4 results about "Magnetic carbon" patented technology

The application discloses a magnetic carbon aerogel with infrared-radar dual stealth function and a preparation method thereof. First, nickel chloride hexahydrate, sodium hydroxide and cetyltrimethylammonium bromide are dissolved in ethylene glycol, hydrazine hydrate is added, and then the mixture is reacted under heating and magnetic field to prepare a nickel chain; then a silanol solution after hydrolysis and condensation is blended with a bacterial cellulose gel to prepare a BC precursor solution, the BC precursor solution is uniformly mixed with the nickel chain and a carbon material dispersion liquid, and then directional freezing and freeze drying are performed to prepare the magnetic carbon aerogel. The method effectively solves the technical problems that in the prior art, it is difficult for infrared-radar dual stealth materials to maintain low infrared emissivity and light weight while realizing wide-frequency, strong and stable radar wave absorption performance, especially after the introduction of a magnetic component, oxidation is easily caused, dispersion is uneven, and the infrared characteristics are deteriorated.

The application discloses a preparation method of a carbonized wood-based electromagnetic shielding material with electrically-conductive and magnetically-conductive properties, which comprises the following steps: immersing Fe3O4@Graphene nanoparticles into the surface of wood after carbonization, and then performing chemical nickel plating to prepare the carbonized wood-based electromagnetic shielding material. The carbonized wood has good corrosion and insect prevention performance, is not easy to absorb water, and is a good moisture-proof wood with a contact angle of 126.2 degrees. Therefore, after the Fe3O4@Graphene nanoparticles are compounded on the surface of the carbonized wood, the chemical nickel plating can endow the carbonized wood with electromagnetic functional properties. By controlling the time for immersing the nanoparticles, the electromagnetic shielding performance of the carbonized wood composite material can be regulated. The conductivity of the carbonized wood composite material prepared after immersing the nanoparticles for 5 hours can reach 631.3 S / cm, and the average electromagnetic shielding efficiency of the carbonized wood composite material in a frequency range of 8.2 to 12.4 GHz can reach 70 dB, and some frequency bands can reach 80 dB.

The application provides a composite diaphragm and a preparation method thereof. The composite diaphragm comprises a diaphragm base and magnetic carbon nanotubes arranged on at least one side of the diaphragm base. One end of the magnetic carbon nanotubes is connected to the diaphragm base, and the other end extends away from the diaphragm base. The magnetic carbon nanotubes comprise first magnetic carbon nanotubes, and the angle between the extending direction of the first magnetic carbon nanotubes and the diaphragm base is 30-90°. The use of the composite diaphragm for assembling a negative electrode-free battery can make lithium metal uniformly deposit on the negative electrode side and improve the cycle performance of the battery.