A stimulus-responsive material for volatile amine detection, preparation method, and application thereof

Abstract

The present invention belongs to the technical field of stimulus-responsive materials, and relates to a stimulus-responsive material for volatile amine detection, and its preparation method and application. Zinc sulfate heptahydrate, 2-hydroxyacetic acid, 2,4,6-tris(4-pyridine)-1,3,5-triazine and N, N-dimethylacetamide are uniformly mixed, phosphoric acid is added to adjust the pH and loaded into a high-pressure stainless steel reactor in a polytetrafluoroethylene lining, after solvent thermal reaction, filtered, washed, and the stimulus-responsive material is obtained; preparation method, process is simple, efficient, and easy to scale production; the stimulus-responsive material has good thermal stability and chemical stability, can effectively adsorb different amines, and can achieve rapid, sensitive and visual detection of ammonia and methylamine by directly observing the color change of the material with the naked eye; detection method is simple and efficient, application scenarios are wide, and market prospects are broad.

Description

Technical field:

[0001] The present invention belongs to the technical field of stimulus-responsive materials and relates to a stimulus-responsive material for detecting volatile amines, a preparation method thereof, and an application thereof. Background technology:

[0002] Volatile organic amines (VOAs), including 24 types such as ammonia (NH3), methylamine (MA), dimethylamine (DEA), and trimethylamine (TEA), are a class of hazardous compounds found in industrial processes and the natural environment. These compounds not only pollute the environment but can also pose a threat to human health. Therefore, the detection and monitoring of these VOAs is of great environmental and health significance.

[0003] Traditional volatile amine detection techniques mainly include chromatography and fluorescent probe methods, which usually require complex sample or material preparation. Therefore, it is imperative to develop a method for rapid, convenient and sensitive detection of volatile amines in the environment. Coordination polymers (CPs) have shown great application potential in organic chemistry, inorganic chemistry, biochemistry, materials science and electrochemistry due to their excellent properties. CPs constructed from viologen derivatives have been widely used in magnetism, luminescence, conductivity, sensing and catalysis due to their electron-deficient properties. In particular, they show unique responses to external stimuli such as light, heat, electricity, humidity and organic amines.

[0004] There are currently many studies on the detection of volatile amines. For example, in 2022, Gao Guanggang et al. reported a polyoxometalate-viologen complex and achieved highly sensitive detection of ethylenediamine, with a detection limit of 0.1 ppb. This was also the most sensitive complex reported for ethylenediamine sensors at the time. In addition, when other amine molecules coexist as interfering substances, the polyoxometalate can achieve high selectivity for ethylenediamine. (X. Zhang, W. Zhu, Z. Yang, Y. Feng, L. Fan, G. Gao and H. Liu. Ultrasensitive photochromic and Raman dual response to ethylenediaminegas through polyoxometalate-viologen crystalline hybrid. J. Mater. Chem. C, 2022, 10, 15451 DOI: 10.1039 / D2TC03053E). In 2023, Zang Shuangquan et al. reported a multi-stimulus-responsive Cd-based chromogenic complex in Inorganic Chemistry. The complex has good stimulus color development properties and exhibits reversible photochromism, thermochromism, electrochromism, and gas-phase color change reactions detectable by the naked eye to different volatile amines. (Yun Luo, Jia-Pei Liu, Lin-Ke Li, and Shuang-Quan Zang. Multi-Stimuli-Responsive Chromic Behaviors of an All-in-One Viologen-Based Cd(II) Complex. Inorg. Chem. 2023 62(35), 14385-14392. DOI: 10.1021 / acs.inorgchem.3c02070).

[0005] Currently, many materials are available for detecting volatile amines. However, these materials suffer from slow response, poor stability, and poor fatigue resistance, severely limiting their practical applications in industrial manufacturing and daily life. Therefore, the design and construction of stimuli-responsive materials for volatile amine detection to unlock and expand their application potential remains a challenging research topic. Summary of the invention:

[0006] The present invention aims to overcome the shortcomings of the prior art by providing a stimuli-responsive material for volatile amine detection, its preparation method, and its application. This material, which uses 2,4,6-tris(4-pyridine)-1,3,5-triazine as an electron acceptor, rapidly changes color upon exposure to ammonia or methylamine, thereby enabling rapid, sensitive, and visual detection of these gases. The present invention also provides a method for synthesizing the target compound using self-assembly technology, which is simple, efficient, and amenable to large-scale production.

[0007] In order to achieve the above objectives, the present invention provides a method for preparing a stimulus-responsive material for volatile amine detection, the specific preparation process is as follows:

[0008] (1) Mix zinc salt (0.09-0.1 g), organic acid (0.30-0.31 g), organic ligand (0.03-0.031 g) and N,N-dimethylacetamide (DMA) (0.19-0.2 mL) until uniform;

[0009] (2) The mixture obtained in step (1) was stirred at room temperature for 0.5 hours. After uniform stirring, 0.15 mL of phosphoric acid (H3PO4) was added to adjust the pH to about 2-3. The mixture was placed in a high-pressure stainless steel reactor lined with polytetrafluoroethylene and reacted at 120°C for 6-7 days. The mixture was taken out and naturally cooled to room temperature to obtain yellow block crystals. The crystals were washed and dried to prepare a stimuli-responsive material for volatile amine detection.

[0010] The zinc salt of the present invention is zinc sulfate heptahydrate; the organic acid is 2-hydroxyacetic acid; the organic ligand is 2,4,6-tris(4-pyridine)-1,3,5-triazine (TPT); and the volume of the stainless steel reactor is 20 mL.

[0011] The stimulus-responsive material of the present invention was tested by single crystal X-ray diffraction. The obtained data were analyzed by Olex2 software and it was found that the asymmetric unit of the material contained a Zn 2+ ions, a SO4 2- Anion, one HSO4 - anion and a protonated TPT cation ( Figure 1 ), the structural formula is Zn(H-TPT)(SO4)(HSO4). The adjacent metal Zn is reacted with HSO4 - The protonated H-TPT ligands are distributed on both sides of the 1D chain. The adjacent inorganic chains are connected by hydrogen bonds to form a two-dimensional (2D) layered structure. The H-TPT ligands between the layers are arranged antiparallel along the a-axis and form a three-dimensional (3D) supramolecular structure through the π-π stacking interaction between the aromatic rings. Figure 2 ), this structure and arrangement play an important role in the detection process of volatile amines.

[0012] The present invention also provides a stimulus-responsive material prepared by the above method, the molecular formula of which is C 18 H 14 N6O8S2Zn is a yellow block crystal.

[0013] The present invention also provides an application of the stimulus-responsive material in the detection of volatile amines, which can be used to detect ammonia and methylamine.

[0014] The present invention aims to apply coordination assembly strategies and crystal engineering principles to develop a new volatile amine detection material based on a 3D supramolecular compound of metal sulfate. This material uses 2,4,6-tris(4-pyridine)-1,3,5-triazine as an electron acceptor and constructs a functional material with a 3D supramolecular structure through a solvent thermal synthesis method. This material can adsorb sterically hindered and small-sized volatile amines (such as NH3 and MA). These amines can form free radicals through an electron transfer process with the above-mentioned electron acceptor through intermolecular forces, resulting in a visual color change, enabling naked eye visual detection. The detection effect of the amine can be judged by observing the color change of the material. The present invention further prepares the material into a coated filter paper, achieving effective detection of NH3 and MA, demonstrating the potential application of this stimulus-responsive material in volatility detection.

[0015] Compared with the existing technology, the present invention provides a simple and efficient preparation method for synthesizing stimulus-responsive materials using solvent thermal self-assembly technology. The process is simple, efficient, and easy to scale up. The stimulus-responsive material has good thermal stability and chemical stability, can effectively adsorb different amines, and can achieve rapid, sensitive, and visual detection of ammonia and methylamine by directly observing the color change of the material with the naked eye. The detection method is simple and efficient, with a wide range of application scenarios and broad market prospects. Description of the drawings:

[0016] Figure 1 This is a schematic diagram of the asymmetric unit structure principle of the stimulus-responsive material involved in the present invention.

[0017] Figure 2 This is a schematic diagram of the 3D supramolecular structure principle of the stimulus-responsive material involved in the present invention.

[0018] Figure 3 The UV-vis spectra of the stimulus-responsive material of the present invention before and after fumigation with volatile amines are shown.

[0019] Figure 4 The EPR spectra of the stimulus-responsive material of the present invention before and after fumigation with volatile amines are shown.

[0020] Figure 5The present invention is a schematic diagram of the structural principle of a test device for detecting amine vapor using a stimulus-responsive material.

[0021] Figure 6 This is a schematic diagram of the color change of the stimulus-responsive material of the present invention in different amine vapor atmospheres.

[0022] Figure 7 Schematic diagram of the coated filter paper made of the stimulus-responsive material of the present invention being used to detect amines. Specific implementation method:

[0023] The present invention will be further described below through examples with reference to the accompanying drawings.

[0024] Example 1:

[0025] This embodiment relates to a method for preparing a stimuli-responsive material for detecting volatile amines, and the specific steps are as follows:

[0026] (1) 0.09 g of zinc sulfate heptahydrate, 0.30 g of 2-hydroxyacetic acid, and 0.03 g of 2,4,6-tris(4-pyridyl)-1,3,5-triazine (TPT) were mixed with 0.2 mL of dimethylacetamide (DMA) and stirred for 0.5 h. 0.15 mL of phosphoric acid (H3PO4) was then added to adjust the pH to approximately 2-3. The mixture was then transferred to a 20 mL stainless steel reactor lined with polytetrafluoroethylene.

[0027] (2) The stainless steel reactor containing the reactants in step (1) was sealed and reacted in an oven at 120° C. for 7 days. After the reaction was completed, the stainless steel reactor was taken out and naturally cooled at room temperature. The crystals obtained in the stainless steel reactor were repeatedly washed with anhydrous ethanol 5 times and dried at room temperature to obtain yellow block crystals, which were the stimulus-responsive materials for volatile amine detection.

[0028] The structural formula of the 2,4,6-tris(4-pyridine)-1,3,5-triazine is:

[0029]

[0030] The structure of the prepared stimulus-responsive material was determined using a single crystal X-ray diffractometer. The unit cell parameters obtained from the test were a = 10.424 (2) angstroms, b = 27.746 (6) angstroms, c = 8.6874 (17) angstroms, α = 90 degrees, β = 123.12 (3) degrees, γ = 90 degrees, V = 2104.4 (9) cubic angstroms, Z = 4, and space group Cc. The obtained single crystal data was structurally analyzed using Olex2 software, and the asymmetric unit formula was Zn (H-TPT) (SO4) (HSO4). The study found that the material has a 3D supramolecular structure. The asymmetric unit contains a Zn2+ ions, a SO4 2- Anion, one HSO4 - and a protonated TPT cation ( Figure 1 The metal center follows the four-coordination mode of [ZnO3N], and the two oxygen atoms come from HSO4 - , one oxygen atom comes from SO4 2- , the nitrogen atom comes from the protonated TPT ligand.

[0031] The molecular formula of the stimulus-responsive material for volatile amine detection prepared by the present invention is C 18 H 14 N6O8S2Zn, molecular weight is 571.84.

[0032] Example 2:

[0033] This example relates to the detection test of volatile amines by the stimulus-responsive material prepared in Example 1. The gas diffusion device used in the test ( Figure 5 ) is as follows: the yellow block crystals of Example 1 are placed in an open small glass bottle, which is placed in a closed large glass bottle (volume 20mL), and 3mL of volatile amine solution is placed in the large glass bottle outside the small glass bottle. The volatile amine solution is ammonia water (NH3·H2O), methylamine (MA) aqueous solution, diethylamine (DEA) or triethylamine (TEA), which is volatilized to emit ammonia gas, methylamine gas, diethylamine gas or triethylamine gas; the color change and response time of the stimulus-responsive material when exposed to different volatile amine solution environments are measured at room temperature. The results are as follows Figure 6 shown.

[0034] The ammonia water (analytical grade, NH3 content 25.0-28.0%), methylamine aqueous solution (analytical grade, methylamine content 25.0-30.0%), diethylamine (analytical grade, diethylamine content 99.0%) and triethylamine (analytical grade, triethylamine content 99.0%) are all commercially available.

[0035] The results showed that when the volatile amine solution was ammonia water, the color of the material changed from yellow to grayish white within 5 minutes (referred to as 1-NH3); when the volatile amine solution was methylamine aqueous solution, the material changed from yellow to grayish green within 30 minutes (referred to as 1-MA); when the volatile amine solution was diethylamine aqueous solution or triethylamine aqueous solution, the color of the material did not change even after 2 days (referred to as 1-DEA and 1-TEA, respectively) ( Figure 6 This is because the material can generate free radicals through electron transfer with volatile amines through intermolecular interactions. Smaller amine molecules (such as NH3 and MA) can be easily adsorbed, resulting in color changes, while larger amine molecules (such as DEA and TEA) are difficult to effectively adsorb due to steric hindrance and size factors.

[0036] In this example, ultraviolet-visible spectroscopy (UV-vis) and electromagnetic paramagnetic resonance (EPR) spectroscopy were performed on the stimulus-responsive material before and after fumigation with volatile amines. The results are as follows: Figure 3 and Figure 4 shown.

[0037] from Figure 3 The UV-visible spectrum shows an increase in absorbance around 650 nm for 1-NH3 and 1-MA, while 1-DEA and 1-TEA show no significant change compared to the original sample. It is speculated that the NH3 and MA treatments generate free radicals, causing the material to darken in color, corresponding to the increased absorbance in the UV-visible spectrum.

[0038] from Figure 4 It can be seen that the material after amine fumigation produces an obvious free radical characteristic peak near 3400 Gauss, which further confirms that the material produces free radicals after amine fumigation.

[0039] Example 3:

[0040] This example relates to the application of the stimulus-responsive material prepared in Example 1. 0.2 g of the material was fully dissolved in 5 mL of trichloromethylamine, and the solution was then evenly dispersed on filter paper to prepare a coated filter paper for detecting volatile amines and preventing their leakage ( Figure 7 ). After the prepared coated filter paper is dried, place it on Figure 5 The device's mouth (with the inner vial and yellow crystals removed) shows different color changes and response times when exposed to NH3 or MA fumigation, respectively, from the volatile solution. Under NH3 fumigation, the coated filter paper turns gray within 5 minutes; under MA fumigation, it turns gray-green within 30 minutes. This example demonstrates the excellent selectivity of this material for volatile amine detection and its potential applications in real-world production.

Claims

1. A method for preparing a stimulus-responsive material for volatile amine detection, characterized in that: The specific steps are as follows: Zinc sulfate heptahydrate, 2-hydroxyacetic acid, 2,4,6-tris(4-pyridine)-1,3,5-triazine and N,N-dimethylacetamide are mixed and stirred evenly; the pH is adjusted to 2-3 with phosphoric acid; the mixture is then placed in a high-pressure stainless steel reactor for hydrothermal reaction; and washed and dried to prepare a stimulus-responsive material for volatile amine detection. The dosage ratio of the zinc sulfate heptahydrate, 2-hydroxyacetic acid, 2,4,6-tris(4-pyridine)-1,3,5-triazine and N,N-dimethylacetamide is (0.09-0.1 g): (0.30-0.31 g): (0.03-0.031 g): (0.19-0.2 mL).

2. The method for preparing a stimulus-responsive material for volatile amine detection according to claim 1, wherein: The stirring time was 0.5 hours.

3. The method for preparing a stimulus-responsive material for volatile amine detection according to claim 1, wherein: Phosphoric acid was added to adjust the pH. The ratio of phosphoric acid to N,N-dimethylacetamide was 0.15 mL:(0.19-0.2 mL).

4. The method for preparing a stimulus-responsive material for volatile amine detection according to claim 1, wherein: The solvent thermal reaction temperature is 120°C and the time is 6-7 days.

5. The stimuli-responsive material for volatile amine detection prepared by the preparation method according to any one of claims 1 to 4, characterized in that: The material is C 18 H 14 N6O8S2Zn is a yellow block crystal.

6. Use of the stimulus-responsive material for volatile amine detection according to claim 5 in volatile amine detection, characterized in that: The rapid, sensitive and visual detection of ammonia and methylamine can be achieved by directly observing the color change of the material with the naked eye.

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