A method for preparing fluorescent chiral helical nanoribbons by hydrothermal reaction of 4-APA
Fluorescent chiral helical nanoribbons were prepared by hydrothermal reaction of 4-APA, which solved the problems of instability and synthesis complexity of CPL polymer materials, and achieved stable luminescence performance and optical chiral signal, thus promoting their application in optoelectronic display and information encryption fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YANGZHOU UNIV
- Filing Date
- 2023-09-18
- Publication Date
- 2026-05-26
AI Technical Summary
Existing CPL polymer materials suffer from structural and performance instability and synthetic complexity, making it difficult to achieve single-chiral structures and high quantum yields. Furthermore, the fluorescence quenching properties of chiral polyaniline nanomaterials limit their applications.
Fluorescent chiral helical nanoribbons were prepared by a one-step hydrothermal reaction using 4-aminophthalic acid (4-APA) as a precursor. By controlling the reaction conditions such as concentration, temperature and time, a stable helical structure and luminescence properties were formed.
A fluorescent chiral helical nanoribbon was prepared that is simple to operate, low in cost, and environmentally friendly. It has stable luminescence properties and obvious optical chiral signal, and is suitable for optoelectronic display and information encryption fields.
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Figure CN117285473B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of chemistry and materials science and technology, specifically relating to a method for preparing fluorescent chiral helical nanoribbons by hydrothermal reaction of 4-APA. Background Technology
[0002] Due to their optical activity, circular dichroism, and selective emission of polarized light, circularly polarized luminescent (CPL) materials are considered the core of many optical and electronic devices, with enormous application prospects in three-dimensional imaging, information storage, biological probes, and spintronic devices. Therefore, CPL materials have gradually become a new research hotspot in the field of chirality in recent years. Luminescence and chirality are the two fundamental elements of a material exhibiting CPL properties, and the key to constructing CPL materials is the chiral arrangement of the luminescent units. Researchers have used various techniques to arrange or assemble different luminescent units into chiral structures, and have developed metal complexes, small organic molecules, supramolecular systems, and polymer materials with CPL properties. Among them, the luminescent units of polymer materials are linked by covalent bonds, giving them the advantage of stable luminescence performance; furthermore, they exhibit higher quantum yields than other materials only in the solution state. With asymmetry factor (g) lum Unlike other materials, polymer materials are easier to process into films, and the CPL properties of these films are even stronger, making them the most likely CPL materials to be applied to related devices.
[0003] Although significant progress has been made in the research of CPL polymers in recent years, much work remains to be done before these materials can be applied practically. On the one hand, structurally, composite polymers suffer from performance instability due to component compatibility issues, while the chemical synthesis of branched polymers is extremely complex. Developing intrinsically luminescent polymers with simple chain structures is more suitable for practical applications. On the other hand, in terms of performance, intrinsically luminescent polymers are usually conjugated polymers, and these conjugated polymers can only achieve high quantum yields and asymmetry factors by forming a single-chiral (helical) structure. Therefore, developing intrinsically luminescent polymers and achieving their single-chiral structure is a cutting-edge issue that urgently needs to be addressed in the current research on CPL polymers.
[0004] In recent years, chiral polyaniline nanomaterials have attracted widespread attention due to their potential applications in chiral recognition and chiral sensing. Chiral polyaniline nanomaterials (such as helical nanoribbons and helical nanotubes) can be constructed through polymerization reactions in chiral organic acid doping, chiral template guidance, and even achiral molecule-mediated systems. However, due to the fluorescence quenching properties of polyaniline, these methods make it difficult to use chiral polyaniline nanomaterials as CPL materials. To obtain chiral organic polymer molecules with luminescent properties, this invention uses aniline derivative 4-aminophthalic acid (4-APA) as a reaction precursor to prepare chiral helical nanoribbons with stable fluorescence luminescence properties via a simple one-step hydrothermal reaction. The application prospects of this material in CPL devices, 3D displays, and other fields are promising. Summary of the Invention
[0005] In view of the above research background and significance, the purpose of this invention is to provide a method for preparing fluorescent chiral helical nanoribbons by hydrothermal reaction of 4-APA. The obtained chiral helical nanoribbons have stable luminescence properties. The preparation method is simple to operate, low in cost, and environmentally friendly.
[0006] To achieve the above objectives, the present invention provides the following technical solution:
[0007] A method for preparing fluorescent chiral helical nanoribbons via a hydrothermal reaction of 4-APA includes the following steps:
[0008] 4-Aminophthalic acid (4-APA) was added to deionized water and ultrasonically mixed until homogeneous. The mixture was then transferred to a hydrothermal reactor and heated to 110–160°C within half an hour. The hydrothermal reaction was carried out for a certain time. Heating was then stopped, and the mixture was allowed to cool naturally to room temperature. Centrifugation was performed, and the precipitate was identified as fluorescent chiral helical nanoribbons. The molecular structure is as follows:
[0009] Furthermore, the concentration of 4-APA in the pre-reaction mixed solution ranges from 0.04 to 0.2 mol / L;
[0010] Furthermore, the hydrothermal reaction time ranges from 1.5 to 11 hours.
[0011] Compared with existing technologies, the advantages of this invention are as follows: This invention uses 4-APA as a precursor and synthesizes meta-condensed 4-APA dimers via a one-step hydrothermal reaction. Testing has confirmed that these are helical nanoribbons with fluorescent chirality. Furthermore, by investigating the effects of precursor dosage, hydrothermal temperature, and reaction time on the morphology and properties of the product, the conditions for helical structure formation and the stability of the product's fluorescence properties were confirmed. The preparation method disclosed in this invention is simple to operate, low in cost, and environmentally friendly. The product simultaneously possesses fluorescence and chirality, showing broad application potential in optoelectronic displays, information encryption, and other fields. Attached Figure Description
[0012] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0013] Figure 1 Scanning electron microscope (SEM) image of the hydrothermal products of Example 1
[0014] Figure 2 This is a transmission electron microscope (TEM) image of the hydrothermal products of Example 1.
[0015] Figure 3 The images show (a) liquid chromatography (LC) chromatogram, (b) mass spectrometry (MS) chromatogram of the components from 7.99 to 8.12 min, (c) Fourier transform infrared (FTIR) spectrum, and (d) other spectra of the hydrothermal products of Example 1. 1 (e) H NMR spectrum, (f) UV-Vis absorption spectrum, and (c) XRD spectrum.
[0016] Figure 4 XPS spectra of the hydrothermal products of Example 1: (a) full spectrum, (b) C1s spectrum, (c) N1s spectrum, (d) O1s spectrum.
[0017] Figure 5 The images show (a) circular dichroism (CD) spectrum and (b) fluorescence spectrum of the hydrothermal products of Example 1.
[0018] Figure 6 TEM images of the products prepared by hydrothermal reaction of 4-APA at different concentrations in Example 2: (a) 0.03 mol / L, (b) 0.04 mol / L, (c) 0.07 mol / L, (d) 0.20 mol / L.
[0019] Figure 7 The (e) CD spectrum and (f) fluorescence spectrum are of the products prepared by hydrothermal reaction of different concentrations of 4-APA in Example 2.
[0020] Figure 8 TEM images of the products prepared by hydrothermal reaction in Example 3 at different temperatures: (a) 100℃, (b) 110℃, (c) 150℃, (d) 160℃.
[0021] Figure 9 The (e) CD spectrum and (f) fluorescence spectrum of the product prepared by hydrothermal reaction at different temperatures in Example 3 are shown.
[0022] Figure 10 TEM images of the products obtained in Example 4 at different reaction times: (a) 1h, (b) 1.5h, (c) 9h, (d) 11h.
[0023] Figure 11 The (e) CD spectrum and (f) fluorescence spectrum of the products obtained in Example 4 at different reaction times are shown. Detailed Implementation
[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0025] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0026] Example:
[0027] A method for preparing fluorescent chiral helical nanoribbons via a hydrothermal reaction of 4-APA includes the following steps:
[0028] 4-Aminophthalic acid (4-APA) was added to deionized water to a concentration of 0.04-0.2 mol / L, and ultrasonically mixed. The mixture was then transferred to a hydrothermal reactor and heated to 110-160°C within half an hour. The hydrothermal reaction was carried out for 1.5-11 hours. Heating was then stopped, and the mixture was allowed to cool naturally to room temperature. The mixture was then centrifuged, and the precipitate was the fluorescent chiral helical nanoribbon.
[0029] Example 1:
[0030] Step 1) Add 0.1358g of 4-APA to an Erlenmeyer flask, then add 15ml of water, and sonicate at room temperature to form a mixed solution with a concentration of 0.05mol / L;
[0031] Step 2) Fill the mixture obtained in Step 1) into a polytetrafluoroethylene liner, place the liner into the stainless steel reactor kit, and tighten the kit.
[0032] Step 3) Place the reactor from Step 2) in an oven and raise it from room temperature to 140°C within half an hour, then maintain the temperature for 7 hours;
[0033] Step 4) Turn off the oven power and let the reactor cool naturally to room temperature; put the solution in the reactor liner into a centrifuge tube, centrifuge at high speed (1000 r / min), obtain the product in the precipitate, and perform morphological characterization, chemical structure characterization and performance testing on the product.
[0034] like Figure 1 and 2 The images show SEM and TEM images of the product obtained in Example 1. As can be seen from the images, the main structure of the product is a helical nanoribbon with a width of about 8 nm, a length of 300-800 nm, and a helical period of about 30 nm.
[0035] Figure 3 The LC chromatogram of the obtained product, the MS chromatogram of the components from 7.99 to 8.12 min, and the FTIR chromatogram are shown. 1 The 1H NMR spectrum, UV-Vis spectrum and XRD spectrum showed that the main chemical component of the product is a meta-condensed 4-APA dimer, and the product has a certain degree of crystallinity.
[0036] Figure 4 XPS spectra of the hydrothermal products obtained: full spectrum, C1s spectrum, N1s spectrum, and O1s spectrum. The results indicate the specific bond types of the products, confirming that the main chemical component of the products is a meta-condensed 4-APA dimer.
[0037] Figure 5 The CD and fluorescence spectra of the obtained product show that the product has optical chirality and can emit yellow light with a wavelength of 538 nm.
[0038] Example 2:
[0039] Following the preparation process of Example 1, the concentration of the reaction precursor was changed (0.03 mol / L, 0.04 mol / L, 0.07 mol / L, 0.20 mol / L), and TEM images of the resulting products were obtained ( Figure 6 CD spectrum and fluorescence spectrum Figure 7 The results showed that as the precursor concentration gradually increased, the proportion of helical structures in the product first increased and then decreased. The product had obvious optical chiral signals, and the fluorescence wavelength of the product was around 400 nm with stable intensity.
[0040] Example 3:
[0041] Following the preparation process of Example 1, the reaction temperature was changed (100℃, 110℃, 150℃, 160℃), and TEM images of the resulting products were obtained ( Figure 8 CD spectrum and fluorescence spectrum Figure 9 The results showed that as the temperature increased, the proportion of helical structures in the product first increased and then decreased, the intensity of the optical chiral signal of the product first increased and then decreased, and the fluorescence wavelength of the product first increased and then decreased.
[0042] Example 4:
[0043] Following the preparation process of Example 1, the reaction time was changed (1 h, 1.5 h, 9 h, 11 h), and TEM images of the resulting products were obtained. Figure 10 CD spectrum and fluorescence spectrum Figure 11 The results showed that as the reaction time increased, the proportion of helical structures in the product gradually increased, the intensity of the optical chiral signal of the product first increased and then decreased, and the fluorescence wavelength of the product red-shifted from 536 nm to 547 nm after the formation of the helix.
[0044] The above results indicate that, under the premise that other experimental conditions remain unchanged, when the concentration of 4-APA varies from 0.04 to 0.20 mol / L, or the hydrothermal reaction temperature varies from 110 to 160℃, or the hydrothermal reaction time varies from 1.5 to 11 hours, the main chemical component of the prepared product is 4-APA dimer. The microstructure consists of helical nanoribbons with a width of approximately 8 nm, a length of 300-800 nm, and a helical period of approximately 30 nm. Its fluorescence emission wavelength is in the range of 528-547 nm, and its CD signal is in the range of 190-250 nm. The obtained products exhibit similar morphology and optical properties.
[0045] In summary, the method for preparing fluorescent chiral helical nanoribbons disclosed in this invention is simple to operate, low in cost, and has relatively relaxed synthesis conditions. Moreover, the product exhibits stable luminescence properties and obvious chiral optical signals, showing promising application prospects.
[0046] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.
Claims
1. A method for preparing fluorescent chiral helical nanoribbons via a hydrothermal reaction of 4-APA, characterized in that, Includes the following steps: 4-Aminophthalic acid (4-APA) was added to deionized water and ultrasonically mixed until homogeneous. The mixture was then transferred to a hydrothermal reactor and heated to 110-160 °C within half an hour. The hydrothermal reaction was carried out for a certain time. Heating was then stopped, and the mixture was allowed to cool naturally to room temperature. Centrifugation was performed, and the precipitate was identified as fluorescent chiral helical nanoribbons. The molecular structure is as follows: The concentration of 4-aminophthalic acid in water is 0.04-0.2 mol / L; the hydrothermal reaction time is 1.5-11 hours.