Modification Method of Rare Earth Ultra-Fine Nanowires, Fluorescent Ink and Preparation Method and Application Thereof

Abstract

The present application discloses a modification method for rare earth ultra-fine nanowires, a fluorescent ink, a preparation method and an application thereof. The modification method includes dispersing rare earth ultra-fine nanowires in an organic solvent to obtain a nanowire dispersion liquid, and modifying the nanowire dispersion liquid with ligand molecules to obtain modified rare earth ultra-fine nanowires. By modifying the rare earth ultra-fine nanowires, their luminescence performance and dispersibility can be significantly improved. The luminescence performance of the fluorescent ink prepared in the present application is significantly improved. By using different ligand molecules to treat the rare earth ultra-fine nanowires, the luminescence performance of the fluorescent ink can also be regulated, and it has the advantages of high fluorescence intensity and strong adjustable performance.

Description

Technical Field

[0001] The present invention relates to the technical field of fluorescent inks, and more specifically, to a method for modifying rare earth ultrafine nanowires, a fluorescent ink, a preparation method thereof, and an application thereof. Background Art

[0002] With the progress of technology, the application demand for fluorescent materials has gradually increased. Fluorescent inks prepared using fluorescent materials have the characteristic of emitting fluorescence under ultraviolet or visible light irradiation, and have a wide range of applications in multiple fields.

[0003] In the related art, fluorescent inks are prepared using organic fluorescent molecules or inorganic fluorescent powders. However, the luminous efficiency and stability of organic fluorescent molecules are low, and the tunability and dispersibility of inorganic fluorescent powders are poor, resulting in low luminous performance and poor adjustable performance of fluorescent inks.

[0004] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The technical task of the present invention is to address the above deficiencies by providing a method for modifying rare earth ultrafine nanowires, a fluorescent ink, a preparation method thereof, and an application thereof. By modifying the rare earth ultrafine nanowires, their luminous performance and dispersibility can be significantly improved. The luminous performance of the fluorescent ink prepared in this application is significantly improved. By using different ligand molecules to treat the rare earth ultrafine nanowires, the luminous performance of the fluorescent ink can also be regulated, and it has the advantages of high fluorescence intensity and strong adjustable performance.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] According to one aspect of the present application, a method for modifying rare earth ultrafine nanowires is provided, including: dispersing rare earth ultrafine nanowires in an organic solvent to obtain a nanowire dispersion; modifying the nanowire dispersion with a ligand molecule to obtain modified rare earth ultrafine nanowires; the modifying the nanowire dispersion with a ligand molecule includes: calibrating the concentration of rare earth ions in the nanowire dispersion; adding a ligand molecule to the nanowire dispersion according to the concentration of the rare earth ions, stirring at room temperature, adding absolute ethanol and then centrifuging, and taking the precipitate after centrifugation to obtain modified rare earth ultrafine nanowires.

[0008] In some embodiments, the rare earth ultrafine nanowires are one of europium ultrafine nanowires, samarium ultrafine nanowires, and terbium ultrafine nanowires.

[0009] In some embodiments, the ligand molecule is one or more of acetylacetone, 1-phenyl-1,3-butanedione, thenoyltrifluoroacetone, 4,4,4-trifluoro-1-(4-methoxyphenyl)-1,3-butanedione, 3-(4-fluorobenzoyl)-1,1,1-trifluoroacetone, 1,3-bis(4-methoxyphenyl)propane-1,3-dione, 1,3-bis(thiophene)propane-1,3-dione, 1,1,1,5,5,5-hexafluoropentane-2,4-dione, benzoyltrifluoroacetone, 2,6-pyridinedicarboxylic acid, 1-(4-bromophenyl)-1,3-butanedione, 1-(4-bromophenyl)-4,4,4-trifluoro-butane-1,3-dione; the molar ratio of the ligand molecule to the rare earth ions in the nanowire dispersion is 5:1.

[0010] In some embodiments, the organic solvent is one or more of n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, dodecane, toluene, chloroform, dichloromethane, carbon tetrachloride, 1-octadecene, N,N-dimethylformamide; the stirring time is 2 h, the centrifugation speed is 6000 - 8000 rpm, and the centrifugation time is 3 - 5 min.

[0011] According to another aspect of the present application, there is also provided a fluorescent ink, including the modified rare earth ultrafine nanowires prepared by the method, and the concentration of rare earth ions in the fluorescent ink is 0.0015 mmol / mL - 0.015 mmol / mL.

[0012] According to another aspect of the present application, there is also provided a preparation method of a fluorescent ink, including: redispersing the modified rare earth ultrafine nanowires in an organic solvent, and introducing nitrogen into the dispersed solution in a bubbling manner to obtain the fluorescent ink.

[0013] In some embodiments, the duration of dispersion is 1 h, the stirring speed during dispersion is 500 rpm, the duration of bubbling is 0.5 h, and the organic solvent is one or more of n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, dodecane, toluene, chloroform, dichloromethane, carbon tetrachloride, 1-octadecene, N,N-dimethylformamide.

[0014] According to another aspect of the present application, there is also provided the application of the fluorescent ink in packaging printing, anti-counterfeiting labels, and intelligent sensors.

[0015] In some embodiments, the intelligent sensor is a flexible temperature sensor.

[0016] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0017] 1. By modifying rare earth ultrafine nanowires, the present application can significantly improve the luminescence performance of fluorescent inks prepared using the modified rare earth ultrafine nanowires.

[0018] 2. By treating rare earth ultrafine nanowires with different ligand molecules, the present application can regulate the luminescence performance of fluorescent inks, solving the problem that the luminescence performance of traditional fluorescent inks cannot be regulated, and having the advantage of high tunability.

[0019] 3. The modified rare earth ultrafine nanowires of the present application have excellent dispersibility and can be dissolved in a variety of organic solvents.

[0020] 4. The ultraviolet light response characteristics of the fluorescent inks prepared by the present application are significantly improved, and they have temperature-sensitive characteristics, which can be repeated multiple times during the process of temperature rise and fall, and the fluorescence intensity after multiple repetitions has high stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 Shows the schematic flow diagram of the present application;

[0023] Figure 2 Shows the digital photos of the fluorescent inks in the comparative example of the present application. Among them, 2a is under natural light, and 2b is under ultraviolet light;

[0024] Figure 3 Shows the digital photos of the modified Eu ultrafine nanowire-based fluorescent ink in Example 1 of the present application. Among them, 3a is before modification, and 3b is after modification;

[0025] Figure 4 Shows the fluorescence emission spectra of the fluorescent inks in the comparative example and Example 1 of the present application;

[0026] Figure 5 Shows the absorption spectra of the fluorescent inks in the comparative example and Example 1 of the present application;

[0027] Figure 6 Shows the schematic diagram of the ligand molecule structure used in Example 2 of the present application and the digital photo under ultraviolet light of the pattern formed by the fluorescent ink prepared after treatment with the corresponding ligand;

[0028] Figure 7 Shows the fluorescence emission spectra of the fluorescent inks prepared after treatment with different ligands in Example 2 of the present application;

[0029] Figure 8 Show the fluorescence emission spectrum of the modified Sm ultrafine nanowire-based fluorescent ink in Example 3 of the present application and its digital photo under ultraviolet light;

[0030] Figure 9 Show the fluorescence emission spectrum of the modified Tb ultrafine nanowire-based fluorescent ink in Example 4 of the present application and its digital photo under ultraviolet light;

[0031] Figure 10 Show the variable-temperature fluorescence emission spectrum diagram of the modified Eu ultrafine nanowire-based fluorescent ink in Example 5 of the present application;

[0032] Figure 11 Show the cyclic curve of the fluorescence emission intensity of the modified Eu ultrafine nanowire-based fluorescent ink in Example 5 of the present application changing with temperature;

[0033] Figure 12 Show the digital photos of the pattern of the modified Eu ultrafine nanowire-based fluorescent ink in Example 5 of the present application changing with temperature.

[0034] Figure 13 Show the schematic diagram of the visible and invisible characteristics of the unmodified Eu ultrafine nanowire-based fluorescent ink after spraying the ligand solvent in Example 6 of the present application;

[0035] Figure 14 Show the schematic diagram of the stability of the unmodified Eu ultrafine nanowire-based fluorescent ink before and after soaking the pattern after spraying the ligand solvent in Example 6 of the present application, where 14a is before soaking and 14b is after soaking. Detailed implementation manners

[0036] In order to be able to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0038] Comparative example: Prepare the unmodified europium (Eu) ultrafine nanowire-based fluorescent ink.

[0039] Disperse Eu ultrafine nanowires in toluene to obtain the unmodified Eu ultrafine nanowire-based fluorescent ink with high viscosity. After centrifuging the unmodified Eu ultrafine nanowire-based fluorescent ink at 2000 rpm for 3 min, keep it at 40 °C for 24 h. As Figure 2 shown in a, obtain the gel-like unmodified Eu ultrafine nanowire-based fluorescent ink. As Figure 2As shown in Fig. b, under ultraviolet light irradiation, the gel-like Eu ultrafine nanowire-based fluorescent ink before modification emits uniform red fluorescence, indicating that the prepared Eu ultrafine nanowire-based fluorescent ink before modification has certain luminescent properties, but the luminescent properties are relatively low.

[0040] Example 1: Prepare the modified Eu ultrafine nanowire-based fluorescent ink.

[0041] S1. Eu ultrafine nanowires are uniformly dispersed in toluene solvent to obtain a Eu ultrafine nanowire dispersion.

[0042] S2. The actual concentration of Eu ions in the dispersion is measured using inductively coupled plasma optical emission spectrometry (ICP-OES), and an appropriate amount of FBFA ligand molecules are weighed according to the molar ratio of 3-(4-fluorobenzoyl)-1,1,1-trifluoroacetone (FBFA) to rare earth ions in the Eu ultrafine nanowire dispersion of 5:1.

[0043] S3. FBFA is added to the Eu ultrafine nanowire dispersion, and the mixture is stirred at room temperature for two hours. After adding absolute ethanol, centrifugation is carried out at a rotational speed of 6000 - 8000 rpm for 3 - 5 minutes. The obtained precipitate is the modified Eu ultrafine nanowires.

[0044] S4. The modified Eu ultrafine nanowires are redispersed in toluene to obtain the modified Eu ultrafine nanowire-based fluorescent ink.

[0045] Figure 3 The digital photos of the fluorescent ink in Example 1 of the present application are shown, where 3a is before modification and 3b is after modification. As Figure 3 shown in Fig. a, the Eu ultrafine nanowire dispersion emits red fluorescence under ultraviolet light irradiation. As Figure 3 shown in Fig. b, the modified Eu ultrafine nanowire-based fluorescent ink emits more dazzling red fluorescence under ultraviolet light irradiation, and its luminescence intensity has been significantly improved compared with that before modification.

[0046] Figure 4 The fluorescence emission spectra of the modified Eu ultrafine nanowire-based fluorescent ink in the comparative example and Example 1 are shown. As Figure 4 shown, the photoluminescence (PL) intensity of the modified Eu ultrafine nanowire-based fluorescent ink in the example has been significantly improved.

[0047] Figure 5 The absorption spectra of the modified Eu ultrafine nanowire-based fluorescent ink in the comparative example and Example 1 of the present application are shown. As Figure 5 shown, before modification, there are two obvious absorption peaks in the absorption spectrum of the nanowires, located at 394 nm and 465 nm respectively, which represent 7 F0→5 L6 and 7 F0→ 5 The transition of D2. However, in the absorption spectrum of the ultrafine nanowires after ligand treatment, a strong absorption peak appeared in the range of 320 - 420 nm, which is the characteristic absorption of the FBFA ligand.

[0048] Therefore, the FBFA ligand significantly enhanced the luminescence intensity of the Eu-based nanowires through the "antenna effect". In this process, the FBFA ligand, as an "antenna", absorbed the excitation light and effectively transferred the excitation energy to the higher energy levels of Eu ions, thus filling the excitation levels of rare earth ions and improving the luminescence efficiency.

[0049] In summary, the luminescence intensity of the fluorescent ink was significantly improved by modifying the ultrafine nanowires through ligand treatment.

[0050] Example 2: Regulation of the luminescence properties of the modified Eu ultrafine nanowire-based fluorescent ink.

[0051] The Eu ultrafine nanowires were modified by ligand treatment according to the method in Example 1, and the modified Eu ultrafine nanowires were used to prepare the fluorescent ink. The difference from Example 1 was that different ligand molecules were used to modify the Eu ultrafine nanowires. Among them, the ligand molecules used were acetylacetone (ACA), 1-phenyl-1,3-butanedione (BA), thenoyltrifluoroacetone (TTA), 4,4,4-trifluoro-1-(4-methoxyphenyl)-1,3-butanedione (MBFA), 3-(4-fluorobenzoyl)-1,1,1-trifluoroacetone (FBFA), 1,3-bis(4-methoxyphenyl)propane-1,3-dione (DMBM), 1,3-bis(thiophene)propane-1,3-dione (DTM), 1,1,1,5,5,5-hexafluoropentane-2,4-dione (HFA), benzoyltrifluoroacetone (BFA), 1-(4-bromophenyl)-1,3-butanedione (BBA), 1-(4-bromophenyl)-4,4,4-trifluoro-butane-1,3-dione (BBFA), and the molar ratio of the ligand molecule to Eu ions in the nanowire dispersion was 5:1.

[0052] Figure 6 The schematic diagrams of the ligand molecule structures used in Example 2 of the present application and the digital photos of the prepared fluorescent ink under ultraviolet light after corresponding ligand treatment are shown. As Figure 6 shown, the selected ligand molecules have similar structures, with different substituents at both ends. The substituents can be roughly divided into the following categories: electron-withdrawing groups such as trifluoromethyl and fluorophenyl; electron-donating groups such as methoxyphenyl, thiophene, and furan; neutral conjugated groups phenyl and inert methyl. Figure 6Also shown are digital photos of the fluorescent inks prepared after treatment with corresponding ligands under ultraviolet light. It can be seen that the effects of different ligands on the luminescence of Eu ultrafine nanowires are significantly different, and not all ligands have a promoting effect. Most notably, when using the two ligands DMBM and DTM, whose substituents are both electron-donating groups, the fluorescence of the nanowires even completely disappears. However, when using ligands with neutral or inert groups, such as ACA and BA ligand molecules, the brightness exhibited by the nanowires is similar to that before treatment. When using ligands containing at least one electron-withdrawing group, including MBFA, HFA, TTA, FFA, BFA, and FBFA, the ultrafine nanowires all exhibit significantly enhanced luminescence, emitting a dazzling red light.

[0053] Figure 7 shows the fluorescence emission spectra of the fluorescent inks prepared after treatment with different ligands in Example 2 of the present application. As Figure 7 shown, the effects of different ligands on the luminescence intensity of ultrafine nanowires are significantly different. Therefore, the regulation of the luminescence properties of rare-earth ultrafine nanowires by using ligands with different properties is achieved. In practical applications, the fluorescence properties of nanowires can be regulated according to the effects of ligand molecules on fluorescence performance, so as to meet the requirements for luminescence brightness in different application scenarios. Also, based on this characteristic, fluorescent inks can be made into sensors sensitive to specific molecules.

[0054] Example 3: Preparation of a modified samarium (Sm) ultrafine nanowire-based fluorescent ink.

[0055] Prepare the modified Sm ultrafine nanowire-based fluorescent ink according to the method in Example 1, where the difference from Example 1 is that the rare-earth ultrafine nanowires used are Sm ultrafine nanowires.

[0056] Figure 8 shows the fluorescence emission spectrum of the modified Sm ultrafine nanowire-based fluorescent ink in Example 3 of the present application and its digital photo under ultraviolet light. As Figure 8 shown, the modified Sm ultrafine nanowire-based fluorescent ink exhibits the characteristic emission peak of rare-earth Sm(III). The modified Sm ultrafine nanowire-based fluorescent ink exhibits characteristic red fluorescence under ultraviolet light irradiation, indicating the successful preparation of the modified Sm ultrafine nanowire-based fluorescent ink.

[0057] Example 4: Preparation of a modified terbium (Tb) ultrafine nanowire-based fluorescent ink.

[0058] Prepare the modified Tb ultrafine nanowire-based fluorescent ink according to the method in Example 1, where the difference from Example 1 is that the rare-earth ultrafine nanowires used are Tb ultrafine nanowires, and the ligand molecule used is 2,6-pyridinedicarboxylic acid.

[0059] Figure 9 Show the fluorescence emission spectrum of the modified Tb ultrafine nanowire-based fluorescent ink in Example 4 of this application and its digital photo under ultraviolet light. As Figure 9 shown, the modified Tb ultrafine nanowire-based fluorescent ink exhibits the characteristic emission peak of rare earth Tb(III). The modified Tb ultrafine nanowire-based fluorescent ink exhibits characteristic green fluorescence under ultraviolet light irradiation, indicating the successful preparation of the modified Tb ultrafine nanowire-based fluorescent ink.

[0060] Example 5: Detection of the temperature-sensitive characteristics of the modified Eu ultrafine nanowire-based fluorescent ink.

[0061] Figure 10 Show the variable-temperature fluorescence emission spectrogram of the modified Eu ultrafine nanowire-based fluorescent ink in this example; Figure 11 Show the cyclic curve of the fluorescence emission intensity of the modified Eu ultrafine nanowire-based fluorescent ink changing with temperature in this example; Figure 12 Show the digital photo of the pattern of the modified Eu ultrafine nanowire-based fluorescent ink changing with temperature in this example.

[0062] The temperature-sensitive characteristic is that the fluorescence intensity of the fluorescent ink decreases with the increase of the ambient temperature. When the ambient temperature reaches 135 - 150 °C, the fluorescence intensity of the fluorescent ink is the lowest. When the ambient temperature drops back to room temperature, the fluorescence intensity of the fluorescent ink increases with the decrease of the ambient temperature and finally returns to the initial state. The temperature response characteristic can be repeated multiple times.

[0063] Specifically, perform variable-temperature photoluminescence spectroscopy testing on the modified Eu ultrafine nanowire-based fluorescent ink prepared in Example 1. As Figure 10 shown, with the increase of temperature, the fluorescence intensity of the modified Eu ultrafine nanowire-based fluorescent ink gradually decreases. Among them, the fluorescence intensity of the main emission peak (615 nm) linearly decreases with the increase of temperature, from 100% at room temperature to less than 10% at 150 °C.

[0064] As Figure 11 shown, the change of fluorescence intensity with temperature is reversible. When the modified Eu ultrafine nanowire-based fluorescent ink undergoes four temperature cycle changes from room temperature to 100 °C, the emission intensity can still recover to its original level.

[0065] As Figure 12 shown, the seal pattern made of the modified Eu ultrafine nanowire-based fluorescent ink also has temperature-dependent fluorescence characteristics. With the increase of temperature, the brightness of the pattern gradually darkens and completely disappears at 135 - 150 °C. When the temperature returns to room temperature, the pattern reappears again.

[0066] Example 6: Detection of the visibility and stability of the ligand molecule on the Eu ultrafine nanowire-based fluorescent ink before modification

[0067] Figure 13 Schematic diagram showing the visibility characteristics of the Eu ultrafine nanowire-based fluorescent ink before modification after spraying the ligand solvent; Figure 14 Schematic diagram showing the stability of the pattern before and after soaking after spraying the ligand solvent on the Eu ultrafine nanowire-based fluorescent ink before modification in Example 6 of this application, where 14a is before soaking and 14b is after soaking.

[0068] As Figure 13 shown, in addition to the above methods, for improving the luminescence performance of the fluorescent ink, the ligand molecules can also be dispersed in an organic solvent to obtain a ligand solvent, and the ligand solvent is sprayed on the pattern formed by the rare earth ultrafine nanowire-based fluorescent ink before modification. After the solvent has completely volatilized, the fluorescence intensity of the pattern can be significantly increased.

[0069] Specifically, first, the Eu ultrafine nanowire-based fluorescent ink before modification is injected into a pen for writing. Since the fluorescence intensity of this Eu ultrafine nanowire-based fluorescent ink before modification is relatively weak, the written letters cannot be recognized initially under ultraviolet light irradiation; next, the ligand molecules used in Example 1 are dispersed in toluene and sprayed on the just-written position. At this time, it can be observed that the red fluorescent letters immediately become clearly visible. After the solvent has completely volatilized, a complete and clear red fluorescent letter pattern can be obtained. Therefore, the ligand molecules can be used to make the written words visible on the Eu ultrafine nanowire-based fluorescent ink before modification.

[0070] As Figure 14 shown, the pattern after spraying the ligand solvent is soaked in n-hexane, toluene, ethanol, and water for half an hour, and the pattern still remains clearly visible without bleeding or fading. Therefore, this fully demonstrates the stability of the pattern obtained by treating the Eu ultrafine nanowire-based fluorescent ink before modification with ligand molecules.

[0071] The above-prepared fluorescent ink can be applied to packaging printing, anti-counterfeiting labels, and intelligent sensors. For example, in flexible anti-counterfeiting labels, the ultraviolet light response characteristics of the fluorescent ink ensure the authenticity verification of products; in flexible temperature sensors, the temperature-sensitive characteristics of the fluorescent ink enable the flexible temperature sensor to accurately display the ambient temperature and can also be used in scenarios such as high-temperature warning; in flexible intelligent packaging printing, the fluorescent ink can achieve intelligent tracking and management of commodities.

[0072] Those skilled in the art can easily implement the present invention through the above specific embodiments. However, it should be understood that the present invention is not limited to the above specific embodiments. Based on the disclosed embodiments, those skilled in the art can arbitrarily combine different technical features to achieve different technical solutions.

Claims

1. A fluorescent ink, characterized in that: The invention comprises modified rare earth ultrafine nanowires, and the method for preparing the modified rare earth ultrafine nanowires comprises: dispersing rare earth ultrafine nanowires in an organic solvent to obtain a nanowire dispersion; Using ligand molecules to modify the nanowire dispersion to obtain modified rare earth ultrafine nanowires; The method of modifying the nanowire dispersion using ligand molecules comprises: calibrating the concentration of rare earth ions in the nanowire dispersion; Adding ligand molecules to the nanowire dispersion according to the concentration of the rare earth ions, stirring at room temperature, adding anhydrous ethanol and centrifuging, collecting the precipitate after centrifugation, and obtaining modified rare earth ultrafine nanowires; The rare earth ultrafine nanowire is one of europium ultrafine nanowire, samarium ultrafine nanowire and terbium ultrafine nanowire; the ligand molecule is acetylacetone, 1-phenyl-1,3-butanedione, thiophenebenzoyltrifluoroacetone, 4,4,4-trifluoro-1-(4-methoxyphenyl)-1,3-butanedione, 3-(4-fluorobenzoyl)-1,1,1 trifluoroacetone, 1,3-bis(4-methoxyphenyl)propane 1,3-dione, 1,3-bis(thiophene)propane 1,3-dione, 1,1,1,5,5,5-hexafluoropentane-2,4-dione, benzoyltrifluoroacetone, 2,6-pyridinedicarboxylic acid, 1-(4-bromophenyl)-1,3-butanedione , 1-(4-bromophenyl)-4,4,4-trifluoro-butane-1,3-dione; the molar ratio of the ligand molecule to the rare earth ion in the nanowire dispersion is 5:1; the organic solvent is one or more of n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, dodecane, toluene, chloroform, dichloromethane, carbon tetrachloride, octadecene, and N,N-dimethylformamide; the stirring time is 2h, the centrifugal speed is 6000-8000rpm, and the centrifugal time is 3-5min; the concentration of rare earth ions in the fluorescent ink is 0.0015mmol / mL-0.015mmol / mL.

2. The method for preparing a fluorescent ink according to claim 1, characterized in that: include: The modified rare earth ultrafine nanowires are redispersed in an organic solvent, and nitrogen is introduced into the dispersed solution in a bubbling manner to obtain fluorescent ink.

3. The method for preparing a fluorescent ink according to claim 2, characterized in that: The duration of the redispersion is 1 hour, the stirring speed of the redispersion is 500 rpm, the duration of the bubbling is 0.5 hours, and the organic solvent in which the modified rare earth ultrafine nanowires are redispersed is one or more of n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, dodecane, toluene, chloroform, dichloromethane, carbon tetrachloride, octadecene, and N,N-dimethylformamide.

4. Application of the fluorescent ink according to any one of claims 1 to 3 in packaging printing, anti-counterfeiting labels, and smart sensors.

5. The use according to claim 4, characterized in that: The intelligent sensor is a flexible temperature sensor.

Images