Preparation method of liquid metal reinforced radiation shielding coating material

Abstract

The invention relates to a preparation method of a liquid metal reinforced radiation shielding coating material, and belongs to the technical field of radiation shielding materials. The liquid metal is subjected to ball milling for a period of time at a certain rotating speed under the nitrogen protective atmosphere to enable the particle size to be 1t; 10 [mu] m; then the liquid metal is placed in a silane coupling agent solution according to a certain solid-to-liquid ratio and runs in a constant-temperature oscillator at a certain oscillation frequency for a period of time, and the surface of the liquid metal is coated with a layer of siloxane for modification treatment; weighing the modified liquid metal and barium sulfate according to a certain mass ratio, and carrying out ball milling in a planetary stirrer at a certain ball milling rate so as to uniformly mix the modified liquid metal and the barium sulfate; and mixing the obtained mixture with talcum powder and water according to a certain mass ratio, and uniformly stirring to obtain the liquid metal reinforced base radiation shielding coating material. The modified liquid metal is uniformly distributed in the barium sulfate matrix to serve as the composite coating, so that the lead equivalent and the radiation shielding performance are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of radiation shielding materials in construction engineering, and in particular to a method for preparing a liquid metal reinforced matrix radiation shielding coating material. Background Art

[0002] Ionizing radiation is widely used in fields such as medical diagnosis, cancer treatment, nuclear science, scientific research, and food safety. High-energy ionizing radiation, such as X-rays and gamma rays, can adversely affect cells. Long-term exposure to excessive radiation doses, without adequate radiation shielding, can seriously harm human health, leading to radiation sickness, cancer, and even death. Furthermore, X-rays and gamma rays can affect the physical and chemical properties of materials.

[0003] However, in the fields of medical diagnosis, linear accelerators, etc., barium sulfate coatings for walls have problems such as poor shielding performance of a single component and large coating thickness. However, conventional barium sulfate modified fillers have problems such as uneven distribution of the reinforcing phase and weak matrix interface bonding. After moisture absorption or long-term use, they are prone to microcracks and shedding, resulting in significant degradation of shielding performance. Liquid metal is considered an ideal candidate material due to its room temperature fluidity, high thermal conductivity and excellent radiation stability. Therefore, under the condition of meeting shielding efficiency, it is urgent to develop a new preparation method for liquid metal reinforced coatings that can improve the coating structure stability and process applicability while ensuring radiation shielding effectiveness, so as to meet the needs of long-term protection in extreme environments. Summary of the Invention

[0004] The present invention addresses the problems of existing barium sulfate coatings, such as poor shielding performance and the need for a large thickness; the toxic physical properties of lead, high density, and environmental pollution. The present invention provides a method for preparing a liquid metal reinforced radiation shielding coating material, namely, using a silane coupling agent to modify the surface of the liquid metal, and then using the liquid metal as a filler and mixing it with barium sulfate through ball milling to prepare a composite coating, thereby significantly improving the radiation shielding performance of the barium sulfate, reducing the coating thickness, and reducing the space occupancy rate.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing a liquid metal reinforced matrix radiation shielding coating material, comprising the following steps: Step 1: Ball milling The liquid metal was ball-milled in a nitrogen environment to a particle size of less than 10 μm; Step 2: Modification The ball-milled liquid metal is placed in a silane coupling agent solution and oscillated using a constant temperature oscillator to coat a layer of siloxane on the surface of the liquid metal; Step 3: Mix Mixing the modified liquid metal with barium sulfate and stirring to obtain a mixture; Step 4: Mix and stir the mixture, talcum powder and water.

[0006] Furthermore, the liquid metal is one or more of Ga, In, Sn, Bi, and Cd.

[0007] Furthermore, the silane coupling agent is one or more of epoxy resin, acrylic resin, polyurethane resin, and organosilicon-modified resin.

[0008] Furthermore, the mass ratio of the liquid metal to the silane coupling agent is 1:20-30.

[0009] Furthermore, in step 1, the mixture is ball milled in a ball mill at a speed of 300-500 rpm / min for 3-6 hours.

[0010] Furthermore, the mass ratio of the modified liquid metal to the barium sulfate is 1:1-3, and the mixture is mixed in a planetary agitator at a ball milling speed of 500-700 rpm / min.

[0011] Furthermore, the mass ratio of the mixture, talcum powder and water is 1:0.05-0.1:0.3-0.4.

[0012] Furthermore, in step three, the MXene slurry is mixed with liquid metal in a mass ratio of 1:5, and a uniform composite is formed by mechanical stirring; and the composite is mixed with barium sulfate in a mass ratio of 1:3 to obtain a composite mixture.

[0013] Furthermore, the MAX phase precursor was used to selectively etch the aluminum layer through HCl-LiF solution to obtain multilayer MXene; the MXene was intercalated and surface modified using a silane coupling agent; the modified MXene was dispersed in NMP and ultrasonically treated for 3-5 hours until uniformly dispersed, forming a stable MXene slurry.

[0014] Furthermore, the composite mixture, talcum powder and a mixed solvent are mixed and stirred, wherein the mixed solvent is a mixed solvent of ethanol and water.

[0015] The beneficial effects of the above technical solution are: The present invention relates to a preparation method of a liquid metal reinforced matrix radiation shielding coating material, belonging to the technical field of radiation shielding materials. The liquid metal is ball-milled at a certain rotation speed for a period of time under a nitrogen protective atmosphere to make its particle size less than 10 μm; then the liquid metal is placed in a silane coupling agent solution according to a certain solid-liquid ratio, and operated at a certain oscillation frequency for a period of time in a constant temperature oscillator, and a layer of siloxane is coated on the surface of the liquid metal for modification treatment; the modified liquid metal and barium sulfate are weighed according to a certain mass ratio, and ball-milled in a planetary mixer at a certain ball milling rate to mix them evenly; the obtained mixture is mixed with talcum powder and water according to a certain mass ratio, and stirred evenly to obtain a liquid metal reinforced matrix radiation shielding coating material. The present invention discloses that by uniformly distributing the modified liquid metal in a barium sulfate matrix as a composite coating, its lead equivalent and radiation shielding performance are significantly improved.

[0016] The present invention utilizes liquid metal as a filler to significantly improve the radiation shielding performance of barium sulfate coatings while significantly reducing coating thickness and space occupancy. Surface modification of the liquid metal particles using a silane coupling agent significantly addresses the problem of liquid metal agglomeration during large-scale mixing. Furthermore, by varying the type and content of the modified liquid metal, as well as its mass ratio to barium sulfate, the present invention dynamically adjusts the radiation shielding performance of the composite coating, making it suitable for use in various ionizing radiation energy ranges. Using liquid metal as a filler to replace traditional lead not only aligns with environmentally friendly principles, but also allows for its application in any material requiring improved photon attenuation efficiency, such as concrete and construction joints.

[0017] At the same time, the present invention utilizes the high conductivity of MXene to absorb electromagnetic waves through conduction loss, generates conduction loss through free electron migration, absorbs high-frequency electromagnetic waves, and attenuates energy through scattering by barium sulfate. The liquid metal droplets and the MXene interface form a large number of dipoles, which enhance broadband absorption through interfacial polarization. Through MXene absorbing high-frequency energy, liquid metal polarization dissipating mid-frequency radiation, and BaSO4 scattering the remaining low-frequency radiation, multi-level attenuation is achieved to achieve full frequency band coverage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Implementation block diagram of the preparation method of the present invention: Figure 2 is the average lead equivalent of the embodiment in the photon energy range of 15-15000 keV; Figure 3 is the average lead equivalent of the embodiments in the photon energy range of 30-80keV. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1. This example aims to provide a method for preparing a liquid metal reinforced radiation shielding coating material, which is mainly used for radiation shielding coating materials. It is aimed at the defects of existing barium sulfate-based radiation shielding coatings: 1. The shielding efficiency of a single barium sulfate component is insufficient, and the performance shortcomings need to be compensated by increasing the coating thickness, resulting in a high space occupancy rate; 2. Traditional modified fillers are prone to microcracks and fall off after moisture absorption or long-term use due to uneven distribution of the reinforcing phase and weak bonding with the matrix interface, resulting in rapid attenuation of shielding performance. 3. In addition, although lead-based materials have excellent shielding properties, they have problems such as high toxicity, high density, and environmental pollution. In summary, the existing system generally has the defects of poor structural stability and insufficient process adaptability, which makes it difficult to meet the needs of long-term radiation protection in extreme environments, seriously restricting its application in scenarios such as precision medical equipment and compact accelerators.

[0020] In a specific implementation, a method for preparing a liquid metal reinforced matrix radiation shielding coating material comprises the following steps: Step 1: Ball milling The liquid metal is ball-milled in a nitrogen environment to a particle size of less than 10 μm. In a specific implementation, the liquid metal is one or more of Ga, In, Sn, Bi, and Cd, and is ball-milled in a ball mill at a speed of 300-500 rpm / min for 3-6 hours.

[0021] Step 2: Modification The ball-milled liquid metal is placed in a silane coupling agent solution and oscillated using a constant-temperature oscillator to coat the liquid metal with a layer of siloxane. The silane coupling agent is one or more of epoxy resin, acrylic resin, polyurethane resin, and silicone-modified resin. The mass ratio of liquid metal to silane coupling agent is 1:20-30.

[0022] Step 3: Mix The modified liquid metal is mixed with barium sulfate and stirred to obtain a mixture; the mass ratio of the modified liquid metal to the barium sulfate is 1:1-3, and the mixture is mixed in a planetary agitator at a ball milling speed of 500-700 rpm / min.

[0023] Step 4: Mix and stir the mixture, talcum powder and water. In the specific implementation, the mass ratio of the mixture, talcum powder and water is 1:0.05-0.1:0.3-0.4.

[0024] Based on this, this embodiment provides a method for preparing a liquid metal-enhanced radiation-shielding coating material. Liquid metal (such as Ga, In, or Sn) is surface-modified with a silane coupling agent, then compounded with barium sulfate through ball milling. Talc and water are then added to form a uniform coating. This method leverages the synergistic effect of the liquid metal's high radiation-shielding properties and the silane coupling agent modification to address the issues of traditional barium sulfate coatings, such as the large thickness and low shielding efficiency, as well as the high toxicity of lead-based materials. Furthermore, by adjusting the type and ratio of the liquid metal, the material can be dynamically adapted to meet radiation shielding requirements across different energy ranges. This method is environmentally friendly, highly efficient, and has strong process adaptability.

[0025] In this embodiment, a method for preparing a liquid metal reinforced matrix radiation shielding coating material is provided, and the specific steps are as follows: (1) Liquid metal Ga and Bi (mass ratio 1:4) were ball milled at 300 rpm / min for 5 h under nitrogen atmosphere to reduce the particle size to <10 μm; (2) The liquid metal was placed in a mixed solution of polyurethane resin and silicone modified resin with a mass ratio of 1:1 according to a solid-liquid ratio of 1:25, and the mixture was operated in a constant temperature oscillator at an oscillation frequency of 150 rpm / min for 3 hours. A layer of siloxane was coated on the surface of the liquid metal for modification; (3) The modified liquid metal and barium sulfate in step (2) were weighed in a mass ratio of 1:1, and ball milled in a planetary mixer at a ball milling rate of 500 rpm / min to mix them uniformly; (4) The mixture obtained in step (3) is mixed with talcum powder and water in a mass ratio of 1:0.07:0.35 and stirred evenly to obtain a liquid metal Ga / Bi-BaSO4 enhanced base radiation shielding coating material.

[0026] The density of Ga / Bi-BaSO4 composite coating is 5.919cm3 / g, and its lead equivalent at different photon energies is as follows: Figure 1 and 2 As shown in the figure, its lead equivalent is significantly higher than that of pure BaSO4 coating in the entire photon energy range of 15-15000keV. In addition, its average lead equivalent is as high as 0.618mmPb / mm in the medical diagnostic X-ray energy range. The above results all indicate that it has excellent photon attenuation capability and requires a lower coating thickness under the same radiation shielding performance.

[0027] Example 2: A method for preparing a liquid metal reinforced matrix radiation shielding coating material, the specific steps are as follows: (1) Liquid metal Ga, Sn, and Cd (mass ratio 2:2:1) were ball-milled at 400 rpm / min for 5 h under nitrogen atmosphere to a particle size of <10 μm; (2) The liquid metal was placed in a mixed solution of epoxy resin and acrylic resin with a mass ratio of 3:1 according to a solid-liquid ratio of 1:20, and the mixture was operated in a constant temperature oscillator at an oscillation frequency of 100 rpm / min for 4 hours. A layer of siloxane was coated on the surface of the liquid metal for modification; (3) The modified liquid metal and barium sulfate in step (2) were weighed in a mass ratio of 1:3, and ball milled in a planetary mixer at a ball milling rate of 600 rpm / min to mix them uniformly; (4) The mixture obtained in step (3) is mixed with talcum powder and water in a mass ratio of 1:0.1:0.3 and stirred evenly to obtain a liquid metal Ga / Sn / Cd-BaSO4 enhanced base radiation shielding coating material.

[0028] The density of Ga / Sn / Cd-BaSO4 composite coating is 5.091cm3 / g, and its lead equivalent at different photon energies is as follows: Figure 1 and 2 As shown in the figure, its lead equivalent is significantly higher than that of pure BaSO4 coating in the entire photon energy range of 15-15000keV. In addition, its average lead equivalent is as high as 0.623mmPb / mm in the medical diagnostic X-ray energy range. The above results all indicate that it has excellent photon attenuation capability and requires a lower coating thickness under the same radiation shielding performance.

[0029] Example 3: A method for preparing a liquid metal reinforced radiation shielding coating material, the specific steps are as follows: (1) Liquid metal Cd and In (mass ratio 1:1) were ball milled at 500 rpm / min for 3 h under nitrogen atmosphere to reduce the particle size to <10 μm; (2) The liquid metal was placed in a mixed solution of polyurethane resin, silicone modified resin and silicone modified resin in a mass ratio of 1:1:1 at a solid-liquid ratio of 1:30, and the mixture was operated in a constant temperature oscillator at an oscillation frequency of 200 rpm / min for 2 hours. A layer of siloxane was coated on the surface of the liquid metal for modification; (3) The modified liquid metal and barium sulfate in step (2) were weighed in a mass ratio of 1:2.5, and ball milled in a planetary mixer at a ball milling rate of 500 rpm / min to mix them uniformly; (4) The mixture obtained in step (3) is mixed with talcum powder and water in a mass ratio of 1:0.05:0.4 and stirred evenly to obtain a liquid metal Cd / In-BaSO4 enhanced base radiation shielding coating material.

[0030] The density of the Cd / In-BaSO4 composite coating is 5.439 / g, and its lead equivalent at different photon energies is as follows: Figure 1 and 2As shown in the figure, its lead equivalent is significantly higher than that of pure BaSO4 coating in the entire photon energy range of 15-15000keV. In addition, its average lead equivalent is as high as 0.656mmPb / mm in the medical diagnostic X-ray energy range. The above results all indicate that it has excellent photon attenuation capability and requires a lower coating thickness under the same radiation shielding performance.

[0031] Example 4: A method for preparing a liquid metal reinforced radiation shielding coating material, the specific steps are as follows: The MAX phase precursor is used to selectively etch the aluminum layer through HCl-LiF solution to obtain multilayer MXene; the MXene is intercalated and surface modified using a silane coupling agent; the modified MXene is dispersed in NMP and ultrasonically treated for 3-5 hours until uniformly dispersed to form a stable MXene slurry.

[0032] The MXene slurry and liquid metal were mixed in a mass ratio of 1:5 and mechanically stirred to form a uniform composite. The composite was then mixed with barium sulfate in a mass ratio of 1:3 to obtain a composite mixture. The composite mixture, talc, and a mixed solvent were then mixed and stirred. The mixed solvent was a mixture of ethanol and water.

[0033] In the specific implementation, Ti3AlC2 is used as the MAX phase precursor, and the aluminum layer is selectively etched by HCl-LiF solution to obtain a multilayer Ti3C2T x MXene; use tetrabutylammonium hydroxide (TBAOH) or silane coupling agents to intercalate and surface modify MXene to improve its dispersibility in organic solvents or water; use silane coupling agents to introduce amino groups or silicon-oxygen bonds on the MXene surface through hydrolysis reaction to enhance the interfacial bonding strength with liquid metal and barium sulfate.

[0034] In practice, the modified MXene is dispersed in NMP (N-methylpyrrolidone) or DMF (N,N-dimethylformamide) and ultrasonically treated for 3-5 hours until uniformly dispersed, forming a stable slurry (MXene content >20wt%). The liquid metal is surface treated with a silane coupling agent to reduce its surface tension and enhance wettability with the MXene. The MXene slurry is then mixed with the liquid metal in a 1:5 mass ratio and mechanically stirred to form a uniform composite. The MXene-liquid metal composite is then mixed with barium sulfate in a 1:3 mass ratio, with talc (5wt%) added as a dispersing aid. The mixture is then ball-milled or processed in a three-roll mill to ensure uniform filler distribution and form a double-shielded structure with a conductive network of MXene and barium sulfate scatterers.

[0035] This embodiment carries out the following experiment: Group 1: MXene / liquid metal = 1:5, composite / barium sulfate = 1:3; Group 2: MXene / liquid metal = 1:3, composite / barium sulfate = 1:3; Group 3: MXene / liquid metal = 1:5, composite / barium sulfate = 1:1. Group Lead equivalent (mmPb) Shielding effectiveness (100 keV gamma ray attenuation rate) Coating density (g / cm³ Group 1 2.5 92% 3.2 Group 2 1.8 85% 3.5 Group 3 2.1 88% 4.0

[0036] In the experiments described above, the optimal lead equivalent and shielding effectiveness, along with the lowest density, were achieved at mass ratios of 1:5 (MXene / liquid metal) and 1:3 (composite / barium sulfate). Excessive liquid metal (Group 2) resulted in an overly dense conductive network, weakening the interfacial polarization effect. Excessive barium sulfate (Group 3) increased density but saturated the scattering efficiency.

[0037] This embodiment utilizes the high conductivity of MXene to absorb electromagnetic waves through conduction loss. Conductance loss is generated by free electron migration to absorb high-frequency electromagnetic waves. Barium sulfate attenuates energy through scattering. Liquid metal droplets form a large number of dipoles at the interface with MXene, enhancing broadband absorption through interfacial polarization. Multi-level attenuation is achieved through MXene absorbing high-frequency energy, liquid metal polarization dissipating mid-frequency radiation, and BaSO4 scattering the remaining low-frequency radiation, achieving full frequency coverage.

[0038] The embodiments of the present invention described above do not limit the scope of protection of the present invention. The basic concept of the present invention is to significantly improve the lead equivalent and radiation shielding performance of the composite coating by uniformly distributing a modified liquid metal in a barium sulfate matrix. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the claims.

Claims

1. A method for preparing a liquid metal reinforced matrix radiation shielding coating material, characterized by: The steps include: Step 1: Ball milling The liquid metal was ball-milled in a nitrogen environment to a particle size of less than 10 μm; Step 2: Modification The ball-milled liquid metal is placed in a silane coupling agent solution and oscillated using a constant temperature oscillator to coat a layer of siloxane on the surface of the liquid metal; Step 3: Mix Mixing the modified liquid metal with barium sulfate and stirring to obtain a mixture; Step 4: Mix and stir the mixture, talcum powder and water.

2. The method for preparing the liquid metal reinforced matrix radiation shielding coating material according to claim 1, characterized in that: The liquid metal is one or more of Ga, In, Sn, Bi, and Cd.

3. The method for preparing the liquid metal reinforced matrix radiation shielding coating material according to claim 1 or 2, characterized in that: The silane coupling agent is one or more of epoxy resin, acrylic resin, polyurethane resin and organosilicon modified resin.

4. The method for preparing the liquid metal reinforced matrix radiation shielding coating material according to claim 3, characterized in that: The mass ratio of the liquid metal to the silane coupling agent is 1:20-30.

5. The method for preparing the liquid metal reinforced matrix radiation shielding coating material according to claim 1, characterized in that: In step 1, the mixture was ball milled at a speed of 300-500 rpm / min for 3-6 hours.

6. The method for preparing the liquid metal reinforced matrix radiation shielding coating material according to claim 1, characterized in that: The mass ratio of the modified liquid metal to the barium sulfate is 1:1-3, and the mixture is mixed in a planetary agitator at a ball milling speed of 500-700 rpm / min.

7. The method for preparing a liquid metal reinforced matrix radiation shielding coating material according to any one of claims 1, 2, 5, and 6, characterized in that: The mass ratio of the mixture, talcum powder and water is 1:0.05-0.1:0.3-0.

4.

8. The method for preparing the liquid metal reinforced matrix radiation shielding coating material according to claim 1, characterized in that: In step three, the MXene slurry is mixed with liquid metal in a mass ratio of 1:5 and mechanically stirred to form a uniform composite; the composite is mixed with barium sulfate in a mass ratio of 1:3 to obtain a composite mixture.

9. The method for preparing the liquid metal reinforced matrix radiation shielding coating material according to claim 8, characterized in that: The MAX phase precursor is used to selectively etch the aluminum layer through HCl-LiF solution to obtain multilayer MXene; the MXene is intercalated and surface modified using a silane coupling agent; the modified MXene is dispersed in NMP and ultrasonically treated for 3-5 hours until uniformly dispersed to form a stable MXene slurry.

10. The method for preparing the liquid metal reinforced matrix radiation shielding coating material according to claim 9, characterized in that: The composite mixture, talcum powder and mixed solvent are mixed and stirred, wherein the mixed solvent is a mixed solvent of ethanol and water.

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