Preparation method of fluorescent probe for detecting viscosity of battery electrolyte

Abstract

The invention belongs to the technical field of detection, and particularly relates to a preparation method of a fluorescence probe for detecting viscosity, which comprises the following steps: dissolving 4-methoxysalicylaldehyde, acrolein and potassium carbonate in 1, 4 dioxane to obtain a product 1; dissolving 1, 1, 2-trimethylbenzo [e] indole and iodoethane in absolute ethyl alcohol to obtain a product 2; dissolving the product 1 and the product 2 in absolute ethyl alcohol, adding piperidine, and obtaining the fluorescent probe MCC-ETB under the protection of nitrogen; the method comprises the following steps: dissolving a fluorescent probe MCC-ETB in DMSO to prepare a mother solution; the fluorescent probe provided by the invention can realize viscosity detection, is simple in synthetic route, simple and convenient in detection equipment and method, can be applied to an electrolyte solution with a complex solvent system, and can qualitatively and quantitatively detect the viscosity change of the electrolyte.

Description

Technical Field

[0001] The invention belongs to the field of detection technology, and particularly relates to a method for preparing a fluorescent probe for detecting battery electrolyte viscosity. Background Art

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

[0003] Traditional electrolyte viscosity measurement methods, such as rotational viscometer, cylindrical viscometer and pipeline flow method, can reflect the viscosity characteristics of electrolyte to a certain extent, but they are cumbersome to operate, complex data post-processing, and the test results are affected by the skills of the operator. These problems limit the accuracy and efficiency of traditional methods in practical applications, making it particularly urgent to explore new measurement methods.

[0004] As an emerging detection tool, small molecule organic fluorescent probes have the advantages of high selectivity, high sensitivity and easy operation, providing a new idea for the measurement of electrolyte viscosity. By designing a fluorescent probe that specifically detects electrolyte viscosity, the change in electrolyte viscosity can be converted into an optical signal, thereby realizing the monitoring and accurate evaluation of electrolyte viscosity. Therefore, it is crucial to develop a fluorescent probe that can detect viscosity changes. Summary of the invention

[0005] In view of the problems existing in the existing detection technology, the present invention provides a method for preparing a fluorescent probe for viscosity detection. The method has simple synthesis steps, convenient and fast post-processing process, low manufacturing cost, fast fluorescence response speed, good selectivity and high sensitivity.

[0006] To solve the above technical problems, the present invention is achieved as follows: A method for preparing a viscosity fluorescent probe comprises the following steps: (1) 4-methoxysalicylaldehyde, acrolein and potassium carbonate are dissolved in 1,4-dioxane, the resulting mixture is heated and stirred, and after the reaction is completed, the mixture is cooled to room temperature, extracted, and separated by column chromatography to obtain product 1; (2) Dissolve 1,1,2-trimethylbenz[e]indole and iodoethane in anhydrous ethanol, cool to room temperature after the reaction, filter, and vacuum dry to obtain product 2; (3) Dissolve the product 1 obtained in step (1) and the product 2 obtained in step (2) in anhydrous ethanol, add piperidine, and heat the resulting mixture with stirring. After the reaction is completed, cool to room temperature, filter, and vacuum dry to obtain the target product, fluorescent probe MCC-ETB. Furthermore, in the step (1), the molar ratio of 4-methoxysalicylaldehyde, acrolein and potassium carbonate is 1:1.2:1.

[0007] Furthermore, in step (2), the molar ratio of 1,1,2-trimethylbenz[e]indole to ethyl iodide is 1:1.

[0008] Furthermore, in step (3), the molar ratio of product 1 to product 2 is 1:1.

[0009] Furthermore, in step (3), the structure of the fluorescent probe MCC-ETB is as follows: .

[0010] Furthermore, in the 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.

[0011] Furthermore, in step (2), 1,1,2-trimethylbenz[e]indole and iodoethane are dissolved in anhydrous ethanol and then stirred at 78° C. for 6 to 9 hours.

[0012] Furthermore, in step (3), the obtained mixture is placed under N2 protection, heated to 80°C and stirred for 1 to 3 hours.

[0013] The specific reaction process of the fluorescent probe obtained by the above viscosity fluorescent probe preparation method is as follows: The present invention uses 4-methoxysalicylaldehyde, acrolein, iodoethane and 1,1,2-trimethylbenz[e]indole to prepare the required fluorescent probe through chemical reaction. Under viscosity conditions, the fluorescent probe will show a significant fluorescence enhancement phenomenon as the viscosity increases, and has the characteristic of detecting viscosity. Compared with some existing detection technologies, the fluorescent chemical probe in the present invention has less cost investment, a simple synthesis route, convenient post-processing, and can realize viscosity detection, especially in the field of energy batteries, and has potential application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be described in detail below through specific examples. These examples are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be subject to the definition of the attached claims. Unless otherwise specified, the various reagents and materials used in the present invention can be purchased from the market.

[0015] Figure 1 This is the H NMR spectrum of the prepared fluorescent probe MCC-ETB; Figure 2 This is the NMR C spectrum of the prepared fluorescent probe MCC-ETB; Figure 3 This is the spectrum of the fluorescence intensity of the fluorescent probe MCC-ETB changing with viscosity; Figure 4 It is the linear fitting curve diagram of the fluorescence intensity of the fluorescent probe MCC-ETB and the corresponding viscosity; Figure 5 The fluorescence intensity diagram is the selective detection of the fluorescent probe MCC-ETB; Figure 6 This is the fluorescence intensity diagram of the fluorescent probe MCC-ETB as the viscosity of the electrolyte changes; Figure 7 The fitting curve of the fluorescent probe MCC-ETB corresponding to the change of electrolyte viscosity. The concentration of added ions is 1×10 -3 mol / L, 545nm as excitation wavelength, 653 nm as emission wavelength. (Note: The probe concentration is 10μM) DETAILED DESCRIPTION

[0016] Example 1 The preparation method of the viscosity fluorescent probe comprises the following steps: (1) Preparation of Product 1 and Product 2.

[0017] 4-Methoxysalicylaldehyde (5 mmol), acrolein (6 mmol) and potassium carbonate (5 mmol) were added into 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 synthesize product 1.

[0018] 1,1,2-Trimethylbenz[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, it was cooled to room temperature, filtered, and the product 2 was dried in vacuo.

[0019] (2) Use products 1 and 2 to synthesize fluorescent probes.

[0020] 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 reflux for 2 h under N2 protection. After the reaction was completed, the precipitated solid was separated and vacuum dried to obtain the fluorescent probe MCC-ETB.

[0021] MCC-ETB (1 mmol) was weighed and dissolved in DMSO to prepare a 1 mM stock solution.

[0022] Viscosity test of MCC-ETB: Take 10 5 mL sample bottles, add glycerol and PBS mixed solution (glycerol content: 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% and 90%), and continue to add 20 μL of MCC-ETB solution prepared by the fluorescent probe obtained in Example 1 (the concentration of the fluorescent probe is 10 μM). After stirring at room temperature for 1 min, the fluorescence intensity of these samples is measured at 545 nm as the excitation wavelength, and the fluorescence intensity emission spectra of the 10 samples are obtained, as shown in FIG. Figure 3 The results show that the fluorescent probe has a high sensitivity to viscosity, and the fluorescence intensity gradually increases with the increase of viscosity. Figure 3 The fluorescence intensity change value can be used to make a function curve after fitting the corresponding glycerol ratio and the function graph corresponding to the curve (y=ax+b, a=7076.422, b=45.90059, R 2 =0.9996) Figure 4 .

[0023] Other analyte comparison tests: Take 14 5 mL sample bottles, add 20 μL of the solution MCC-ETB prepared by the fluorescent probe obtained in Example 1 (the concentration of the fluorescent probe is 10 μM), and then add 1×10 -2 mol / L other analytes and 90% glycerol / water, take 28μL of each and add them to the other 13 sample bottles, and sample No. 1 is the blank sample. Then measure the fluorescence emission intensity of the 13 samples at 545nm as excitation and 653nm as emission wavelength. The results are shown in 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.

[0024] Response of fluorescent probe MCC-ETB to viscosity in battery electrolyte: During the test, the concentration of the fluorescent probe MCC-ETB was kept at 10 μM in different mass ratios of glycerol / electrolyte. The test system of glycerol and electrolyte with different mass ratios was prepared, and the total test volume was kept at 5 mL. The mass percentages of glycerol were 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%, respectively. The spectrum of the fluorescence intensity change with viscosity was tested with a wavelength of 545 nm as the excitation wavelength. Figure 6 As shown. Figure 6 The fluorescence intensity change value can be used to make a function curve after the corresponding glycerol ratio fitting and the function graph corresponding to the curve (y=ax+b, a=6324.29, b=70.37, R 2 =0.99889) Figure 7 .

[0025] The above embodiments are used to illustrate the present invention rather than to limit the present invention. Any modifications and changes made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a fluorescent probe for detecting battery electrolyte viscosity, characterized in that: The following steps are involved: (1) 4-methoxysalicylaldehyde, acrolein and potassium carbonate are dissolved in 1,4-dioxane, the resulting mixture is heated and stirred, and after the reaction is completed, the mixture is cooled to room temperature, extracted, and separated by column chromatography to obtain product 1; (2) Dissolve 1, 1, 2-trimethylbenz[e]indole and iodoethane in anhydrous ethanol. After the reaction is completed, cool to room temperature, filter, and vacuum dry to obtain product 2. (3) The product 1 obtained in step (1) and the product 2 obtained in step (2) are dissolved in ethanol, piperidine is added, and the resulting mixture is heated and stirred. After the reaction is completed, the mixture is cooled to room temperature, filtered, and vacuum dried to obtain the target product, fluorescent probe MCC-ETB.

2. The method for preparing a fluorescent probe for detecting battery electrolyte viscosity according to claim 1, characterized in that: In the step (1), the molar ratio of 4-methoxysalicylaldehyde, acrolein and potassium carbonate is 1:1.2:

1.

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

1.

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

1.

5. The method for preparing a fluorescent probe for detecting battery electrolyte viscosity according to claim 4, characterized in that: In the step (3), the structure of the fluorescent probe MCC-ETB is as follows: 。 6. The method for preparing a fluorescent probe for detecting battery electrolyte viscosity according to claim 5, characterized in that: In the 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.

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

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

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

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