CN-122000106-A - Neutron-gamma ray shielding carbon fiber material and preparation method thereof

Abstract

A neutron-gamma ray shielding carbon fiber material and a preparation method thereof belong to the technical field of high-performance composite materials. The material is of a core-shell composite structure from inside to outside, and specifically comprises a modified carbon fiber matrix, a metal aluminum layer, a nano-scale copper layer and a nano-scale copper layer, wherein a neutron absorption phase and a gamma ray shielding phase are uniformly dispersed in the modified carbon fiber matrix, the metal aluminum layer is coated on the surface of the modified carbon fiber matrix, and the nano-scale copper layer is deposited on the surface of the metal aluminum layer. The neutron absorption phase is boron carbide, and the gamma ray shielding phase is a high-entropy alloy phase containing at least three of lead (Pb), tungsten (W), tantalum (Ta), bismuth (Bi), vanadium (V), molybdenum (Mo) and niobium (Nb). According to the invention, through the design of 'boron oxide in-situ conversion boron carbide' and 'high-entropy alloy multielement cooperation', a high-efficiency neutron absorption phase and a gamma ray attenuation phase are constructed in the body fiber at the same time, so that the cooperation shielding of a mixed radiation field is realized.

Inventors

• ZHENG WEI
• JIANG ZAIXING
• LIU LI
• HUANG YUDONG
• LI JUN
• LI YINUO
• YAN ZEYU
• FU LEI
• ZHONG BOWEN
• DU YUNCHEN
• CHEN SHUAI
• BAI YONGPING

Assignees

• 哈尔滨工业大学

Dates

Publication Date

20260508

Application Date

20260209

Claims (10)

1. 1. A neutron-gamma ray shielding carbon fiber material is characterized by comprising a modified carbon fiber matrix, a metal aluminum layer, and a nano-scale copper layer, wherein neutron absorption phases and gamma ray shielding phases are uniformly dispersed in the modified carbon fiber matrix, the metal aluminum layer is coated on the surface of the modified carbon fiber matrix, and the nano-scale copper layer is deposited on the surface of the metal aluminum layer.
2. 2. The neutron-gamma ray shielding carbon fiber material according to claim 1, wherein the neutron absorbing phase is boron carbide (B 4 C), and the gamma ray shielding phase is a high entropy alloy phase containing at least three of lead (Pb), tungsten (W), tantalum (Ta), bismuth (Bi), vanadium (V), molybdenum (Mo), niobium (Nb).
3. 3. The neutron-gamma ray shielding carbon fiber material of claim 1 or 2, wherein the modified carbon fiber matrix is made of a polyacrylonitrile precursor and a filler by high temperature sintering, wherein the filler comprises a boron oxide (B 2 O 3 ) precursor for in situ generation of boron carbide and high-entropy alloy powder for forming a high-entropy alloy phase.
4. 4. The neutron-gamma ray shielding carbon fiber material of claim 3, wherein the mass of the boron oxide precursor is 5% -25% and the mass of the high-entropy alloy powder is 10% -40% based on the mass of the polyacrylonitrile precursor.
5. 5. The neutron-gamma ray shielding carbon fiber material of claim 1, wherein the thickness of the metal aluminum layer is 0.1-2.0 microns, the thickness of the nano-scale copper layer is 1-15 microns, and the sheet diameter of the nano-scale copper layer is 50 nanometers-3 microns.
6. 6. A method for preparing the neutron-gamma ray shielding carbon fiber material according to any one of claims 1 to 5, which is characterized in that the method comprises the following steps: S1, uniformly dispersing polyacrylonitrile, boron oxide powder and high-entropy alloy powder in an organic solvent to prepare spinning solution with the concentration of 10-20wt%, and spinning and pre-oxidizing to prepare precursor fibers; S2, sintering the precursor fiber in a protective atmosphere to obtain a modified carbon fiber matrix; S3, carrying out surface activation treatment on the modified carbon fiber matrix, and then depositing a metal aluminum layer on the surface of the modified carbon fiber matrix through chemical plating; and S4, depositing a nano-scale copper layer on the surface of the fiber with the metal aluminum layer deposited on the surface by using an electrophoretic deposition method as a working electrode.
7. 7. The method according to claim 6, wherein in step S1, the high-entropy alloy powder is PbWTa-, pbWTaMo-or PbWTaNb-series alloy powder having an equal atomic ratio or a near equal atomic ratio.
8. 8. The method according to claim 6, wherein in the step S2, the protective atmosphere is nitrogen or argon, the sintering comprises low-temperature carbonization at 400-800 ℃ and high-temperature carbonization at 800-1500 ℃ and the sintering time is 60-180 minutes.
9. 9. The method of claim 6, wherein in the step S3, the surface activation treatment is a sensitization-activation method or a plasma surface activation treatment, the plasma surface activation treatment is specifically performed in an activation gas (such as oxygen, nitrogen or air), the flow is controlled within a range of 20-50 sccm, the radio frequency power is 100-300W, the treatment time is 5-15 minutes, the plating solution used in the electroless plating is performed in a nonaqueous solvent system by using an organic aluminum compound as a main salt, the concentration is 0.05-0.15 mol/L, the deposition temperature is 80-180 ℃, and the deposition time is 1-900 seconds.
10. 10. The method according to claim 6, wherein in the step S4, the electrophoretic deposition is performed in a suspension of nano-scale copper, the concentration of nano-scale copper in the suspension is 5-50 g/L, the applied direct current voltage is 20-80V, and the deposition time is 2-20 minutes.

Description

Neutron-gamma ray shielding carbon fiber material and preparation method thereof Technical Field The invention relates to the technical field of high-performance composite materials, in particular to a multifunctional carbon fiber material with high-efficiency neutron and gamma ray comprehensive shielding performance, high heat conduction and high electric conduction performance and a preparation method thereof. Background Carbon fiber has irreplaceable functions in the fields of aerospace, national defense and military industry and high-end equipment due to the excellent characteristics of light weight, high strength and high modulus. Along with the complicating of application scenes (such as a nuclear power device, a space radiation environment, medical radiation equipment and the like), a pressing requirement of multifunctional integration is provided for structural materials, namely, the structural materials are required to have effective shielding capability on ionizing radiation such as neutrons, gamma rays and the like while maintaining the mechanical properties, and excellent heat conduction and electric conduction performance so as to meet the requirements of thermal management and electromagnetic compatibility. At present, radiation shielding mainly depends on thick and heavy materials such as lead plates, concrete and the like, and the requirements for light weight and flexibility are difficult to meet. In the prior art, an attempt is made to blend shielding fillers (such as boron carbide, tungsten, lead and the like) with polymer matrixes (such as polyethylene and epoxy resin) to prepare a composite material, but the method often leads to remarkable reduction of mechanical properties of the material, and the polymer matrixes have poor heat resistance, so that the application of the polymer matrixes in high-temperature environments is limited. The other thinking is that the surface of the carbon fiber fabric is coated with a shielding coating, but the coating is easy to peel off, the interfacial binding force is weak, and the flexibility and the braiding processability of the fiber are seriously affected. Therefore, developing an integrated carbon fiber material with a body having a radiation shielding function and excellent mechanical and thermal/electrical properties is a technical problem to be solved in the art. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides a neutron-gamma ray shielding carbon fiber material and a preparation method thereof. The material realizes the cooperative shielding of neutrons and gamma rays, unification of high heat conduction, high electric conduction and high strength, has stable process and is suitable for continuous production. In order to achieve the above purpose, the invention adopts the following technical scheme: The neutron-gamma ray shielding carbon fiber material has a core-shell composite structure from inside to outside, and specifically comprises a modified carbon fiber matrix, a metal aluminum layer, and a nano-scale copper layer, wherein a neutron absorption phase and a gamma ray shielding phase are uniformly dispersed in the modified carbon fiber matrix, the metal aluminum layer is coated on the surface of the modified carbon fiber matrix, and the nano-scale copper layer is deposited on the surface of the metal aluminum layer. Further, the neutron absorbing phase is boron carbide (B 4 C), and the gamma ray shielding phase is a high entropy alloy phase containing at least three of lead (Pb), tungsten (W), tantalum (Ta), bismuth (Bi), vanadium (V), molybdenum (Mo), niobium (Nb). Further, the modified carbon fiber matrix is prepared by sintering a polyacrylonitrile precursor and a filler at high temperature, wherein the filler comprises a boron oxide (B 2O3) precursor for generating boron carbide in situ and high-entropy alloy powder for forming a high-entropy alloy phase. The key role of boron oxide is that it reacts with carbon to form boron carbide (B 4 C) in situ during PAN high temperature carbonization, which is a recognized high efficiency thermal neutron absorber (10 B has a high neutron absorption cross section). The high-entropy alloy filler has the effects that the high-entropy alloy filler contains various high-atomic number (high Z) elements, the high-efficiency attenuation of wide-energy-spectrum gamma rays can be realized through a synergistic shielding effect, and the high-entropy alloy has better high-temperature structural stability and irradiation swelling resistance compared with pure metals. Further, based on the mass of the polyacrylonitrile precursor, the adding mass of the boron oxide precursor is 5% -25%, and the adding mass of the high-entropy alloy powder is 10% -40%. Further, the thickness of the metal aluminum layer is 0.1-2.0 micrometers, the thickness of the nano-scale copper layer is 1-15 micrometers, and the sheet diameter of the nano-scale copper layer is 50 nanometers-