Application of terbium rare earth metal-organic framework material in quantitative detection of ethylbenzene content in styrene / ethylbenzene solution
The fluorescence detection method of terbium rare earth metal-organic framework material solves the problem of difficult efficient detection of ethylbenzene content in mixed solution of styrene and ethylbenzene in the existing technology, and realizes low-cost, rapid and sensitive quantitative analysis.
Patent Information
- Application Number
- CN202511039327.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-28
- Publication Date
- 2025-09-12
AI Technical Summary
It is difficult to separate and quantitatively detect the content of ethylbenzene in a mixed solution of styrene and ethylbenzene efficiently and at low cost in existing technologies, and gas chromatography is complex and costly to operate.
Terbium rare earth metal-organic framework material was used to detect the ethylbenzene content at room temperature through fluorescence testing. Portable test strips were prepared for rapid detection, utilizing the changes in the fluorescence response of the material at different concentrations.
The method realizes simple, low-cost, rapid and sensitive detection of ethylbenzene content, provides a color change visible to the naked eye, and is suitable for the quantitative analysis of styrene and ethylbenzene mixtures.
Smart Images
Figure CN120629097A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of metal-organic framework materials, and particularly relates to application of a terbium rare earth metal-organic framework material in quantitatively detecting the content of ethylbenzene in a styrene / ethylbenzene solution. Background Art
[0002] Styrene is one of the most important monomers in synthetic rubber and plastics, widely used in the production of styrene-butadiene rubber, polystyrene, and polystyrene foam. Styrene is also used in the pharmaceutical, dye, pesticide, and mineral processing industries. Industrially, styrene is synthesized by catalytic dehydrogenation of ethylbenzene. Due to the similar boiling points of ethylbenzene and styrene, styrene often coexists with ethylbenzene, reducing its purity. Various analytical techniques, such as gas chromatography, have been used to analyze these mixtures, but these techniques are limited by high costs and relatively complex operating procedures.
[0003] In recent years, MOFs have attracted significant attention from scientists due to their diverse chemical structures and excellent properties. They are widely used in gas storage and separation, heterogeneous catalysis, optics, electronics, magnetic materials, chemical sensing, drug delivery, and biomedicine. MOFs can systematically regulate the pores within the framework through different combinations of metal ions and organic linkers, and the functional sites within the framework provide a platform for specific recognition. Summary of the Invention
[0004] In view of the problems existing in the above-mentioned prior art, the object of the present invention is to provide an application of a terbium rare earth metal-organic framework material in the quantitative detection of ethylbenzene content in a styrene / ethylbenzene solution.
[0005] In order to achieve the above object, the present invention adopts the following technical solutions:
[0006] The first aspect of the present invention is to provide a terbium rare earth metal-organic framework material for quantitatively detecting the content of ethylbenzene in a styrene / ethylbenzene solution. The chemical formula of the terbium rare earth metal-organic framework material is {[Tb2(TDA)2(H2O)4]·3H2O·0.5DMF} n , where n is a non-zero natural number, TDA is the deprotonated 1-hydrogen-1,2,3-triazole-4,5-dicarboxylate ion, and DMF is N,N-dimethylformamide.
[0007] Preferably, the method for quantitatively detecting the content of ethylbenzene in a styrene / ethylbenzene solution using a terbium rare earth metal-organic framework material comprises the following steps:
[0008] The terbium rare earth metal-organic framework material was dispersed in methanol to obtain a standard suspension, and then styrene / ethylbenzene solutions containing different concentrations of ethylbenzene were added to the standard suspension, and then fluorescence testing was performed at room temperature with an excitation wavelength of 280 nm.
[0009] The second aspect of the present invention is to provide a portable test paper derived from a terbium rare earth metal-organic framework material, wherein the portable test paper comprises a filter paper strip and a terbium rare earth metal-organic framework material, wherein the terbium rare earth metal-organic framework material is loaded on the filter paper.
[0010] The third aspect of the present invention is to provide an application of the portable test paper, wherein the portable test paper is used to detect the ethylbenzene content in a styrene / ethylbenzene solution;
[0011] The method for detecting the ethylbenzene content in the styrene / ethylbenzene solution is as follows: a portable test paper is immersed in the styrene / ethylbenzene solution containing different concentrations of ethylbenzene, then taken out and dried, and placed under 254nm ultraviolet light for optical detection.
[0012] Compared with the prior art, the present invention has the following beneficial effects:
[0013] (1) The method of the present invention for quantitatively detecting the content of ethylbenzene in a styrene / ethylbenzene solution using the existing material terbium rare earth metal-organic framework material has the characteristics of simple operation, mild test conditions, low cost, convenience and speed, and therefore has broad application prospects.
[0014] (2) The portable test paper developed based on terbium rare earth metal-organic framework material has a highly sensitive fluorescence response to the content of ethylbenzene in styrene / ethylbenzene solution. When the content of ethylbenzene in the mixture increases, the color of the test paper changes from colorless (0-10%), gray-green (30%), slightly green (50%), light green (70%), dark green (90%), to bright green (100%), which is visible to the naked eye, providing possible application for the detection of styrene and ethylbenzene mixtures. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0016] Figure 1 This is the solid fluorescence excitation and emission spectrum of terbium rare earth metal-organic framework material at room temperature;
[0017] Figure 2 The following are X-ray powder diffraction patterns of terbium rare earth metal-organic framework materials after being immersed in styrene and ethylbenzene for three days respectively;
[0018] Figure 3 The fluorescence spectra of terbium rare earth metal-organic framework materials immersed in dilute styrene and ethylbenzene solutions, respectively (wherein the inset is the optical image of the standard suspension after adding ethylbenzene and styrene, recorded at 254nm);
[0019] Figure 4 Fluorescence spectra (a) and linear relationship diagram (b) of terbium rare earth metal-organic framework materials immersed in mixtures containing styrene / ethylbenzene at different volume ratios (the inset is an optical image recorded at 254 nm of a standard suspension immersed in mixtures containing styrene / ethylbenzene at different volume ratios);
[0020] Figure 5 This is a fluorescence intensity graph of the terbium rare earth metal-organic framework material after five rounds of recycling through the above detection method;
[0021] Figure 6 These are optical images of the fluorescence response of test paper made of terbium rare earth metal-organic framework materials to styrene solutions containing different amounts of ethylbenzene (the upper row shows the color of the test paper before the test, and the lower row shows the color of the test paper after the test). DETAILED DESCRIPTION
[0022] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may also be implemented in other embodiments without these specific details.
[0023] Example 1
[0024] 1. Detection of terbium rare earth metal-organic framework material (whose chemical formula is {[Tb2(TDA)2(H2O)4]·3H2O·0.5DMF} n , where n is a non-zero natural number, TDA is 1-hydrogen-1,2,3-triazole-4,5-dicarboxylate ion, and DMF is N,N-dimethylformamide) solid fluorescence excitation and emission spectra at room temperature
[0025] Specific steps: 1) 0.6 mg of terbium rare earth metal-organic framework material powder sample was dispersed in 2 mL of methanol and ultrasonicated for 30 minutes to form a standard suspension; 2) a diluted styrene / ethylbenzene solution (styrene / ethylbenzene: methanol = 1:500, 100 μL) was added to the above standard suspension and ultrasonicated for 30 minutes, and then a fluorescence test was performed at room temperature with an excitation wavelength of 280 nm to obtain the solid fluorescence excitation and emission spectra of the terbium rare earth metal-organic framework material at room temperature, see Figure 1 .
[0026] Depend on Figure 1 The results show that under the excitation wavelength of 280nm, there are four main emission peaks at 487nm, 544nm, 585nm, and 621nm, corresponding to Tb 3+ Ionic 5 D4→ 7 F J (J=6,5,4,3) transition. The inset is the color map of the sample under sunlight and 254nm ultraviolet excitation light. It can be seen that the terbium rare earth metal-organic framework material exhibits strong green fluorescence, which is mainly derived from the 544nm 5 D4→ 7 F5 jump.
[0027] 2. Detection of the stability of terbium rare earth metal-organic framework materials in styrene and ethylbenzene
[0028] The specific steps are as follows: the terbium rare earth metal-organic framework material crystals are ground evenly into powder, respectively immersed in styrene and ethylbenzene, filtered after 3 days, dried in air, and then tested at room temperature in the range of 5-50° at 0.2° / s to obtain the X-ray powder diffraction pattern of the terbium rare earth metal-organic framework material after being immersed in styrene and ethylbenzene for three days, as shown in FIG. Figure 2 .
[0029] Depend on Figure 2 The results show that the diffraction spectra of the samples soaked in styrene and ethylbenzene are highly consistent with the spectra of single crystal simulation, indicating that the terbium rare earth metal-organic framework material has high stability in both styrene and ethylbenzene.
[0030] 3. Detect the fluorescence spectra of terbium rare earth metal-organic framework materials in diluted styrene solution and ethylbenzene solution respectively
[0031] Specific steps: 0.6 mg of terbium rare earth metal-organic framework material was dispersed in 2 mL of methanol and ultrasonicated for 30 minutes to form a standard suspension; diluted styrene solution and ethylbenzene solution (styrene:methanol = 1:500, 100 μL; ethylbenzene:methanol = 1:500, 100 μL) were added to the above standard suspension and ultrasonicated for 30 minutes, and then fluorescence test was performed at room temperature with an excitation wavelength of 280 nm. The fluorescence spectra of the terbium rare earth metal-organic framework material immersed in diluted styrene solution and ethylbenzene solution were obtained. Figure 3 .
[0032] Depend on Figure 3 The results showed that the fluorescence intensity of the standard suspension was significantly quenched after adding styrene solution, while the fluorescence intensity of the standard suspension remained almost unchanged after adding ethylbenzene solution.
[0033] 4. Detect the fluorescence spectrum of terbium rare earth metal-organic framework materials immersed in styrene / ethylbenzene mixed solutions containing different volume ratios
[0034] Specific steps: add diluted styrene / ethylbenzene mixed solutions of different volume ratios (total volume: 100 μL) to the standard suspension, ultrasonicate for 30 minutes, and then perform fluorescence testing at room temperature with an excitation wavelength of 280 nm to obtain the fluorescence spectra and linear relationship results of the terbium rare earth metal-organic framework material immersed in styrene / ethylbenzene mixed solutions of different volume ratios, see Figure 4 .
[0035] Depend on Figure 4 (a) The results show that as the ethylbenzene content in the styrene / ethylbenzene mixed solution increases, the fluorescence intensity of the terbium rare earth metal-organic framework material gradually increases.
[0036] Figure 4 (b) The results show that the volume ratio φ is the content of ethylbenzene in the styrene / ethylbenzene mixture, and I0 is the value obtained after adding pure styrene solution. 5 D4→ 7 F5 characteristic fluorescence intensity, I is measured after adding styrene / ethylbenzene mixture with different volume ratios φ 5 D4→ 7 F5 characteristic fluorescence intensity, Tb 3+ Ionic 5 D4→ 7 The F5 transition intensity ratio is I0 / I, that is, I N , which is closely related to the volume ratio φ of ethylbenzene in the mixture of styrene and ethylbenzene. There is a good linear relationship between them, which can be expressed as follows: ln(I NThe above experimental results show that the terbium rare earth metal-organic framework material can be used to quantitatively detect the content of ethylbenzene in a mixture of styrene and ethylbenzene.
[0037] 5. Recycling and reuse of terbium rare earth metal-organic framework materials.
[0038] Specific steps: After testing, the terbium rare earth metal-organic framework material sample is simply filtered and washed with methanol. The solid sample is collected and redispersed in methanol to form a standard suspension, and its fluorescence intensity is tested. Figure 5 .
[0039] Depend on Figure 5 The results show that the fluorescence intensity of the terbium rare earth metal-organic framework material sample after the test can be restored to the fluorescence intensity before the test, and the fluorescence recognition ability of the terbium rare earth metal-organic framework material to the styrene / ethylbenzene mixed solution can be cycled for at least five rounds, and the initial fluorescence intensities of these five rounds are 100%, 97.6%, 96.5%, 96.0% and 94.3% of the original fluorescence intensity respectively.
[0040] 6. Detection of ethylbenzene content in styrene / ethylbenzene mixed solution using portable test strips made of terbium rare earth metal-organic framework materials
[0041] Specific steps: At room temperature, the terbium rare earth metal-organic framework material powder sample is evenly dispersed and adhered to a 1.2×2.4cm 2 The test paper was then immersed in styrene solutions containing different contents of ethylbenzene, and then taken out and placed under 254nm ultraviolet light to record its optical image, and the fluorescence response optical image of the test paper made of terbium rare earth metal-organic framework material to styrene solutions containing different contents of ethylbenzene was obtained, as shown in FIG. Figure 6 .
[0042] Depend on Figure 6 The results show that as the ethylbenzene content in styrene increases, the color of the test paper changes visibly from colorless (0-10%), gray-green (30%), slightly green (50%), light green (70%), dark green (90%), to bright green (100%). This rapid, sensitive, and reusable sensor-based portable test paper provides potential applications for the detection of styrene and ethylbenzene mixtures.
[0043] The present invention is not limited to the above-mentioned specific implementation methods. Various changes made by ordinary technicians in this field based on the above-mentioned concept without creative work are all within the scope of protection of the present invention.
Claims
1. An application of a terbium rare earth metal-organic framework material in the quantitative detection of ethylbenzene content in a styrene / ethylbenzene solution, characterized in that: The chemical formula of the terbium rare earth metal-organic framework material is {[Tb2(TDA)2(H2O)4]·3H2O·0.5DMF} n , where n is a non-zero natural number, TDA is the deprotonated 1-hydrogen-1,2,3-triazole-4,5-dicarboxylate ion, and DMF is N,N-dimethylformamide.
2. The use according to claim 1, characterized in that The method for quantitatively detecting the content of ethylbenzene in a styrene / ethylbenzene solution using a terbium rare earth metal-organic framework material comprises the following steps: The terbium rare earth metal-organic framework material was dispersed in methanol to obtain a standard suspension, and then styrene / ethylbenzene solutions containing different concentrations of ethylbenzene were added to the standard suspension, and then fluorescence testing was performed at room temperature with an excitation wavelength of 280 nm.
3. A portable test paper derived from a terbium rare earth metal-organic framework material, characterized in that: The portable test paper comprises a filter paper strip and the terbium rare earth metal-organic framework material as claimed in claim 1 , wherein the terbium rare earth metal-organic framework material is loaded on the filter paper strip.
4. A use of the portable test strip according to claim 3, characterized in that: The test paper is used to detect the content of ethylbenzene in styrene / ethylbenzene solution; The method for detecting the ethylbenzene content in the styrene / ethylbenzene solution is as follows: a portable test paper is immersed in the styrene / ethylbenzene solution containing different concentrations of ethylbenzene, then taken out and dried, and placed under 254nm ultraviolet light for optical detection.