Zirconium-based metal organic framework fluorescence sensing material, 3D printing product containing same and application

Abstract

The invention provides a zirconium-based metal organic framework fluorescent sensing material, a 3D printing product containing the same and application. The zirconium-based metal organic framework fluorescence sensing material is obtained by coordination of zirconium tetrachloride and an organic ligand with a plurality of amino groups, and is a metal organic framework with a three-dimensional hole structure. The material has a neutral amino group which has a specific chemical reaction with formaldehyde, has extremely high selectivity on formaldehyde, and can effectively avoid the interference of other common VOCs (Volatile Organic Compounds); and on the other hand, the MOF with a specific chemical recognition function can be embedded into a 3D printing structural body by the material, so that the integration of a perception-color development function and a complex three-dimensional structure is realized, the 3D printing device is endowed with the advantages of good mechanical strength and stable and difficult loss of active sites, and the material has a remarkable application prospect in harmful gas detection.

Description

Technical Field

[0001] This invention relates to the field of metal-organic framework fluorescent materials technology, specifically to zirconium-based metal-organic framework fluorescent sensing materials, 3D printed products containing the same, and their applications. Background Technology

[0002] With industrial and urbanization development, the need for monitoring harmful substances in the air (such as formaldehyde and CH2O) is becoming increasingly urgent. Traditional detection methods, such as gas chromatography-mass spectrometry, while highly accurate, have drawbacks such as expensive equipment, complex operation, the need for professional personnel, and difficulty in real-time, in-situ monitoring.

[0003] To achieve rapid, on-site detection of specific gases, color-change-based chemical sensors have been extensively studied. Among them, metal-organic frameworks (MOFs) are considered ideal gas sensing materials due to their ultra-high specific surface area, tunable pore structure, and surface chemical properties, enabling highly selective and sensitive interactions with specific gas molecules, often accompanied by visible color changes. Currently, researchers typically coat MOFs onto paper, fabric, or solid substrates to create simple test strips or sensor devices. However, these devices suffer from limitations such as poor mechanical strength, easy detachment of the MOF layer, limited functionality, uncontrollable shape, and difficulty in integrating into complex systems.

[0004] On the other hand, 3D printing (additive manufacturing) technology, especially based on photopolymerization, offers unprecedented flexibility for fabricating devices with complex structures. Currently, research has attempted to combine functional nanomaterials (such as carbon nanotubes, graphene, and nano-metal particles) with 3D printing resins to prepare structural components with conductive or mechanically enhanced properties. However, applying these materials to the field of gas detection, especially utilizing their color-changing properties, still faces significant challenges. The main problem is:

[0005] 1. Dispersion problem: MOF materials are micro-nano-scale powders, which are difficult to disperse stably and uniformly in resin and are prone to agglomeration. This not only affects the smoothness of the printing process and the mechanical properties of the molded parts, but also seriously obscures its active sites, resulting in a significant decrease in sensing performance.

[0006] 2. Challenges in maintaining functionality: The resin matrix may encapsulate MOF particles, hindering their contact with target gas molecules, and UV irradiation or high temperature during the printing process may damage the structure of the MOF, leading to the deactivation of its sensing activity.

[0007] 3. Limited Device Functionality: Most current 3D printing research focuses on manufacturing mechanical structural parts, and the printed objects themselves are "passive." How to directly endow 3D printed structural parts with sensitive chemical recognition functions (such as the color change characteristics of MOFs), making them "active" and intelligent devices with sensing capabilities, is a cutting-edge challenge in this field.

[0008] Therefore, there is an urgent need in this field for a new technology that can solve the above problems, which can achieve uniform dispersion and functional retention of MOFs in printing materials, and can also utilize the technological advantages of 3D printing to manufacture intelligent devices with complex structures, good mechanical properties, and the ability to intuitively and quickly detect harmful substances in the air through color changes. Summary of the Invention

[0009] This invention proposes a zirconium-based metal-organic framework fluorescent sensing material to meet the material performance requirements for detecting harmful gases after 3D printing.

[0010] The technical solution of this invention is implemented as follows:

[0011] The first aspect of this invention is to propose a zirconium-based metal-organic framework fluorescent sensing material, obtained by a coordination reaction between zirconium tetrachloride and an organic ligand; the structural formula of the organic ligand is shown in Formula I:

[0012] .

[0013] The second aspect of this invention is to provide a method for preparing the zirconium-based metal-organic framework fluorescent sensing material described in the first aspect, wherein zirconium tetrachloride is reacted with an organic ligand of Formula I in a solvent by a solvothermal method or a stirring method to obtain a crude product, which is then washed and dried to obtain the zirconium-based metal-organic framework fluorescent sensing material.

[0014] Furthermore, the solvent is selected from N,N-dimethylformamide and dichloromethane.

[0015] Furthermore, the organic ligand represented by Formula I is prepared by the following steps:

[0016] S1,2,3-Diaminoterephthalic acid reacts with monomethyl adipic acid under acidic conditions to give intermediate one;

[0017] S2. Intermediate 1 is placed in a mixed solution of hexamethyldisilazane and / or trimethylhalosilane and heated under reflux to generate intermediate 2;

[0018] S3. The intermediate di was reacted with 5-benzyl halide-1,3-diamine under reflux conditions to obtain the organic ligand shown in Formula I;

[0019] The reaction route for the above preparation method is as follows:

[0020] .

[0021] Preferably, in step S3, the 5-halogenated benzyl 1,3-diamine is obtained by amino protection of 5-toluene-1,3-diamine, followed by halogenation with a halogenating agent and amino deprotection.

[0022] Preferably, the amino protection reagent is di-tert-butyl dicarbonate;

[0023] And / or, the halogenating agent is N-chlorosuccinimide or N-bromosuccinimide.

[0024] A third aspect of the present invention is to provide a 3D printing resin composition, characterized in that its components, by weight, include: 3-10 parts of a metal-organic framework Zr-MOF, 50-60 parts of acrylate monomer, 10-30 parts of an reactive diluent, 1-3 parts of a photoinitiator, 0-1 parts of an antifoaming agent, and 0-1 parts of a polymerization inhibitor; wherein the metal-organic framework Zr-MOF is the zirconium-based metal-organic framework fluorescent sensing material described in the first aspect, or the zirconium-based metal-organic framework fluorescent sensing material prepared by the preparation method described in the second aspect.

[0025] Furthermore, in the above resin composition:

[0026] The acrylate monomer is at least one of bisphenol A type epoxy diacrylate or polyester acrylate;

[0027] And / or, the active diluent is tripropylene glycol diacrylate or 1,6-hexanediol diacrylate;

[0028] And / or, the photoinitiator is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide;

[0029] And / or, the defoamer is BYK-UV 3500;

[0030] And / or, the polymerization inhibitor is hydroquinone monomethyl ether.

[0031] A fourth aspect of the present invention is to provide a 3D printed article obtained by 3D printing and curing the 3D printing resin composition described in the third aspect.

[0032] A fifth aspect of the present invention is to provide the application of the 3D printing resin composition described in the third aspect above, or the 3D printed article described in the fourth aspect, in formaldehyde detection.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] The zirconium-based metal-organic framework fluorescent sensing material of this invention is synthesized by coordination reaction of zirconium tetrachloride and an organic ligand with multiple amino groups, forming a metal-organic framework with a three-dimensional porous structure. On the one hand, the amino groups in this material can achieve detection through specific chemical reactions with formaldehyde, rather than simple physical adsorption, thus exhibiting extremely high selectivity for formaldehyde and effectively avoiding interference from other common VOCs. On the other hand, this material successfully embeds MOFs with specific chemical recognition functions into 3D printed structures, realizing the integration of "sensing-color development" function with complex three-dimensional structures, endowing 3D printed devices with good mechanical strength and stable active sites that are not easily lost.

[0035] The 3D printing resin composition of the present invention contains zirconium-based metal-organic framework fluorescent sensing material. After printing the support device, the detection is intuitive and low-cost: the detection results are presented through color change, without the need for electricity and complex instruments, and can realize real-time, in-situ, semi-quantitative visual detection of formaldehyde.

[0036] The material described in this invention is used to prepare formaldehyde detection devices, which can achieve controllable shape and easy integration through 3D printing: using 3D printing technology, sensors of arbitrary shape and structure can be customized and produced, which can be easily integrated into specific devices, spaces or wearable devices, with a wide range of application scenarios. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the zirconium-based metal-organic framework fluorescent sensing material described in this invention.

[0039] Figure 2 The above is the hydrogen nuclear magnetic resonance spectrum of the organic ligand of Formula I described in this invention. Detailed Implementation

[0040] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] This invention proposes a zirconium-based metal-organic framework fluorescent sensing material (Zr-MOF), a three-dimensional metal-organic framework obtained by coordination reaction between zirconium tetrachloride and organic ligands. This material possesses a central amino group that specifically reacts with formaldehyde, exhibiting extremely high selectivity for formaldehyde and effectively avoiding interference from other common VOCs. Furthermore, this material allows MOFs with specific chemical recognition functions to be embedded into 3D-printed structures, achieving integration of "sensing-color development" functionality with complex three-dimensional structures. This endows 3D-printed devices with advantages such as high mechanical strength and stable, non-leaking active sites. The detection limit of this Zr-MOF material can reach 0.01 mg / m³. 3 Specifically, the structural formula of the organic ligand is shown in Formula I:

[0042] .

[0043] In this invention, the preparation method of the above-mentioned Zr-MOF material is as follows: zirconium tetrachloride and the organic ligand shown in Formula I are subjected to a coordination reaction in a solvent by a solvothermal method or a stirring method to obtain a crude product, which is then washed and dried to obtain the zirconium-based metal-organic framework fluorescent sensing material.

[0044] In a preferred embodiment, the Zr-MOF material is prepared by placing the ligand of Formula I and zirconium tetrachloride (ZrCl4) in a polytetrafluoroethylene reactor, adding N,N-dimethylformamide (DMF) and a few drops of concentrated hydrochloric acid, and then sonicating the mixture in the reactor to ensure uniform dispersion. The mixture is then placed in a 120 °C oven for 24 h and allowed to cool naturally to room temperature to obtain coarse crystals. The crystals are washed with mother liquor (DMF), collected, and then dried in air to obtain crystals (Zr-MOF). The topological diagram of the crystal structure is shown below. Figure 1 As shown. The oxygen atom (red dot) on the carboxyl group of the ligand is related to Zr. 4+ Coordination occurs to form metal clusters (green irregular geometry), and six metal clusters combine to form a hexanuclear secondary structural unit (blue dot). Subsequently, multiple secondary structural units are connected by the p-carboxybenzene structure on the ligand (red box region) to form a regular octahedral structure.

[0045] In a preferred embodiment, the organic ligand represented by Formula I is prepared as follows:

[0046] (1) Mix 2,3-diaminoterephthalic acid (0.1-0.3 mol) with water (60-100 ml), sulfuric acid (2-6 ml), and monomethyl adipic acid (0.1-0.3 mol) and heat under reflux at 90°C for 10 h. After cooling to room temperature, add water (200-400 ml). To avoid excessive gas emission and bubbles, add a small amount of sodium carbonate (3-5 g) to the mixture. Then adjust the pH to about 10 with ammonia. Filter the precipitate and recrystallize it. Dry the solid under vacuum heating to obtain the following intermediate one.

[0047]

[0048] (2) Take the above intermediate one (15-20 mmol) and place it in a mixture of hexamethyldisilazane (40-50 mmol) and trimethylchlorosilane (10-15 mmol). Reflux at 130°C for 2 hours. After the reaction is complete, transfer the mixture to a beaker and remove the solvent to obtain intermediate two. The reaction process is as follows:

[0049]

[0050] (3) Dissolve 5-toluene-1,3-diamine (5-10 mmol) in an appropriate amount of anhydrous THF, cool in an ice-water bath, and add triethylamine (5-10 mmol) to the solution. Then, slowly add di-tert-butyl dicarbonate solution (20-30 mmol). After the addition is complete, remove the ice-water bath and stir continuously at room temperature for 12 hours. Finally, wash the reaction solution with water, separate the liquids, dry the organic phase with anhydrous sodium sulfate, filter, remove the solvent by rotary evaporation, and obtain the crude product. Recrystallize the crude product to obtain a high-purity Boc protected product. The reaction process is as follows:

[0051]

[0052] (4) Dissolve the product (15-20 mmol) from (3) above with N-bromosuccinimide (NBS) (20-25 mmol) and benzoyl peroxide (BPO) (0.3-0.5 mmol) in 200 ml of carbon tetrachloride (CCl4), heat under reflux for 12 h, remove the solvent by rotary evaporation, wash with ice-cold ethanol, and filter to obtain the bromination product. The reaction process is as follows:

[0053]

[0054] (5) Dissolve the product from (4) above in an appropriate amount of dichloromethane (DCM), add excess trifluoroacetic acid (TFA), stir at room temperature for 2 hours. After the reaction is complete, concentrate the reaction solution on a rotary evaporator to remove most of the TFA and solvent. Neutralize the obtained solid with saturated sodium bicarbonate solution to alkalinity (pH≈8), and then extract the product with ethyl acetate (EA). Combine the organic phases, dry, and concentrate to obtain the pure deBoc protected product 5-bromotoluene-1,3-diamine. The reaction process is as follows:

[0055]

[0056] (6) The above intermediate di (10-15 mmol) and 5-bromotoluene-1,3-diamine (20-30 mmol) were mixed and dissolved in 100 ml of acetonitrile (MeCN) and heated under reflux at 90 °C for 24 h. The solid obtained by vacuum filtration was washed repeatedly with tetrahydrofuran (THF) and then dried under reduced pressure in a vacuum oven to obtain the ligand 4,7-dicarboxy-1,3-bis(3,5-diaminobenzyl)-2-(5-methoxy-N-acetyltryptamine-5-oxopentyl)-1H-benzo[d]imidazolium-3-onium salt. The reaction process is as follows:

[0057]

[0058] The above preparation method can yield crystals of Formula I compound with a yield of 65-70% (based on 2,3-diaminoterephthalic acid) and a purity greater than 98%.

[0059] This invention also proposes a 3D printing resin composition comprising the metal-organic framework Zr-MOF prepared above. Specifically, it comprises the following components in parts by weight: acrylate monomer: 50-60 parts; reactive diluent: 10-30 parts; photoinitiator: 1-3 parts; defoamer: 0-1 part; polymerization inhibitor: 0-1 part; and the prepared metal-organic framework Zr-MOF: 3-10 parts.

[0060] In a preferred embodiment, the acrylate monomer is bisphenol A epoxy diacrylate or polyester acrylate; the reactive diluent is tripropylene glycol diacrylate (TPGDA) or 1,6-hexanediol diacrylate (HDDA); the photoinitiator is phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (TPO); the defoamer is BYK-UV3500; and the polymerization inhibitor is hydroquinone monomethyl ether (MEHQ).

[0061] The above-mentioned method for preparing the 3D printing resin composition involves first mixing acrylate monomers and an reactive diluent in a reaction vessel at room temperature and stirring continuously for 30 minutes. Then, in a light-protected environment, Zr-MOF metal-organic framework material, a photoinitiator, an antifoaming agent, and a polymerization inhibitor are added to the mixture, and stirring continues for 60 minutes to ensure uniform distribution of the components. Finally, the resulting resin solution is filtered to remove air bubbles, thus obtaining the 3D printing resin composition.

[0062] This invention also provides a 3D-printed device or a smart formaldehyde detection device, which is obtained by 3D printing and curing the above-mentioned 3D printing resin composition. By introducing Zr-MOF material into the device, the detection process is made convenient, highly specific, and highly sensitive. The presence and approximate concentration of formaldehyde can be determined simply by irradiating the device with ultraviolet light and observing the fluorescence intensity. Verification has shown that the concentration can reach 0.03 mg / m³. 3 The detection limit.

[0063] The specific detection mechanism is as follows:

[0064] Initial state (before exposure to formaldehyde): The synthesized MOF ligand has its intramolecular electronic structure in a specific state. When irradiated with ultraviolet light (e.g., a 365nm ultraviolet flashlight), the molecule absorbs the ultraviolet light energy, and the electrons transition to an excited state. Subsequently, when it falls back to the ground state, it emits fluorescence of a specific wavelength (e.g., strong blue fluorescence).

[0065] Post-reaction state (after contact with formaldehyde): When the amino group on the ligand reacts with formaldehyde to form a Schiff base (C=N), this C=N double bond becomes a strong "fluorescence quencher group." It can effectively "consume" the energy generated by the molecule after being excited by ultraviolet light through intramolecular energy transfer, resulting in a significant reduction or even complete disappearance of fluorescence.

[0066] Therefore, when observed under ultraviolet light, 3D printed parts will change from bright fluorescence (such as blue) to pale blue or no fluorescence. This change in fluorescence "from strong to weak" is a very sensitive color signal.

[0067] High selectivity: It relies on the specific chemical reaction between amino groups and formaldehyde, rather than simple physical adsorption, which can effectively eliminate interference from other VOCs. Furthermore, because the ligand contains multiple amino groups, its ability to capture formaldehyde molecules is enhanced.

[0068] High sensitivity: Utilizing fluorescence changes as the detection signal. The sensitivity of fluorescence detection is typically several orders of magnitude higher than that of visually observed color changes; even trace amounts of formaldehyde can cause a significant decrease in fluorescence. Furthermore, because the prepared metal-organic framework material (Zr-MOF) has a porous structure, it can also adsorb and store some formaldehyde molecules within it.

[0069] In a preferred embodiment, the 3D printing parameters are:

[0070] 1. Laser wavelength: 355nm;

[0071] 2. Laser power: 100-300mW, preferably 200mW;

[0072] 3. Scanning speed: 3000-6000mm / s, preferably 4000mm / s;

[0073] 4. Layer thickness: 50-100, preferably 100μm.

[0074] After printing, place the sample in a UV curing chamber for 0.5 hours and then heat it in a 50°C oven for 1 hour. If necessary, the sample can be sanded and polished to obtain a higher surface quality.

[0075] The following are preferred implementation examples. Unless otherwise specified, the reagents used are commercially available reagents, and the procedures used are experimental techniques already known in the art.

[0076] Examples 1-4

[0077] 1. Synthesis of organic ligands with the structure described in Formula I:

[0078] (1) 2,3-Diaminoterephthalic acid (0.2 mol) was mixed with water (80 ml), sulfuric acid (4 ml) and monomethyl adipic acid (0.15 mol) and heated under reflux at 90°C for 10 h. After cooling to room temperature, water (300 ml) was added. To avoid excessive gas emission and bubbles, a small amount of sodium carbonate (5 g) was added to the mixture. Then, the pH was adjusted to about 10 with ammonia. The resulting precipitate was filtered and recrystallized. The solid obtained was dried under vacuum heating to obtain intermediate one.

[0079] (2) Take the above intermediate one (16.7 mmol) and place it in a mixture of hexamethyldisilazane (48 mmol) and trimethylchlorosilane (11.8 mmol). Reflux and heat at 130°C for 2 hours. After the reaction is complete, transfer the mixture to a beaker and remove the solvent to obtain intermediate two.

[0080] (3) Dissolve 5-toluene-1,3-diamine (10 mmol) in an appropriate amount of anhydrous THF, cool it in an ice-water bath, add triethylamine (10 mmol) to the solution, and then slowly add di-tert-butyl dicarbonate solution (25 mmol). After the addition is complete, remove the ice-water bath and stir continuously at room temperature for 12 h. Finally, wash the reaction solution with water, separate the liquids, dry the organic phase with anhydrous sodium sulfate, filter, remove the solvent by rotary evaporation, and obtain the crude product. Recrystallize the crude product to obtain a high-purity Boc protected product.

[0081] (4) Dissolve the product (19.22 mmol) from (3) above with N-bromosuccinimide (NBS) (20 mmol) and benzoyl peroxide (BPO) (0.34 mmol) in 200 ml of carbon tetrachloride (CCl4), heat under reflux for 12 h, remove the solvent by rotary evaporation, wash with ice-cold ethanol and filter to obtain the brominated product.

[0082] (5) Dissolve the product from (4) above in an appropriate amount of dichloromethane (DCM), add excess trifluoroacetic acid (TFA), stir at room temperature for 2 h, after the reaction is complete, concentrate the reaction solution on a rotary evaporator to remove most of the TFA and solvent, neutralize the obtained solid with saturated sodium bicarbonate solution to alkalinity (pH≈8), and then extract the product with ethyl acetate (EA). Combine the organic phases, dry, and concentrate to obtain the pure deBoc protected product 5-bromotoluene-1,3-diamine.

[0083] (6) The above intermediate di (10 mmol) and 5-bromotoluene-1,3-diamine (20 mmol) were mixed and dissolved in 100 ml of acetonitrile (MeCN) and heated under reflux at 90 °C for 24 h. The solid obtained by vacuum filtration was washed repeatedly with tetrahydrofuran (THF) and then dried under reduced pressure in a vacuum oven to obtain the ligand 4,7-dicarboxy-1,3-bis(3,5-diaminobenzyl)-2-(5-methoxy-N-acetyltryptamine-5-oxopentyl)-1H-benzo[d]imidazol-3-onium salt. The 1H NMR spectrum of the product is shown below. Figure 2 As shown, the organic ligand was identified as having the structure of Formula I.

[0084] 2. Synthesis of three-dimensional metal-organic frameworks (Zr-MOF)

[0085] The ligand of formula I and zirconium tetrachloride (ZrCl4) were placed in a polytetrafluoroethylene reactor, and N,N-dimethylformamide (DMF) and a few drops of concentrated hydrochloric acid were added. The mixture was then sonicated to ensure uniform dispersion in the reactor. The reactor was then placed in an oven at 120 °C for 24 h and allowed to cool naturally to room temperature to obtain coarse crystals. The crystals were washed and collected using mother liquor (DMF) and then dried in air to obtain crystals (Zr-MOF).

[0086] 3. Formulation of 3D Printing Resin Composition

[0087] The acrylate monomer and reactive diluent were mixed in a reaction vessel at room temperature and stirred continuously for 30 minutes. Then, in a light-protected environment, the metal-organic framework material Zr-MOF, photoinitiator, defoamer, and polymerization inhibitor were added to the mixture, and stirring was continued for 60 minutes to ensure uniform distribution of the components. Finally, the resulting resin solution was filtered to remove air bubbles, thus obtaining the target photosensitive resin. The specific formulation is shown in Table 1, with corresponding comparative examples.

[0088] Table 1: 3D Printing Resin Compositions

[0089]

[0090] The organic complex preparation process in Comparative Example 2 differs from that in Example 1 in that formic acid is used instead of monomethyl adipic acid in step 1), while other steps remain unchanged, and the 3D printing composition formulation is the same as that in Example 1.

[0091] Test case

[0092] The resin compositions of Examples 1-4 and Comparative Examples 1-2 were 3D printed and cured under the following conditions: laser wavelength 355nm, laser power 200mW, scanning speed 4000mm / s, and layer thickness 100μm. After printing, the samples were placed in a curing chamber for 0.5h and then heated in a 50℃ oven for 1h.

[0093] 1) The viscosity of the composition and the mechanical properties of the printed parts, as well as the color change under 365nm ultraviolet light, were tested. The results are shown in Table 1. The test standards were: viscosity (NDJ-8S test); flexural strength (ASTM D790 standard); tensile strength (ASTM D638 standard).

[0094] Table 2:

[0095]

[0096] As can be seen from Table 2, Examples 1-4 all exhibited a fluorescent color change. The color difference between Example 1 and Comparative Example 1 under UV light was particularly noticeable, indicating the effect of Zr-MOF addition on the fluorescent color change. Furthermore, the mechanical properties of Examples 1-4 were excellent and met the requirements for the manufactured parts. Additionally, the viscosity (25°C) of the compositions in Table 2 shows that Comparative Example 2 (452 ​​Cps) > Example 1 (367 Cps). A significant increase in viscosity usually indicates strong interaction between the filler (in this case, MOF) and the resin matrix, or agglomeration, leading to poor flowability. This may be an indirect signal of poor compatibility. Furthermore, the flexural strength (51 MPa) and tensile strength (40 MPa) of Comparative Example 2 were slightly lower than those of Example 1 (62 MPa, 43 MPa). The decrease in mechanical properties is often related to uneven filler dispersion and the formation of stress concentration points, which is also a common manifestation of poor compatibility.

[0097] 2) Detection limit of formaldehyde in printed parts

[0098] Air samples with different formaldehyde concentrations were prepared in sealed containers. The printed part was placed in the sealed container and exposed to 365nm ultraviolet light. The detection limit was determined by observing the color change. The results are shown in Table 3.

[0099] Table 3:

[0100]

[0101] Under ultraviolet light, 3D printed parts change from bright fluorescence (e.g., blue) to pale blue or no fluorescence. This fluorescence transitions from strong to weak, so no fluorescence indicates that it is detectable. As shown in Table 3, Zr-MOF can detect 0.01 mg / m³. 3 Even after the dopant entered the printed sample, 0.03 mg / m³ could still be detected. 3 In terms of sensitivity, Example 1 is better than Comparative Example 2 at low concentrations (0.03 mg / m³). 3 When the concentration was measured, Example 1 was detected first, turning pale blue, while Comparative Example 2 required a slightly higher concentration (0.05 mg / m³). 3 The fact that it can only be detected under certain conditions indicates that the dispersibility of ester groups affects the detection performance of the sample.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A zirconium-based metal-organic framework fluorescent sensing material, characterized in that, It is obtained by coordination reaction of zirconium tetrachloride with an organic ligand; the structural formula of the organic ligand is shown in Formula I: 。 2. The method for preparing the zirconium-based metal-organic framework fluorescent sensing material according to claim 1, characterized in that, Zirconium tetrachloride is reacted with the organic ligand shown in Formula I in a solvent by a solvothermal method or a stirring method to obtain a crude product, which is then washed and dried to obtain the zirconium-based metal-organic framework fluorescent sensing material.

3. The preparation method according to claim 2, characterized in that, The solvent is selected from N,N-dimethylformamide and dichloromethane.

4. The preparation method according to claim 2, characterized in that, The organic ligand represented by Formula I is prepared by the following steps: S1,2,3-Diaminoterephthalic acid reacts with monomethyl adipic acid under acidic conditions to give intermediate one; S2. Intermediate 1 is placed in a mixed solution of hexamethyldisilazane and / or trimethylhalosilane and heated under reflux to generate intermediate 2; S3. The intermediate di was reacted with 5-benzyl halide-1,3-diamine under reflux conditions to obtain the organic ligand shown in Formula I; The reaction route for the above preparation method is as follows: 。 5. The preparation method according to claim 4, characterized in that, In step S3, the 5-halogenated benzyl 1,3-diamine is obtained by amino protection of 5-toluene-1,3-diamine, followed by halogenation with a halogenating agent and deprotection of the amino group.

6. The preparation method according to claim 5, characterized in that, The amino protection reagent used is di-tert-butyl dicarbonate; And / or, the halogenating agent is N-chlorosuccinimide or N-bromosuccinimide.

7. A 3D printing resin composition, characterized in that, Its components, by weight, include: 3-10 parts of metal-organic framework Zr-MOF, 50-60 parts of acrylate monomer, 10-30 parts of reactive diluent, 1-3 parts of photoinitiator, 0-1 part of defoamer, and 0-1 part of polymerization inhibitor; wherein the metal-organic framework Zr-MOF is the zirconium-based metal-organic framework fluorescent sensing material according to claim 1, or the zirconium-based metal-organic framework fluorescent sensing material prepared by the preparation method according to any one of claims 2-6.

8. The resin composition according to claim 7, characterized in that, The acrylate monomer is at least one of bisphenol A type epoxy diacrylate or polyester acrylate; And / or, the active diluent is tripropylene glycol diacrylate or 1,6-hexanediol diacrylate; And / or, the photoinitiator is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; And / or, the defoamer is BYK-UV 3500; And / or, the polymerization inhibitor is hydroquinone monomethyl ether.

9. A 3D printed product, characterized in that, The 3D printing resin composition of claim 7 or 8 is obtained by 3D printing and curing.

10. The application of the 3D printing resin composition of claim 7 or 8, or the 3D printed article of claim 9, in formaldehyde detection.

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