Preparation method of fluorescent probe for detecting battery electrolyte viscosity

Abstract

This invention belongs to the field of detection technology, specifically relating to a method for preparing a fluorescent probe for viscosity detection, comprising: dissolving 4-methoxysalicylaldehyde, acrolein, and potassium carbonate in 1,4-dioxane to obtain product 1; dissolving 1,1,2-trimethylbenzo[e]indole and iodoethane in anhydrous ethanol to obtain product 2; dissolving product 1 and product 2 in anhydrous ethanol, adding piperidine, and obtaining the fluorescent probe MCC-ETB under nitrogen protection; and dissolving the fluorescent probe MCC-ETB in DMSO to prepare a mother liquor. The fluorescent probe of this invention can achieve viscosity detection, has a simple synthesis route, and requires convenient detection equipment and methods. It can be applied to electrolyte solutions with complex solvent systems, enabling qualitative and quantitative detection of electrolyte viscosity changes.

Description

Technical Field

[0001] This invention belongs to the field of detection technology, specifically relating to a method for preparing a fluorescent probe for detecting the viscosity of battery electrolyte. Background Technology

[0002] As a core component of a battery system, the performance of the electrolyte has a crucial impact on the overall battery efficiency. Viscosity, a fundamental physical property of the electrolyte, not only relates to the transport characteristics of particles within the electrolyte but also directly affects the wettability of battery materials and the overall performance of the battery. Therefore, accurate and efficient detection of battery electrolyte viscosity is of great significance for battery research, development, production, and use.

[0003] Traditional methods for measuring electrolyte viscosity, such as rotational viscometers, cylindrical viscometers, and pipe flow methods, can reflect the viscosity characteristics of electrolytes to some extent, but they suffer from cumbersome operation, complex data post-processing, and the influence of operator skill on the test results. These problems limit the accuracy and efficiency of traditional methods in practical applications, making the exploration of new measurement methods particularly urgent.

[0004] Small molecule organic fluorescent probes, as an emerging detection tool, offer advantages such as high selectivity, high sensitivity, and ease of operation, providing new insights for measuring electrolyte viscosity. By designing a fluorescent probe specifically for detecting electrolyte viscosity, changes in electrolyte viscosity can be converted into optical signals, thereby enabling the monitoring and accurate assessment of electrolyte viscosity. Therefore, developing a fluorescent probe capable of detecting viscosity changes is crucial. Summary of the Invention

[0005] To address the problems existing in current detection technologies, this invention provides a method for preparing a fluorescent probe for viscosity detection. This method has simple synthesis steps, convenient and quick post-processing, low manufacturing cost, fast fluorescence response, good selectivity, and high sensitivity.

[0006] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0007] A method for preparing a viscosity fluorescent probe includes the following steps:

[0008] (1) Dissolve 4-methoxysalicylaldehyde, acrolein and potassium carbonate in 1,4-dioxane, heat and stir the resulting mixture, cool to room temperature after the reaction is complete, extract, and separate product 1 by column chromatography.

[0009] (2) Dissolve 1,1,2-trimethylbenzo[e]indole and iodoethane in anhydrous ethanol. After the reaction is complete, cool to room temperature, filter, and dry under vacuum to obtain product 2.

[0010] (3) Dissolve product 1 obtained in step (1) and product 2 obtained in step (2) in anhydrous ethanol, add piperidine, and heat and stir the resulting mixture. After the reaction is complete, cool to room temperature, filter, and dry under vacuum to obtain the target product fluorescent probe MCC-ETB.

[0011] Furthermore, in step (1), the molar ratio of 4-methoxysalicylaldehyde, acrolein and potassium carbonate is 1:1.2:1.

[0012] Furthermore, in step (2), the molar ratio of 1,1,2-trimethylbenzo[e]indole to iodoethane is 1:1.

[0013] Furthermore, in step (3), the molar ratio of product 1 to product 2 is 1:1.

[0014] Furthermore, in step (3), the fluorescent probe MCC-ETB has the following structural formula:

[0015] .

[0016] Further, in step (1), 4-methoxysalicylaldehyde, acrolein and potassium carbonate are dissolved in 1,4-dioxane, and the resulting mixture is heated to 100°C and stirred for 10 to 16 hours.

[0017] Further, in step (2), 1,1,2-trimethylbenzo[e]indole and iodoethane are dissolved in anhydrous ethanol and then stirred at 78°C for 6 to 9 hours.

[0018] Further, in step (3), the resulting mixture is placed under N2 protection and heated to 80°C and stirred for 1 to 3 hours.

[0019] The specific reaction process of the fluorescent probe obtained by the above-mentioned viscosity fluorescent probe preparation method is as follows:

[0020]

[0021] This invention utilizes a chemical reaction to prepare a fluorescent probe from 4-methoxysalicylaldehyde, acrolein, iodoethane, and 1,1,2-trimethylbenzo[e]indole. This fluorescent probe exhibits significant fluorescence enhancement with increasing viscosity, demonstrating its ability to detect viscosity. Compared to existing detection technologies, the fluorescent chemical probe of this invention requires less investment, has a simpler synthesis route, is easier to process, and can achieve viscosity detection, making it particularly valuable for applications in the energy battery field. Attached Figure Description

[0022] The present invention will now be described in detail through specific embodiments. These embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art. As used throughout the specification and claims, the terms "comprising" or "including" are open-ended and are interpreted as "comprising but not limited to". The following description is a preferred embodiment for carrying out the invention; however, this description is intended to illustrate the general principles of the specification and is not intended to limit the scope of the invention. The scope of protection of the invention is determined by the appended claims. Unless otherwise specified, all reagents and materials used in the present invention are commercially available.

[0023] Figure 1 The NMR spectrum of the prepared fluorescent probe MCC-ETB is shown below.

[0024] Figure 2 The NMR C-scan spectrum of the prepared fluorescent probe MCC-ETB;

[0025] Figure 3 This is a spectrum showing the fluorescence intensity of the fluorescent probe MCC-ETB as a function of viscosity.

[0026] Figure 4 The graph shows the linear fitting curve of the fluorescence intensity of the fluorescent probe MCC-ETB versus its corresponding viscosity.

[0027] Figure 5 This is a fluorescence intensity graph for selective detection by the fluorescent probe MCC-ETB;

[0028] Figure 6 The fluorescence intensity graph of the fluorescent probe MCC-ETB as a function of electrolyte viscosity is shown.

[0029] Figure 7 This is a fitted curve of the fluorescent probe MCC-ETB as a function of electrolyte viscosity. The concentration of added ions was 1×10⁻⁶. -3 The concentration is mol / L, with 545 nm as the excitation wavelength and 653 nm as the emission wavelength. (Note: The probe concentration is 10 μM) Detailed Implementation

[0030] Example 1

[0031] The preparation method of the viscosity fluorescent probe includes the following steps:

[0032] (1) Preparation of product 1 and product 2.

[0033] 4-Methoxysalicylaldehyde (5 mmol), acrolein (6 mmol), and potassium carbonate (5 mmol) were added to a round-bottom flask containing 15 mL of 1,4-dioxane and heated under reflux for 12 h. After the reaction was completed, the mixture was cooled to room temperature, extracted, and separated by column chromatography to obtain the synthetic product 1.

[0034] 1,1,2-Trimethylbenzo[e]indole (5 mmol) and iodoethane (5 mmol) were dissolved in 15 mL of anhydrous ethanol. The resulting mixture was stirred at 78 °C for 8 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and dried under vacuum to obtain product 2.

[0035] (2) Synthesize fluorescent probes using products 1 and 2.

[0036] Product 1 (1 mmol) and Product 2 (1 mmol) were dissolved in 10 mL of anhydrous ethanol, 2 drops of piperidine were added, and the mixture was heated under N2 protection and refluxed for 2 h. After the reaction was completed, the solid was separated and dried under vacuum to obtain the fluorescent probe MCC-ETB.

[0037] Weigh out 1 mmol of MCC-ETB and dissolve it in DMSO to prepare a 1 mM stock solution.

[0038] MCC-ETB viscosity testing:

[0039] Take 10 5mL sample vials and add a mixture of glycerol and PBS (glycerol content: 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%) to each vial. Then add 20μL of the MCC-ETB solution (10μM concentration) prepared with the fluorescent probe obtained in Example 1. After stirring at room temperature for 1 min, measure the fluorescence intensity of each sample at an excitation wavelength of 545nm. The fluorescence intensity emission spectra of the 10 samples are shown below. Figure 3 The measurement results showed that the fluorescent probe has high sensitivity to viscosity, and the fluorescence intensity gradually increases with increasing viscosity. Based on... Figure 3 The fluorescence intensity change values ​​can be used to plot the corresponding glycerol ratio fitted function curve and the corresponding function graph (y=ax+b, a=7076.422, b=45.90059, R). 2 =0.9996) See Figure 4 .

[0040] Other analyte comparison tests:

[0041] Take 14 5mL sample vials and add 20μL of the MCC-ETB solution (10μM concentration) prepared with the fluorescent probe obtained in Example 1 to each vial. Then, add 1×10⁻⁶ solution to each vial. -228 μL of each of the other analytes (mol / L) and 90% glycerol / water were added to the remaining 13 sample vials, with sample 1 serving as the blank. The fluorescence emission intensity of each of the 13 samples was then measured at an excitation wavelength of 545 nm and an emission wavelength of 653 nm. The results are shown in [Figure number missing]. Figure 5 The results showed that the fluorescent probe had good selectivity, and the other analytes had no significant effect on the intensity of the prepared fluorescent probe.

[0042] The response of the fluorescent probe MCC-ETB to viscosity in battery electrolyte:

[0043] During testing, the concentration of the fluorescent probe MCC-ETB was maintained at 10 μM in glycerol / electrolyte solutions with different mass ratios. Test systems with different mass ratios of glycerol and electrolyte were prepared, maintaining a total test volume of 5 mL. The mass percentages of glycerol were 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%. The fluorescence intensity as a function of viscosity was measured using an excitation wavelength of 545 nm, as shown in the following graph. Figure 6 As shown. According to Figure 6 The fluorescence intensity changes can be used to plot the corresponding glycerol ratio fitted function curve and the corresponding function graph (y=ax+b, a=6324.29, b=70.37, R). 2 =0.99889) See Figure 7 .

[0044] The above embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims fall within the protection scope of the present invention.

Claims

1. A method for preparing a fluorescent probe for detecting the viscosity of battery electrolyte, characterized in that, Includes the following steps: (1) 4-Methoxysalicylaldehyde, acrolein, and potassium carbonate were dissolved in 1,4-dioxane. The resulting mixture was heated and stirred. After the reaction was completed, the mixture was cooled to room temperature, extracted, and separated by column chromatography to obtain product 1. The structural formula of product 1 is: ； (2) 1,1,2-Trimethylbenzo[e]indole was dissolved in anhydrous ethanol with iodoethane. After the reaction was completed, the mixture was cooled to room temperature, filtered, and dried under vacuum to obtain product 2. The structural formula of product 2 is: ； (3) Dissolve product 1 obtained in step (1) and product 2 obtained in step (2) in ethanol, add piperidine, heat and stir the mixture, cool to room temperature after the reaction is complete, filter, and vacuum dry to obtain the target product fluorescent probe MCC-ETB. The structure of the fluorescent probe MCC-ETB is as follows: 。 2. The method for preparing the fluorescent probe for detecting battery electrolyte viscosity according to claim 1, characterized in that: In step (1), the molar ratio of 4-methoxysalicylaldehyde, acrolein and potassium carbonate is 1:1.2:

1.

3. The method for preparing the fluorescent probe for detecting battery electrolyte viscosity according to claim 2, characterized in that: In step (2), the molar ratio of 1,1,2-trimethylbenzo[e]indole to iodoethane is 1:

1.

4. The method for preparing the fluorescent probe for detecting battery electrolyte viscosity according to claim 3, characterized in that: In step (3), the molar ratio of product 1 to product 2 is 1:

1.

5. The method for preparing the fluorescent probe for detecting battery electrolyte viscosity according to claim 4, characterized in that: In step (1), 4-methoxysalicylaldehyde, potassium carbonate and acrolein are dissolved in 1,4-dioxane, and the resulting mixture is heated to 100°C and stirred for 10 to 16 hours.

6. The method for preparing the fluorescent probe for detecting battery electrolyte viscosity according to claim 5, characterized in that: In step (2), 1,1,2-trimethylbenzo[e]indole and iodoethane are dissolved in anhydrous ethanol and then stirred at 78°C for 6 to 9 hours.

7. The method for preparing the fluorescent probe for detecting battery electrolyte viscosity according to claim 6, characterized in that: In step (3), the resulting mixture is placed under N2 protection and stirred at 78°C for 1 to 3 hours.

8. A fluorescent probe obtained by the preparation method of the fluorescent probe for detecting the viscosity of battery electrolyte as described in any one of claims 1 to 7.

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