Preparation method of luminescent iodine adsorbent and protective application thereof

Abstract

The present invention discloses a preparation method of a luminescent iodine adsorbent and its protective application, which relates to the technical field of radioactive waste gas and waste liquid treatment. The method comprises dissolving an organic ligand and a metal ion in a solvent to obtain a mixed solution, reacting the mixed solution at room temperature, and assembling a luminescent MSOFs adsorbent; wherein the organic ligand is a thiol ligand or a phenylphosphine derivative with a nitrogen heterocycle; and the central atom of the ligand comprises gold, silver, copper, platinum, palladium, iron, aluminum, nickel or cobalt. The iodine adsorbent and protective device prepared by the present invention have excellent adsorption capacity, low cost, can be quickly synthesized in large quantities, have a high adsorption rate, and are conducive to efficient treatment and real-time monitoring of iodine; and the preparation method of the present invention has simple steps, is easy to operate, and has low equipment requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of radioactive waste gas and waste liquid treatment, and in particular to a preparation method of a luminescent iodine adsorbent and its protective application. Background Art

[0002] With the rapid growth of energy demand, nuclear energy, as a sustainable green energy, is expected to play a more important role in the future. However, the safety issues caused by the large-scale waste generated by the nuclear industry have always been one of the main factors restricting the rapid development of the nuclear energy field. Among them, volatile radionuclides produced during the reprocessing of nuclear fuel are one of the main safety hazards. For example, volatile radionuclides in the form of molecular iodine 129 I and 131 I. These radioactive iodine particles are highly volatile, easily forming a highly mobile gas and being easily soluble in water. This not only harms the environment but also severely impacts human metabolism by damaging the thyroid gland. Therefore, the research and development of efficient radioactive iodine capture and storage technologies is crucial. This will help reduce the risks posed by volatile radioactive waste to the environment and human health, and promote the sustainable development of the nuclear energy sector.

[0003] To date, a wide variety of materials, including zeolites, aerogels, porous organic polymers, porous organic cages, metal-organic frameworks, and covalent organic frameworks, have attracted attention as iodine adsorbents. Recently, supramolecular crystalline materials, such as supramolecular organic frameworks and nonporous adaptive crystals, characterized by their crystalline structures composed of modular building blocks, have emerged as promising alternatives for iodine adsorption. The inherent crystallinity of supramolecular crystalline materials provides complete accessibility to the adsorption sites required for precise control of high iodine capacity, enabling in-depth investigation of iodine adsorption mechanisms at the molecular level. Furthermore, researchers have employed molecular-level design strategies to enhance iodine uptake. For example, incorporating electron-rich heteroatoms, such as nitrogen, sulfur, and oxygen, along with π-donors (such as double / triple bonds and phenyl groups), has been shown to be an effective approach to enhance electron-deficient iodine uptake by forming charge-transfer species. Therefore, in-depth investigation of the type and number of electron-rich adsorption sites is crucial for guiding the molecular design of materials with high iodine uptake capacity. Furthermore, most studies have focused primarily on the uptake capacity of developed adsorbents, neglecting effective means of visually tracking the uptake process. This method is crucial for studying the saturation level during the absorption process, a key consideration for the efficient capture of radioiodine and timely replacement of absorption adsorbents in industrial settings. Furthermore, the preparation of protective products based on these adsorbents is crucial for protecting the health of workers. However, little research has been conducted on this topic.

[0004] Therefore, while developing protective equipment, there is an urgent need to design high-performance iodine adsorbents with fluorescence monitoring capabilities. This is of great significance to protecting personnel health and is also a problem that technical personnel in this field urgently need to solve. Summary of the Invention

[0005] To address the shortcomings of the aforementioned background technology, the present invention provides a method for preparing a luminescent iodine adsorbent and its protective application. The primary purpose is to provide a simple method for preparing a luminescent MSOFs adsorbent that efficiently captures iodine and enables real-time fluorescence monitoring of the adsorption process. The MSOFs are then loaded onto the non-woven fabric of the middle layer of a mask to achieve efficient protective applications, aiming to address the issues of iodine adsorption and prevent the dangers associated with radioactive iodine.

[0006] The first object of the present invention is to provide a method for preparing a luminescent iodine adsorbent, comprising the following steps:

[0007] The organic ligand and the metal ion are dissolved in a solvent to obtain a mixed solution, and the mixed solution is reacted at room temperature to assemble a luminescent MSOFs adsorbent;

[0008] The organic ligand is a thiol ligand with a nitrogen heterocycle or a phenylphosphine derivative; the metal atom coordinated with the organic ligand includes gold, silver, copper, platinum, palladium, iron, aluminum, nickel or cobalt.

[0009] Preferably, the adsorbent is prepared according to the following steps:

[0010] Silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride were reacted in a mixed solution of methanol, dichloromethane and ultrapure water to obtain a silver-organic coordination compound Ag(4-Mpy)2(PPh3)2, which was then o C conditions, the MSOF-1 adsorbent was obtained by hierarchical supramolecular self-assembly;

[0011] The molar ratio of silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride is 1:1:6:0.5-1.5;

[0012] The volume ratio of the methanol, dichloromethane and ultrapure water is 2-4:0.2:0.1.

[0013] A second object of the present invention is to provide a method for preparing a luminescent iodine adsorbent, comprising the following steps:

[0014] The prepared MSOF-1 adsorbent was soaked in dichloromethane, chloroform, N,N -dimethylformamide or N,N -dimethylacetamide solution and soaked for 24 to 48 hours to obtain MSOF-2 adsorbent.

[0015] Preferably, the adsorbent is prepared according to the following steps:

[0016] Silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride were reacted in a mixed solution of methanol, dichloromethane and ultrapure water for 8-12 hours, and iodine molecules were slowly diffused into the mixed solution by liquid phase diffusion method. o C environment, the reaction is allowed to stand to generate silver-organic coordination compound Ag(PPh3)3I, and then the reaction is continued at 3~5 o C conditions, MSOF-3 adsorbent was obtained by hierarchical supramolecular self-assembly;

[0017] The molar ratio of silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride is 1:1:6:0.5-1.5;

[0018] The volume ratio of methanol, dichloromethane and ultrapure water is 2-4:0.2:0.1;

[0019] When the iodine molecules slowly diffuse into the mixed solution, the iodine molecules are dissolved in n-hexane or methanol to obtain an iodine solution, and then the iodine solution is diffused into the mixed solution, wherein the volume ratio of the iodine solution to the mixed solution is 1:1; the concentration of the iodine solution is 1~2mM; and the iodine molecules are elemental iodine.

[0020] The third object of the present invention is to provide a MSOF-1 adsorbent.

[0021] The fourth object of the present invention is to provide a MSOF-2 adsorbent.

[0022] The fifth object of the present invention is to provide a MSOF-3 adsorbent.

[0023] A sixth object of the present invention is to provide an adsorbent for use in adsorbing radioactive gaseous iodine and liquid iodine.

[0024] The seventh object of the present invention is to provide a functional fiber, which includes a non-woven fiber and the adsorbent loaded on the non-woven fiber.

[0025] The eighth object of the present invention is to provide a functional fiber for use in a protective mask, protective clothing or an air purifier.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention provides a method for preparing a luminescent iodine adsorbent and its protective applications. Through surface ligand engineering, a series of porous materials (MSOFs, MSOF-1, -2, and -3) based on silver-organic coordination compounds were successfully synthesized. These materials exhibit different surface charge properties. Iodine adsorption in MSOF-1 is located on the nitrogen heterocycle and benzene ring of its surface ligand; in MSOF-2, on the nitrogen heterocycle; and in MSOF-3, on the benzene ring. Electron-rich groups on the surface of the MSOFs can form charge-transfer complexes with electron-deficient iodine molecules, resulting in excellent iodine adsorption. Iodine adsorption on the MSOFs induces an efficient charge transfer process from the surface ligands to the iodine molecules, resulting in a gradual quenching of the MSOFs' fluorescence as the amount of iodine adsorbed increases. The MSOFs were loaded onto non-woven fabrics via an impregnation method to fabricate a mask with iodine removal properties, real-time fluorescence sensing, and antibacterial properties.

[0028] The synthesis process of the invention is simple, operability is strong, and it is suitable for high-efficiency and large-scale production.

[0029] The MSOFs prepared by the present invention have a high adsorption capacity for iodine vapor, with MSOF-1, MSOF-2, and MSOF-3 having adsorption capacities of 1.78, 1.86, and 3.62 g / g, respectively, surpassing most other adsorbents. Furthermore, the MSOFs prepared by the present invention have excellent adsorption properties for iodine solutions. The MSOFs have good iodine storage capacity, high stability, and good reusability. In iodine vapor adsorption experiments, they demonstrated high adsorption capacity and strong desorption capacity, making them excellent iodine vapor adsorption materials.

[0030] The MSOFs prepared by the present invention exhibit obvious fluorescence quenching performance during the iodine adsorption process, so that a real-time fluorescence monitoring system can be established to monitor the iodine adsorption process.

[0031] The MSOFs-loaded protective mask of this invention has great potential for iodine removal. The iodine removal rate in an aerogel environment was 99.1%, far exceeding that of conventional commercial masks. Fluorescence quenching detection can be used to prompt timely mask replacement. Furthermore, the mask exhibits antibacterial potential. It is expected to be used as a new iodine adsorption material for personal health protection in extreme environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the synthesis process in Example 1 of the present invention;

[0033] Figure 2 is the powder X-ray diffraction pattern of the MSOFs in Example 1 of the present invention;

[0034] Figure 3This is a scanning electron microscope image of the MSOFs in Example 1 of the present invention;

[0035] Figure 4 Graph showing the fluorescence emission spectrum of the MSOFs in Example 1 of the present invention;

[0036] Figure 5 This is a diagram showing the adsorption kinetics of iodine vapor by MSOFs in Example 1 of the present invention;

[0037] Figure 6 1 is the adsorption kinetics of iodine solution by MSOFs in Example 1 of the present invention;

[0038] Figure 7 This is a fluorescence emission spectrum of MSOF-1 in Example 1 of the present invention for different iodine adsorption amounts;

[0039] Figure 8 This is the powder X-ray diffraction pattern of the non-woven fabric fiber loaded with MSOF-1 in Example 1 of the present invention;

[0040] Figure 9 This is a scanning electron microscope image of the non-woven fabric fiber loaded with MSOF-1 in Example 1 of the present invention;

[0041] Figure 10 This is a comparison chart of the iodine removal rates of the protective mask in Example 1 of the present invention and the commercial mask.

[0042] Figure 11 This is a fluorescence emission spectrum of the protective mask in Example 1 of the present invention before and after iodine removal. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments and drawings, but the embodiments are not intended to limit the present invention.

[0044] A first aspect of the present invention provides a method for preparing a luminescent iodine adsorbent, comprising the following steps:

[0045] The organic ligand and the metal ion are dissolved in a solvent to obtain a mixed solution, and the mixed solution is reacted at room temperature to assemble a luminescent MSOFs adsorbent;

[0046] The organic ligand is a thiol ligand with a nitrogen heterocycle or a phenylphosphine derivative; the metal atom coordinated with the organic ligand includes gold, silver, copper, platinum, palladium, iron, aluminum, nickel or cobalt.

[0047] This invention uses luminescent metal-organic coordination compound-based supramolecular organic frameworks (MSOFs) as adsorbents to absorb iodine, and monitors the adsorption process in real time using in situ fluorescence. This allows for the development of protective masks with iodine adsorption, fluorescence detection, and antibacterial properties.

[0048] Wherein, the adsorbent is prepared according to the following steps:

[0049] Silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride were reacted in a mixed solution of methanol, dichloromethane and ultrapure water to obtain a silver-organic coordination compound Ag(4-Mpy)2(PPh3)2, which was then o C conditions, the MSOF-1 adsorbent was obtained by hierarchical supramolecular self-assembly;

[0050] The molar ratio of silver nitrate, 4-mercaptopyridine, triphenylphosphine, and sodium borohydride is 1:1:6:1;

[0051] The volume ratio of the methanol, dichloromethane and ultrapure water is 3:0.2:0.1.

[0052] In one embodiment, a method for preparing a luminescent iodine adsorbent comprises the following steps:

[0053] At 30 o C and under conditions of vigorous stirring, silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride react in a mixed solution of methanol, dichloromethane and ultrapure water to form a silver-organic coordination compound Ag(4-Mpy)2(PPh3)2. o C conditions by Ag (4-Mpy) 2 (PPh 3) 2 hierarchical supramolecular self-assembly preparation of MSOF-1 adsorbent. The white precipitate at the bottom was collected by high-speed centrifugation at 9000g relative centrifugal force, and the obtained precipitate was washed three times with methanol and n-hexane respectively. The final product was placed in a vacuum drying oven at 50 o Dry overnight at C.

[0054] A second aspect of the present invention provides a method for preparing a luminescent iodine adsorbent, comprising the following steps:

[0055] The MSOF-1 adsorbent prepared above was soaked in dichloromethane, chloroform, N,N -dimethylformamide or N, N -dimethylacetamide solution and soaked for 24 to 48 hours to obtain MSOF-2 adsorbent.

[0056] In one embodiment, a method for preparing a luminescent iodine adsorbent comprises the following steps: soaking MSOF-1 in dichloromethane, chloroform, N,N -dimethylformamide or N,NThe yellow precipitate at the bottom was collected by high-speed centrifugation at 9000 g relative centrifugal force, and the obtained precipitate was washed three times with methanol and n-hexane respectively. The final product was placed in a vacuum drying oven at 50 o Dry overnight at C.

[0057] Wherein, the adsorbent is prepared according to the following steps:

[0058] Silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride were reacted in a mixed solution of methanol, dichloromethane and ultrapure water for 8-12 hours, and iodine molecules were slowly diffused into the mixed solution by liquid phase diffusion method. o C environment, the reaction is allowed to stand to generate silver-organic coordination compound Ag(PPh3)3I, and then the reaction is continued at 3~5 o C conditions, MSOF-3 adsorbent was obtained by hierarchical supramolecular self-assembly;

[0059] The molar ratio of silver nitrate, 4-mercaptopyridine, triphenylphosphine, and sodium borohydride is 1:1:6:1;

[0060] The volume ratio of methanol, dichloromethane and ultrapure water is 3:0.2:0.1;

[0061] When the iodine molecules slowly diffuse into the mixed solution, the iodine molecules are dissolved in n-hexane or methanol to obtain an iodine solution, and then the iodine solution is diffused into the mixed solution, wherein the volume ratio of the iodine solution to the mixed solution is 1:1; the concentration of the iodine solution is 1~2mM; and the iodine molecules are elemental iodine.

[0062] In one embodiment, a method for preparing a luminescent iodine adsorbent comprises the following steps: o C and under vigorous stirring, silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride were reacted in a mixed solution of methanol, dichloromethane and ultrapure water for 10 hours, and then iodine molecules were slowly diffused into the mixed solution by liquid phase diffusion method. o C environment and then allowed to stand for reaction to generate a silver-organic coordination compound Ag(PPh3)3I. o C, the MSOF-3 adsorbent was prepared by hierarchical supramolecular self-assembly of Ag(PPh3)3I molecules. The white precipitate at the bottom was collected by high-speed centrifugation at 9000g relative centrifugal force. The obtained precipitate was washed three times with methanol and n-hexane respectively. The final product was placed in a vacuum drying oven at 50 o Dry overnight at C.

[0063] The coordination center atoms selected for preparing the luminescent iodine adsorbent of the present invention are gold (Au), silver (Ag), copper (Au), platinum (Pt), palladium (Pd), iron (Fe), aluminum (Al), nickel (Ni), and cobalt (Co).

[0064] A third aspect of the present invention provides an MSOF-1 adsorbent.

[0065] A fourth aspect of the present invention provides an MSOF-2 adsorbent.

[0066] A fifth aspect of the present invention provides an MSOF-3 adsorbent.

[0067] A sixth aspect of the present invention provides use of an adsorbent in adsorbing radioactive gaseous iodine and liquid iodine.

[0068] The present invention uses fluorescence spectroscopy to monitor the fluorescence changes of MSOFs during the iodine adsorption process.

[0069] A seventh aspect of the present invention provides a functional fiber, which includes non-woven fibers and the above-mentioned adsorbent supported on the non-woven fibers.

[0070] In one embodiment, a method for preparing a protective device loaded with luminescent MSOFs comprises the following steps:

[0071] MSOF powder is ultrasonically dispersed in ultrapure water. Non-woven fabric fibers are then placed in this dispersion and shaken overnight at 200 rpm. The resulting functional fibers are then rinsed with ultrapure water and dried. These functional fibers are then used to manufacture protective devices such as masks, protective clothing, and air purifier filters.

[0072] An eighth aspect of the present invention provides an application of a functional fiber in a protective mask, protective clothing or an air purifier.

[0073] Through surface ligand engineering, this study successfully synthesized a series of porous materials (MSOFs) based on silver-organic coordination compounds (MSOF-1, -2, and -3), each with distinct surface charge properties. Iodine adsorption sites for MSOF-1 are located on the nitrogen heterocycle and benzene ring of its surface ligands; those for MSOF-2 are located on the nitrogen heterocycle of its surface ligands; and those for MSOF-3 are located on the benzene ring of its surface ligands. Electron-rich groups on the surface of the MSOFs can form charge-transfer complexes with electron-deficient iodine molecules, resulting in excellent iodine adsorption. Iodine adsorption on the MSOFs induces an efficient charge transfer process from the surface ligands to the iodine molecules, resulting in a gradual quenching of the MSOFs' fluorescence as the amount of iodine adsorbed increases. The MSOFs were loaded onto non-woven fabrics via an impregnation method to fabricate a mask with iodine removal properties, real-time fluorescence sensing, and antibacterial properties.

[0074] It should be noted that the experimental methods used in the present invention are all conventional methods unless otherwise specified; the reagents and materials used are all commercially available unless otherwise specified.

[0075] Example 1

[0076] The preparation method of the luminescent MSOF-1 adsorbent comprises the following steps:

[0077] At 30 o C temperature and 1500rpm under vigorous stirring, a freshly prepared aqueous solution of silver nitrate (1mL, 25mM) was added dropwise to a methanol solution of 4-mercaptopyridine (2mL, 12.5mM). While stirring vigorously, a dichloromethane solution of triphenylphosphine (0.2mL, 40mg) was quickly added, and the turbid solution immediately became clear and transparent. A freshly prepared aqueous solution of sodium borohydride (0.1mL, 0.5mg) was immediately added to the above mixed solution. After 10h of reaction, the solution was milky white. The product was collected by high-speed centrifugation at 9000g relative centrifugal force for 5min. The obtained precipitate was washed 3 times with methanol and n-hexane respectively. The final product was placed in a vacuum drying oven and 50 o Dry overnight at C.

[0078] The method for preparing the luminescent MSOF-2 adsorbent comprises the following steps:

[0079] 5 mg of MSOF-1 single crystal was immersed in 2 mL of dichloromethane solution. o C) for one day to obtain a yellow powder. The precipitate was washed three times with methanol and n-hexane respectively, and the final product was placed in a vacuum drying oven at 50 o Dry overnight at C.

[0080] The preparation method of the luminescent MSOF-3 adsorbent comprises the following steps:

[0081] At 30 o Under conditions of temperature of 3700 °C and vigorous stirring at 1500 rpm, a freshly prepared methanol solution of silver nitrate (1 mL, 25 mM) was added dropwise to a methanol solution of 4-mercaptopyridine (2 mL, 12.5 mM). While stirring vigorously, a dichloromethane solution of triphenylphosphine (0.2 mL, 40 mg) was quickly added, and the turbid solution immediately became clear and transparent. A freshly prepared aqueous sodium borohydride solution (0.1 mL, 2.1 mg) was immediately added to the above mixed solution. The dark brown solution became a colorless solution after stirring for 10 h. The colorless solution was filtered with a 0.22 μm organic filter membrane into a 20 mL sample bottle, and an equal volume of methanol solution of iodine (2 mM) was slowly added above the filtrate. At 4 o After standing in a refrigerator at 400 °C overnight, the product was collected by high-speed centrifugation at 9000 g for 5 min. The precipitate was washed three times with methanol and n-hexane respectively. The final product was placed in a vacuum drying oven for 50 o Dry overnight at C.

[0082] The preparation method of the protective mask loaded with luminescent MSOFs comprises the following steps:

[0083] 5 mg of MSOF-1 powder was ultrasonically dispersed in 5 mL of ultrapure water, and the middle layer of the medical surgical mask was placed in the dispersed suspension and shaken overnight at 200 rpm. After that, it was taken out, rinsed with ultrapure water, and then compounded with the upper and bottom layers to prepare a protective mask.

[0084] Example 2

[0085] The preparation method of the luminescent MSOF-1 adsorbent is the same as that in Example 1.

[0086] The method for preparing the luminescent MSOF-2 adsorbent comprises the following steps:

[0087] 5 mg of MSOF-1 single crystal was immersed in 2 mL of chloroform solution. o C) for one day to obtain a yellow long strip powder. The obtained precipitate was washed with methanol and n-hexane three times respectively, and the final product was placed in a vacuum drying oven at 50 o Dry overnight at C.

[0088] The preparation method of the luminescent MSOF-3 adsorbent is the same as that in Example 1.

[0089] The preparation method of the protective mask loaded with luminescent MSOFs is the same as that in Example 1.

[0090] Example 3

[0091] The preparation method of the luminescent MSOF-1 adsorbent comprises the following steps:

[0092] The synthesis conditions and steps were the same as those in Example 1, except that silver nitrate was dissolved in methanol and the amount of sodium borohydride was 0.21 mg. The dark brown solution became colorless after stirring for 10 h. The colorless solution was filtered with a 0.22 μm organic filter membrane and the filtrate was heated at 4 o C refrigerator for 2 days to obtain colorless square crystals. The obtained precipitate was washed 3 times with methanol and n-hexane respectively, and the final product was placed in a vacuum drying oven at 50 o Dry overnight at C.

[0093] The method for preparing the luminescent MSOF-2 adsorbent comprises the following steps:

[0094] 5 mg of MSOF-1 single crystal was immersed in 2 mL of N,N -dimethylformamide solution. At room temperature (25 oC) for two weeks to obtain yellow long crystals. The precipitate was washed three times with methanol and n-hexane respectively, and the final product was placed in a vacuum drying oven at 50 o Dry overnight at C.

[0095] The preparation method of the luminescent MSOF-3 adsorbent comprises the following steps:

[0096] The synthesis conditions and steps are the same as those in Example 1, except that iodine is dissolved in n-hexane solution at a concentration of 1 mM. o C refrigerator for 10 days to obtain colorless block crystals. The obtained precipitate was washed 3 times with methanol and n-hexane respectively, and the final product was placed in a vacuum drying oven at 50 o Dry overnight at C.

[0097] The preparation method of the protective mask loaded with luminescent MSOFs is the same as that in Example 1.

[0098] Example 4

[0099] The preparation of the luminescent MSOF-1 adsorbent was the same as in Example 3.

[0100] The method for preparing the luminescent MSOF-2 adsorbent comprises the following steps:

[0101] 5 mg of MSOF-1 single crystal was immersed in 2 mL of N,N -dimethylacetamide solution. At room temperature (25 o C) for two weeks to obtain yellow long crystals. The precipitate was washed three times with methanol and n-hexane respectively, and the final product was placed in a vacuum drying oven at 50 o Dry overnight at C.

[0102] The preparation method of the luminescent MSOF-3 adsorbent is the same as that in Example 3.

[0103] The preparation method of the protective mask loaded with luminescent MSOFs is the same as that in Example 1.

[0104] Example 5

[0105] The preparation method of the luminescent MSOF-1 adsorbent is the same as that in Example 1.

[0106] The preparation method of the luminescent MSOF-2 adsorbent is the same as that in Example 1.

[0107] The preparation method of the luminescent MSOF-3 adsorbent is the same as that in Example 1.

[0108] The preparation method of the protective mask loaded with luminescent MSOFs comprises the following steps:

[0109] 5 mg of MSOF-2 powder was ultrasonically dispersed in 5 mL of ultrapure water, and the middle layer of the medical surgical mask was placed in the dispersed suspension and shaken overnight at 200 rpm. After that, it was taken out, rinsed with ultrapure water, and compounded with the upper and bottom layers to prepare a protective mask.

[0110] Example 6

[0111] The preparation method of the luminescent MSOF-1 adsorbent is the same as that in Example 1.

[0112] The preparation method of the luminescent MSOF-2 adsorbent is the same as that in Example 1.

[0113] The preparation method of the luminescent MSOF-3 adsorbent is the same as that in Example 1.

[0114] The preparation method of the protective mask loaded with luminescent MSOFs comprises the following steps:

[0115] 5 mg of MSOF-3 powder was ultrasonically dispersed in 5 mL of ultrapure water, and the middle layer of the medical surgical mask was placed in the dispersed suspension and shaken overnight on a shaker at 200 rpm. After that, it was taken out, rinsed with ultrapure water, and composited with the upper and bottom layers to prepare a protective mask.

[0116] In order to illustrate the performance of the adsorbent provided by the present invention, since the luminescent MSOFs adsorbents and the protective masks loaded with luminescent MSOFs prepared in Examples 1-6 of the present invention have basically the same effects, the luminescent MSOFs adsorbent and the protective mask loaded with luminescent MSOFs of Example 1 are taken as examples below to test the iodine adsorption and real-time fluorescence monitoring capabilities of the luminescent MSOFs adsorbent and the protective mask loaded with luminescent MSOFs prepared in Example 1. The specific results are shown below:

[0117] The crystal structure of the MSOFs assembly element silver-organic coordination compound in Example 1 is as follows Figure 1 As shown. In order to systematically adjust the electron-rich adsorption sites for better iodine absorption, the type and amount of surface ligands of the silver-organic coordination compound were designed at the molecular level. The structure of Ag(4-Mpy)2(PPh3)2 presents π-electron-rich and electron-rich N structures, which are contributed by triphenylphosphine and 4-mercaptopyridine groups on the surface, respectively. Accordingly, [Ag(4-Mpy)2] n The results show that the three silver-organic coordination compounds all have a significant negative surface potential, which makes it possible to absorb positively charged iodine through charge transfer.

[0118] The crystal structure of the MSOFs prepared in Example 1 was characterized by powder X-ray diffractometer. Figure 2As shown in Figure 3, the diffraction peak signals of the prepared MSOFs powder crystals all match the simulated XRD data, indicating the successful synthesis of the material.

[0119] The morphology of the MSOFs prepared in Example 1 was characterized by scanning electron microscopy. Figure 3 As shown, the morphologies of MSOF-1, MSOF-2 and MSOF-3 are square, strip and diamond blocks, respectively, and the sizes are all at the μm level.

[0120] The fluorescence emission spectrum of the MSOFs in Example 1 is as follows: Figure 4 The surface ligands of MSOFs also have a significant effect on their fluorescence properties. The fluorescence emission peaks of MSOF-1, MSOF-2, and MSOF-3 are located at 475, 540, and 485 nm, respectively.

[0121] The adsorption kinetics of iodine vapor by the MSOFs in Example 1 was studied, and the specific test method was as follows:

[0122] Static iodine adsorption experiments were performed in a custom-made system. Typically, two 3 mL glass vials were placed in a 50 mL wide-mouth bottle containing 500 mg of iodine. The first vial contained 10 mg of activated MSOFs (MSOF-1, MSOF-2, and MSOF-3) powder crystal sample, while the second vial was empty as a reference. After the wide-mouth bottles were sealed, the system was placed at 75 o C in an oven. The weight of the adsorbent (MSOFs) was measured every hour until it reached a stable value. The maximum static capture capacity was determined by the weight increase of the MSOFs sample. The adsorption capacity Q was calculated by the following formula e (g / g):Q e =(m e -m0) / m0, where m0 is the initial mass of MSOFs iodine adsorbent, m e is the mass of MSOFs iodine adsorbent after adsorption, and the results are as follows Figure 5 shown.

[0123] The experimental results show that the equilibrium adsorption capacities of MSOF-1, MSOF-2, and MSOF-3 as adsorbents are 1.78, 1.86, and 3.62 g / g, respectively. These results demonstrate the great potential of MSOFs as adsorbents for iodine adsorption.

[0124] The adsorption kinetics of iodine solution by MSOFs in Example 1 was studied, and the specific test method was as follows:

[0125] Under normal pressure, 3 mg of MSOFs was used as an adsorbent and added to 3 mL of 1 mM iodine in n-hexane solution to conduct an iodine adsorption experiment. The iodine adsorption process was monitored by UV-visible absorption spectroscopy. The results are as follows: Figure 6 shown.

[0126] After the addition of MSOFs, the color of the iodine solution gradually changed from dark purple to colorless, indicating that the MSOFs gradually absorbed the iodine in the solution. In the adsorption systems containing MSOF-1, -2, and -3, the time it took for the solution to become colorless was 4, 5, and 2 hours, respectively. Iodine in n-hexane solution exhibits significant UV absorption at 522 nm. With increasing adsorption time, the UV absorption intensity at 522 nm gradually decreases until it disappears. We plotted the variation of the UV absorption intensity of iodine in n-hexane solution at 522 nm as a function of MSOF adsorption time. The iodine adsorption capacity of MSOF-1, MSOF-2, and MSOF-3 approached 100% within 5, 6, and 2 hours, respectively. These results indicate that MSOFs can be used as candidate materials for adsorbing radioactive iodine from nuclear wastewater.

[0127] The fluorescence emission spectra of MSOF-1 in Example 1 for different iodine adsorption amounts are as follows: Figure 7 As shown in Figure 2, the fluorescence of MSOF-1 gradually decreases with increasing iodine adsorption, completely disappearing at an adsorption capacity of 1 g / g. Therefore, at the maximum adsorption capacity (1.78 g / g), I2@MSOF-1 exhibits no fluorescence signal. Unlike traditional adsorbents, the fluorescence response of MSOFs during iodine adsorption will be beneficial for establishing a real-time fluorescence monitoring system for monitoring iodine adsorption.

[0128] The crystal structure of the non-woven fabric loaded with MSOF-1 prepared in Example 1 was characterized by powder X-ray diffractometer. Figure 8 The non-woven fibers loaded with MSOF-1 exhibit characteristic diffraction peaks of both MSOF-1 and non-woven fibers, indicating that MSOF-1 is successfully loaded on the non-woven fibers.

[0129] The morphology of the non-woven fabric loaded with MSOF-1 prepared in Example 1 was characterized by scanning electron microscopy. Figure 9 The surface of the non-woven fabric is smooth, and after being immersed in the MSOF-1 dispersion, a large number of MSOF-1 particles are attached to the surface of the non-woven fabric, indicating the successful loading of the material.

[0130] The iodine removal rate of the protective mask in Example 1 was studied, and the specific testing method was as follows:

[0131] The MSOF-1-loaded nonwoven fabric was used as the middle layer, sandwiched between the upper and lower layers of a commercial mask to create a mask with iodine adsorption capacity. 6mL of a 1mM iodine-containing aqueous solution of KI (KI concentration of 5mM) was used for aerogel emission. The top layer of the mask was exposed to the side of a microbial aerosol generator, and the airflow rate was controlled at 0.3mL / min. Each layer of the mask was then immersed in a methanol solution to release iodine. The iodine removal rate was measured by UV-visible absorption spectroscopy, as shown in the following figure. Figure 10 shown.

[0132] Iodine was largely removed by the nonwoven fiber layer of either the MSOF-1-loaded or commercial masks, with no significant iodine absorption by the other two layers. However, the commercial masks were significantly less efficient at removing iodine than the MSOF-1-loaded masks. The MSOF-1-loaded masks achieved an iodine removal efficiency of 99.1%, significantly higher than the 1.3% efficiency of the commercial masks, demonstrating that the prepared MSOF-1-loaded masks possess significant iodine adsorption and protective properties.

[0133] The fluorescence emission spectra of the protective mask before and after iodine removal in Example 1 are as follows: Figure 11 The fluorescence of the protective mask loaded with MSOF-1 is significantly quenched after iodine adsorption, which can remind users to replace it in time.

[0134] In summary, the present invention provides a method for regulating the surface charge properties of MSOFs through surface ligand engineering for iodine adsorption, and real-time in-situ monitoring of the adsorption process through fluorescence. Based on MSOFs, protective devices with iodine adsorption and fluorescence monitoring are prepared, such as protective masks, protective clothing, air purifier filter elements, etc., and are expected to have antibacterial protection at the same time. The iodine adsorbent and protective device prepared by the present invention have excellent adsorption capacity, low cost, can be quickly synthesized in large quantities, and have a high adsorption rate, which is conducive to efficient processing and real-time monitoring of iodine; and the preparation method of the present invention has simple steps, easy operation, and low equipment requirements.

[0135] The present invention describes preferred embodiments and their effects. However, those skilled in the art, once informed of the basic inventive concept, may make additional changes and modifications to these embodiments. Therefore, it is intended that the appended claims be interpreted to include the preferred embodiments as well as all changes and modifications that fall within the scope of the invention.

[0136] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a luminescent iodine adsorbent, characterized in that: The adsorbent is prepared according to the following steps: Silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride were reacted in a mixed solution of methanol, dichloromethane and ultrapure water at room temperature for 8-12 hours, and iodine molecules were slowly diffused into the mixed solution by liquid phase diffusion method. o C environment, the reaction is allowed to stand to generate silver-organic coordination compound Ag(PPh3)3I, and then the reaction is continued at 3~5 o Under C conditions, MSOF-3 adsorbent was obtained by hierarchical supramolecular self-assembly, which is a luminescent iodine adsorbent; The molar ratio of silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride is 1:1:6:0.5-1.5; The volume ratio of methanol, dichloromethane and ultrapure water is 2-4:0.2:0.1; When the iodine molecules slowly diffuse into the mixed solution, the iodine molecules are dissolved in n-hexane or methanol to obtain an iodine solution, and then the iodine solution is diffused into the mixed solution, wherein the volume ratio of the iodine solution to the mixed solution is 1:1; the concentration of the iodine solution is 1~2 mM; and the iodine molecules are elemental iodine.

2. A luminescent iodine adsorbent prepared by the method according to claim 1.

3. Use of the adsorbent according to claim 2 in adsorbing radioactive gaseous iodine and liquid iodine.

4. A functional fiber, characterized in that The functional fibers include non-woven fibers and the adsorbent according to claim 2 supported on the non-woven fibers.

5. Use of the functional fiber according to claim 4 in a protective mask, protective clothing or an air purifier.

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