Method for synthesizing silicon oxide nanostructures with different morphologies by using injection pump
By using an injection pump to control the rate of synthesis of silica nanostructures with different morphologies in colloidal solutions, the problem of asymmetric nanostructure synthesis in existing technologies has been solved, enabling simple and efficient application of asymmetric nanostructures in catalysis and biomedicine.
Patent Information
- Application Number
- CN202410615263.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-11-18
AI Technical Summary
Existing technologies are difficult to synthesize efficiently for various asymmetric nanostructures, and the synthesis steps are cumbersome, time-consuming, and the principles are unclear, which limits their application in fields such as catalysis and biomedicine.
Silica nanostructures with different morphologies were synthesized in colloidal solutions using an injection pump. The droplet growth and silica coating rate were controlled by adjusting the injection pump rate, thus achieving continuous structural transformation.
The synthesis of asymmetric nanostructures, characterized by simple operation, mild conditions, and high stability, has been achieved. These structures are suitable for nanoreactors and drug carriers, demonstrating strong practicality and broad application prospects.
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Figure CN120964828A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a technique for directly synthesizing silicon oxide with different morphologies in colloidal solutions using a syringe pump. Silica is a highly stable and biocompatible material, therefore the aforementioned structures can be applied in fields such as catalysis, biomedicine, and adsorption. Background Technology
[0002] Definition of asymmetric structures: Asymmetric nanostructures refer to nanoscale materials or structures with asymmetric shapes or compositions. This asymmetry may involve differences in shape, chemical composition, surface properties, etc. Typically, asymmetric nanostructures possess unique properties and applications because they can provide specific functions under certain conditions, such as enhancing the mechanical properties of materials, improving catalytic activity, and modulating optical properties.
[0003] Asymmetric structures: Compared with traditional symmetrical structures, asymmetric structures have several unique advantages, such as multifunctionality (simultaneously incorporating several different properties), larger effective surface area and more active sites, and stronger synergistic effects (different regions of an asymmetric structure can work independently without interfering with each other, or even cooperate to significantly improve structural performance). For example, multi-chamber structures synthesized based on asymmetric structures allow for the creation of multifunctional partitions in different chambers, enabling multiple biochemical processes to operate without interference, which is crucial for expanding the application prospects of nanoparticles in nanoreactors, catalysis, and drug delivery. For instance, a 2011 article used a pentanol-water mixture as a solvent to prepare bullet-shaped asymmetric silica nanomaterials with tunable lengths. These nanomaterials can form liquid crystal phases as well as isotropic and nematic phases, making them unique and highly suitable as a model system for real-world studies of colloidal liquid crystals (J. Am. Chem. Soc. 2011, 133, 8, 2346–2349). A 2016 article introduced the synthesis of high-strength silica nanowires in an emulsion system using octadecyltrimethoxysilane and TBOS as precursors. These nanowires can be used as building blocks for novel three-dimensional porous superhydrophobic functional materials. The constructed silica films have superhydrophobic surfaces (water contact angle greater than 150°) and can also be used as adsorbents for oil / water separation (Angewandte Chemie International Edition, 2016, 55(29): 8375-8380.). A 2022 article proposed a nanodroplet reconstruction strategy for the synthesis of hierarchical multi-chamber mesoporous silica nanoparticles with tunable chamber numbers (from single-chamber to three-chamber nanostructures). This nanodroplet reconstruction strategy can promote the selective assembly of functional units (Fe3O4, Pd, Pt, etc.) in multi-chamber nanoparticles. The authors constructed a dual-chamber nanoreactor with Au nanocrystals anchored in the first chamber and Pd nanocrystals anchored in the second chamber for the synthesis of 2-phenylindole via a 1-nitro-2-(phenylethynyl)benzene cascade reaction. Due to the different spatial distribution of catalytic active centers, the dual-chamber nanoreactor exhibited excellent catalytic performance in the cascade reaction synthesis of 2-phenylindole, with a selectivity as high as 76.5%, which is 1.85 times (approximately 41.3%) that of the single-chamber nanoreactor. Simulation results show that the dual-chamber structure can ensure efficient mass transfer between reactants and intermediates, thus improving the selectivity for the 2-phenylindole product (Nature Communications 2022, 3, number: 6136). Asymmetric structures have very broad application prospects; however, the above methods are relatively limited, only capable of synthesizing a single specific structure and lacking universality. Furthermore, some methods involve cumbersome steps, are relatively time-consuming, and lack a clear understanding of the underlying synthetic principles. Summary of the Invention
[0004] This invention relates to a technique for synthesizing silica nanostructures with different morphologies directly in colloidal solutions using an injection pump. Firstly, this technique is simple to operate and allows for batch synthesis. Secondly, the synthesis conditions are mild, the stability is good, and the morphology is tunable; the structures can be directly used in nanoreactors and drug carriers, demonstrating strong practicality.
[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is: a method for preparing silicon oxide nanostructures with different morphologies using an injection pump, characterized in that: the method can be carried out in the following steps sequentially:
[0006] (1) The mixed solution (ethanol / octanol) is thickened with a thickener, that is, the reaction system is a mixed solution thickened with polyvinylpyrrolidone;
[0007] (2) Add an ammonia solution of sodium citrate to the solution in step (1) to induce phase separation and generate nanodroplets;
[0008] (3) In step (2), tetraethyl orthosilicate (TEOS) is added to nucleate and coat the droplet surface. By controlling the rates of both, silicon oxide structures with different morphologies can be obtained.
[0009] (4) Introduce an injection pump into the solution in step (3) and synthesize silicon oxide structures with different morphologies by adjusting the rate at which water or TEOS is added by the injection pump.
[0010] Preferably, the reaction system in step (1) is a mixed solution thickened with polyvinylpyrrolidone (PVP = 100 mg / ml); in step (2), a 0.2 M sodium citrate solution with 6 M ammonia is added to induce phase separation and generate nanodroplets.
[0011] Preferably, in step (1) the ethanol / octanol (volume ratio = 3:2) and in step (2) the amount of sodium citrate ammonia solution added is 50 μL. After 10 min intervals, the morphology of silica is adjusted by injecting pure water. The injection rate depends on the water addition rate. If a hollow sphere structure is required, the injection rate is 0 μL / min. If a hollow teardrop structure is desired, the injection rate is 1-4 μL / min (total injection volume is 40 μL). If a bottle structure is desired, the injection rate is 8 μL / min (total injection volume is 40 μL).
[0012] Preferably, in step (1) the ethanol / octanol (volume ratio = 1:4) and in step (2) the amount of sodium citrate ammonia solution added is 30 μL. The morphology of silica is adjusted immediately by injecting TEOS, depending on the injection rate of TEOS. If a tadpole-shaped structure is desired, the injection rate is 0 μL / min. If a hollow teardrop structure is desired, the injection rate is 8-64 μL / min (total injection volume is 200 μL). If a spherical structure is desired, the injection rate is 100 μL / min (total injection volume is 200 μL).
[0013] To solve the above-mentioned technical problems, another technical solution of the present invention is to prepare silicon oxide nanostructures with different morphologies using an injection pump.
[0014] Beneficial effects:
[0015] 1. This invention is a technique for preparing silica nanostructures with different morphologies using an injection pump. The morphology of the structure can be adjusted using the injection pump, allowing for the synthesis of structures with specific morphologies for specific applications.
[0016] 2. In this invention, the morphological transformation of the structure can be achieved by increasing the droplet growth rate by accelerating the injection water addition rate, thereby realizing the continuous transformation of the structure from spherical to teardrop shape, bottle shape and bullet shape in the same system.
[0017] 3. In this invention, the morphological transformation of the structure can be achieved by increasing the droplet growth rate by accelerating the injection rate of TEOS, thereby realizing a continuous transformation of the structure from spherical to teardrop shape, bottle shape and bullet shape in the same system.
[0018] 4. The resulting teardrop-shaped and bottle-shaped asymmetric structures conform to hydrodynamic configurations and have higher transport efficiency in the fields of drug delivery and nanorobotics.
[0019] 5. This invention can synthesize specific structures as needed, including open, closed, asymmetric, etc., to meet different application requirements.
[0020] 6. The core of this invention is to regulate the interaction between the droplet growth rate and the silica coating rate; to achieve a continuous transformation of the structure from spherical to teardrop-shaped, and then to bottle-shaped.
[0021] 7. The asymmetric structure obtained by this invention can be further grown, such as the bottle-shaped nanostructure can be further grown into nanowires. It can be used as a building block of special hydrophobic materials for adsorption, filtration and other applications, and has broad application prospects.
[0022] 8. In this invention, a continuous transformation of morphology is achieved by precisely controlling the injection rates of water and TEOS using an injection pump. The inverse trend of the TEOS injection rate and the water injection rate implies an interaction between the two factors. To best explain the underlying mechanism, it is helpful to first consider the following two extreme cases, where the interaction is not yet a key factor: In experiments without subsequent injections (injection rate of 0).
[0023] ( Figure 1 a) The droplets exist in a spherical shape with minimal surface energy, and after being coated with silica, they form hollow nanospheres. At the other extreme ( Figure 1 At very high TEOS implantation rates (100 μL / min), silica encapsulation becomes sufficiently effective to coat the droplet surface before the liquid growth domain extends, possibly through an initial thin silica layer. In both cases, the interacting factors (droplet growth and silica encapsulation) are largely misaligned. That is, the droplet forms first, followed by silica passivation, and the resulting product does not exhibit symmetry disruption. Figure 3 Using these two scenarios as a reference, faster water injection rates or lower TEOS supplies lead to greater extension of the droplet growth domain, resulting in increased neck length. Attached Figure Description
[0024] Figure 1 The morphological transformation was controlled by adjusting the injection rate of the syringe pump. TEM images of TEOS were obtained at injection rates of 0, 1, 4, and 8 μL / min, respectively. TEM images of the TEOS were obtained at injection rates of 0, 8, 64, and 100 μL / min, respectively.
[0025] Figure 2 The morphological transformation was controlled by adjusting the injection rate of the syringe pump. TEM images of ab under no-stirring conditions at water injection rates of 1 and 4 μL / min, respectively.
[0026] Figure 3 This is a schematic diagram of droplet growth and silicon oxide coating, where the droplet growth rate (V) is shown. E ) and silicon oxide coating rate (V P The interaction between the two elements determines the geometry of the product. Detailed Implementation
[0027] Example 1:
[0028] A method for preparing silica nanostructures with different morphologies using an injection pump, the method comprising the following steps:
[0029] (1) Thicken 1 mL of mixed alcohol (ethanol / octanol (v / v) = 3:2) with a thickener, i.e., the reaction system is a mixed solution thickened with polyvinylpyrrolidone (PVP = 100 mg / ml);
[0030] (2) Add 50 μL of sodium citrate (0.2 M) in ammonia (6 M) solution to the solution in step (1) to induce phase separation and generate nanodroplets;
[0031] (3) Add 10 μL of tetraethyl orthosilicate (TEOS) to step (2) so that silicon dioxide can be nucleated and gradually coated on the surface of the droplet. After reacting for 10 min.
[0032] (4) Introduce an injection pump into the solution in step (3), and under stirring conditions (50 rpm), control the rate of water injection to regulate the rate of droplet growth and silica coating to synthesize silica structures with different morphologies.
[0033] Figure 1 The images in the figure are TEM images taken at injection rates of 0, 1, 4, and 8 μL / min (total injection volume of 40 μL), respectively. Figure 1 As can be seen, the asymmetry of the structure becomes more pronounced with increasing injection rate, transforming from a spherical shape to a teardrop shape and a bottle-shaped structure. If a spherical structure is desired, the injection rate is 0 μL / min; if a hollow teardrop structure is desired, the injection rate is 1–4 μL / min (total injection volume 40 μL); and if a bottle-shaped structure is desired, the injection rate is 8 μL / min (total injection volume 40 μL).
[0034] Example 2:
[0035] A method for preparing silica nanostructures with different morphologies using an injection pump, the method comprising the following steps:
[0036] (1) Thicken 1 mL of mixed alcohol (ethanol / octanol (v / v) = 1:4) with a thickener, i.e., the reaction system is a mixed solution thickened with polyvinylpyrrolidone (PVP = 100 mg / ml);
[0037] (2) Add 30 μL of sodium citrate (0.2 M) in ammonia (6 M) solution to the solution in step (1) to induce phase separation and generate nanodroplets;
[0038] (3) Add 10 μL of tetraethyl orthosilicate (TEOS) in step (2) to allow silicon dioxide to nucleate and gradually coat the droplet surface.
[0039] (4) Introduce an injection pump into the solution in step (3), and synthesize silicon oxide structures with different morphologies by controlling the injection rate of TEOS to regulate the rates of droplet growth and silicon oxide coating under stirring conditions (50 rpm).
[0040] Figure 1 TEM images of the product at concentrations of 0, 8, 64, and 100 μL / min (total injection volume of 200 μL). From the above... Figure 1 As can be seen from the results, the symmetry of the structure becomes more pronounced with increasing injection rate, transforming from a bottle-shaped to a teardrop-shaped and spherical structure. This trend is opposite to that of water injection, indicating that the water addition rate is proportional to the droplet growth rate; the TEOS addition rate is proportional to the silica coating rate.
[0041] The morphology of silica adjusted by injecting TEOS in step (4) depends on the injection rate of TEOS; if a bottle-shaped structure is desired, the injection rate is 0 μL / min; if a hollow teardrop-shaped structure is desired, the injection rate is 8–64 μL / min (total injection volume is 200 μL); and if a spherical structure is desired, the injection rate is 100 μL / min (total injection volume is 200 μL).
[0042] Example 3:
[0043] A method for preparing silica nanostructures with different morphologies using an injection pump, the method comprising the following steps:
[0044] (1) Thicken 1 mL of mixed alcohol (ethanol / octanol (v / v) = 3:2) with a thickener, i.e., the reaction system is a mixed solution thickened with polyvinylpyrrolidone (PVP = 100 mg / ml);
[0045] (2) Add 50 μL of sodium citrate (0.2 M) in ammonia (6 M) solution to the solution in step (1) to induce phase separation and generate nanodroplets;
[0046] (3) Add 10 μL of tetraethyl orthosilicate (TEOS) to step (2) to allow silicon dioxide to nucleate and gradually coat the droplet surface, and react for 10 min.
[0047] (4) Introduce an injection pump into the solution in step (3). Under no stirring conditions, control the rate of water injection to regulate the rate of droplet growth and silicon oxide coating to synthesize silicon oxide structures with different morphologies.
[0048] Figure 2 The images shown in the figures are TEM images taken at injection rates of 1 μL / min and 4 μL / min (total injection volume of 40 μL), respectively. Figure 2It can be seen that as the injection rate increases, spherical, teardrop-shaped and bottle-shaped nanostructures appear simultaneously in the product, indicating that stirring itself does not affect the morphology, but only allows each droplet to be evenly distributed with water for growth.
[0049] A continuous morphological transformation was achieved by precisely controlling the injection rates of water and TEOS using a syringe pump. The inverse trend of the TEOS injection rate to the water injection rate implies an interaction between the two factors. To best explain the underlying mechanism, it is helpful to first consider the following two extreme cases, where the interaction is not yet a key factor. In the experiment without subsequent injections (injection rate of 0)... Figure 1 a) The droplets exist in a spherical shape with minimal surface energy, and after being coated with silica, they form hollow nanospheres. At the other extreme ( Figure 1 At very high TEOS implantation rates (100 μL / min), silica encapsulation becomes sufficiently effective to coat the droplet surface before the liquid growth domain extends, possibly through an initial thin silica layer. In both cases, the interacting factors (droplet growth and silica encapsulation) are largely misaligned. That is, the droplet forms first, followed by silica passivation, and the resulting product does not exhibit symmetry disruption. Figure 3 Using these two scenarios as a reference, faster water injection rates or lower TEOS supplies lead to greater extension of the droplet growth domain, resulting in increased neck length.
[0050] Finally, it should be emphasized that the range of technical parameters such as concentration, volume, and solvent ratio mentioned in this invention is adjustable and not limited to the actual parameters mentioned herein. Furthermore, the above detailed description of this invention is for illustrative purposes only and is not intended to limit it to the specific examples described. Those skilled in the art should understand that any modifications or equivalent substitutions to this invention to achieve the same technical effect are within the scope of protection of this invention.
Claims
1. A method for synthesizing different morphologies of silicon oxide nanostructures using a syringe pump, characterized by: The method comprises the following steps: (1) thickening the mixed solution ethanol / octanol with a thickening agent, i.e. the reaction system is a mixed solution thickened by polyvinylpyrrolidone; (2) adding an ammonia solution of sodium citrate to the solution in step (1) to induce phase separation to generate nanodroplets; (3) adding tetraethyl orthosilicate (TEOS) in step (2) to nucleate and coat on the surface of the droplets; (4) introducing a syringe pump in the solution in step (3) to synthesize silicon oxide structures with different morphologies by adjusting the rate of adding TEOS or water by the syringe pump.
2. The method for synthesizing different morphologies of silicon oxide nanostructures using a syringe pump according to claim 1, wherein: The method comprises the following steps: The reaction system in step (1) is a mixed solution thickened by polyvinylpyrrolidone (PVP = 100 mg / ml); In step (2), an ammonia solution of sodium citrate 0.2 M is added to induce phase separation to generate nanodroplets.
3. The method for synthesizing different morphologies of silicon oxide nanostructures using a syringe pump according to claim 2, wherein: The volume ratio of the mixed solution in step (1), the ammonia solution of sodium citrate in step 2 and the tetraethyl orthosilicate in step 3 is 100:5:1; the mixed solution is 1 mL, and the adjustment of the morphology of silicon oxide by adding water by injection in step (4) depends on the injection rate of water; if a spherical structure is needed, the injection rate is 0 μL / min, if a hollow tear drop structure is needed, the injection rate is 1-4 μL / min (the total injection amount is 40 μL), and if a bottle structure is needed, the injection rate is 8 μL / min (the total injection amount is 40 μL).
4. The method for synthesizing different morphologies of silicon oxide nanostructures using a syringe pump according to claim 3, wherein: The volume ratio of ethanol to octanol in the mixed solution is 3:2, and the volume ratio of the ammonia solution of sodium citrate to the mixed solution is 1:
20.
5. The method for synthesizing different morphological silica nanostructures using a syringe pump according to claim 2, wherein: The volume ratio of the mixed solution in step (1), the ammonia solution of sodium citrate in step 2 and the tetraethyl orthosilicate in step 3 is 100:3:1; the mixed solution is 1 mL, and the adjustment of the morphology of silicon oxide by adding TEOS by injection in step (4) depends on the injection rate of TEOS; if a bottle structure is needed, the injection rate is 0 μL / min, if a hollow tear drop structure is needed, the injection rate is 8-64 μL / min (the total injection amount is 200 μL), and if a spherical structure is needed, the injection rate is 100 μL / min (the total injection amount is 200 μL).
6. The method for synthesizing different morphological silica nanostructures using a syringe pump according to claim 5, wherein: The volume ratio of ethanol to octanol in the mixed solution is 1:4, and the volume ratio of the ammonia solution of sodium citrate to the mixed solution is 3:100.