or the health of hot people or achieve the purpose of infrared stealth. Therefore, the development of the wave-absorbing-heat-insulating integrated material which is light in weight, thin in thickness, wide in absorption frequency band, strong in absorption capacity and good in flexibility is very important in order to adapt to the application environment of portable electronic equipment and multiple stealth materials. Disclosure of Invention The invention provides a method for preparing light high-efficiency heat-insulating and wave-absorbing integrated carbon-based nano aerogel by taking chitosan crosslinking agent modified graphene oxide as a framework, growing MOFs nano arrays on the surface of the graphene oxide in situ through a liquid phase reaction, and further preparing the light high-efficiency heat-insulating and wave-absorbing integrated carbon-based nano aerogel through a high-temperature cracking method. 1. Preparation of heat-insulating-wave-absorbing integrated carbon-based nano aerogel (CoNC/rGO) The preparation method of the high-efficiency heat-insulating wave-absorbing integrated light carbon-based nano aerogel comprises the following steps: 1) Uniformly mixing the graphene oxide dispersion liquid and a chitosan solution, reacting for 2-24 hours at 20-80 ℃, and freeze-drying to obtain chitosan modified graphene oxide aerogel; the mass ratio of the graphene oxide to the chitosan is 1:1-1:4. 2) Immersing the chitosan modified graphene oxide aerogel into a mixed solution of metal salt and an organic ligand to obtain graphene oxide composite aerogel loaded with MOFs nano-sheet arrays; The metal salt is one or the combination of two of nickel nitrate, cobalt nitrate and zinc nitrate, and the organic ligand is one of terephthalic acid, tribenzoic acid or 2-methylimidazole. Preferably, the metal salt is a combination of cobalt nitrate and zinc nitrate, wherein the molar ratio of the cobalt nitrate to the zinc nitrate is 1:3-3:1 based on the molar ratio of Co 2+/Zn2+, and the organic ligand is 2-methylimidazole. The mass ratio of the metal salt to the organic liga