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CN-122010098-A - Graphitized carbon nano tube and preparation method and application thereof

CN122010098ACN 122010098 ACN122010098 ACN 122010098ACN-122010098-A

Abstract

A graphitized carbon nano tube and a preparation method and application thereof belong to the technical field of nano materials and fibers. According to the invention, the electrolyte with strong ionization, moderate ion size and certain hydration is added into the precursor solution, and the environment provided by the electrolyte and the precursor aqueous solution enables natural high molecules or polymer molecules to generate self-assembly behaviors based on intermolecular acting force in the low-temperature freezing process, so that the nanotubes with orderly arranged molecules are obtained. And carbonizing and graphitizing the obtained nano tube to obtain the graphitized carbon nano tube. Graphitized carbon nanotubes have graphite lattice fringes, which are highly ordered in the interior, have few defects, and have extremely high crystallinity, so that the material has ultra-high strength, ultra-high modulus, excellent electrical and thermal conductivity, and excellent stability.

Inventors

  • JIANG MAN
  • CHEN QI
  • HU CHUNFENG
  • CUI SHUXUN
  • FENG QINGGUO
  • ZHAN YULIN
  • SONG YUQI

Assignees

  • 西南交通大学

Dates

Publication Date
20260512
Application Date
20260204

Claims (10)

  1. 1. The graphitized carbon nanotube is characterized by having a graphite lattice stripe structure, the diameter is 400-900 nm, the length is in the order of centimeters or more, and the graphitization degree is 60-90%.
  2. 2. The preparation method of the graphitized carbon nano tube is characterized by comprising the following steps of: Step 1, dissolving a natural polymer raw material or a polymer raw material in deionized water, and then adding an electrolyte solution to obtain a precursor solution, wherein the mass concentration of the natural polymer raw material or the polymer raw material in the precursor solution is 1-5wt% and the concentration of the electrolyte is 0.01-0.05mol/L; Step 2, stirring, dialyzing and freeze-drying the precursor solution obtained in the step 1 to obtain a nanotube; and 3, carbonizing and graphitizing the nano tube obtained in the step 2 to obtain the graphitized carbon nano tube.
  3. 3. The method for preparing graphitized carbon nanotubes according to claim 2, wherein in the step 1, the natural polymer raw material is chitosan, sodium alginate, hydroxypropyl cellulose, hydroxyethyl cellulose, carboxymethyl-beta-cyclodextrin, lignin or sodium carboxymethyl cellulose, and the polymer raw material is polyacrylic acid, sodium polyacrylate, polyglycerol ester, polyvinylidene fluoride-hexafluorophosphate copolymer or polyvinyl alcohol.
  4. 4. The method of preparing graphitized carbon nanotubes according to claim 2, wherein in the step 1, the electrolyte is sodium chloride, sodium sulfate, sodium sulfite, silver nitrate or copper chloride.
  5. 5. The method for preparing graphitized carbon nanotubes according to claim 2, wherein in the step 1, when the raw material is sodium alginate, sodium carboxymethylcellulose or sodium polyacrylate, an electrolyte solution is not introduced into the precursor solution, and the concentration of sodium ions in the precursor solution is controlled to be 0.01-0.05mol/L.
  6. 6. The method for preparing graphitized carbon nanotubes according to claim 2, wherein in the step 3, the carbonization process is that the nanotubes are placed in a tube furnace, heated to 200-300 ℃ at a rate of 2-5 ℃ per minute under an inert gas atmosphere, kept for 0.5-3 hours, then heated to 400-600 ℃ at a rate of 5-10 ℃ per minute, and kept for 2-6 hours to complete carbonization.
  7. 7. The method for preparing graphitized carbon nanotubes according to claim 2, wherein in the step 3, graphitization is performed by placing the carbonized nanotubes in a graphitization furnace, adjusting the temperature range to 1600-2000 ℃ for 10s by pulse current, and repeating the process of 'adjusting the temperature range to 1600-2000 ℃ for 10 s' for 5-10 times to complete graphitization.
  8. 8. A method for preparing nanotube fibers based on graphitized carbon nanotubes is characterized in that graphitized carbon nanotubes are formed into fibers with adjustable length and diameter by a wet spinning method.
  9. 9. A method for preparing nanotube fibers based on graphitized carbon nanotubes, which is characterized by comprising the following steps: Step 1, mixing graphitized carbon nano tubes and a surfactant in water, wherein the concentration of the graphitized nano tubes in the mixed solution is 0.5-1wt%; step 2, after ultrasonic treatment is carried out on the obtained mixed solution at room temperature for 60min, the mixed solution is injected into a coagulating bath through a needle head at the speed of 0.1-0.5 cm/min; and 3, immersing the graphitized nanotube fiber obtained by wet spinning into deionized water for 24 hours after complete solidification to remove residual surfactant, and then standing overnight at the ambient temperature to obtain the final graphitized nanotube fiber.
  10. 10. Use of graphitized carbon nanotubes prepared by the method of any one of claims 2-7 in electromagnetic wave absorbing materials, high performance composites or flexible electronic devices.

Description

Graphitized carbon nano tube and preparation method and application thereof Technical Field The invention belongs to the technical field of nano materials and fibers, and particularly relates to a graphitized carbon nano tube and a preparation method and application thereof. Background The carbon nanotubes can be assembled into continuous one-dimensional fibers by virtue of excellent mechanical properties, excellent electrical properties and thermal properties, and can be used in the fields of national defense, military industry, aerospace, flexible electronics and the like, so that the carbon nanotubes are one of key paths for realizing application of the carbon nanotubes. At present, the main method for preparing the carbon nano tube is a chemical vapor deposition method, specifically, carbon source gas passes through the surface of a nano-scale metal catalyst at a medium temperature (500-1000 ℃), and after the carbon source gas is decomposed, carbon atoms are dissolved and separated out on catalyst particles to grow the carbon nano tube. However, the method relies on carbon source gas and metal catalyst, the raw materials are not renewable, and the energy consumption in the production process is high. Therefore, it is very interesting to develop a method of carbon nanotubes that is easy to obtain raw materials, simple in process and capable of obtaining excellent properties. Disclosure of Invention In order to solve the defects in the prior art, the invention aims to provide a graphitized carbon nano tube, a preparation method and application thereof, wherein the method is simple and easy to implement, and the prepared carbon nano tube has excellent performance. The technical scheme adopted by the invention is as follows: The graphitized carbon nanotube has a graphite lattice stripe structure, the diameter is 400-900 nm, the length can reach the centimeter level, and the graphitization degree is as high as 60-90%. A method for preparing graphitized carbon nanotubes, comprising the steps of: Step 1, dissolving a natural polymer raw material or a polymer raw material in deionized water, and then adding an electrolyte solution to obtain a precursor solution, wherein the mass concentration of the natural polymer raw material or the polymer raw material in the precursor solution is 1-5wt% and the concentration of the electrolyte is 0.01-0.05mol/L; Step 2, stirring, dialyzing and freeze-drying the precursor solution obtained in the step 1 to obtain a nanotube; And 3, sequentially carbonizing and graphitizing the nanotubes obtained in the step 2 to obtain graphitized carbon nanotubes. In the step 1, the natural polymer raw materials are chitosan, sodium alginate, hydroxypropyl cellulose, hydroxyethyl cellulose, lignin, carboxymethyl-beta-cyclodextrin and sodium carboxymethyl cellulose, and the polymer raw materials are polyacrylic acid, sodium polyacrylate, polyglycerol ester, polyvinylidene fluoride-hexafluorophosphate copolymer and polyvinyl alcohol. Further, in step 1, the electrolyte is sodium chloride, sodium sulfate, sodium sulfite, silver nitrate or copper chloride. In the step 1, when the raw materials are electrolyte raw materials such as sodium alginate, sodium carboxymethylcellulose, sodium polyacrylate and the like, the electrolyte solution is not introduced into the precursor solution, and the concentration of sodium ions in the precursor solution is controlled to be 0.01-0.05mol/L. Further, in the step 2, after the precursor solution is stirred, the precursor solution is dialyzed for 1 to 3 days, and then the precursor solution is sufficiently frozen in a liquid nitrogen environment and then is freeze-dried, so that the nanotube is obtained. Further, in the step 3, the carbonization process is that the nano tube is placed in a tube furnace, heated to 200-300 ℃ at a rate of 2-5 ℃ per minute under an inert gas atmosphere, kept for 0.5-3 hours, heated to 400-600 ℃ at a rate of 5-10 ℃ per minute, and kept for 2-6 hours, so that carbonization is completed. In the step 3, the graphitization process is that the carbonized nano tube is placed in a graphitization furnace, the temperature range is regulated to 1600-2000 ℃ through pulse current for 10s, and the process of 'the pulse current is regulated to 1600-2000 ℃ for 10 s' is repeated for 5-10 times, so that graphitization is completed. Further, the graphitized carbon nanotube prepared in the step 3 has a graphite lattice fringe structure. A method for preparing nanotube fiber based on graphitized carbon nanotubes is characterized in that graphitized carbon nanotubes are subjected to wet spinning and other methods to form fiber with adjustable length and diameter. A method for preparing nanotube fibers based on graphitized carbon nanotubes, comprising the steps of: Step 1, mixing graphitized carbon nano tubes and a surfactant in water, wherein the concentration of the graphitized nano tubes in the mixed solution is 0.5-1wt%; step 2, after ultrasonic tre