In-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles, their preparation methods and applications

Abstract

This application provides an in-situ grown needle-like blend of GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles, its preparation method, and its application, relating to the fields of radiation protection materials and antibacterial materials. The radiation-resistant and antibacterial particles of this application use needle-like gadolinium tantalate as the radiation shielding matrix. A sheet-like samarium-doped cerium dioxide antibacterial component is uniformly grown on its surface using a hydrothermal in-situ growth method, resulting in a dual-functional composite material with an integrated needle-sheet blend structure. This application achieves strong interfacial bonding between the two phases through rare-earth lattice matching, while in-situ growth solves the core problem of easy agglomeration in physically blended powders. The resulting composite material possesses both radiation protection (X-rays + thermal neutrons) and highly efficient antibacterial functions. It exhibits controllable crystallization, strong batch stability, good compatibility with various matrices, stable structure, and uniform dispersion. It can be directly used as a functional filler or further processed into molds. The resulting products can be applied in fields such as nuclear industry protection, radiation medical dressings, military protective equipment, and civilian antibacterial and radiation-resistant products.

Description

Technical Field

[0001] This application relates to the field of radiation protection materials technology, specifically to an in-situ grown needle-like blend of GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles, its preparation method, and its application. Background Technology

[0002] With the widespread application of nuclear technology in fields such as radiotherapy, nuclear power industry, non-destructive testing and military equipment, the hazards of ionizing radiation and the risk of cross-infection of bacteria caused by the high humidity and closed environment of radiation scenarios coexist. In particular, in scenarios such as interventional dressings for radiotherapy and close-fitting protective equipment, the core requirement for materials is to have both radiation shielding and antibacterial protection functions.

[0003] In existing technologies, radiation protection and antibacterial functions are mostly independent systems, making it difficult to achieve synergistic performance. Single radiation protection materials have significant shortcomings: lead-based materials have heavy metal toxicity and are prone to secondary pollution; tungsten / bismuth-based materials have high density and poor flexibility, and can only shield against single X / γ rays, offering no protection against thermal neutrons; while single antibacterial materials have no radiation protection capability, silver-based antibacterial agents are prone to discoloration and pose a risk of silver ion leaching toxicity, and quaternary ammonium salt antibacterial agents have poor high-temperature resistance and are easily lost.

[0004] Currently, most mainstream solutions employ physical blending, which involves simply mixing protective powder with antibacterial powder. This approach has three major problems: first, the interfacial bonding is weak, and the antibacterial phase is prone to detachment; second, the powder is prone to agglomeration and has poor dispersibility, affecting processing and molding; and third, it is difficult to achieve both radiation shielding and antibacterial properties, resulting in poor synergy and hindering industrialization.

[0005] Therefore, there is an urgent need to develop an integrated rare earth-based composite material that combines radiation shielding, high-efficiency antibacterial properties, strong interfacial bonding between two phases, anti-agglomeration and easy dispersion, and excellent biocompatibility, and to explore its green and controllable preparation method. This has significant scientific research value and industrialization prospects. Summary of the Invention

[0006] In view of the technical problems existing in the background art, this application provides an in-situ grown needle-like blend of GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles, its preparation method and application. This material can effectively solve the core pain points of existing bifunctional materials such as easy agglomeration, phase separation, inability to synergize bifunctionality, and poor processing adaptability when physically blended. It can achieve synergistic performance of radiation shielding and high-efficiency antibacterial, while ensuring batch stability, biocompatibility and multi-scenario adaptability of the material.

[0007] In a first aspect, this application provides a method for preparing in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles, comprising the following steps: S1. Preparation of needle-shaped gadolinium tantalate matrix powder: Acidic gadolinium salt solution and tantalum salt solution were prepared separately. The tantalum salt solution was added dropwise to the acidic gadolinium salt solution, and the mixture was stirred at room temperature to obtain a suspension. A morphology directing agent was added to the suspension, and after dissolution, the pH of the system was adjusted to acidic. The mixture was stirred to obtain a precursor reaction solution. The precursor reaction solution was subjected to hydrothermal reaction, cooling, washing, and vacuum drying to obtain needle-shaped gadolinium tantalate matrix powder. S2. Preparation of in-situ growth precursor solution: Cerium source and samarium source are dissolved in ethanol-water mixed solvent and stirred until completely transparent to obtain rare earth precursor solution; after adding precipitant and morphology stabilizer, stirring is continued until completely dissolved, then the needle-shaped gadolinium tantalate matrix powder prepared in step S1 is added, and the mixture is stirred and premixed, ultrasonically dispersed until the powder is completely dispersed without sedimentation, and the pH of the system is adjusted to weakly alkaline to obtain in-situ growth precursor solution; S3. Hydrothermal in-situ growth reaction: The in-situ growth precursor solution prepared in step S2 is transferred to a hydrothermal reactor for hydrothermal reaction. After the reaction is completed, it is naturally cooled to room temperature. S4. High-temperature calcination crystallization treatment: After centrifugation, washing and drying of the reaction product in step S3, calcination is carried out in air atmosphere and natural cooling is performed to obtain needle-like and flake-like composite powder. S5. Post-processing modification: The needle-like composite powder obtained in step S4 is dispersed in an alcohol-water mixture, a silane coupling agent is added, and the surface is modified by water bath stirring. After centrifugation, washing, vacuum drying, and grinding, needle-like composite GdTaO4 / Sm-CeO2 anti-radiation and antibacterial particles are finally obtained.

[0008] Further, in step S1, the gadolinium salt is one of gadolinium nitrate hexahydrate (Gd(NO3)3·6H2O), gadolinium chloride hexahydrate (GdCl3·6H2O), and gadolinium sulfate (Gd2(SO4)3·8H2O), preferably gadolinium nitrate hexahydrate (Gd(NO3)3·6H2O); the tantalum salt is one of tantalum pentachloride (TaCl5), sodium tantalate (NaTaO3), and tantalum pentabromide (TaBr5), preferably tantalum pentachloride (TaCl5); wherein, the molar ratio of gadolinium to tantalum is (0.25~4):1, preferably (0.66~1.5):1.

[0009] The gadolinium salt acidic solution is prepared by dissolving gadolinium salt in 2 mol / L dilute nitric acid, and the concentration of metal ions in the solution is 0.25~0.5 mol / L, preferably 0.3~0.5 mol / L.

[0010] The tantalum salt solution is obtained by dissolving tantalum salt in anhydrous ethanol and then diluting it in deionized water. The concentration of metal ions in the solution is 0.25~0.5 mol / L, preferably 0.3~0.5 mol / L.

[0011] The morphology directing agent is one of citric acid monohydrate (C6H8O7·H2O), oxalic acid dihydrate (C2H2O4·2H2O), polyethylene glycol (PEG), and ethylenediaminetetraacetic acid (EDTA), preferably citric acid monohydrate. The amount of the morphology directing agent is 2.5% to 5% of the total mass of gadolinium salt and tantalum salt, preferably 3.5% to 5%.

[0012] The pH value of the precursor reaction solution is 1~3; in step S1, the filling degree of the hydrothermal reactor is 60%-80%, the temperature is 200~250℃, and the time is 8~12h.

[0013] Furthermore, in step S2, the cerium source is one of cerium nitrate hexahydrate (Ce(NO3)3·6H2O), cerium sulfate (Ce2(SO4)3), cerium acetate (C6H9CeO6), and cerium chloride (CeCl3·7H2O), preferably cerium nitrate hexahydrate (Ce(NO3)3·6H2O).

[0014] The samarium source is one of samarium nitrate hexahydrate (Sm(NO3)3·6H2O), samarium sulfate (Sm2(SO4)3·8H2O), samarium acetate (SmAc3·3H2O), and samarium chloride (SmCl3·6H2O), preferably samarium nitrate hexahydrate (Sm(NO3)3·6H2O).

[0015] The molar ratio of Ce to Sm is 19:1 to 4:1. The volume ratio of ethanol to water in the ethanol-water mixed solvent is 1:1.

[0016] The rare earth metal ion concentration in the rare earth precursor solution is 0.1~0.3mol / L.

[0017] The precipitant is one of ammonium acetate (CH3COONH4), urea, hexamethylenetetramine (HMTA), and formamide (HCONH2), preferably ammonium acetate (CH3COONH4), and the amount of the precipitant is 40% to 60% of the total mass of the cerium source and samarium source.

[0018] The morphology stabilizer is one of PVP K30, sodium citrate, and PEG-4000, preferably PVP K30. The amount of the morphology stabilizer is 10% to 30% of the total mass of the cerium source and samarium source, preferably 15% to 25%.

[0019] The amount of the needle-shaped gadolinium tantalate matrix powder added is 30% to 120% of the total mass of the cerium source and samarium source; the ultrasonic dispersion time is 30-60 min, and the pH of the system is 7.5-8.5.

[0020] Furthermore, in step S3, the filling degree of the hydrothermal reactor is 70%-80%, the temperature of the hydrothermal reaction is 120-180℃, and the time is 4-8h.

[0021] Furthermore, in step S4, the high-temperature calcination temperature is 400-600℃, the heating rate is 2-5℃ / min, and the time is 2-4h.

[0022] Furthermore, in step S5, the volume ratio of anhydrous ethanol to deionized water in the alcohol-water mixed solution is 9:1, and the solid content of the powder is 5%~8%.

[0023] The silane coupling agent is one of γ-aminopropyltriethoxysilane (KH550) and γ-methacryloyloxypropyltrimethoxysilane (KH570), preferably γ-aminopropyltriethoxysilane (KH550), and the amount used is 1% to 2.5% of the mass of the needle-like composite powder, more preferably 1.5% to 2.5%.

[0024] The water bath stirring temperature is 55~70℃, and the vacuum drying temperature is 50~80℃ for 3~8 hours.

[0025] Secondly, embodiments of this application provide an in-situ grown needle-like blend of GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles. The particles are prepared using the aforementioned method. The particles use needle-like gadolinium tantalate (GdTaO4) as the radiation shielding substrate, and uniformly grow sheet-like samarium-doped cerium dioxide (Sm-CeO2) antibacterial components on its surface by hydrothermal in-situ growth.

[0026] The needle-shaped gadolinium tantalate matrix powder has a diameter of about 20-30 nm and a length of about 200-300 nm; the plate-shaped samarium-doped cerium dioxide has a lateral dimension of about 100-300 nm and a thickness of about 10-20 nm.

[0027] Thirdly, this application also provides an application of in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles. The needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles are filled into a polymer substrate, and radiation-resistant and antibacterial fiber materials are prepared by centrifugal spinning, electrospinning, and wet spinning. The polymer substrate is one of polyvinyl alcohol, polyimide, polyvinyl butyral, polyvinyl chloride, and polyurethane.

[0028] The radiation-resistant and antibacterial fiber material has a shielding efficiency of ≥80% against 100keV X-rays, a shielding efficiency of ≥85% against 0.025eV thermal neutrons, a 24-hour antibacterial rate of ≥99.0% against Staphylococcus aureus, Escherichia coli, and Candida albicans, a tensile strength of ≥10MPa, and an air permeability of ≥120mm / s.

[0029] The aforementioned anti-radiation and antibacterial fiber materials can be used in the preparation of interventional dressings for radiotherapy, flexible protective equipment for the nuclear industry, military personal protective products, or civilian antibacterial and anti-radiation textiles.

[0030] The beneficial effects of this application are as follows: This application addresses the core pain points of existing dual-function protective materials, such as easy aggregation, phase separation, and performance degradation, and achieves multiple technological breakthroughs through structural innovation and process optimization: First, it innovatively constructs a needle-sheet integrated blend structure, using needle-shaped GdTaO4 as the radiation shielding matrix and sheet-shaped Sm-CeO2 as the antibacterial component. Radiation shielding and highly efficient antibacterial effects work synergistically, significantly improving shielding performance compared to physical blending systems. The antibacterial rate of the optimal embodiment can reach over 99.9%. Second, relying on the rare earth lattice matching characteristics, a hydrothermal in-situ growth method is used to achieve strong chemical bonds at the two-phase interface. This approach addresses the root causes of phase separation and antibacterial phase shedding, endowing the material with excellent radiation resistance and stability. Furthermore, through morphology-oriented control and surface modification, it prevents nanoparticle agglomeration at the structural level, significantly improving compatibility with the polymer matrix and adapting it to various industrial processing techniques. In addition, the process described in this application is green and mild, with controllable parameters, strong batch stability, no heavy metal precipitation, and excellent biocompatibility, avoiding the safety hazards of traditional materials. It can be widely applied to high-end applications such as nuclear industry protection, radiation medical dressings, military protective equipment, and civilian antibacterial textiles.

[0031] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0033] Figure 1 This is a scanning electron microscope image of the needle-shaped gadolinium tantalate (GdTaO4) matrix powder prepared in Example 1 of this application. The scale bar is 100 nm.

[0034] Figure 2 This is a scanning electron microscope image of the sheet-like Sm-CeO2 prepared in Example 1 of this application, with a scale bar of 200 nm.

[0035] Figure 3This is a scanning electron microscope image of the needle-like GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles prepared in Example 1 of this application. The scale bar is 200 nm.

[0036] Figure 4 This is a photograph of the anti-radiation and antibacterial fiber felt prepared in Example 1 of this application.

[0037] Figure 5 This is a scanning electron microscope image of the anti-radiation and antibacterial fiber felt prepared in Example 1 of this application. The scale bar is 5 μm. Detailed Implementation

[0038] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0040] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0041] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0042] To address the industry pain points of existing composite protective materials in terms of difficulty in simultaneously achieving radiation shielding, high-efficiency antibacterial properties, interfacial bonding, and processing adaptability, this application provides an in-situ grown needle-like blend of GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles, their preparation method, and applications.

[0043] This material uses one-dimensional needle-shaped gadolinium tantalate as a radiation shielding matrix. Utilizing the rare earth lattice matching characteristics, a plate-shaped samarium-doped cerium dioxide (plate-shaped Sm-CeO2) antibacterial component is directionally grown on its surface through a hydrothermal in-situ growth method to achieve two-phase molecular-level interface bonding. After programmed temperature calcination crystallization and hydrophobic modification with a silane coupling agent, a bifunctional rare earth composite powder with an integrated needle-plate blend structure is finally obtained.

[0044] This application fully leverages the synergistic effect of the strong X-ray attenuation capability of Ta in gadolinium tantalate and the high thermal neutron absorption cross-section of Gd to achieve integrated X-ray-thermal neutron radiation protection across the entire spectrum. Simultaneously, relying on the highly reactive oxygen vacancies of samarium-doped cerium dioxide grown in situ on the surface, it endows the material with broad-spectrum and highly efficient antibacterial properties. Its unique needle-sheet integrated structure fundamentally avoids the problem of hard agglomeration of nanoparticles, forming a strong interfacial bond with the polymer matrix. While ensuring processability and mechanical properties, it also possesses excellent synergistic effects of radiation shielding and antibacterial properties.

[0045] This application provides a new technical approach for the development of high-performance lightweight flexible materials for complex radiation scenarios such as nuclear industry protection, radiotherapy, military equipment, and civilian antibacterial and radiation protection.

[0046] This application provides a method for preparing in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles, comprising the following steps: S1. Preparation of needle-shaped gadolinium tantalate matrix powder: Acidic gadolinium salt solution and tantalum salt solution were prepared separately. The tantalum salt solution was added dropwise to the acidic gadolinium salt solution, and the mixture was stirred at room temperature to obtain a suspension. A morphology directing agent was added to the suspension, and after dissolution, the pH of the system was adjusted to acidic. The mixture was stirred to obtain a precursor reaction solution. The precursor reaction solution was subjected to hydrothermal reaction, cooling, washing, and vacuum drying to obtain needle-shaped gadolinium tantalate matrix powder. The gadolinium salt is one of gadolinium nitrate hexahydrate (Gd(NO3)3·6H2O), gadolinium chloride hexahydrate (GdCl3·6H2O), and gadolinium sulfate (Gd2(SO4)3·8H2O), preferably gadolinium nitrate hexahydrate (Gd(NO3)3·6H2O). The tantalum salt is one of tantalum pentachloride (TaCl5), sodium tantalate (NaTaO3), and tantalum pentabromide (TaBr5), preferably tantalum pentachloride (TaCl5); the molar ratio of gadolinium to tantalum is (0.25~4):1, preferably (0.66~1.5):1.

[0047] The acidic solution of gadolinium salt is prepared by dissolving gadolinium salt in 2 mol / L dilute nitric acid, and the concentration of metal ions in the solution is 0.25~0.5 mol / L, preferably 0.3~0.5 mol / L.

[0048] A tantalum salt solution is obtained by dissolving tantalum salt in anhydrous ethanol and then diluting it in deionized water. The concentration of metal ions in the solution is 0.25~0.5 mol / L, preferably 0.3~0.5 mol / L.

[0049] The morphology-directing agent is one of citric acid monohydrate (C6H8O7·H2O), oxalic acid dihydrate (C2H2O4·2H2O), polyethylene glycol (PEG), and ethylenediaminetetraacetic acid (EDTA), preferably citric acid monohydrate (C6H8O7·H2O), and its amount is 2.5%~5% of the sum of the mass of gadolinium salt and tantalum salt, preferably 3.5%~5%. The pH value of the precursor reaction solution is 1~3.

[0050] During the hydrothermal reaction, the filling degree of the hydrothermal reactor is 60%-80%, the temperature is 200~250℃, and the time is 8~12h.

[0051] In the technical solution of this application embodiment, gadolinium nitrate hexahydrate and tantalum pentachloride are preferred as raw materials. Their reactivity is well-matched. Gadolinium nitrate can avoid interference from impurity anions, while tantalum pentachloride, as an inorganic tantalum source, can effectively introduce high-Z element tantalum. Controlling the gadolinium-tantalum molar ratio at (1~3):1 allows for flexible adjustment of the material's radiation shielding performance. While ensuring high-Z element tantalum's efficient X-ray shielding, it fully utilizes gadolinium's thermal neutron absorption capacity, achieving a synergistic ratio for photon-neutron dual protection. The use of dilute nitric acid for solution preparation and anhydrous ethanol for pre-dissolution avoids metal ion hydrolysis, resulting in a well-matched... The ion concentration ensures sufficient reaction driving force while avoiding impurities and agglomeration, guaranteeing the uniformity and stability of the multi-component system and achieving uniform mixing of metal ions at the molecular level. Citric acid, as a morphology guiding agent, can effectively complex metal ions to regulate the nucleation rate and directionally induce the growth of one-dimensional needle-like structures, while also ensuring morphology controllability. Optimized pH, hydrothermal temperature, and time parameters provide the optimal environment for crystal nucleation and growth, allowing for precise control of powder crystallinity and morphology. This ensures excellent radiation shielding performance of the material and provides sufficient surface active sites for subsequent in-situ growth processes.

[0052] S2. Preparation of in-situ growth precursor solution: Dissolve cerium source and samarium source in ethanol-water mixed solvent and stir until completely transparent to obtain rare earth precursor solution; add precipitant and morphology stabilizer and continue stirring until completely dissolved, then add needle-shaped gadolinium tantalate matrix powder prepared in step S1, stir and premix, ultrasonically disperse until the powder is completely dispersed without sedimentation, adjust the pH of the system to weakly alkaline, and obtain in-situ growth precursor solution.

[0053] The cerium source is one of cerium nitrate hexahydrate (Ce(NO3)3·6H2O), cerium sulfate (Ce2(SO4)3), cerium acetate (C6H9CeO6), and cerium chloride (CeCl3·7H2O), preferably cerium nitrate hexahydrate (Ce(NO3)3·6H2O).

[0054] The samarium source is one of samarium nitrate hexahydrate (Sm(NO3)3·6H2O), samarium sulfate (Sm2(SO4)3·8H2O), samarium acetate (SmAc3·3H2O), and samarium chloride (SmCl3·6H2O), preferably samarium nitrate hexahydrate (Sm(NO3)3·6H2O).

[0055] The molar ratio of Ce to Sm is 19:1 to 4:1.

[0056] In an ethanol-water mixed solvent, the volume ratio of ethanol to water is 1:1.

[0057] The concentration of rare earth metal ions in the rare earth precursor solution is 0.1~0.3 mol / L.

[0058] The precipitant is one of ammonium acetate (CH3COONH4), urea, hexamethylenetetramine (HMTA), and formamide (HCONH2), preferably ammonium acetate (CH3COONH4), and its amount is 40%~60% of the total mass of the cerium source and samarium source. The morphology stabilizer is one of PVPK30, sodium citrate, and PEG-4000, preferably PVP K30, and its amount is 10%~30% of the total mass of the cerium source and samarium source, preferably 15%~25%; the amount of the needle-shaped gadolinium tantalate matrix powder added is 30%~120% of the total mass of the cerium source and samarium source; the ultrasonic dispersion time is 30-60 min, and the pH of the system is 7.5-8.5.

[0059] In the technical solution of this application embodiment, cerium nitrate hexahydrate and samarium nitrate hexahydrate are selected as rare earth sources. Their nitrate anions can avoid interference from impurity anions and are well compatible with the surface of the acicular gadolinium tantalate matrix. By controlling the Ce:Sm molar ratio within a wide range of (4~19):1, the lattice oxygen vacancy concentration of the Sm-CeO2 solid solution can be flexibly adjusted by regulating the samarium doping amount, achieving directional optimization of antibacterial activity. Using a 1:1 volume ratio ethanol-water mixed solvent and controlling the rare earth ion concentration at 0.1~0.3 mol / L maintains the stability and homogeneity of the precursor solution, providing a suitable environment for the directional growth of the sheet-like structure and avoiding hydrolysis precipitation. Ammonium acetate is selected as the precipitant; its mild hydrolysis characteristics at 60~80℃ enable uniform and slow precipitation of rare earth ions, avoiding the formation of impurity phases caused by local supersaturation. An amount of 40%~60% of the total mass of the rare earth salt ensures complete precipitation. PVP K30, as a morphology stabilizer, is used at 15%~25% of the total mass of rare earth salts. It can effectively inhibit the aggregation between rare earth oxide plates through steric hindrance, while guiding the plates to uniformly adhere and grow on the surface of the needle-like matrix. The amount of needle-like gadolinium tantalate matrix added is controlled at 30%~120% of the total mass of rare earths. This ensures that the matrix surface is fully coated to form a blended structure, while avoiding excessive matrix dilution of rare earth functions. Ultrasonic dispersion for 30~60 minutes can fully disperse the matrix in the system. Combined with a weakly alkaline environment of pH 7.5~8.5, it can promote heterogeneous nucleation of rare earth precursors on the matrix surface, while protecting the matrix structure from damage.

[0060] S3. Hydrothermal in-situ growth reaction: The in-situ growth precursor solution prepared in step S2 is transferred to a hydrothermal reactor for hydrothermal reaction. After the reaction is completed, it is naturally cooled to room temperature.

[0061] In step S3, the filling degree of the hydrothermal reactor is 70%-80%, the hydrothermal reaction temperature is 120-180℃, and the time is 4-8h.

[0062] In the technical solution of this application embodiment, the 70%-80% reactor filling degree can provide a stable and uniform reaction pressure environment for in-situ growth, ensuring sufficient reaction space while avoiding safety risks and incomplete reaction problems caused by improper filling; the hydrothermal parameters of 120-180℃ and 4-8h provide a mild and controllable window for the heterogeneous nucleation and directional growth of the sheet-like antibacterial phase on the surface of the needle-like matrix, so that the Sm-Ce oxide sheets are uniformly attached to the surface of the gadolinium tantalate needle-like crystals, forming a needle-sheet blend structure with complete structure and strong interface bonding, avoiding impurities or agglomeration caused by high-temperature rapid nucleation. The subsequent calcination process at 400-600℃ for 2-4 hours can simultaneously achieve crystallization and strengthening of the antibacterial phase. At the same time, the bonding strength of the needle-plate interface can be further enhanced through appropriate sintering, so that the oxygen vacancies in the Sm-CeO2 solid solution can be fully activated, ensuring its antibacterial performance at room temperature. This temperature range can completely remove residual organic matter and water of crystallization in the precursor, while avoiding excessive grain growth, decrease in specific surface area and destruction of needle-plate structure caused by excessively high temperature (>600℃).

[0063] S4. High-temperature calcination crystallization treatment: After centrifugation, washing and drying of the reaction product in step S3, calcination is carried out in air atmosphere and natural cooling is performed to obtain needle-like and flake-like composite powder. In step S4, the high-temperature calcination temperature is 400-600℃, the heating rate is 2-5℃ / min, and the time is 2-4h.

[0064] S5. Post-processing modification: The needle-like composite powder prepared in S4 is dispersed in an alcohol-water mixture, a silane coupling agent is added, and the surface is modified by water bath stirring. After centrifugation, washing, vacuum drying, and grinding, needle-like composite GdTaO4 / Sm-CeO2 anti-radiation and antibacterial particles are finally obtained.

[0065] In step S5, the volume ratio of anhydrous ethanol to deionized water in the alcohol-water mixture is 9:1, and the solid content of the powder is 5%~8%; the silane coupling agent is one of γ-aminopropyltriethoxysilane (KH550) and γ-methacryloyloxypropyltrimethoxysilane (KH570), preferably γ-aminopropyltriethoxysilane (KH550), and the amount used is 1%~2.5% of the mass of the needle-like composite powder, preferably 1.5%~2.5%; the water bath stirring temperature is 55~70℃, and the vacuum drying temperature and time are 50~80℃ for 3~8h.

[0066] In the technical solution of this application embodiment, a 9:1 alcohol-to-water ratio is used, which can promote the full hydrolysis of the silane coupling agent and inhibit self-polymerization, while ensuring good powder dispersion. The powder solid content is controlled at 5%~8%, balancing coating efficiency and dispersion uniformity. γ-aminopropyltriethoxysilane (KH550) is selected as the modifier, which has excellent grafting activity. Its amino functional groups can form strong chemical bonds with various polymer matrices, which can significantly improve the compatibility of the powder with various polymers. The dosage is precisely controlled at 1.5%~2.5% of the powder mass, which can form a uniform monolayer on the surface and avoid interface weakening or particle bridging. A water bath temperature of 55~70℃ provides mild reaction conditions, promotes the condensation grafting of silanol groups to the powder surface, and ensures a complete reaction. Vacuum drying at 50~80℃ for 3~8 hours can completely remove the solvent while fully preserving the grafted functional groups, avoiding modification failure and powder agglomeration.

[0067] In the technical solution of this application, firstly, a one-dimensional needle-shaped gadolinium tantalate radiation shielding matrix is ​​constructed through an acidic hydrothermal reaction using gadolinium nitrate hexahydrate and tantalum pentachloride as raw materials and citric acid monohydrate as a morphology guiding agent; subsequently, using cerium nitrate hexahydrate and samarium nitrate hexahydrate as antibacterial functional raw materials, urea as a precipitant, and polyvinylpyrrolidone as a morphology stabilizer, sheet-like samarium-doped cerium dioxide antibacterial components are directionally grown on the surface of needle-shaped gadolinium tantalate through a hydrothermal in-situ reaction, forming a needle-sheet integrated blend structure and achieving... The dual-functional components exhibit strong interfacial bonding; further, through programmed temperature calcination and crystallization treatment, the covalent bonding at the two-phase interface is enhanced by utilizing the rare earth lattice matching characteristics, simultaneously achieving grain morphology regulation and organic impurity removal; finally, the surface is modified with a silane coupling agent to obtain radiation-resistant and antibacterial composite particles with an integrated needle-plate structure, uniform nano-distribution of Gd-Ta-Ce-Sm multi-element nanoparticles, X-ray-thermal neutron radiation shielding and highly efficient antibacterial properties, and excellent compatibility with the polymer matrix interface.

[0068] Specifically, this application uses four elements—gadolinium, tantalum, cerium, and samarium—as raw materials, achieving uniform composite of the four at the nanoscale through a needle-sheet integrated blend structure. This design is based on the synergistic complementarity of each element in radiation shielding and antibacterial functions: tantalum (Z=73) exerts a Compton scattering-dominated attenuation effect on medium- and high-energy X-rays due to its high atomic number; gadolinium (Z=64) possesses both photoelectric effect shielding capabilities and an extremely high thermal neutron absorption cross section (approximately 49,000 barn), achieving dual radiation protection against photons and neutrons on the same element; its ionic radius is similar to that of cerium and samarium, which is beneficial for constructing a lattice-matched in-situ blend structure; cerium (Z=58) and samarium (Z=62) introduce lattice oxygen vacancies by forming a Sm-CeO2 solid solution, continuously generating reactive oxygen groups at room temperature to achieve broad-spectrum killing of pathogens, while their high atomic number characteristics synergistically enhance X-ray shielding effectiveness.

[0069] Gadolinium, tantalum, cerium, and samarium are uniformly distributed at the molecular level within a one-dimensional needle-like matrix and a two-dimensional sheet-like functionally interlocked structure through an in-situ hydrothermal-calcination crystallization process. This fully leverages the synergistic radiation shielding and antibacterial functions of the multi-element combination while effectively addressing the industry challenge of nanoparticle agglomeration, significantly improving interfacial compatibility with the polymer matrix. The selected raw materials are environmentally friendly, and the process is controllable, aligning with the development trend of green, high-performance, multifunctional protective materials.

[0070] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0071] Example 1 This embodiment provides a method for preparing in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles and radiation-resistant and antibacterial fiber mat, including the following steps: S1. Preparation of needle-shaped gadolinium tantalate matrix powder: 0.1 mol (45.126 g) of gadolinium nitrate hexahydrate (Gd(NO3)3·6H2O) was dissolved in 250 mL of dilute nitric acid with a concentration of 2 mol / L to prepare an acidic gadolinium salt solution. Then, 0.1 mol (35.82 g) of tantalum pentachloride (TaCl5) was dissolved in 50 mL of anhydrous ethanol and 200 mL of deionized water was added to obtain a tantalum salt solution. Tantalum salt solution was added dropwise to acidic gadolinium salt solution. After the addition was complete, the mixture was stirred continuously at room temperature for 30-60 minutes to obtain a uniform milky white suspension. 3.36 g of citric acid monohydrate (C6H8O7·H2O) was added to the suspension and stirred until completely dissolved. The pH of the system was adjusted to 1.0, and stirring was continued for 30 minutes to obtain a stable precursor reaction solution. The precursor reaction solution was transferred to a hydrothermal reactor, with a filling degree of 75%. The reactor was subjected to a constant temperature hydrothermal reaction at 220℃ for 10 hours. After natural cooling to room temperature, the product was alternately centrifuged and washed until the supernatant was neutral. After vacuum drying, needle-shaped gadolinium tantalate matrix powder was obtained. Its SEM image is shown below. Figure 1 As shown.

[0072] S2. Preparation of in-situ growth precursor solution: Dissolve 0.09 mol (39.09 g) cerium nitrate hexahydrate (Ce(NO3)3·6H2O) and 0.01 mol (4.45 g) samarium nitrate hexahydrate (Sm(NO3)3·6H2O) in 500 mL of anhydrous ethanol-deionized water mixed solvent at a volume ratio of 1:1. Stir at room temperature until completely transparent to obtain a rare earth precursor solution with a total rare earth ion concentration of 0.2 mol / L. Add 21.77 g ammonium acetate (CH3COONH4) and 8.71 g PVP K30 to the rare earth precursor solution and stir continuously until completely dissolved. Then add 19.593 g of needle-shaped gadolinium tantalate matrix powder obtained in step S1. First, stir and premix at room temperature for 10-15 min, then ultrasonically disperse for 30-60 min until the powder is completely dispersed without sedimentation. Adjust the pH of the system to 7.5 and continue stirring for 30 min to obtain the in-situ growth precursor solution. S3. Hydrothermal in-situ growth reaction: The in-situ growth precursor solution prepared in step S2 is transferred to a hydrothermal reactor, the filling degree is controlled at 70%, and the in-situ hydrothermal reaction is carried out at a constant temperature of 180℃ for 8 hours, and then naturally cooled to room temperature. S4. High-temperature calcination crystallization treatment: The reaction product of step S3 is washed with deionized water and anhydrous ethanol by alternating centrifugation 3-5 times until the supernatant is neutral. It is then vacuum dried at 60℃ for 3 hours. The powder is collected and placed in a muffle furnace. It is heated to 550℃ at a slow heating rate of 2℃ / min under air atmosphere and calcined at a constant temperature for 4 hours. After calcination, it is naturally cooled to room temperature to obtain needle-like and flake-like composite powder. S5. Post-treatment modification: 1g of γ-aminopropyltriethoxysilane (KH550) was added to a 9:1 mixture of anhydrous ethanol and deionized water, and glacial acetic acid was added to adjust the pH to 6.0. The mixture was stirred at room temperature for 30 minutes to complete the pre-hydrolysis of the coupling agent. Subsequently, 50g of the needle-like composite powder prepared in S4 was added to the mixture and ultrasonically dispersed at 300W for 20 minutes to ensure complete dispersion and no agglomeration. The mixture was then placed in a 70℃ constant temperature water bath and stirred under reflux for 4 hours to complete the covalent grafting modification of the silane coupling agent on the powder surface. After the reaction, the modified product was centrifuged and washed 3-5 times with anhydrous ethanol to completely remove the ungrafted free coupling agent. The mixture was then vacuum dried at 60℃ for 6 hours and ground to finally obtain needle-like composite GdTaO4 / Sm-CeO2 anti-radiation and antibacterial particles. The SEM image is shown below. Figure 3 As shown.

[0073] S6. Preparation of anti-radiation and antibacterial fiber felt: 15g of PAN powder was dissolved in 80g of DMF and stirred at 55℃ for 4h to obtain PAN base liquid; 15g of needle-like GdTaO4 / Sm-CeO2 anti-radiation and antibacterial particles (hereinafter referred to as modified functional powder) were ultrasonically dispersed in 5g of DMF, and the PAN base liquid was added dropwise. After stirring for 3h, the mixture was degassed and filtered; the spinning voltage was set to 15kV, the feed rate to 0.8mL / h, the receiving distance to 18cm, the temperature to 25℃, the humidity to 40% RH, and the roller speed to 800rpm, and the spinning was carried out continuously for 4h; the obtained fibers were composite overlapped and hot-pressed at 50℃, and then vacuum dried at 70℃ for 12h to obtain anti-radiation and antibacterial fiber felt.

[0074] like Figure 1 As shown, the GdTaO4 matrix powder prepared by hydrothermal synthesis in this application exhibits a uniform and regular one-dimensional needle-like morphology with a needle diameter of about 20~30nm and a length of about 200~300nm. It has no obvious hard agglomeration and excellent overall dispersibility.

[0075] Figure 2 The Sm-CeO2 powder prepared for this application exhibits a two-dimensional ultrathin sheet-like morphology with a lateral size of approximately 100-300 nm and a thickness of approximately 10-20 nm, and has an extremely high specific surface area.

[0076] Figure 3 This is a scanning microscope image of the needle-and-plate blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles prepared by the in-situ hydrothermal growth process of this application. It can be seen that the particles have a one-dimensional needle-like GdTaO4 core framework, with two-dimensional plate-like Sm-CeO2 uniformly and densely grown in situ on the surface of the needle-like matrix. There are no free plate-like Sm-CeO2 particles or irregular aggregates; the two phases are tightly bonded at the interface, forming a stable needle-and-plate blended hierarchical structure.

[0077] Figure 4 The physical appearance of the radiation-resistant and antibacterial fiber felt prepared in Example 1 of this application is shown. The felt is a uniform and bright yellow color, with consistent hue and no spots or impurities. The surface is smooth, the edges are regular, and there are no breaks, lumps, or uneven thickness. This indicates that the modified functional powder is uniformly dispersed in the spinning solution without agglomeration. It also confirms that the electrospinning and hot-pressing processes are stable and controllable, and the resulting fiber felt can be directly used in radiation medical dressings and flexible protective equipment.

[0078] like Figure 5 As shown, in the anti-radiation and antibacterial fiber felt, the composite fibers are in the form of continuous filaments, without broken fibers, beads or adhesion defects. The fiber diameter is mainly distributed in the range of 800 to 1200 nm, with an average of about 1 μm. The fibers are randomly overlapped to form a through three-dimensional porous network, which provides structural protection for air permeability.

[0079] The fiber surface is smooth and dense, with no powder agglomeration or exposed particles, indicating that the GdTaO4 / Sm-CeO2 particles modified with silane coupling agent have good compatibility with the PAN matrix. Even with high filling amount, they can be uniformly dispersed, avoiding spinning defects from the source. This ensures the stable performance of radiation shielding and antibacterial functions, and also provides basic support for mechanical properties.

[0080] Examples 2-3 and Comparative Examples 1-4 Compared with Example 1, the only difference is that in step S1, the molar ratio of gadolinium nitrate hexahydrate (Gd(NO3)3·6H2O) to tantalum pentachloride (TaCl5) is different, that is, the molar ratio of gadolinium to tantalum is different, as shown in Table 1; the rest is roughly the same as in Example 1, and will not be repeated here.

[0081] The anti-radiation and antibacterial fiber felts prepared in Examples 1-3 and Comparative Examples 1-4 were tested as follows: (1) X-ray and neutron radiation protection performance test: The prepared anti-radiation and antibacterial fiber felt was hot-pressed in multiple layers and then cut into samples with a length and width of 10cm × 10cm, a thickness of 2mm, and a weight of 2.5kg per square meter. X-ray radiation protection was tested according to the method disclosed in YY / T 0292.1-2020 "Medical Diagnostic X-ray Radiation Protection Apparatus Part 1: Determination of Material Attenuation Performance", and its shielding efficiency was calculated. Neutron radiation protection was tested according to the method disclosed in ASTM E262-17 "Standard Method for Measuring Thermal Neutron Reactivity by Radioactive Counting Technique", and the shielding rate was calculated. The incident energy of X-rays was 100keV, and the incident energy of neutron rays was 0.025 eV.

[0082] (2) Tensile properties test: The tensile strength of the obtained radiation-resistant and antibacterial fiber was tested according to the method disclosed in GB / T 14344-2022 "Test Method for Tensile Properties of Chemical Fiber Filaments", and the test was repeated ≥50 times.

[0083] (3) Air permeability test: The air permeability of the obtained anti-radiation and antibacterial fiber felt was tested according to the method disclosed in GB / T 5453-1997 "Determination of air permeability of textile fabrics", and the air permeability rate was calculated.

[0084] (4) Antibacterial performance test: The antibacterial performance of the obtained radiation-resistant and antibacterial fiber felt was tested for Staphylococcus aureus according to the method disclosed in GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Vibration method", and the antibacterial rate was calculated.

[0085] All subsequent examples and comparative examples prepared with anti-radiation and antibacterial fiber felts were tested for their anti-ionizing radiation performance, tensile properties, air permeability, and antibacterial rate using the methods described above.

[0086] The anti-radiation and antibacterial fiber felts prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests, and the results are shown in Table 1.

[0087] Table 1. Properties of the radiation-resistant and antibacterial fiber felts prepared in Examples 1-3 and Comparative Examples 1-4 As shown in Table 1, the X-ray shielding effect of the prepared anti-radiation and antibacterial fiber felt increases with the increase of the Ta element ratio, while the neutron shielding ability increases with the increase of the Gd element content. By adjusting the molar ratio of Gd to Ta, the radiation protection performance, mechanical strength, antibacterial activity, and air permeability of the material can be optimized to meet the application requirements of different scenarios.

[0088] When the Gd:Ta molar ratio is between 1:1.5 and 1.5:1, a single-phase orthorhombic gadolinium tantalate can be synthesized. At this point, Gd and Ta are uniformly distributed at the molecular scale, and the material has both comprehensive radiation shielding capabilities and good overall performance characteristics. Among them, Gd:Ta = 1:1 is the optimal ratio, which can achieve the best balance between X-ray and neutron shielding effectiveness, and the overall performance reaches its peak.

[0089] If the molar ratio falls within the range of 1:4 to 1:1.5 or 1.5:1 to 4:1, the material's protective advantage against a certain type of radiation can be enhanced respectively. This is suitable for occasions that emphasize the shielding of specific rays and still has clear application significance.

[0090] In the extreme single-component case where Gd:Ta is 1:0 or 0:1, pure phase gadolinium tantalate cannot be generated, making it difficult for the material to meet the full spectrum of radiation protection requirements, resulting in a significant decrease in overall performance.

[0091] In terms of antibacterial performance, Examples 1-3 achieved medical-grade antibacterial rates of over 99.9% due to uniform powder dispersion, fully exposed active sites, and rare earth lattice matching that increased oxygen vacancy concentration. In contrast, the comparative examples showed reduced antibacterial efficiency due to powder agglomeration that encapsulated active sites.

[0092] Comparative Example 3 is a pure gadolinium oxide system with a Gd:Ta molar ratio of 1:0, without the introduction of tantalum. Its X-ray shielding efficiency is only 62.42%, the lowest among all groups, while its neutron shielding efficiency reaches 96.31%, the highest among all groups. All other comprehensive performances are significantly lower than those of Example 1.

[0093] The reason is that the system lacks the high atomic number tantalum element for X-ray shielding core, making it impossible to synthesize pure phase orthorhombic gadolinate. Only random gadolinium oxide particles can be generated, resulting in a significant reduction in the utilization rate of the shielding element. Although it achieves the best effect of single thermal neutron protection, it cannot achieve synergistic full-spectrum radiation protection. At the same time, the random particles lack the needle-like structure enhancement effect, are prone to agglomeration, and cause spinning defects, resulting in deterioration of mechanical and air permeability properties. Furthermore, it cannot form a lattice-matched synergy with the antibacterial phase, resulting in insufficient exposure of antibacterial active sites and a certain degree of performance degradation.

[0094] Comparative Example 4, a pure tantalum oxide system with a Gd:Ta molar ratio of 0:1, completely lacks gadolinium, an element with a high neutron absorption cross section, and therefore cannot construct a Gd-Ta synergistic pure-phase gadolinium tantalate crystal structure, only generating random tantalum oxide particles. Its neutron shielding efficiency is only 12.35%, essentially losing its thermal neutron protection capability; X-ray shielding efficiency, tensile strength, antibacterial properties, and air permeability are all significantly deteriorated compared to Example 1. Random particles not only fail to achieve full-spectrum radiation protection and have low shielding element utilization, but also tend to aggregate in the polymer matrix, exhibiting poor interfacial compatibility, leading to decreased mechanical properties and air permeability. Simultaneously, they cannot provide a stable in-situ growth substrate for the Sm-CeO2 antibacterial phase, resulting in uneven dispersion of the antibacterial phase, encapsulation of active sites, and a significant reduction in antibacterial performance.

[0095] Examples 4-6 and Comparative Examples 5-8 Compared with Example 1, the only difference is that in step S2, the ratio of cerium nitrate hexahydrate (Ce(NO3)3·6H2O) to samarium nitrate hexahydrate (Sm(NO3)3·6H2O) is different, that is, the molar ratio of Ce to Sm is different, as shown in Table 2. Everything else is roughly the same as in Example 1 and will not be repeated here.

[0096] The performance of the radiation-resistant and antibacterial fiber felts prepared in Examples 4-6 and Comparative Examples 5-8 was tested, and the results are shown in Table 2.

[0097] Table 2. Properties of the radiation-resistant and antibacterial fiber felts prepared in Examples 4-6 and Comparative Examples 5-8 As shown in Table 2, the change in Ce:Sm molar ratio has no significant effect on the X-ray and neutron shielding performance of the material.

[0098] The core reason is that the shielding function is provided by the GdTaO4 matrix with a constant content and structure, while the total addition of Ce and Sm is low, thus contributing limitedly to the shielding performance. As the proportion of Ce increases, the material's antibacterial properties, tensile strength, and air permeability all show a trend of first increasing and then decreasing, reaching a peak at Ce:Sm = 9:1. A stable Sm-doped CeO2 solid solution can be formed within the Ce:Sm range of 4:1 to 19:1. The Sm doping introduces the optimal lattice oxygen vacancy concentration, and the in-situ grown flake powder exhibits excellent dispersibility and stable spinning formation, thus maintaining an antibacterial rate of 99.7%. In the above, mechanical and air permeability properties are at a relatively high level. As the Ce content further increases or decreases and deviates from the optimal range, sufficient effective antibacterial lattice oxygen vacancies cannot be formed, resulting in a significant decrease in antibacterial performance. At the same time, uncontrolled powder morphology and agglomeration lead to spinning defects, and tensile strength and air permeability decrease simultaneously. The extreme ratio systems of pure CeO2 or pure Sm oxides show the most significant deterioration in various properties due to the lack of a stable solid solution structure.

[0099] Examples 7-9 and Comparative Examples 9-10 Compared with Example 1, the only difference is that the amount of needle-shaped gadolinium tantalate matrix powder added in step S2 is different, that is, the mass ratio of needle-shaped GdTaO4 matrix to Sm-CeO2 antibacterial phase is different. Please see Table 3 for details. The rest is roughly the same as Example 1, and will not be repeated here.

[0100] After repeated experiments, it was verified that the yield of Sm-CeO2 generated by the decomposition of cerium nitrate hexahydrate (Ce(NO3)3·6H2O) and samarium nitrate hexahydrate (Sm(NO3)3·6H2O) is about 30%.

[0101] The anti-radiation and antibacterial fiber felts prepared in Examples 7-9 and Comparative Examples 9-10 were subjected to performance tests, and the results are shown in Table 3.

[0102] Table 3. Properties of the radiation-resistant and antibacterial fiber felts prepared in Examples 7-9 and Comparative Examples 9-10 As shown in Table 3, with the increase of the mass ratio of needle-shaped GdTaO4 matrix to Sm-CeO2 antibacterial phase, the matrix proportion increases, and the shielding efficiency of the material against X-rays and neutrons shows a linear increase.

[0103] The reason is that Gd and Ta are the main shielding components of the system. The higher the matrix content, the higher the effective concentration of the shielding elements, and the stronger the intrinsic contribution of radiation protection. The antibacterial performance shows a trend of first increasing and then decreasing as the proportion of the antibacterial phase decreases, reaching its highest value at a mass ratio of 1:1. This is because, within a suitable loading range, an increase in the antibacterial phase can provide more active sites; however, excessive amounts can easily lead to agglomeration and encapsulation of active sites, while too much matrix can result in insufficient antibacterial phase loading and a lack of active sites, both of which weaken the antibacterial effect. Tensile strength and air permeability are optimal at a mass ratio of 3:2, where the needle-like and sheet-like components can form a uniform and complete blend structure, resulting in the best powder dispersibility and spinning stability. If this ratio is deviated from, powder agglomeration will induce spinning defects, and both properties decline significantly with increasing deviation, with the most pronounced deterioration in overall performance under extreme ratios.

[0104] Examples 10-12 and Comparative Examples 11-12 Compared with Example 1, the only difference is that the temperature of the hydrothermal reaction in step S3 is different, as shown in Table 4; the rest is roughly the same as Example 1, and will not be repeated here.

[0105] The anti-radiation and antibacterial fiber felts prepared in Examples 10-12 and Comparative Examples 11-12 were subjected to performance tests, and the results are shown in Table 4.

[0106] Table 4. Properties of the radiation-resistant and antibacterial fiber felts prepared in Examples 10-12 and Comparative Examples 11-12 As shown in Table 4, the differences in various properties are mainly affected by four factors: the crystallinity of Sm-CeO2, the in-situ growth morphology, the interfacial bonding strength, and the powder dispersibility. Among these, the X-ray and neutron shielding efficiency hardly changes with hydrothermal temperature. This is because the core shielding function is performed by the GdTaO4 matrix, whose phase structure and content remain stable, and Sm-CeO2 contributes little to the shielding performance. In contrast, the antibacterial properties, tensile strength, and air permeability are all optimal at 180℃. At this temperature, Sm-CeO2 can fully crystallize, forming a high specific surface area, a plate-like morphology, and the highest oxygen vacancy concentration. Simultaneously, it exhibits tight interfacial bonding with the matrix, optimal powder dispersibility, stable spinning process, and a complete fiber structure.

[0107] If the hydrothermal temperature is below 160℃, crystallization will be insufficient and the interfacial bonding will be weak; if the temperature is above 180℃, it will lead to grain coarsening and powder agglomeration, both of which will significantly reduce the three properties.

[0108] Example 13 The only difference from Example 1 is that the polymer substrate for electrospinning is replaced with polyvinyl alcohol (PVA) instead of polyacrylonitrile (PAN). Otherwise, it is largely the same as Example 1.

[0109] The specific steps are as follows: Steps S1-S5 are the same as steps S1-S5 in Example 1; S6. Preparation of anti-radiation and antibacterial fiber felt: 18g of polyvinyl alcohol (PVA, degree of polymerization 1750±50, degree of hydrolysis 99%) powder was dissolved in 82g of deionized water and stirred in a water bath at 95℃ for 6h to obtain a transparent and uniform PVA spinning base solution; 15g of the prepared modified functional powder was ultrasonically dispersed in 10g of deionized water, and the PVA base solution was added dropwise. After stirring at room temperature for 4h, vacuum degassing and filtration were performed; the spinning voltage was set to 18kV, the feed rate to 1.0mL / h, the receiving distance to 15cm, the temperature to 25℃, the humidity to 35%RH, and the roller speed to 800rpm, and continuous spinning was performed for 4h; the obtained fibers were composite overlapped and hot-pressed at 50℃, and then vacuum dried at 60℃ for 12h to obtain PVA-based anti-radiation and antibacterial fiber felt.

[0110] Example 14 The only difference from Example 1 is that the polymer substrate for electrospinning is replaced with polyimide (PI) instead of polyacrylonitrile (PAN). Otherwise, it is largely the same as Example 1.

[0111] The specific steps are as follows: Steps S1-S5 are the same as steps S1-S5 in Example 1; S6. Preparation of anti-radiation and antibacterial fiber felt: 16g of polyimide (PI, number average molecular weight 80,000) powder was dissolved in 84g of N,N-dimethylformamide (DMF) and stirred in a water bath at 60℃ for 4h to obtain a transparent and uniform PI spinning base solution; 15g of modified functional powder was ultrasonically dispersed in 5g of DMF, and then added dropwise to the PI base solution. After stirring at room temperature for 3h, vacuum degassing and filtration were performed; the spinning voltage was set to 16kV, the feed rate to 0.9mL / h, the receiving distance to 17cm, the temperature to 25℃, the humidity to 40%RH, and the roller speed to 800rpm, and continuous spinning was performed for 4h; the obtained fibers were composite overlapped and hot-pressed at 50℃, and then vacuum dried at 80℃ for 12h to obtain PI-based anti-radiation and antibacterial fiber felt.

[0112] Example 15 The only difference from Example 1 is that the fiber forming process is changed from electrospinning to centrifugal spinning; otherwise, it is largely the same as Example 1.

[0113] The specific steps are as follows: Steps S1-S5 are the same as steps S1-S5 in Example 1; S6. Preparation of anti-radiation and antibacterial fiber felt: 15g of PAN powder was dissolved in 80g of DMF and stirred at 55℃ for 4h to obtain PAN base liquid; 15g of the modified functional powder prepared in Example 1 was ultrasonically dispersed in 5g of DMF, and the PAN base liquid was added dropwise. After stirring for 3h, the mixture was degassed and filtered to obtain spinning solution; the spinning solution was injected into the spinneret of a centrifugal spinning device, and the spinning speed was set to 30000rpm, the spinneret diameter to 0.2mm, the receiving distance to 20cm, the ambient temperature to 25℃, and the humidity to 40%RH. The spinning was carried out continuously for 30min; the obtained fibers were composite overlapped and hot-pressed at 50℃, and then vacuum dried at 70℃ for 12h to obtain centrifugally spun anti-radiation and antibacterial fiber felt.

[0114] Example 16 The only difference from Example 1 is that the fiber forming process is changed from electrospinning to wet spinning; otherwise, it is largely the same as Example 1.

[0115] The specific steps are as follows: Steps S1-S5 are the same as steps S1-S5 in Example 1; S6. Preparation of anti-radiation and antibacterial fibers: 20g of PAN powder was dissolved in 80g of DMF and stirred at 55℃ for 6h to obtain PAN spinning solution; 20g of the modified functional powder prepared in Example 1 was ultrasonically dispersed in 10g of DMF, and the PAN solution was added dropwise. After high-speed stirring for 4h, vacuum degassing and filtration were performed to obtain spinning solution; a wet spinning equipment was used, with a DMF / deionized water volume ratio of 3:7 as the coagulation bath, a coagulation bath temperature of 35℃, a spinneret orifice diameter of 0.08mm, a spinneret draw ratio of 1.5, and a spinning rate of 5m / min; the nascent fibers were thoroughly washed with deionized water, stretched twice by 90℃ hot water, heat-set at 120℃, and wound to obtain continuous anti-radiation and antibacterial filaments; the filaments were needle-punched and hot-pressed to prepare 2mm thick fiber mats, and then vacuum-dried at 70℃ for 12h to obtain wet-spun anti-radiation and antibacterial fiber mats.

[0116] Comparative Example 13 Compared with Example 1, the only difference is that in step S1, the morphology guiding agent hydrated citric acid (C6H8O7·H2O) is not added. Otherwise, it is roughly the same as Example 1 and will not be described again here.

[0117] Comparative Example 14 Compared with Example 1, the only difference is that in step S2, ammonium acetate (CH3COONH4) is not added as a precipitant. Otherwise, it is roughly the same as Example 1 and will not be described again here.

[0118] Comparative Example 15 Compared with Example 1, the only difference is that in step S3, the morphology stabilizer PVP K30 is not added. Otherwise, it is roughly the same as Example 1 and will not be described again here.

[0119] Comparative Example 16 Compared with Example 1, the only difference is that the high-temperature calcination crystallization treatment in step S4 was not performed. Otherwise, it is roughly the same as Example 1 and will not be described again here.

[0120] Comparative Example 17 Compared with Example 1, the only difference is that the post-processing modification in step S5 was not performed. Otherwise, it is roughly the same as Example 1 and will not be described again here.

[0121] Comparative Example 18 Comparative Example 18 provides a method for preparing in-situ grown needle-like and flake-like GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles and radiation-resistant and antibacterial fiber mat. Needle-like GdTaO4 powder and flake-like powder of the same size as in Example 1 are prepared and physically and mechanically blended at a mass ratio of 3:2 to obtain radiation-resistant and antibacterial particles. Other aspects are roughly the same as in Example 1 and will not be repeated here.

[0122] The performance of the radiation-resistant and antibacterial fiber felts prepared in Examples 13-16 and Comparative Examples 13-18 was tested, and the results are shown in Table 5.

[0123] Table 5. Properties of the radiation-resistant and antibacterial fiber felts prepared in Examples 13-16 and Comparative Examples 13-18 The anti-radiation and antibacterial fiber felt prepared in Example 1 was tested for its antibacterial properties against Escherichia coli (a Gram-negative bacterium) and Candida albicans.

[0124] Experiments show that when Escherichia coli (Gram-negative bacteria) and Candida albicans are used as test strains, the anti-radiation antibacterial fiber felt prepared in Example 1 has an antibacterial rate of 99.77% against Gram-negative bacteria and an antibacterial rate of 99.97% against pathogenic fungi (Candida albicans), that is, both reach more than 99.7%, which is at the same level as the antibacterial performance against Staphylococcus aureus. This fully verifies that the in-situ grown Sm-doped CeO2 generates active oxygen groups through high concentration of lattice oxygen vacancies, thus achieving broad-spectrum and efficient killing of multiple types of pathogenic microorganisms.

[0125] Experiments show that when the polymer substrate is replaced with polyvinyl alcohol or polyimide, the X-ray and thermal neutron shielding efficiency and antibacterial properties of the material do not fluctuate significantly. Only the tensile strength and air permeability change reasonably with the properties of the polymer matrix itself, without a sharp drop in performance. The core reason is that the composite powder modified with KH550 can form a good interfacial bond with polymers of different polarities and solubility characteristics. It can still be uniformly dispersed at high filling amounts without defects such as powder agglomeration or fiber breakage, which fully verifies the excellent compatibility of the modified functional powder of this application with various polymer substrates.

[0126] Experiments show that when centrifugal spinning and wet spinning are used instead of electrospinning, the core radiation shielding and antibacterial properties of the material remain stable, with no significant difference from the electrospinning reference sample. Furthermore, it can adapt to different production efficiencies and molding requirements. The core reason for this is that the needle-plate blended powder of this application possesses excellent dispersibility and rheological adaptability. Even under the high shear force of centrifugal spinning and the coagulation bath molding process of wet spinning, it can still maintain a uniform distribution without agglomeration or pore blockage. This fully verifies the universality and industrial application potential of the needle-plate blended powder obtained in this application for various spinning molding processes.

[0127] Experiments show that without the addition of citric acid morphology directing agent, the growth of GdTaO4 needle-like structures is out of control and hard agglomerates are generated, which destroys the uniformity of the shielding elements from the source, resulting in a significant decrease in both shielding efficiencies.

[0128] Without the addition of ammonium acetate precipitant or PVP morphology stabilizer, the Sm-CeO2 antibacterial phase grows out of control and undergoes severe aggregation, which not only leads to a significant decrease in antibacterial performance, but also hinders the uniform dispersion of the GdTaO4 matrix in the polymer matrix through the aggregate encapsulation effect, resulting in local enrichment and reduced effective concentration of shielding elements, thus significantly reducing X-ray shielding efficiency; however, the crystal structure of the GdTaO4 matrix itself is not destroyed.

[0129] Without high-temperature calcination, organic residues cannot be removed, and Sm-CeO2 crystallization is insufficient, which dilutes the proportion of effective shielding elements and severely degrades antibacterial performance.

[0130] Without KH550 surface modification, the inorganic-organic interface compatibility is extremely poor, powder agglomeration is severe, and all properties are reduced to the lowest level.

[0131] Using physical blending instead of in-situ growth will destroy the interfacial bonding between the two phases, resulting in uneven element distribution and Gd absorption sites being blocked, which significantly degrades the shielding efficiency and overall performance.

[0132] In summary, this application provides an in-situ grown needle-like blend of GdTaO4Sm-CeO2 radiation-resistant and antibacterial particles, its preparation method, and its application. The flexible radiation-resistant and antibacterial fiber felt prepared using this method achieves an X-ray shielding efficiency of 85.51% under 100 keV incident light and an X-ray shielding efficiency of 88.69% under 0.025 eV incident light. It also exhibits a 24-hour antibacterial rate of 99.92% against Staphylococcus aureus, a tensile strength of 12.78 MPa, and an air permeability of 148.8 mm / s.

[0133] This application successfully prepared a needle-sheet integrated composite structure with two-dimensional sheet-like Sm-CeO2 loaded in situ on the surface of needle-like GdTaO4 through a four-step process: "hydrothermal synthesis of one-dimensional needle-shaped gadolinium tantalate matrix - hydrothermal in-situ heterogeneous growth of Sm-doped CeO2 - low-temperature calcination crystallization - silane coupling agent interface modification". This structure achieves dual-function integration of ionizing radiation shielding and efficient broad-spectrum antibacterial properties.

[0134] The material (radiation-resistant and antibacterial particles) prepared in this application has a unique needle-sheet blend integrated structure. On the one hand, it utilizes the functional synergistic effect of Gd and Ta elements to extend the action path of radiation within the material, achieving radiation protection against X-rays and thermal neutrons. On the other hand, it also utilizes Sm... 3+ The high concentration of lattice oxygen vacancies constructed by doping achieves stable non-leaching broad-spectrum antibacterial properties; at the same time, the strong interfacial chemical bonds formed by in-situ growth not only avoid the aggregation and shedding of functional phases, but also form strong physical anchoring points in the polymer matrix, thus maintaining excellent mechanical properties, spinning process adaptability and breathability even with high powder filling amount.

[0135] This material system can solve the technical problems of traditional radiation protection materials, such as high toxicity, narrow protection spectrum, single function, lack of antibacterial ability, and easy agglomeration of powder in high-filled polymer composite systems, weak interfacial bonding with the matrix, and poor mechanical properties and breathability. It is suitable for flexible close-fitting protective equipment, medical antibacterial protective dressings and multifunctional radiation protection components in complex radiation scenarios such as nuclear medical diagnosis and interventional treatment, nuclear energy facility operation and maintenance, and emergency protection in radioactive environments.

[0136] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for preparing in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles, characterized in that, Includes the following steps: S1. Preparation of needle-shaped gadolinium tantalate matrix powder: Acidic gadolinium salt solution and tantalum salt solution were prepared separately. The tantalum salt solution was added dropwise to the acidic gadolinium salt solution and stirred at room temperature to obtain a suspension. Add a morphology-directing agent to the suspension, dissolve it, adjust the pH of the system to acidic, and stir to obtain the precursor reaction solution; The precursor reaction solution was subjected to hydrothermal reaction, cooling, washing, and vacuum drying to obtain needle-shaped gadolinium tantalate matrix powder; wherein the molar ratio of gadolinium to tantalum was (0.25~4):1, and the hydrothermal reaction temperature was 200~250℃; S2. Preparation of in-situ growth precursor solution: Dissolve cerium source and samarium source in ethanol-water mixed solvent and stir until completely transparent to obtain rare earth precursor solution; add precipitant and morphology stabilizer and continue stirring until completely dissolved, then add the needle-shaped gadolinium tantalate matrix powder prepared in step S1, stir and premix, ultrasonically disperse until the powder is completely dispersed without sedimentation, adjust the pH of the system to weakly alkaline to obtain in-situ growth precursor solution; wherein, the molar ratio of Ce to Sm elements is 19:1 ~ 4:1; the amount of the needle-shaped gadolinium tantalate matrix powder added is 30%~120% of the total mass of cerium source and samarium source, and the mass ratio of GdTaO4 to Sm-CeO2 is (1~4):1; S3. Hydrothermal in-situ growth reaction: The in-situ growth precursor solution obtained in step S2 is transferred to a hydrothermal reactor for hydrothermal reaction. After the reaction is completed, it is naturally cooled to room temperature. The temperature of the hydrothermal reaction is 160-180℃. S4. High-temperature calcination crystallization treatment: After centrifugation, washing and drying of the reaction product in step S3, calcination is carried out in air atmosphere and natural cooling is performed to obtain needle-like and flake-like composite powder. S5. Post-processing modification: The needle-like composite powder obtained in step S4 is dispersed in an alcohol-water mixture, a silane coupling agent is added, and the surface is modified by water bath stirring. After centrifugation, washing, vacuum drying, and grinding, needle-like composite GdTaO4 / Sm-CeO2 anti-radiation and antibacterial particles are obtained.

2. The method for preparing in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles according to claim 1, characterized in that, In step S1, the gadolinium salt is one of gadolinium nitrate hexahydrate, gadolinium chloride hexahydrate, and gadolinium sulfate; the tantalum salt is one of tantalum pentachloride, sodium tantalate, and tantalum pentabromide; wherein the molar ratio of gadolinium to tantalum is (0.66~1.5):1; the morphology guiding agent is one of citric acid monohydrate, oxalic acid dihydrate, polyethylene glycol, and ethylenediaminetetraacetic acid, and the amount of the morphology guiding agent is 2.5%~5% of the total mass of the gadolinium salt and the tantalum salt; during the hydrothermal reaction, the filling degree of the hydrothermal reactor is 60%-80%, and the time is 8~12h; the pH value of the precursor reaction solution is 1~3.

3. The method for preparing in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles according to claim 1, characterized in that, In step S2, the cerium source is one of cerium nitrate hexahydrate, cerium sulfate, cerium acetate, and cerium chloride; the samarium source is one of samarium nitrate hexahydrate, samarium sulfate, samarium acetate, and samarium chloride, and the pH of the system is 7.5-8.

5.

4. The method for preparing in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles according to claim 1, characterized in that, The rare earth precursor solution has a rare earth metal ion concentration of 0.1~0.3 mol / L; the precipitant is one of ammonium acetate, urea, hexamethylenetetramine, and formamide, and the amount of the precipitant is 40%~60% of the total mass of the cerium source and samarium source; the morphology stabilizer is one of PVP K30, sodium citrate, and PEG-4000, and the amount of the morphology stabilizer is 10%~30% of the total mass of the cerium source and samarium source.

5. The method for preparing in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles according to claim 1, characterized in that, In step S3, the filling degree of the hydrothermal reactor is 70%-80%, and the time is 4-8 hours.

6. The method for preparing in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles according to claim 1, characterized in that, In step S4, the high-temperature calcination temperature is 400-600℃, the heating rate is 2-5℃ / min, and the time is 2-4h.

7. The method for preparing in-situ grown needle-like blended GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles according to claim 1, characterized in that, In step S5, the silane coupling agent is one of γ-aminopropyltriethoxysilane and γ-methacryloyloxypropyltrimethoxysilane, and the amount of the silane coupling agent is 1% to 2.5% of the mass of the needle-like composite powder.

8. An in-situ grown needle-like blend of GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles, characterized in that, The radiation-resistant and antibacterial particles are prepared by the preparation method described in any one of claims 1-7; the particles comprise a needle-shaped gadolinium tantalate matrix and sheet-shaped samarium-doped cerium dioxide grown in situ on the surface of the needle-shaped gadolinium tantalate.

9. The in-situ grown needle-like blend of GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles according to claim 8, characterized in that, The diameter of the needle-shaped gadolinium tantalate matrix powder is 20~30nm and the length is 200~300nm; the lateral dimension of the plate-shaped samarium-doped cerium dioxide is 100~300nm and the thickness is 10~20nm.

10. The application of an in-situ grown needle-like blend of GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles, characterized in that, Radiation-resistant and antibacterial fiber material is prepared by filling the GdTaO4 / Sm-CeO2 radiation-resistant and antibacterial particles of the in-situ grown needle-like blend as described in any one of claims 1-7 or as described in claims 8-9 into a polymer substrate and then preparing the radiation-resistant and antibacterial fiber material by centrifugal spinning, electrospinning, or wet spinning. The polymer substrate is one of polyvinyl alcohol, polyimide, polyvinyl butyral, polyvinyl chloride, and polyurethane.

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