Manganese-based chiral enantiomeric nanowires and methods of making the same
Manganese-based chiral enantiomeric nanowires were synthesized via an amino acid-induced hydrothermal reaction, solving the problem of chiral signal modulation in the visible and near-infrared regions of existing chiral nanomaterials, and achieving symmetrical circular dichroism optical response and large-scale production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2024-11-27
- Publication Date
- 2026-05-29
AI Technical Summary
Existing technologies struggle to effectively control the enantiomeric structure and chiral signal of chiral nanomaterials in the visible and near-infrared regions.
Manganese-based chiral enantiomeric nanowires were synthesized via a hydrothermal reaction using an amino acid-induced method and a cationic surfactant as a template agent, mixed with a manganese source and a chiral ligand under alkaline conditions.
The prepared manganese-based chiral enantiomeric nanowires exhibit good chiral optical response in the visible and near-infrared regions, possess symmetrical circular dichroism optical properties, and are easy to mass-produce.
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Figure CN122103035A_ABST
Abstract
Description
Technical Field
[0001] This application relates to a manganese-based chiral enantiomeric nanowire and its preparation method, belonging to the field of nanomaterial synthesis technology. Background Technology
[0002] Chirality research is an important field in chemistry and biology, primarily studying chiral phenomena in molecular structure and their applications across various domains. Chiral molecules are those that cannot be superimposed on their mirror image by rotation or flipping; they typically exhibit distinct physical, chemical, and biological activities. In biological systems, many key molecules, such as amino acids, carbohydrates, and drugs, are chiral, thus chirality has a profound impact on life processes. Chirality research encompasses the synthesis of chiral molecules, the development of chiral catalysts, the application of chiral separation techniques, and their importance in drug design, materials science, and biorecognition. Developments in this field provide a crucial scientific foundation for the precise regulation of chemical reactions, improved drug efficacy, and the design of novel materials.
[0003] Chiral nanomaterials are nanoscale materials with chiral structures and properties. They can interact uniquely with polarized light, exhibiting optical properties such as circular dichroism (CD). They hold broad application prospects in fields such as chiral recognition, drug delivery, sensors, and molecular detection. Particularly in the biomedical field, chiral nanomaterials, due to their chirality matching with biomolecules, can improve drug targeting and reduce side effects. Through self-assembly, template methods, or directed synthesis, scientists can control the chiral structure of these materials, thereby modulating their physical and chemical properties.
[0004] Chiral nanowires are fundamental to the development of novel functional materials. By precisely controlling chiral structures, various electrical, optical, and magnetic properties of materials can be modulated, opening up new research directions for fields such as spintronics, nanoelectronic devices, and optoelectronic devices. They can also self-assemble into nanostructures or superstructures with complex functions, expanding the possibilities of material design.
[0005] Manganese is an abundant and readily available element in the Earth's crust, and compared to rare or precious metals, manganese-based materials have the advantage of low cost. Manganese-based nanomaterials, such as manganese oxides (MnO, MnO2) and manganese ferrites, typically possess good magnetic properties and tunable magnetization. This makes them promising for applications in magnetic memories, spintronics, and magnetic nanodevices. Furthermore, manganese-based nanomaterials can be used as contrast agents in magnetic resonance imaging (MRI) due to their ability to provide a strong magnetic response. They have significant research and application value in multiple fields, including energy, environment, catalysis, and biomedicine. Summary of the Invention
[0006] To address the problems of mirror symmetry of enantiomeric structures and difficulty in controlling chiral signals in the visible and near-infrared regions in existing technologies for preparing chiral nanomaterials, this application proposes a technique for preparing chiral nanowires using amino acid induction. The synthetic method is simple, the product has a uniform morphology, and it is easy to achieve large-scale preparation. The prepared manganese-based chiral enantiomeric nanowires have a symmetrical circular dichroism optical response.
[0007] The technical solution adopted in this application is as follows:
[0008] According to a first aspect of this application, a method for preparing manganese-based chiral enantiomeric nanowires is provided, comprising the following steps:
[0009] An alkaline aqueous solution containing a mixture of template agent, manganese source, chiral ligand, and base is placed in a sealed container and reacted to obtain the manganese-based chiral enantiomer nanowires.
[0010] The chiral ligand is selected from L-histidine and / or D-histidine;
[0011] The template agent is selected from cationic surfactants.
[0012] Optionally, the preparation method specifically includes the following steps:
[0013] An aqueous solution containing a template agent, an aqueous solution containing a chiral ligand, and an alkaline solution are stirred and pre-reacted. Then, an aqueous solution containing a manganese source is added to obtain an alkaline aqueous solution of the mixture. The alkaline aqueous solution of the mixture is placed in a sealed container and reacted to obtain the manganese-based chiral enantiomer nanowires.
[0014] The chiral ligand is selected from L-histidine and / or D-histidine;
[0015] The template agent is selected from cationic surfactants.
[0016] Optionally, the cationic surfactant is selected from at least one of hexadecyltrimethylammonium bromide and hexadecyltrimethylammonium chloride.
[0017] Optionally, the manganese source is selected from at least one of potassium permanganate and potassium manganate.
[0018] Optionally, the alkali is selected from at least one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, and sodium carbonate.
[0019] Optionally, the pH of the alkaline aqueous solution of the mixture is 9 to 11.
[0020] Optionally, the concentration of the manganese source aqueous solution is 3 to 9 mg / mL.
[0021] Optionally, the concentration of the manganese source aqueous solution is selected from any value of 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 7 mg / mL, 8 mg / mL, 9 mg / mL, or a range between any two of the above.
[0022] Optionally, the concentration of the chiral ligand aqueous solution is 15–30 mg / mL.
[0023] Optionally, the concentration of the chiral ligand aqueous solution is selected from any value of 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, 35 mg / mL, or a range between any two of the above.
[0024] Optionally, the concentration of the template agent aqueous solution is 5–10 mg / mL.
[0025] Optionally, the concentration of the template agent aqueous solution is selected from any value of 5 mg / mL, 6 mg / mL, 7 mg / mL, 8 mg / mL, 9 mg / mL, 10 mg / mL, or a range between any two of the above.
[0026] Optionally, the volume ratio of the template agent aqueous solution, the manganese source aqueous solution, the chiral ligand aqueous solution, and the alkaline solution is (1-5):(1-10):1:(0.5-4).
[0027] Optionally, the volume ratio of the manganese source aqueous solution to the chiral ligand aqueous solution is selected from any value among 10:1, 8:1, 6:1, 4:1, 2:1, 1:1 or any range between the two.
[0028] Optionally, the conditions for the stirring pre-reaction include: a stirring speed of 200–800 rpm / min and a stirring pre-reaction time of 5–20 min.
[0029] Optionally, the stirring speed is selected from any value of 400 rpm / min, 500 rpm / min, 600 rpm / min, 700 rpm / min, 800 rpm / min or a range between any two of the above.
[0030] Optionally, the reaction conditions include: a reaction temperature of 40–120°C and a reaction time of 2–6 h.
[0031] Optionally, the reaction temperature is selected from any value of 40℃, 80℃, 90℃, 100℃, 110℃, 120℃ or a range between any two of the above.
[0032] Optionally, the reaction time is selected from any value of 4h, 5h, 6h, 7h, 8h or a range between any two of the above.
[0033] According to another aspect of this application, a manganese-based chiral enantiomer nanowire prepared by the above method is provided, wherein the characteristic peak of the circular dichroism spectral signal of the manganese-based chiral enantiomer nanowire is 400-450.
[0034] Optionally, the asymmetry factor g of the manganese-based chiral enantiomeric nanowire is 0.005-0.008.
[0035] Optionally, the manganese-based chiral enantiomeric nanowires have a diameter of 50–200 nm and a length greater than 1 μm.
[0036] The beneficial effects of this application include:
[0037] The manganese-based chiral enantiomeric nanowires and their preparation method provided in this application are both synthesized in a hydrothermal reactor, which is simple to operate, has stable optical properties, and is easy to scale up. The prepared chiral manganese-based nanowires have a certain helical chiral configuration, and the histidine chiral ligand induces chiral optical responses in both the visible and near-infrared regions. The two types of manganese-based superparticles with L and D configurations synthesized exhibit good chiral optical activity in the visible region, and their circular dichroism spectra show excellent symmetry. This is of great research significance for preparing enantiomeric chiral nanowires using surfactants as templates and for studying the assembly mechanism of chiral ligand-induced chiral nanomaterials. Attached Figure Description
[0038] Figure 1 The image shown is a scanning electron microscope (SEM) image of the L-histidine-induced manganese-based nanowires prepared in Example 1 of this application. The scale bar is 1.00 μm.
[0039] Figure 2 The image shown is a scanning electron microscope (SEM) image of the manganese-based nanowires synthesized by D-histidine induced synthesis prepared in Example 1 of this application. The scale bar is 1.00 μm.
[0040] Figure 3 The circular dichroism spectra of the manganese-based nanowires synthesized by L-histidine and D-histidine in Example 2 of this application are shown.
[0041] Figure 4 The images show the absorption spectra of the manganese-based nanowires synthesized by L-histidine and D-histidine in Example 2 of this application.
[0042] Figure 5 The images show the g-factor spectra of the manganese-based nanowires synthesized by L-histidine and D-histidine in Example 2 of this application.
[0043] Figure 6The images show the infrared spectra of the manganese-based nanowires synthesized by L-histidine and D-histidine in Example 2 of this application.
[0044] Figure 7 The images show the X-ray diffraction spectra of the manganese-based nanowires synthesized by L-histidine and D-histidine in Example 2 of this application. Detailed Implementation
[0045] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0046] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0047] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.
[0048] Circular dichroism spectroscopy characterization: Circular dichroism spectroscopy was performed using a J1500 circular dichroism spectrometer from Japan Spectrophotometer Co., Ltd., with a detection wavelength range of 200-800 nm. Ultraviolet-visible absorption spectra were also collected simultaneously.
[0049] Scanning electron microscopy characterization: Scanning electron microscopy (SEM) images were taken using a JEOL JSM-7610Plus with an accelerating voltage of 5 kV.
[0050] Fourier transform infrared spectroscopy characterization: Fourier transform infrared spectra were measured using an INVENIO S infrared spectrometer from Bruker Instruments, Germany, with a detection wavelength range of 400-4000 nm.
[0051] X-ray diffraction spectroscopy characterization: X-ray diffraction spectra were measured using Empyream X-ray diffraction spectroscopy from Malvern Panaco Instruments Ltd., UK, with a detection angle of 5-90°.
[0052] As a specific implementation method, this application is achieved through the following technical solution:
[0053] A method for preparing chiral manganese-based nanowire materials induced by cationic surfactants includes the following steps: using hexadecyltrimethylammonium bromide as a template agent, L-histidine and D-histidine as chiral inducers, and potassium permanganate as a manganese source, chiral manganese-based enantiomeric nanowires are obtained through hydrothermal reaction under alkaline conditions.
[0054] Furthermore, the synthesis method specifically includes the following steps:
[0055] S1. Adjust the concentration of the surfactant cetyltrimethylammonium bromide in the solution, control the amount of L-histidine or D-cystine chiral ligand added, adjust the pH value of the reaction system with sodium hydroxide, then add an aqueous solution of potassium permanganate, stir evenly, and place it in a hydrothermal reactor. Under the conditions of 80-120℃, the reaction time is 4-8h to obtain the reaction solution of manganese-based chiral enantiomeric nanowires.
[0056] S2. The obtained final product was purified by centrifugation to obtain the manganese-based chiral enantiomeric nanowires.
[0057] Further, in step S1, in the presence of the surfactant hexadecyltrimethylammonium bromide, when the potassium permanganate solution reacts with L-histidine and D-histidine solutions respectively, the pH of the L-histidine and D-histidine solutions is adjusted to 9-11, and the alkaline solution is a sodium hydroxide solution, a potassium hydroxide solution, or a sodium carbonate solution.
[0058] In this invention, during specific operation, an aqueous solution of potassium permanganate can be prepared at room temperature, followed by aqueous solutions of L-histidine and D-histidine. A cetyltrimethylammonium bromide solution is prepared in a 60°C water bath to promote the dissolution of the surfactant. The prepared surfactant and L-cysteine or D-cysteine solution are then added sequentially to an Erlenmeyer flask containing ultrapure water. The pH of the reaction system is adjusted to 9-11 with sodium hydroxide solution. Finally, potassium permanganate solution is added, and the mixture is magnetically stirred at room temperature for 5-10 minutes. The mixture is then transferred to a hydrothermal reactor and placed in a constant temperature drying oven for reaction. The final reaction product is observed to be brownish-black in color.
[0059] Example 1: Preparation of chiral cystine-induced manganese-based chiral enantiomeric nanowires
[0060] (1) Weigh 3.6g of hexadecyltrimethylammonium bromide powder and dissolve it in 100mL of ultrapure water. Weigh 80mg of potassium permanganate solid powder and dissolve it in 50mL of ultrapure water. Then, prepare 100mM L-histidine and D-histidine aqueous solutions respectively. Weigh 160mg of each chiral ligand and dissolve them in 10mL of water respectively. Weigh 40mg of sodium hydroxide and dissolve it in 10mL of ultrapure water. Then, add 1.5mL of the prepared hexadecyltrimethylammonium bromide solution and L-histidine or D-histidine... 0.5 mL of amino acid solution and 0.5 mL of sodium hydroxide solution were added to a glass bottle containing 3 mL of ultrapure water. The mixture was stirred magnetically for 10 minutes, then 4.5 mL of potassium permanganate was added and stirred for 5 minutes. The entire solution was then transferred to a 25 mL hydrothermal reactor and reacted at 100 °C for 4 hours to obtain L-type chiral manganese-based nanowires (labeled Mn-L-His) and D-type chiral manganese-based nanowires (labeled Mn-DHis). The solution was observed to be brownish-black in color.
[0061] (2): The L-type and D-type chiral manganese-based nanowires were obtained by centrifugation. The centrifugation speed was 7000 rpm for 10 minutes. The supernatant was removed to obtain L-type chiral manganese-based nanowires and D-type chiral manganese-based nanowire precipitates, respectively (the precipitates were resuspended in ultrapure water and could be used for circular dichroism spectroscopy and morphological characterization by scanning electron microscopy).
[0062] (3) Drying: The obtained L-type and D-type chiral manganese-based nanowires were separated by centrifugation. The centrifugation speed was 7000 rpm for 10 minutes. The supernatant was removed and the precipitate was dried in a vacuum drying oven at 60℃ to obtain solid powders of L-type manganese-based chiral enantiomer nanowires and D-type manganese-based chiral enantiomer nanowires (the solid powders can be used for Fourier transform infrared spectroscopy and X-ray diffraction spectroscopy characterization).
[0063] Test Example 1: Characterization Method of Chiral Amino Acid Analog-Induced Manganese-Based Chiral Enantiomer Nanowires
[0064] Scanning electron microscopy characterization: The chiral manganese-based nanowires obtained by centrifugation purification were resuspended in ultrapure water and diluted to a concentration of 0.5 mg / mL. 8 μL of the solution was dropped onto a silicon wafer surface and allowed to stand until the water completely evaporated. The wafer was then dried under an infrared lamp for 2 minutes, and its morphology was observed under a cold field scanning electron microscope at 3-5 kV. (SEM image of L-histidine-involved nanowires). Figure 1 Electron micrograph of materials synthesized with D-histidine ( Figure 2 Its diameter is 50–200 nm, and its length is greater than 1 μm. From Figure 1 and Figure 2 It can be seen that L-histidine and D-histidine are involved in the synthesis of nanowires with similar diameters and lengths, exhibiting a certain helical orientation. Furthermore, the scanning electron microscopy results of L-type and D-type materials show a certain loose and porous structure.
[0065] Circular dichroism spectroscopy characterization: The chiral manganese-based nanowires obtained by centrifugation purification were resuspended in ultrapure water and diluted to 0.2 mg / mL. Using ultrapure water as the baseline background, the scanning wavelength range was 200 to 800 nm, and the scanning speed was 0.5 s / nm. Circular dichroism, UV-Vis absorption spectra, and g-factor diagrams of the materials synthesized with L-histidine and D-histidine were obtained. Figure 3 , Figure 4 and Figure 5 ),from Figure 3 and Figure 5It can be seen that the chiral optical signals generated by the nanowires synthesized with L-histidine and D-histidine exhibit symmetry and the characteristic peaks appear at the same positions, showing obvious circular dichroism characteristic peaks at wavelengths of 400-450 nm. Furthermore, the circular dichroism spectra and g-factor spectra of the chiral nanowires synthesized with L-histidine and D-histidine show a symmetrical distribution. Figure 4 It can be seen that the material has obvious absorption characteristic peaks in the range of 200-500nm.
[0066] Fourier transform infrared spectroscopy and X-ray electron diffraction characterization: The powder obtained by vacuum drying of the chiral manganese-based nanowires purified by centrifugation was used to determine the infrared spectrum. Figure 6 ) and X-ray electron diffraction spectroscopy ( Figure 7 ),from Figure 6 It can be seen that the carboxyl group (1650 cm⁻¹) in the chiral ligand histidine (L-His) -1 The synthesized manganese-based nanowires, which participate in the reaction, have a crystal structure similar to that of manganese oxide, as indicated by X-ray electron diffraction.
[0067] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing manganese-based chiral enantiomeric nanowires, characterized in that, Includes the following steps: An alkaline aqueous solution containing a mixture of template agent, manganese source, chiral ligand, and base is placed in a sealed container and reacted to obtain the manganese-based chiral enantiomer nanowires. The chiral ligand is selected from L-histidine and / or D-histidine; The template agent is selected from cationic surfactants.
2. The preparation method according to claim 1, characterized in that, The preparation method specifically includes the following steps: An aqueous solution containing a template agent, an aqueous solution containing a chiral ligand, and an alkaline solution are stirred and pre-reacted. Then, an aqueous solution containing a manganese source is added to obtain an alkaline aqueous solution of the mixture. The alkaline aqueous solution of the mixture is placed in a sealed container and reacted to obtain the manganese-based chiral enantiomer nanowires. The chiral ligand is selected from L-histidine and / or D-histidine; The template agent is selected from cationic surfactants.
3. The preparation method according to claim 2, characterized in that, The cationic surfactant is selected from at least one of hexadecyltrimethylammonium bromide and hexadecyltrimethylammonium chloride.
4. The preparation method according to claim 2, characterized in that, The manganese source is selected from at least one of potassium permanganate and potassium manganate.
5. The preparation method according to claim 2, characterized in that, The alkali is selected from at least one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, and sodium carbonate.
6. The preparation method according to claim 2, characterized in that, The pH of the alkaline aqueous solution of the mixture is 9 to 11.
7. The preparation method according to claim 2, characterized in that, The concentration of the manganese source aqueous solution is 3–9 mg / mL; Preferably, the concentration of the chiral ligand aqueous solution is 15–30 mg / mL; Preferably, the concentration of the template agent aqueous solution is 5-10 mg / mL; Preferably, the volume ratio of the template agent aqueous solution, the manganese source aqueous solution, the chiral ligand aqueous solution, and the alkaline solution is (1-5):(1-10):1:(0.5-4).
8. The preparation method according to claim 2, characterized in that, The conditions for the stirring pre-reaction include: a stirring speed of 200-800 rpm / min and a stirring pre-reaction time of 5-20 min; Preferably, the reaction conditions include: a reaction temperature of 40–120°C and a reaction time of 2–6 h.
9. The manganese-based chiral enantiomeric nanowires obtained by the preparation method according to any one of claims 1 to 8, characterized in that, The characteristic peak of the circular dichroism spectral signal of the manganese-based chiral enantiomer nanowire is 400–450. Preferably, the asymmetry factor g of the manganese-based chiral enantiomeric nanowire is 0.005-0.
008.
10. The manganese-based chiral enantiomeric nanowire according to claim 9, characterized in that, The manganese-based chiral enantiomeric nanowires have a diameter of 50–200 nm and a length greater than 1 μm.