A method for preparing sub-10 nm iron oxide composite materials by 3D printing and applications

Abstract

A method for preparing sub-10 nm iron oxide composite materials by 3D printing and its application, sub-10 nm iron oxide nanoparticles are synthesized by a solvothermal method and uniformly dispersed in a polymer matrix material such as acrylic resin, and then the mixed material is shaped using 3D printing technology. By adjusting the printing conditions and post-processing technology, a stable structure and uniform particle size of the iron oxide composite material are obtained. The composite material has a high specific surface area, good dispersibility and customizable structure, which significantly improves its performance in environmental catalysis, magnetic separation and energy storage. The method has the characteristics of strong operability, low cost, environmental protection and non-toxicity, is suitable for large-scale production, and promotes the wide application of iron oxide nanomaterials in many fields.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nanomaterial preparation and additive manufacturing, and particularly relates to a method for preparing sub-10 nm iron oxide composite material through 3D printing and application. BACKGROUND

[0002] Iron oxide nanomaterials have attracted extensive attention due to their unique properties in catalysis, energy, environmental remediation, medical imaging and sensing, especially sub-10 nm iron oxide nanoparticles. They have high specific surface area, abundant active sites and quantum size effect, which can significantly improve the performance of materials in these applications. However, traditional preparation methods such as chemical precipitation, solvothermal method, thermal decomposition, etc. have significant technical bottlenecks in controlling iron oxide particle size, realizing structure customization and preventing agglomeration. Due to the large surface energy of iron oxide nanoparticles, they are prone to agglomeration to form aggregates, resulting in a decrease in specific surface area and active sites, affecting their catalytic, magnetic and other properties. Even if a surfactant is added during preparation to reduce agglomeration, impurities may still be introduced, affecting the purity and electrochemical performance of the material.

[0003] Traditional preparation methods also have limitations in the macroscopic structure customization of iron oxide materials, making it difficult to meet the application requirements in complex environments. For example, in the field of photocatalysis, iron oxide materials need to be made into porous structures or specific shapes to improve light absorption and catalytic efficiency; in biomedical imaging, iron oxide materials need to be combined with specific carriers to achieve targeted delivery. In addition, the stability and regenerability of iron oxide nanomaterials in catalytic, energy storage and other applications are also crucial to the practical application of the materials. Iron oxide materials may undergo oxidation or deactivation under repeated use and high temperature, high humidity, etc., thereby reducing their performance, so improving the durability of the material and maintaining stable active sites has become a difficult problem to be solved.

[0004] 3D printing, as a new additive manufacturing technology, has unique advantages in structure design, manufacturing customization and material utilization, providing a new method for the preparation and structural control of iron oxide nanomaterials. 3D printing not only enables precise control of macroscopic morphology, but also allows precise adjustment of the microstructure of the material through printing parameters. For example, 3D printing combines iron oxide nanomaterials with a high polymer matrix to form a composite material, which not only prevents the agglomeration of nanoparticles, but also improves the uniform distribution of particles within the material. Through 3D printing, the unique properties of iron oxide nanomaterials are combined with the advantages of structuralization, enabling size control, distribution optimization and structural stability, making their application in multiple fields more feasible.

[0005] In addition, traditional nanomaterial preparation processes often involve toxic chemicals, high temperature and pressure, and complex post-processing steps, resulting in high costs and potential environmental risks. With the increasing awareness of environmental protection, low-energy, low-pollution, and cost-effective preparation processes have become increasingly important. 3D printing technology not only simplifies the preparation process of iron oxide composite materials, but also reduces the use of harmful solvents, meeting the needs of sustainable development. Therefore, by 3D printing technology to build a stable structure, uniform distribution of sub-10 nm iron oxide composite materials will effectively solve the technical problems of traditional methods in particle size control, agglomeration and structure customization, and promote the wide application of the material in environmental catalysis, energy storage and biomedical fields. SUMMARY

[0006] The purpose of the present application is to provide a method for preparing sub-10 nm iron oxide composite materials by 3D printing, which overcomes the shortcomings of traditional preparation techniques in particle size control, agglomeration stability and macrostructure customization. Through the preparation method of the present application, sub-10 nm iron oxide composite materials with high specific surface area, good dispersibility and customizable structure can be obtained, thereby significantly improving their performance in environmental catalysis, magnetic separation and energy storage, etc.

[0007] The preparation method of the present application first synthesizes sub-10 nm iron oxide nanoparticles by solvothermal method, then uniformly disperses them in a high molecular weight substrate material such as acrylic resin, and uses a 3D printing device to shape the mixed material. By adjusting the printing conditions and post-processing process, a stable structure, uniform particle size iron oxide composite material is finally obtained, which exhibits excellent catalytic, magnetic and conductive properties. This method has the characteristics of strong operability, low cost, environmental protection and non-toxicity, and is suitable for large-scale production.

[0008] The technical scheme adopted by the present application to achieve the above-mentioned purposes is as follows:

[0009] A method for preparing sub-10 nm iron oxide composite materials by 3D printing, comprising the following steps:

[0010] Step (1) Preparation of iron oxide nanoparticles: Dissolve ferric nitrate in ethylene glycol solution to prepare a solution with a concentration of 0.5 to 1.25 M. Transfer the solution to a high-pressure reaction kettle and react at a temperature of 105 to 115°C for 3 to 5 hours. Cool to room temperature, remove impurities by repeated washing with deionized water and ethanol, then centrifuge, and finally dry the separated nanoparticles to obtain iron oxide nanoparticles with a particle size of 5 to 10 nm;

[0011] Step (2) Preparation of nanoparticle dispersion: The iron oxide nanoparticles prepared in step a) are dispersed in an acrylic resin solution with a solid content controlled in the range of 10% to 30%, and a surfactant accounting for 1% to 10% of the mass of the iron oxide nanoparticles is added. The nanoparticles are uniformly distributed in the resin solution through stirring and ultrasonic dispersion treatment, forming a dispersion;

[0012] Step (3) 3D printing forming: The dispersion prepared in step b) is loaded into a 3D printing device, and 3D printing is performed by adjusting the printing parameters. After printing, drying and heat treatment are performed to obtain an iron oxide composite material with stable structure and uniform particle size.

[0013] The present application provides a method for preparing sub-10 nm iron oxide composite materials by 3D printing and its application. Compared with existing processes, the present application has the following obvious advantages:

[0014] 1. Accurate control of nanostructure and material macroscopic morphology: The combination of solvothermal method and 3D printing technology can control the particle size and distribution of iron oxide particles at the nanoscale, and accurately control the macroscopic shape of the material through 3D printing technology, which is suitable for the construction of various complex structures.

[0015] 2. High physical and chemical performance: The composite material of the present application has high specific surface area, good electronic conductivity and chemical stability, which is beneficial to achieve excellent performance in photocatalytic degradation and electrochemical energy storage applications. Experiments show that the photocatalytic degradation rate of the material under visible light irradiation is more than 95%, and the material exhibits excellent cycle stability in lithium battery applications.

[0016] 3. Green and environmentally friendly, low cost: The raw materials used in the present application are non-toxic and environmentally friendly, and the preparation process is simple, without the need for high temperature or toxic chemicals, meeting the requirements of green manufacturing. The 3D printing preparation process has the characteristics of low energy consumption and low cost, is suitable for large-scale production, and meets the needs of industrial applications.

[0017] 4. Wide application potential: The 3D printed iron oxide composite material of the present application is suitable for a variety of applications, including photocatalytic degradation of water pollutants, magnetic separation, lithium battery negative materials, supercapacitors, etc. It exhibits good performance and potential market in wastewater treatment, air purification and clean energy applications.

[0018] 5. Excellent repeated use performance: The material maintains high stability during multiple uses and regeneration, and still maintains more than 90% of the catalytic performance after recycling, greatly reducing the use cost. The good dispersibility and stability of the iron oxide nanoparticles make the composite material perform excellently in efficient degradation and separation applications. DETAILED DESCRIPTION

[0019] The technical solutions of the present application will be described in detail below in combination with embodiments:

[0020] A method for preparing sub-10 nm iron oxide composite materials by 3D printing, comprising the following steps:

[0021] Step (1) Preparation of iron oxide nanoparticles: Dissolve ferric nitrate (Fe(NO3)3·9H2O) in ethylene glycol solution to prepare a solution with a concentration of 0.5 to 1.25 M, preferably in the range of 0.75 to 1.0 M. Then, transfer the solution to a high-pressure reaction kettle and react at a temperature of 105 to 115°C for 3 to 5 hours to ensure uniform growth of iron oxide nanoparticles. After the reaction is completed, cool the solution to room temperature, remove impurities by repeated washing with deionized water and ethanol, and centrifuge at a speed of 8000 to 12000 rpm, preferably 10000 rpm. Finally, dry the separated nanoparticles to obtain iron oxide nanoparticles with a particle size of 5 to 10 nm.

[0022] Step (2) Preparation of nanoparticle dispersion: Disperse the above-prepared iron oxide nanoparticles in an acrylic resin solution with a solid content controlled in the range of 10% to 30%. At the same time, add 1% to 10%, preferably 3% to 5%, of the mass of the iron oxide nanoparticles, of a surfactant (such as polyethylene glycol (PEG) or polyvinylpyrrolidone (PVP)) to improve the dispersibility of the nanoparticles in the resin solution. Through thorough stirring and ultrasonic dispersion for 30 to 60 minutes, preferably 40 to 50 minutes, ensure uniform distribution of the nanoparticles in the resin solution to form a stable dispersion.

[0023] Step (3) 3D printing molding: Load the prepared dispersion into a light-curing 3D printing device, and realize high-precision and high-efficiency 3D printing by precisely controlling the parameters of the printing device, such as exposure time (1 to 10 seconds), layer thickness (0.01 to 0.1 mm), and scanning speed. After printing, place the composite material in a vacuum drying oven and dry at a temperature of 50 to 80°C for 2 to 24 hours to remove residual solvents. Then, perform heat treatment at a temperature of 100 to 130°C, preferably 110 to 120°C, for no more than 2 hours to further improve the mechanical and thermal stability of the material.

[0024] A method for preparing sub-10 nm iron oxide composite materials by 3D printing, comprising the following steps: Example

[0025] A method for preparing sub-10 nm iron oxide composite material by 3D printing, comprising the following steps:

[0026] Step (1) Iron oxide nanoparticle preparation: 15.21 g of ferric nitrate (Fe(NO3)3·9H2O) was accurately weighed and dissolved in 100 ml of ethylene glycol to prepare a solution with an accurate concentration of 1.0 M. The solution was sealed and transferred to a high-pressure reaction kettle, and reacted at a strictly controlled temperature of 110±1℃ for 4 hours. After the reaction was completed, it was quickly cooled, washed repeatedly with deionized water and ethanol 3 times, and centrifuged at a speed of 10000 rpm for 15 minutes, finally obtaining iron oxide nanoparticles with a uniform particle size of about 7 nm.

[0027] Step (2) Dispersion liquid preparation: the above nanoparticles were dispersed in 200 mL of an acrylic resin solution containing 20% solid content, and 5% of the mass of the nanoparticles was added as a surfactant. PEG-4000) After stirring for 30 minutes using a magnetic stirrer, ultrasonic dispersion treatment was performed for 45 minutes to ensure uniform dispersion of the particles.

[0028] Step (3) 3D printing forming: load the dispersion liquid into a high-precision light-curing 3D printing device, set the exposure time to 5 seconds, the layer thickness to 0.05 mm, and the scanning speed to 20 mm / s. After printing, vacuum drying was performed at 60±5℃ for 12 hours, followed by heat treatment at 120±5℃ for 1 hour to enhance the mechanical properties of the material.

[0029] The specific surface area of the iron oxide composite material prepared by the present application is 190 m² / g, the iron oxide particle size is uniformly distributed between 7-9 nm, the particle size is small and has good uniformity, the porosity of the iron oxide composite material is 0.48 cm³ / g, and the pore size distribution is mainly concentrated in 2-4 nm. The density of the material is 2.25 g / cm³, and it exhibits excellent thermal stability at 250°C, with almost negligible mass loss.

[0030] Comparative example

[0031] For comparison, three sets of control materials are provided. The first set of control materials is prepared by a conventional sol-gel method, with a specific surface area of 140 m² / g, an iron oxide particle size of 18-22 nm, a porosity of 0.38 cm³ / g, and a wide pore size distribution, indicating a loose structure. The second set of control materials is prepared by a high-temperature solid-phase method, with a specific surface area of 125 m² / g, an iron oxide particle size of 15-18 nm, a porosity of 0.40 cm³ / g, and overall performance inferior to the material of the present patent. The third set of control materials is a commercially available iron oxide composite material, with a specific surface area of 100 m² / g, an iron oxide particle size of 25-30 nm, and a low porosity of only 0.30 cm³ / g. By comparison, it can be seen that the material of Example 1 of the present invention is significantly superior to the control materials in terms of specific surface area, particle size, and porosity, and exhibits more superior structural performance. Example

[0032] A method for preparing a sub-10 nm iron oxide composite material by 3D printing, comprising the following steps:

[0033] Step (1) Iron oxide nanoparticle preparation: 7.6 g of iron nitrate is dissolved in 100 mL of ethylene glycol to prepare a 0.5 M solution. The reaction is carried out at 105±2°C for 6 hours, and the obtained nanoparticle has a particle size of about 9 nm.

[0034] Step (2) Dispersion liquid preparation: The nanoparticles are dispersed in an acrylic resin solution containing 15% solid content, and 3% polyvinylpyrrolidone (PVP K30) by mass of the nanoparticles is added. The mixture is subjected to ultrasonic dispersion treatment for 30 minutes, while being slightly stirred to ensure uniformity.

[0035] Step (3) 3D printing forming: The printing parameters are adjusted to an exposure time of 3 seconds, a layer thickness of 0.1 mm, and a scanning speed that remains unchanged. The drying and heat treatment conditions are the same as those of Example 1.

[0036] The prepared iron oxide composite material has a specific surface area of 175 m² / g, an iron oxide particle size of 9-12 nm, a uniform particle size distribution, a porosity of 0.44 cm³ / g, and a pore size mainly concentrated in 3-5 nm, showing excellent micro-pore structure and larger surface contact area. The density of the iron oxide composite material is 2.30 g / cm³, and it shows good thermal stability at 250°C, with a mass loss of not more than 3%. Compared with three groups of control materials: the first group of control materials (prepared by traditional sol-gel method) has a specific surface area of 140 m² / g, an iron oxide particle size of 18-22 nm, and a porosity of 0.38 cm³ / g; the second group of control materials (prepared by high-temperature solid-phase method) has a specific surface area of 125 m² / g, an iron oxide particle size of 15-18 nm, and a porosity of 0.40 cm³ / g; and the third group of control materials (commercially available materials) has a specific surface area of 100 m² / g, an iron oxide particle size of 25-30 nm, and a porosity of only 0.30 cm³ / g. The material of Example 2 of the present application has obvious advantages in specific surface area, particle size distribution and pore structure compared with the control materials, showing a more compact structure and superior surface performance. Example

[0037] A method for preparing sub-10 nm iron oxide composite material by 3D printing, comprising the following steps:

[0038] Step (1) Iron oxide nanoparticle preparation: 22.8 g of iron nitrate is used to prepare a 1.25 M solution, and the reaction is carried out at a wide temperature of 118-122°C for 3 hours to obtain nanoparticles with a particle size of about 6 nm, and the purity is ensured by more rigorous washing and centrifugation process.

[0039] Step (2) Dispersion liquid preparation: dispersed in a resin solution containing 30% solid content, 10% PEG-6000 by mass of nanoparticles is added, and ultrasonic dispersion is carried out for 60 minutes, during which an ice bath is used to keep the dispersion liquid temperature stable.

[0040] Step (3) 3D printing forming: the exposure time is prolonged to 10 seconds, and the layer thickness is reduced to 0.01 mm to improve the printing precision. The drying temperature is 80±5°C, and the time is prolonged to 12 hours to ensure complete drying, and the heat treatment is carried out at a wide temperature of 125-135°C for 1.5 hours to explore the effect of higher temperature on the performance of the material.

[0041] The iron oxide composite prepared by the method has a specific surface area of 160 m2 / g, an iron oxide particle size of 10-13 nm, a uniform distribution, a porosity of 0.40 cm3 / g, and a pore size concentrated in 4-6 nm. The iron oxide composite has a density of 2.28 g / cm3 and good thermal stability at 250°C, with a mass loss of less than 2%. For comparison of the properties of three groups of control materials: the first group of control materials (prepared by a traditional sol-gel method) has a specific surface area of 140 m2 / g, an iron oxide particle size of 18-22 nm, and a porosity of 0.38 cm3 / g; the second group of control materials (prepared by a high-temperature solid-phase method) has a specific surface area of 125 m2 / g, an iron oxide particle size of 15-18 nm, and a porosity of 0.40 cm3 / g; and the third group of control materials (commercially available materials) has a specific surface area of only 100 m2 / g, an iron oxide particle size of 25-30 nm, and a porosity of 0.30 cm3 / g. Compared with the above-mentioned control materials, the material of Example 3 of the present application is superior to the prior art materials in terms of specific surface area, iron oxide particle size, and pore distribution, and exhibits more significant structural advantages, and is suitable for high-efficiency application scenarios. Example

[0042] A method for preparing sub-10 nm iron oxide composite materials by 3D printing, comprising the following steps:

[0043] Step (1) Iron oxide nanoparticle preparation: 12.16 g of iron nitrate was dissolved in 100 mL of ethylene glycol to prepare a 0.8 M solution, which was reacted at 113-117°C for 5 hours to obtain nanoparticles with a particle size of about 8 nm.

[0044] Step (2) Dispersion liquid preparation: dispersed in a resin solution containing 25% solid content, 5% PVP K90 was added, and ultrasonic dispersion was performed for 40 minutes, while a magnetic stirrer was used to assist dispersion.

[0045] Step (3) 3D printing forming: the printing parameters were an exposure time of 7 seconds and a layer thickness of 0.06 mm. The drying and heat treatment conditions were the same as in Example 1, but an additional step of X-ray diffraction (XRD) and scanning electron microscope (SEM) characterization of the dried sample was added to evaluate the structure and morphology of the material.

[0046] The specific surface area of the prepared iron oxide composite material is 180 m² / g, the particle size of the iron oxide is 6-8 nm, the particle size is small and uniformly distributed, and the structure is more compact. The porosity is 0.46 cm³ / g, and the pore size distribution is mainly concentrated in 2-4 nm, indicating that the material has a large surface contact area and excellent micro-pore structure. The density of the iron oxide composite material is 2.25 g / cm³, and it has excellent thermal stability at 250°C, with a mass loss of not more than 1.5%. For comparison, three sets of control material characterization data are provided. The first set of control materials is prepared by a traditional sol-gel method, with a specific surface area of 140 m² / g, an iron oxide particle size of 18-22 nm, and a porosity of 0.38 cm³ / g, and a wide pore size distribution. The second set of control materials is prepared by a high-temperature solid-phase method, with a specific surface area of 125 m² / g, an iron oxide particle size of 15-18 nm, and a porosity of 0.40 cm³ / g. The third set of control materials is a commercially available iron oxide composite material, with a specific surface area of 100 m² / g, an iron oxide particle size of about 25-30 nm, and a low porosity of only 0.30 cm³ / g. By comparison, it can be seen that the material of the present application is significantly superior to the control materials of the prior art in terms of specific surface area, iron oxide particle size and porosity, and exhibits more superior structural performance. Example

[0047] A method for preparing sub-10 nm iron oxide composite material by 3D printing, comprising the following steps:

[0048] Step (1) Iron oxide nanoparticle preparation: 0.75M solution (the specific mass is accurately calculated according to the concentration) is prepared using ferric nitrate, and is reacted at 110-114°C for 4.5 hours to obtain nanoparticles with a particle size of about 5.5 nm.

[0049] Step (2) Dispersion liquid preparation: dispersed in a resin solution containing 18% solid content, 4% PEG-2000 is added, and ultrasonic dispersion is performed for 55 minutes, during which nitrogen is used for purging to prevent oxidation.

[0050] Step (3) 3D printing forming: the printing parameters are optimized to be an exposure time of 6 seconds, a layer thickness of 0.04 mm, and a scanning speed reduced to 15 mm / s to improve the printing quality. The drying and heat treatment conditions are similar to those of Example 1, but a step of testing the magnetic performance of the sample after heat treatment is added.

[0051] The prepared iron oxide composite material has a specific surface area of 175 m² / g, an iron oxide particle size of 7-9 nm, a small particle size and uniform distribution, and a compact structure. The porosity is 0.44 cm³ / g, and the pore size distribution is concentrated in 3-5 nm, indicating that the material has a high specific surface area and a stable microporous structure. The density of the iron oxide composite material is 2.28 g / cm³, and it exhibits good thermal stability at 250°C, with a mass loss of not more than 2%. For comparison, three sets of control material characterization data are provided. The first set of control materials is prepared by a traditional sol-gel method, with a specific surface area of 140 m² / g, an iron oxide particle size of 18-22 nm, and a porosity of 0.38 cm³ / g, and a wide pore size distribution. The second set of control materials is prepared by a high-temperature solid-phase method, with a specific surface area of 125 m² / g, an iron oxide particle size of 15-18 nm, and a porosity of 0.40 cm³ / g. The third set of control materials is a commercially available iron oxide composite material, with a specific surface area of 100 m² / g, an iron oxide particle size of about 25-30 nm, and a low porosity of only 0.30 cm³ / g. Through comparison, it can be seen that the material of the present application is superior to the control materials of the prior art in terms of specific surface area, iron oxide particle size and porosity, and exhibits significant structural advantages. Example

[0052] A method for preparing sub-10 nm iron oxide composite material by 3D printing, comprising the following steps:

[0053] Step (1) Iron oxide nanoparticle preparation: A slightly lower concentration of 0.75M iron nitrate solution is used, and the reaction is carried out at a precisely controlled temperature of 112±0.5°C for 5 hours to obtain nanoparticles with a particle size of about 7.5 nm and excellent dispersibility.

[0054] Step (2) Dispersion liquid preparation: The nanoparticles are dispersed in a resin solution containing 18% solid content, and 3% PVP K30 is added, and ultrasonic dispersion treatment is carried out for 50 minutes, while a circulating water cooling system is used to maintain the dispersion liquid temperature constant.

[0055] Step (3) 3D printing forming: The printing parameters are set as exposure time 4 seconds, layer thickness 0.07 mm, and scanning speed moderate. The drying condition is 50±2°C, and the time is extended to 24 hours to ensure complete curing, and the heat treatment is carried out at 100±2°C for 1.5 hours, and finally the printed sample is tested for electrical performance to evaluate its application potential in conductive materials.

[0056] The iron oxide composite material prepared by the application has a specific surface area of 170 m² / g, an iron oxide particle size of 10-12 nm, a uniform particle size distribution, a compact structure, a porosity of 0.42 cm³ / g, a pore size distribution mainly concentrated in 4-6 nm, and a density of 2.30 g / cm³. The iron oxide composite material has excellent thermal stability at 250°C, and the mass loss is less than 1.8%. For comparison, three sets of control material characterization data are provided. The first set of control material is prepared by a traditional sol-gel method, has a specific surface area of 140 m² / g, an iron oxide particle size of 18-22 nm, and a porosity of 0.38 cm³ / g with a wide pore size distribution. The second set of control material is prepared by a high-temperature solid-phase method, has a specific surface area of 125 m² / g, an iron oxide particle size of 15-18 nm, and a porosity of 0.40 cm³ / g. The third set of control material is a commercially available iron oxide composite material, has a specific surface area of 100 m² / g, an iron oxide particle size of about 25-30 nm, and a low porosity of only 0.30 cm³ / g. Through comparison, it can be seen that the material of the application is superior to the control materials of the prior art in terms of specific surface area, iron oxide particle size and porosity, and exhibits a more compact structure and optimized pore distribution.

[0057] A method for preparing sub-10 nm iron oxide composite material by 3D printing and its application. Sub-10 nm iron oxide nanoparticles are synthesized by a solvothermal method and uniformly dispersed in a polymer matrix such as acrylic resin. The mixed material is then shaped using 3D printing technology. By adjusting the printing conditions and post-processing techniques, a stable structure and uniform particle size of the iron oxide composite material are obtained. The composite material has a high specific surface area, good dispersibility and customizable structure, significantly improving its performance in environmental catalysis, magnetic separation and energy storage. The preparation method of the application has the characteristics of strong operability, low cost, environmental friendliness and non-toxicity, is suitable for large-scale production, and promotes the wide application of iron oxide nanomaterials in various fields.

[0058] Those skilled in the art can understand that the above embodiments are specific examples for implementing the application, and in actual application, various changes can be made in form and details without departing from the spirit and scope of the application. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the application, therefore the protection scope of the application should be limited by the scope defined in the claims.

Claims

1. A method for preparing sub-10nm iron oxide composite materials by 3D printing, characterized in that... Includes the following steps: Step (1) Preparation of iron oxide nanoparticles: Iron nitrate was dissolved in ethylene glycol solution to prepare a solution with a concentration between 0.5 and 1.25 M; then, the solution was transferred to a high-pressure reactor and reacted at a temperature of 105°C to 115°C for 3 to 5 hours; after the reaction, the solution was cooled to room temperature, and impurities were removed by repeated washing with deionized water and ethanol, and centrifuged at a speed of 8000 to 12000 rpm; finally, the separated nanoparticles were dried to obtain iron oxide nanoparticles with a particle size of 5 to 10 nm. Step (2) Preparation of nanoparticle dispersion: The iron oxide nanoparticles obtained above are dispersed in an acrylic resin solution, and the solid content of the acrylic resin solution is controlled within the range of 10% to 30%; at the same time, a surfactant accounting for 1% to 10% of the mass of the iron oxide nanoparticles is added, wherein the surfactant is polyethylene glycol or polyvinylpyrrolidone; the nanoparticles are uniformly distributed in the resin solution and a stable dispersion is formed by thorough stirring and ultrasonic dispersion treatment for 30 to 60 minutes. Step (3) 3D printing: The prepared dispersion is loaded into the photopolymerization 3D printing equipment. The parameters of the printing equipment are precisely adjusted, with an exposure time of 1 to 10 seconds and a layer thickness of 0.01 to 0.1 mm, and 3D printing is performed. After printing, the composite material is placed in a vacuum drying oven and dried at a temperature of 50°C to 80°C for 2 to 24 hours to remove residual solvent. Subsequently, heat treatment is performed, with the temperature controlled between 100°C and 130°C and the time not exceeding 2 hours, to obtain a structurally stable and uniformly sized iron oxide composite material.

2. An application of 3D printing to prepare sub-10nm iron oxide composite materials, wherein the 10nm iron oxide composite material... It is prepared according to the method of claim 1, characterized in that, It is used in environmental catalysis, magnetic separation, energy storage and biomedicine.