Preparation method of composite carrier based on magnetic silicon-based nanoflowers

Abstract

The invention provides a preparation method of a composite carrier based on magnetic silicon-based nanoflowers, and relates to the technical field of nanotechnology and composite materials, and the preparation method comprises the following steps: S1, uniformly dispersing a reaction mixture containing a silicon source, magnetic iron oxide nanoparticles and a surface modifier in a solvent to obtain a reaction mixture, s2, the reaction mixture is treated under the hydrothermal reaction condition of 180-250 DEG C, the reaction time is 4-8 hours, the magnetic silicon-based nanoflower composite material is formed, the reaction temperature and time can promote magnetic iron oxide nanoparticles to be evenly distributed on the surface of a silicon-based carrier, and the magnetism and catalytic activity of the material are ensured. According to the preparation method of the composite carrier based on the magnetic silicon-based nanoflowers, the ionic liquid is adopted as a solvent and a surface functionalizing agent, so that the problems of aggregation, poor dispersity and the like of magnetic particles in a traditional method are effectively solved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of nanotechnology and composite materials, and particularly relates to a preparation method of a magnetic silicon-based nanoflower composite carrier. BACKGROUND

[0002] In recent years, the rapid development of nanotechnology has promoted the emergence of various new materials. Magnetic nanomaterials have been widely used in catalysis, drug delivery, environmental pollution treatment and other fields due to their adjustable magnetic properties and surface characteristics. Silicon-based nanomaterials, as an important carrier material, have excellent specific surface area, good biocompatibility and adjustable surface properties, and thus have become a research hotspot in many applications. By combining magnetic materials with silicon-based nanomaterials, the advantages of magnetic nanoparticles and silicon-based carriers can be combined, so as to play an excellent performance in catalytic reactions, drug delivery and environmental remediation. Magnetic silicon-based nanoflower composite carriers have attracted much attention in the field of material science in recent years. Silicon-based materials such as silicon dioxide and silica gel can be prepared into nanoparticles through physical and chemical methods, and the surfaces of these materials can be functionalized to realize the adsorption or catalysis of other substances. Magnetic nanoparticles can provide efficient separation ability due to their responsiveness under an external magnetic field, especially in the application of liquid phase separation or recovery. The magnetic silicon-based nanoflower composite carrier combines the advantages of both, and can not only be quickly separated by an external magnetic field, but also has good chemical stability and catalytic activity.

[0003] In the existing preparation method of the magnetic silicon-based nanoflower composite carrier, the following defects exist: the co-precipitation method or the sol-gel method adopted by the prior art is difficult to precisely control the uniform distribution between the magnetic particles and the silicon-based carrier, and when large-scale preparation is performed, the magnetic particles tend to aggregate into groups, which reduces the performance of the material and leads to unstable magnetic properties and catalytic activity of the composite material. SUMMARY

[0004] In view of the deficiencies of the prior art, the application provides a preparation method of a magnetic silicon-based nanoflower composite carrier, and the technical problems to be solved by the application are how to significantly improve the dispersity, stability and catalytic activity of the composite material through ion liquid functionalization treatment, optimization of hydrothermal reaction conditions and catalytic performance testing.

[0005] To achieve the above object, the application is implemented by the following technical scheme: a preparation method of a magnetic silicon-based nanoflower composite carrier, comprising:

[0006] S1. uniformly dispersing a reaction mixture containing a silicon source, magnetic iron oxide nanoparticles and a surface modifier in a solvent to obtain a reaction mixture;

[0007] S2. The reaction mixture is treated under hydrothermal reaction conditions at 180-250°C for 4-8 hours to form a magnetic silicon-based nanoflower composite material, wherein the reaction temperature and time promote the uniform distribution of magnetic iron oxide nanoparticles on the surface of the silicon-based carrier and ensure the magnetic properties and catalytic activity of the material;

[0008] S3. The surface of the composite material is functionalized using an ionic liquid to significantly improve the compatibility between the magnetic particles and the silicon-based carrier, effectively prevent the aggregation of magnetic particles, and ensure the stability and high dispersibility of the composite material in subsequent applications;

[0009] S4. The composite material is treated to remove unreacted substances using ultrasonic cleaning, centrifugal separation, and vacuum drying processes;

[0010] S5. The catalytic performance of the obtained composite material is tested, including methanol oxidation and benzene ring hydrogenation. By adjusting the distribution of magnetic particles, the degree of surface functionalization, and the reaction conditions of the composite material, the catalytic activity of the composite material is optimized to obtain the best reaction rate and high selectivity.

[0011] Preferably, the silicon source is dimethyldiethoxysilane, the particle size of the magnetic iron oxide nanoparticles is 5-30 nm, and the surface modifier is glycine and sodium dodecylbenzenesulfonate

[0012] Preferably, the ionic liquid solvent is hexafluorophosphate ion and 1-butyl-3-methylimidazole amine, the molar ratio of hexafluorophosphate ion and 1-butyl-3-methylimidazole amine is 1:1, and the concentration is 0.1-1 mol / L.

[0013] Preferably, the pH value of the reaction mixture is controlled at 4-6 to prevent unnecessary precipitation or dissolution of the silicon-based carrier and magnetic particles during the reaction, ensuring the high stability and uniformity of the composite material.

[0014] Preferably, the functionalization treatment is carried out at 25-80°C, and the surface functionalization degree of the composite material is 80-95%.

[0015] Preferably, the ultrasonic cleaning frequency is 20-40 kHz, and the centrifugal separation speed is 3000-5000 rpm for 10-20 minutes.

[0016] Preferably, the vacuum pressure of the vacuum drying is controlled in the range of 0.01-0.1 MPa.

[0017] Preferably, the catalytic performance test includes the following steps:

[0018] S5.1. The obtained composite material is subjected to a methanol oxidation reaction test, the reaction temperature of the methanol oxidation reaction is 150-200 DEG C, the reaction time is 2-4 hours, the methanol concentration is 10-30%, and then the products of the methanol oxidation reaction are analyzed by gas chromatography to determine the catalytic activity and conversion rate of the composite material in the methanol oxidation reaction;

[0019] S5.2. The obtained composite material is subjected to a benzene ring hydrogenation reaction test, the benzene ring hydrogenation reaction is carried out at a temperature of 100-150 DEG C, the benzene concentration of the benzene ring hydrogenation reaction is 5-10%, the reaction time is 4-6 hours, and the hydrogenation reaction products are quantitatively and qualitatively analyzed by gas chromatography to evaluate the catalytic effect of the composite material;

[0020] S5.3. According to the test results, the magnetic particle distribution, surface functionalization degree and reaction conditions of the composite material are adjusted to improve the rate, selectivity and stability of the catalytic reaction.

[0021] The application provides a preparation method of a magnetic silicon-based nanoflower composite carrier.

[0022] The preparation method of the magnetic silicon-based nanoflower composite carrier effectively solves the problems of magnetic particle aggregation and poor dispersibility in traditional methods by using ionic liquid as a solvent and a surface functionalization agent. The ionic liquid can not only stabilize the solvent environment, but also improve the compatibility between the magnetic particles and the silicon-based carrier, thereby significantly improving the surface properties of the composite material. By accurately controlling the reaction temperature, time and pH value, the high stability, uniformity and excellent catalytic performance of the composite material are ensured.

[0023] By optimizing the magnetic particle distribution, surface functionalization degree and reaction conditions of the composite material, the catalytic activity of the material in the methanol oxidation and benzene ring hydrogenation reactions is significantly improved. This method not only improves the catalytic reaction rate and selectivity, but also shows a wide application prospect of the composite material in different organic catalytic reactions. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a flowchart of the implementation of the application. DETAILED DESCRIPTION

[0025] The described embodiments are obviously only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0026] Example 1

[0027] As Figure 1 shown, the embodiment of the present application provides a preparation method of a magnetic silicon-based nanoflower composite carrier, comprising: S1. uniformly dispersing a reaction mixture containing a silicon source, magnetic iron oxide nanoparticles and a surface modifier in a solvent to obtain a reaction mixture, the silicon source is dimethyldiethoxysilane, the particle size of the magnetic iron oxide nanoparticles is 5-30 nm, the surface modifier is glycine and sodium dodecyl benzene sulfonate, the solvent of the ionic liquid is hexafluorophosphate ion and 1-butyl-3-methylimidazolium amine, the molar ratio of hexafluorophosphate ion and 1-butyl-3-methylimidazolium amine is 1:1 and the concentration is 0.1-1 mol / L.

[0028] S2. treating the reaction mixture under hydrothermal reaction conditions of 180-250°C for 4 hours to form a magnetic silicon-based nanoflower composite material, wherein the reaction temperature and time can promote the uniform distribution of the magnetic iron oxide nanoparticles on the surface of the silicon-based carrier and ensure the magnetic properties and catalytic activity of the material, the pH value of the reaction mixture is controlled at 4 to prevent unnecessary precipitation or dissolution of the silicon-based carrier and magnetic particles during the reaction, and ensure the high stability and uniformity of the composite material.

[0029] S3. functionalizing the surface of the composite material with ionic liquid to significantly improve the compatibility between the magnetic particles and the silicon-based carrier, effectively prevent the aggregation of the magnetic particles, and ensure the stability and high dispersibility of the composite material in subsequent applications, the functionalization is carried out at 25°C, and the surface functionalization degree of the composite material is between 80%.

[0030] S4. removing unreacted substances from the composite material by ultrasonic cleaning, centrifugal separation and vacuum drying process, the frequency range of the ultrasonic cleaning is 20 kHz, the rotation speed of the centrifugal separation is 3000 rpm, the centrifugal time is 10 minutes, and the vacuum pressure of the vacuum drying is controlled at 0.01 MPa.

[0031] S5. testing the catalytic performance of the obtained composite material, which includes methanol oxidation and benzene ring hydrogenation, by adjusting the distribution of magnetic particles, the surface functionalization degree and the reaction conditions of the composite material to optimize the catalytic activity of the composite material and obtain the best reaction rate and high selectivity.

[0032] The catalytic performance test includes the following steps:

[0033] S5.1. testing the obtained composite material for methanol oxidation reaction, the reaction temperature of the methanol oxidation reaction is 150°C, the reaction time is 2 hours, and the methanol concentration is 10%, then analyzing the products of the methanol oxidation reaction by gas chromatography to determine the catalytic activity and conversion rate of the composite material in the methanol oxidation reaction.

[0034] S5.2. The obtained composite material is subjected to a benzene ring hydrogenation reaction test, the benzene ring hydrogenation reaction is carried out at a temperature of 100°C, the benzene ring hydrogenation reaction has a benzene concentration of 5%, a reaction time of 4 hours, and the hydrogenation reaction product is quantitatively and qualitatively analyzed by using gas chromatography, and the catalytic effect of the composite material is evaluated.

[0035] S5.3. According to the test results, the magnetic particle distribution, surface functionalization degree and reaction conditions of the composite material are adjusted to improve the rate, selectivity and stability of the catalytic reaction.

[0036] Example Two

[0037] As Figure 1 shown, the embodiment of the present application provides a preparation method of a magnetic silicon-based nanoflower composite carrier, which comprises: S1. uniformly dispersing a reaction mixture containing a silicon source, magnetic iron oxide nanoparticles and a surface modifier in a solvent to obtain a reaction mixture, the silicon source is dimethyldiethoxysilane, the particle size of the magnetic iron oxide nanoparticles is 5-30 nm, the surface modifier is glycine and sodium dodecylbenzenesulfonate, the solvent of the ionic liquid is hexafluorophosphate ion and 1-butyl-3-methylimidazolium amine, the molar ratio of hexafluorophosphate ion and 1-butyl-3-methylimidazolium amine is 1:1 and the concentration is 1 mol / L.

[0038] S2. The reaction mixture is treated under hydrothermal reaction conditions at 180-250°C for 8 hours to form a magnetic silicon-based nanoflower composite material, wherein the reaction temperature and time can promote the uniform distribution of the magnetic iron oxide nanoparticles on the surface of the silicon-based carrier and ensure the magnetic properties and catalytic activity of the material, the pH value of the reaction mixture is controlled at 6 to prevent unnecessary precipitation or dissolution of the silicon-based carrier and the magnetic particles during the reaction, and the stability and uniformity of the composite material are ensured.

[0039] S3. The solvent is an ionic liquid, which is used for functionalizing the surface of the composite material, significantly improving the compatibility between the magnetic particles and the silicon-based carrier, effectively preventing the aggregation of the magnetic particles into clusters, and ensuring the stability and high dispersibility of the composite material in subsequent applications. The functionalization treatment is carried out at a temperature of 80°C, and the surface functionalization degree of the composite material is between 95%.

[0040] S4. The composite material is subjected to a treatment for removing unreacted substances, which adopts ultrasonic cleaning, centrifugal separation and vacuum drying processes, the frequency range of the ultrasonic cleaning is 40 kHz, the rotation speed of the centrifugal separation is 5000 rpm, the centrifugal time is 20 minutes, and the vacuum pressure of the vacuum drying is controlled within the range of 0.1 MPa.

[0041] S5. The obtained composite material is subjected to catalytic performance test, the catalytic performance test includes methanol oxidation and benzene ring hydrogenation, by adjusting the magnetic particle distribution, surface functionalization degree and reaction condition of the composite material, the catalytic activity of the composite material is optimized, the best reaction rate and high selectivity are obtained.

[0042] The catalytic performance test includes the following steps:

[0043] S5.1. The obtained composite material is subjected to methanol oxidation reaction test, the reaction temperature of the methanol oxidation reaction is 200℃, the reaction time is 4 hours, the methanol concentration is 30%, then the product of the methanol oxidation reaction is analyzed by gas chromatography, the catalytic activity and conversion rate of the composite material in the methanol oxidation reaction are determined.

[0044] S5.2. The obtained composite material is subjected to benzene ring hydrogenation reaction test, the benzene ring hydrogenation reaction is carried out at a temperature of 150℃, the benzene ring hydrogenation reaction has a benzene concentration of 10%, a reaction time of 6 hours, and the hydrogenation reaction product is quantitatively and qualitatively analyzed by gas chromatography, the catalytic effect of the composite material is evaluated.

[0045] S5.3. According to the test results, the magnetic particle distribution, surface functionalization degree and reaction condition of the composite material are adjusted, the rate, selectivity and stability of the catalytic reaction are improved.

[0046] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a magnetic silicon-based nanoflower composite carrier, characterized in that: include: S1. The reaction mixture containing a silicon source, magnetic iron oxide nanoparticles and a surface modifier is uniformly dispersed in a solvent to obtain a reaction mixture; S2. The reaction mixture is treated under hydrothermal reaction conditions at 180°C to 250°C for a reaction time of 4 to 8 hours to form a magnetic silicon-based nanoflower composite material; S3. Solvent functionalization of the composite surface using ionic liquid; S4 the composite material is treated to remove unreacted substances, using ultrasonic cleaning, centrifugation and vacuum drying process; S5. Performing catalytic performance tests on the obtained composite material, wherein the catalytic performance tests include methanol oxidation and benzene ring hydrogenation.

2. The method for preparing a magnetic silicon-based nanoflower composite carrier according to claim 1, characterized in that: The silicon source is dimethyldiethoxysilane, the particle size of the magnetic iron oxide nanoparticles is 5 nanometers to 30 nanometers, and the surface modifiers are glycine and sodium dodecylbenzenesulfonate.

3. The method for preparing a magnetic silicon-based nanoflower composite carrier according to claim 1, characterized in that: The solvent of the ionic liquid is hexafluorophosphate ion and 1-butyl-3-methylimidazolium ammonia, the molar ratio of the hexafluorophosphate ion and 1-butyl-3-methylimidazolium ammonia is 1:1, and the concentration is 0.1 mol / L to 1 mol / L.

4. The method for preparing a magnetic silicon-based nanoflower composite carrier according to claim 1, characterized in that: The pH value of the reaction mixture is controlled at 4 to 6.

5. The method for preparing a magnetic silicon-based nanoflower composite carrier according to claim 1, characterized in that: The functionalization treatment is carried out in the range of 25° C. to 80° C., and the surface functionalization degree of the composite material is between 80% and 95%.

6. The method for preparing a magnetic silicon-based nanoflower composite carrier according to claim 1, characterized in that: The frequency range of the ultrasonic cleaning is 20kHz to 40kHz, the rotation speed of the centrifugal separation is 3000rpm to 5000rpm, and the centrifugation time is 10 minutes to 20 minutes.

7. The method for preparing a magnetic silicon-based nanoflower composite carrier according to claim 1, characterized in that: The vacuum pressure of the vacuum drying is controlled in the range of 0.01 MPa to 0.1 MPa.

8. The method for preparing a magnetic silicon-based nanoflower composite carrier according to claim 1, characterized in that: The catalytic performance test comprises the following steps: S5.

1. The obtained composite material was subjected to a methanol oxidation reaction test, wherein the reaction temperature of the methanol oxidation reaction was 150°C to 200°C, the reaction time was 2 hours to 4 hours, and the methanol concentration was 10% to 30%. The product of the methanol oxidation reaction was analyzed by gas chromatography to determine the catalytic activity and conversion rate of the composite material in the methanol oxidation reaction; S5.

2. The obtained composite material was subjected to a benzene ring hydrogenation reaction test, wherein the benzene ring hydrogenation reaction was carried out at a temperature of 100 ° C to 150 ° C, the benzene concentration of the benzene ring hydrogenation reaction was 5% to 10%, the reaction time was 4 hours to 6 hours, and the hydrogenation reaction product was quantitatively and qualitatively analyzed using gas chromatography; S5.

3. Based on the above test results, adjust the magnetic particle distribution, surface functionalization degree and reaction conditions of the composite material.

Images