A multi-level pore fluorescent monolithic material, a preparation method and application thereof

Abstract

This invention discloses a hierarchical porous fluorescent monolithic material, its preparation method, and its applications, belonging to the technical field of fluorescent monolithic materials. The preparation method disclosed in this invention includes: mixing a fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission, a compound containing amino functional groups, and a solvent to obtain a homogeneous solution; introducing the homogeneous solution into a capillary tube and then placing it in a heating device for heating reaction to obtain a solid product; and post-processing the solid product to obtain the hierarchical porous fluorescent monolithic material. This method solves the technical problems of poor universality of existing fluorescent materials and the difficulty of connecting the separation unit and the sensing unit in series.

Description

Technical Field

[0001] This invention belongs to the field of fluorescent monolithic materials technology, specifically relating to a hierarchical porous fluorescent monolithic material, its preparation method, and its application. Background Technology

[0002] Highly sensitive fluorescence sensors, as portable devices, have demonstrated significant advantages in environmental analysis, food safety monitoring (such as meat freshness assessment), and public safety (such as detection of illicit drugs, chemical warfare agents, and explosives). However, with the increasing complexity of practical applications and the growing stringency of relevant industry standards, fluorescence sensing technology still faces many challenges in distinguishing and detecting complex samples. First, traditional fluorescence sensing media (such as random fluorescent powder materials or fluorescent substances coated on substrates such as glass plates) have significant limitations: their physical forms are difficult to standardize, resulting in low device integration; at the same time, these materials are susceptible to interference from environmental factors (such as temperature, humidity, and light), leading to fluorescence quenching or signal drift, which seriously affects the stability and reproducibility of detection. In addition, due to the lack of effective front-end separation media, traditional fluorescence sensors struggle to achieve specific identification and distinguishing detection of multi-component mixed samples in complex matrices. To address these challenges, researchers have developed two main strategies: principal component analysis (PCA) and sensor array technology. PCA, as a multivariate statistical analysis method, can extract feature information from fluorescence response data through dimensionality reduction. However, this method is highly dependent on the quality and completeness of the original data. Matrix effects and environmental variables (such as humidity fluctuations and coexisting interfering substances) in real samples can significantly affect the reliability of the data, leading to large deviations in quantitative analysis results. Sensor array technology constructs multi-channel detection systems and utilizes the differences in response patterns of different sensing units to target analytes to achieve differentiated detection. However, it also faces problems such as environmental interference and signal crosstalk, and the data processing process is complex, making it difficult to meet the needs of rapid on-site detection. In recent years, the development of novel fluorescence sensing materials has provided a possibility for overcoming these technical bottlenecks. For example, metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) with regular pore structures have shown great potential in the front-end separation and specific identification of complex samples due to their tunable fluorescence properties and excellent selective adsorption capabilities. In addition, intelligent sensing systems based on machine learning algorithms are emerging. By establishing a nonlinear mapping relationship between multidimensional response signals and target analyte concentrations, they are expected to achieve accurate quantitative detection of trace targets in complex environments. In the future, the development of fluorescence sensing technology will focus on improving the anti-interference ability of materials, optimizing device integration processes, and developing more advanced signal processing algorithms to meet the higher requirements for sensitivity, selectivity, and reliability in practical application scenarios.

[0003] Fluorescent sensors show promising application prospects in various fields, but in practical applications, technical challenges such as the difficulty in molding and processing fluorescent materials, the complexity of mass transfer processes, and poor universality must be addressed. Therefore, the molding of fluorescent materials and the cascading connection of the separation unit and the sensing unit are crucial for the practical application of fluorescent sensors. This is a key approach to solving the problem of poor differentiation and recognition of mixtures by the sensing medium in fluorescent sensors. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-level porous fluorescent monolithic material, its preparation method and application, in order to solve the technical problems of poor universality of existing fluorescent materials and difficulty in connecting the separation unit and the sensing unit in series.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] This invention discloses a method for preparing a hierarchical porous fluorescent monolithic material, comprising the following steps:

[0007] A homogeneous solution was obtained by mixing a fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission, and a compound containing amino functional groups with a solvent.

[0008] The homogeneous solution was introduced into a capillary tube and then placed in a heating device for heating reaction to obtain a solid product; the solid product was then post-processed to obtain a hierarchical porous fluorescent monolithic material.

[0009] Furthermore, when the compound containing the amino functional group is a solid, the specific steps are as follows:

[0010] A fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission is mixed with a solvent to obtain mixed solution A;

[0011] A compound containing an amino functional group is mixed with a solvent to obtain a mixed solution B;

[0012] Mixed solution A and mixed solution B are mixed to obtain a homogeneous solution; the homogeneous solution is introduced into a capillary tube and then placed in a heating device for heating reaction to obtain a solid product; the solid product is post-processed to obtain a hierarchical porous fluorescent monolithic material.

[0013] When the compound containing the amino functional group is a liquid, the specific steps are as follows:

[0014] A fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission is mixed with a solvent to obtain a mixed solution A. An amino functional group is added to the mixed solution A to obtain a homogeneous solution. The homogeneous solution is introduced into a capillary tube and then placed in a heating device for heating reaction to obtain a solid product. The solid product is post-processed to obtain a hierarchical porous fluorescent monolithic material.

[0015] Furthermore, the solvent is an organic solvent or a mixture of an organic solvent and water; the compound containing an aldehyde functional group and exhibiting aggregation-induced luminescence is a tetraaldehyde tetraphenylethylene.

[0016] The amino-functionalized compound is trans-1,2-cyclohexanediamine, 1,4-butanediamine, 1,4-cyclohexanediamine, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, or hydrazine hydrate.

[0017] Furthermore, the ratio of the fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced luminescence to the solvent is 91.6 mg:(426-535) μL.

[0018] Furthermore, the ratio of the amino-functionalized compound to the solvent is (25-47) mg: (426-535) μL.

[0019] Furthermore, the heating device is a water bath; the heating reaction temperature is 40–80°C, and the time is 4–12 hours.

[0020] Furthermore, the post-processing includes sequential washing and drying processes.

[0021] Furthermore, the washing process involves rinsing with ethanol and n-hexane sequentially.

[0022] The present invention also discloses a method for preparing a hierarchical porous fluorescent monolithic material obtained by the above preparation method.

[0023] The present invention also discloses a method for preparing the above-mentioned hierarchical porous fluorescent monolithic material.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention discloses a method for preparing a hierarchical porous fluorescent monolithic material. The method involves mixing a fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission, a compound containing amino functional groups, and a solvent, and then introducing the mixture into a capillary. The hierarchical porous fluorescent monolithic material is then prepared in situ within the capillary. Due to the aggregation-induced emission properties of the multiple aldehyde functional group compound, the resulting solid hierarchical porous fluorescent monolithic material exhibits ideal fluorescence properties. Simultaneously, its rigid framework endows the fluorescent monolithic material with a high specific surface area and a hierarchical porous structure. In contrast, existing fluorescent materials are either random fluorescent powders or fluorescent substances coated on substrates such as glass plates, making them unsuitable for practical applications and unable to separate mixed samples. The capillary used in this method acts as a medium for filling and loading, realizing the series connection between the separation unit and the sensing unit. The hierarchical pores in the hierarchical porous fluorescent monolithic material improve the mass transfer process and facilitate sample adsorption and separation. Furthermore, its fluorescence properties allow it to function as a sensing medium, enabling the distinguishing detection of mixed samples. Attached Figure Description

[0026] Figure 1 The images show physical models and fluorescence emission patterns of the hierarchical porous fluorescent monolithic materials prepared according to different embodiments of the present invention.

[0027] Figure 2 The images show the fluorescence emission spectra of the hierarchical porous fluorescent monolithic materials prepared in different embodiments of the present invention.

[0028] Figure 3 The images show the physical specimen and fluorescence emission pattern of the monolithic capillary column prepared in Example 1 of this invention.

[0029] Figure 4 This is a scanning electron microscope image of the monolithic capillary column prepared in Example 1 of the present invention;

[0030] Wherein: a-morphology of the hierarchical fluorescent monolithic material; b-enlarged view of the hierarchical fluorescent monolithic material bonded to the inner wall of the capillary;

[0031] Figure 5 This is a macropore size distribution diagram of the hierarchical porous fluorescent monolithic material prepared in Example 1 of the present invention;

[0032] Figure 6 This is a microporous physical adsorption test diagram of the hierarchical porous fluorescent monolithic material prepared in Example 1 of the present invention;

[0033] Figure 7 This is a microporous physical adsorption test diagram of the hierarchical porous fluorescent monolithic material prepared in Example 7 of the present invention. Detailed Implementation

[0034] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0035] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0036] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0037] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0038] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0039] This invention provides a method for preparing a hierarchical porous fluorescent monolithic material, comprising the following steps:

[0040] First, a fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission, a compound containing aldehyde functional groups and exhibiting aggregation-induced emission characteristics, an organic solvent, and water are mixed evenly. Then, the homogeneous solution is placed in a heating device for heating reaction to obtain a solid product. Finally, the solid product is washed and dried to obtain a hierarchical porous fluorescent monolithic material.

[0041] The specific steps are as follows:

[0042] Step 1: Mix a fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission with an organic solvent until homogeneous, or mix a fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission with an organic solvent and water until homogeneous to obtain mixed solution A.

[0043] Step 2: Mix the compound containing the amino functional group and the organic solvent evenly, or mix the compound containing the amino functional group, the organic solvent and water evenly to obtain mixed solution B;

[0044] Step 3: Mix solution A and solution B thoroughly to obtain a homogeneous solution;

[0045] Step 4: After the homogeneous solution C is introduced into the capillary, it is placed in a heating device for heating reaction to obtain a solid product; the solid product is then post-processed to obtain a hierarchical porous fluorescent monolithic material (hierarchical porous capillary monolithic column).

[0046] This invention, based on a polymerization-induced phase separation method, employs a one-pot method to prepare a hierarchical porous fluorescent monolithic material in situ within a capillary, possessing both separation and sensing properties, thus achieving a series connection between the separation and sensing units. The hierarchical porous structure of the fluorescent monolithic material enables selective adsorption and separation of complex samples, while its fluorescence properties can be detected, achieving an integrated adsorption, separation, and detection approach. This solves the problem of difficult differentiation and identification of mixtures and allows for real-time and rapid detection of mixtures. This invention selects a capillary as the medium for packing, constructing a bifunctional material—a hierarchical porous fluorescent monolithic material—within the capillary in situ, thereby realizing a series connection between the separation and sensing units.

[0047] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0048] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0049] Example 1

[0050] A method for preparing a hierarchical porous fluorescent monolithic material includes the following steps:

[0051] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene, 321 μL of dimethyl sulfoxide and 214 μL of N,N-dimethylformamide to a glass bottle to obtain mixed solution A;

[0052] Step 2: Sonicate mixed solution A at room temperature for 2 minutes;

[0053] Step 3: Add 49.5 μL of trans-1,2-cyclohexanediamine to mixed solution A, and sonicate to form a homogeneous solution.

[0054] Step 4: After introducing the homogeneous solution into the capillary, it is transferred to an 80°C water bath and reacted for 12 hours to obtain a monolithic capillary column; the monolithic capillary column is washed sequentially with ethanol and n-hexane, and then dried with nitrogen to obtain a hierarchical porous fluorescent monolithic material.

[0055] Example 2

[0056] A method for preparing a hierarchical porous fluorescent monolithic material includes the following steps:

[0057] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene, 295 μL of dimethyl sulfoxide and 197 μL of N,N-dimethylformamide to a glass bottle to obtain mixed solution A;

[0058] Step 2: Sonicate mixed solution A at room temperature for 2 minutes;

[0059] Step 3: Add 40 μL of 1,4-butanediamine to mixed solution A, and sonicate to form a homogeneous solution.

[0060] Step 4: After introducing the homogeneous solution into the capillary, it was transferred to a 40°C water bath and reacted for 4 hours to obtain a solid product. The solid product was washed with ethanol and n-hexane in sequence, and then dried with nitrogen to obtain a hierarchical porous fluorescent monolithic material.

[0061] Example 3

[0062] A method for preparing a hierarchical porous fluorescent monolithic material includes the following steps:

[0063] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene and 499 μL of dimethyl sulfoxide to a glass bottle to obtain mixed solution A;

[0064] Step 2: Sonicate mixed solution A at room temperature for 2 minutes;

[0065] Step 3: Add 50.8 μL of 1,4-cyclohexanediamine to mixed solution A, and sonicate to form a homogeneous solution.

[0066] Step 4: After introducing the homogeneous solution into the capillary, it was transferred to a 40°C water bath and reacted for 6 hours to obtain a solid product. The solid product was washed with ethanol and n-hexane in sequence, and then dried with nitrogen to obtain a hierarchical porous fluorescent monolithic material.

[0067] Example 4

[0068] A method for preparing a hierarchical porous fluorescent monolithic material includes the following steps:

[0069] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene and 235.5 μL of dimethyl to a glass bottle to obtain mixed solution A;

[0070] Step 2: Add 44.1 mg of p-phenylenediamine, 235.5 μL of dimethylamine and 25 μL of water to a glass bottle to obtain mixed solution B;

[0071] Step 3: Sonicate mixed solution A and mixed solution B at room temperature for 2 minutes respectively, then add mixed solution B to mixed solution A and continue sonicating to form a homogeneous solution.

[0072] Step 4: After introducing the homogeneous solution into the capillary, it was transferred to a 60°C water bath and reacted for 6 hours to obtain a solid product. The solid product was washed with ethanol and n-hexane in sequence, and then dried with nitrogen to obtain a hierarchical porous fluorescent monolithic material.

[0073] Example 5

[0074] A method for preparing a hierarchical porous fluorescent monolithic material includes the following steps:

[0075] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene and 235.5 μL of dimethyl to a glass bottle to obtain mixed solution A;

[0076] Step 2: Add 44.1 mg of m-phenylenediamine, 235.5 μL of dimethylamine, and 25 μL of water to a glass bottle to obtain mixed solution B;

[0077] Step 3: Sonicate mixed solution A and mixed solution B at room temperature for 2 minutes respectively, then add mixed solution B to mixed solution A and continue sonicating to form a homogeneous solution.

[0078] Step 4: After introducing the homogeneous solution into the capillary, transfer it to an 80°C water bath and react for 8 hours to obtain a solid product; wash the solid product with ethanol and n-hexane in sequence, and then dry it in a constant temperature oven or blow it with nitrogen to obtain a hierarchical porous fluorescent monolithic material.

[0079] Example 6

[0080] A method for preparing a hierarchical porous fluorescent monolithic material includes the following steps:

[0081] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene and 235.5 μL of dimethyl to a glass bottle to obtain mixed solution A;

[0082] Step 2: Add 44.1 mg of o-phenylenediamine, 235.5 μL of dimethylamine, and 25 μL of water to a glass bottle to obtain mixed solution B;

[0083] Step 3: Sonicate mixed solution A and mixed solution B at room temperature for 2 minutes respectively, then add mixed solution B to mixed solution A and continue sonicating to form a homogeneous solution.

[0084] Step 4: After introducing the homogeneous solution into the capillary, it is transferred to an 80°C water bath and reacted for 10 hours to obtain a solid product. The solid product is washed with ethanol and n-hexane in sequence, and then dried with nitrogen to obtain a hierarchical porous fluorescent monolithic material.

[0085] Example 7

[0086] A method for preparing a hierarchical porous fluorescent monolithic material includes the following steps:

[0087] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene, 405 μL of dimethyl sulfoxide and 21 μL of water to a glass bottle to obtain mixed solution A;

[0088] Step 2: Sonicate mixed solution A at room temperature for 2 minutes;

[0089] Step 3: Add 24.3 μL of hydrazine hydrate (85% by mass) to mixed solution A, and sonicate to form a homogeneous solution.

[0090] Step 4: After introducing the homogeneous solution into the capillary, it was transferred to an 80°C water bath and reacted for 12 hours to obtain a solid product. The solid product was washed with ethanol and n-hexane in sequence, and then dried with nitrogen to obtain a hierarchical porous fluorescent monolithic material.

[0091] Figure 1 The images show physical pictures and fluorescence emission diagrams of the hierarchical porous fluorescent monolithic materials prepared in different embodiments of the present invention. As can be seen from the figures, hierarchical porous fluorescent monolithic materials with different fluorescence properties can be prepared by using different amine functional group compounds.

[0092] Figure 2 The figures show the fluorescence emission spectra of the hierarchical porous fluorescent monolithic materials prepared in different embodiments of the present invention. It can be seen from the figures that the fluorescence emission wavelength of the hierarchical porous fluorescent monolithic material synthesized from aniline and hydrazine hydrate exhibits a red shift, indicating the formation of a conjugated structure. Figure 1 This study confirms that different amine functional group compounds can be used to prepare hierarchical porous fluorescent monolithic materials with different fluorescence properties.

[0093] Figure 3 The images show the physical structure and fluorescence emission diagram of the capillary monolithic column prepared in Example 1 of this invention. It can be seen that the hierarchical porous fluorescent monolithic material prepared in the capillary retains good fluorescence properties.

[0094] Figure 4 The image shown is a scanning electron microscope image of the capillary monolithic column prepared in Example 1 of the present invention. It can be seen that the uniform through-pore structure is beneficial to the mass transfer process and adsorption separation, and the material is tightly attached to the inner wall of the capillary, making it less likely to fall off during use.

[0095] Figure 5 The figure shows the macropore size distribution of the hierarchical porous fluorescent monolithic material prepared in Example 1 of the present invention. It can be seen from the figure that the macropore size is 0.6 μm.

[0096] Figure 6Micropore physical adsorption test chart of the hierarchically porous fluorescent monolith prepared in Example 1. It can be seen from the chart that the specific surface area of the fluorescent monolith is 399 m 2 / g, and the micropore diameters are 0.8, 1.27, and 1.7 nm. Combining Figure 5 with the description, it shows that the synthesized fluorescent monolith has a hierarchically porous structure of macropores - micropores.

[0097] Figure 7 Micropore physical adsorption test chart of the hierarchically porous fluorescent monolith prepared in Example 7. It can be seen from the chart that the specific surface area of the fluorescent monolith is 530 m 2 / g, and the micropore diameter is 0.5 nm.

[0098] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a hierarchically porous fluorescent monolith, characterized in that, Includes the following steps: A homogeneous solution was obtained by mixing a fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission, and a compound containing amino functional groups with a solvent. The homogeneous solution is introduced into a capillary tube and then placed in a heating device for heating and reaction to obtain a solid product. The solid product was post-processed to obtain a hierarchical porous fluorescent monolithic material; When the compound containing the amino functional group is a solid, the specific steps are as follows: A fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission is mixed with a solvent to obtain mixed solution A; A compound containing an amino functional group is mixed with a solvent to obtain a mixed solution B; Mixing solution A and mixed solution B yields a homogeneous solution; The homogeneous solution is introduced into a capillary tube and then placed in a heating device for heating and reaction to obtain a solid product. The solid product was post-processed to obtain a hierarchical porous fluorescent monolithic material; When the compound containing the amino functional group is a liquid, the specific steps are as follows: A fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced emission is mixed with a solvent to obtain a mixed solution A; an amino functional group is added to mixed solution A to obtain a homogeneous solution; the homogeneous solution is introduced into a capillary tube and then placed in a heating device for heating reaction to obtain a solid product. The solid product was post-processed to obtain a hierarchical porous fluorescent monolithic material; The ratio of the fluorescent compound containing multiple aldehyde functional groups and exhibiting aggregation-induced luminescence to the solvent is 91.6 mg: (426~535) µL; The ratio of the amino-functionalized compound to the solvent is (25~47) mg: (426~535) µL; The heating device is a water bath; the heating reaction temperature is 40~80 ℃, and the time is 4~12 h; The solvent is an organic solvent or a mixture of an organic solvent and water; the compound containing an aldehyde functional group and exhibiting aggregation-induced emission is a tetraaldehyde tetraphenylethylene. The organic solvent is one or both of dimethyl sulfoxide or N,N-dimethylformamide; The amino-functionalized compound is trans-1,2-cyclohexanediamine, 1,4-butanediamine, 1,4-cyclohexanediamine, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, or hydrazine hydrate.

2. The method of claim 1, wherein the method further comprises the step of: The post-processing includes sequential washing and drying.

3. The method of claim 2, wherein the method further comprises the step of: The washing process involves rinsing with ethanol and n-hexane sequentially.

4. A hierarchically porous fluorescent monolith material, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 3.

5. The application of the multi-level porous fluorescent monolithic material as described in claim 4 in a fluorescence sensor.

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