Preparation method and protection application of luminous iodine adsorbent

Abstract

The invention discloses a preparation method and protection application of a luminous iodine adsorbent, and relates to the technical field of radioactive waste gas and waste liquid treatment. The method comprises the following steps: jointly dissolving an organic ligand and metal ions in a solvent to obtain a mixed solution, carrying out room-temperature reaction on the mixed solution, and assembling to obtain the luminous MSOFs adsorbent, wherein the organic ligand is a sulfydryl ligand with a nitrogen heterocyclic ring or a phenylphosphine derivative; the ligand central atom comprises gold, silver, copper, platinum, palladium, iron, aluminum, nickel or cobalt. The prepared iodine adsorbent and the protection device are excellent in adsorption capacity, low in cost, capable of being rapidly and massively synthesized, high in adsorption rate and beneficial to efficient treatment and real-time monitoring of iodine; the preparation method is simple in step, convenient to operate and low in equipment requirement.

Description

Technical Field

[0001] The 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 are highly volatile, easily form highly mobile gases, and are easily soluble in water. While causing harm to the environment, they also have a serious impact on human metabolism by damaging the thyroid gland. Therefore, it is particularly important to research and develop efficient capture and storage technology for radioactive iodine, which will help reduce the risks of volatile radioactive waste to the environment and human health and promote sustainable development in the field of nuclear energy.

[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 and in-depth studies of the iodine adsorption mechanism at the molecular level. In addition, researchers have also adopted molecular-level design strategies to enhance iodine uptake. For example, incorporating electron-rich heteroatoms, such as nitrogen, sulfur, and oxygen, and π donors, such as double / triple bonds and phenyl groups, have been shown to be an effective way to enhance electron-deficient iodine uptake by forming charge-transfer species. Therefore, in-depth studies on the types and numbers of electron-rich adsorption sites are of great guiding significance for the molecular design of materials with high iodine uptake capacity. In addition, most studies have focused on the uptake capacity of the developed adsorbents, while ignoring the effective means of visually tracking the uptake process. This method is essential for studying the saturation during the absorption process, which is a key consideration for the effective capture of radioactive iodine and the timely replacement of absorption adsorbents in industrial environments. In addition, the preparation of protective products based on these adsorbents is crucial for the health protection of practitioners. However, the relevant research is scarce.

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

[0005] In view of the shortcomings of the above-mentioned background technology, the present invention provides a preparation method of a luminescent iodine adsorbent and its protective application. The main purpose is to provide a simple preparation method of a luminescent MSOFs adsorbent that efficiently captures iodine and has real-time fluorescence monitoring of the adsorption process, and loads the MSOFs on the non-woven fabric fibers of the middle layer of the mask in order to achieve efficient protective applications, aiming to solve the problem of iodine adsorption treatment 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: 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; Wherein, 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.

[0007] Preferably, the adsorbent is prepared according to the following steps: Silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride are reacted in a mixed solution of methanol, dichloromethane and ultrapure water to obtain a silver-organic coordination compound Ag(4-Mpy) 2 (PPh 3 ) 2 , then 3~5 o C conditions, the MSOF-1 adsorbent was obtained by hierarchical supramolecular self-assembly; The molar ratio of silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride is 1:1:6:0.5-1.5; The volume ratio of the methanol, dichloromethane and ultrapure water is 2-4:0.2:0.1.

[0008] The second object of the present invention is to provide a method for preparing a luminescent iodine adsorbent, comprising the following steps: The prepared MSOF-1 adsorbent was immersed in dichloromethane, chloroform, N,N -dimethylformamide or N,N -dimethylacetamide solution and soaked for 24 to 48 hours to obtain MSOF-2 adsorbent.

[0009] Preferably, 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 for 8-12 hours, and iodine molecules were slowly diffused into the mixed solution by liquid phase diffusion method. o C environment, the reaction was allowed to stand to generate a silver-organic coordination compound Ag(PPh 3 ) 3 I, continue at 3~5 o C conditions, the MSOF-3 adsorbent was obtained by hierarchical supramolecular self-assembly; 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 1~2mM; and the iodine molecules are elemental iodine.

[0010] The third object of the present invention is to provide a MSOF-1 adsorbent.

[0011] The fourth object of the present invention is to provide a MSOF-2 adsorbent.

[0012] The fifth object of the present invention is to provide a MSOF-3 adsorbent.

[0013] A sixth object of the present invention is to provide an adsorbent for use in adsorbing radioactive gaseous iodine and liquid iodine.

[0014] 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.

[0015] 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.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a preparation method of a luminescent iodine adsorbent and its protective application. The present invention successfully synthesizes a series of porous materials (MSOFs, MSOF-1, -2, -3) based on silver-organic coordination compounds through surface ligand engineering, which have different surface charge properties. The iodine adsorption position of MSOF-1 is located on the nitrogen heterocyclic ring and benzene ring of its surface ligand; the iodine adsorption position of MSOF-2 is located on the nitrogen heterocyclic ring of its surface ligand; and the iodine adsorption position of MSOF-3 is on the benzene ring of its surface ligand. The electron-rich groups on the surface of MSOFs can form charge transfer complexes with electron-deficient iodine molecules, thereby showing excellent adsorption capacity for iodine. After MSOFs adsorb iodine, they induce an efficient charge transfer process from the surface ligand to the iodine molecule, resulting in the gradual quenching of the fluorescence of MSOFs as the amount of iodine adsorption increases. MSOFs are loaded on non-woven fabric fibers by an impregnation method to prepare masks with iodine removal performance, real-time fluorescence sensing and antibacterial properties.

[0017] The synthesis process of the invention is simple, operability is strong, and it is suitable for high-efficiency and mass production.

[0018] The MSOFs prepared by the present invention have a large adsorption capacity for iodine vapor, and the adsorption capacities of MSOF-1, MSOF-2 and MSOF-3 are 1.78, 1.86 and 3.62 g / g respectively, which are superior to most adsorbents. In addition, the MSOFs prepared by the present invention have excellent adsorption performance for iodine solution. The present invention has good iodine storage capacity, high stability and good reusability, and exhibits high adsorption capacity and strong desorption capacity in iodine vapor adsorption experiments, and is an iodine vapor adsorption material with excellent performance.

[0019] The MSOFs prepared by the present invention exhibit obvious fluorescence quenching performance during the iodine adsorption process, so as to establish a real-time fluorescence monitoring system to monitor the iodine adsorption process.

[0020] The MSOFs-loaded protective mask of the present invention has great potential in iodine removal. The iodine removal rate in the aerogel environment is 99.1%, which is much higher than that of ordinary commercial masks. Fluorescence quenching detection can remind timely replacement of masks. In addition, the mask has antibacterial potential. The mask is expected to be used as a new iodine adsorption material for personal health protection in extreme environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the synthesis process in Example 1 of the present invention; Figure 2 is the powder X-ray diffraction pattern of the MSOFs in Example 1 of the present invention; Figure 3 This is a scanning electron microscope image of the MSOFs in Example 1 of the present invention; Figure 4 is the fluorescence emission spectrum of MSOFs in Example 1 of the present invention; Figure 5 This is a diagram showing the adsorption kinetics of iodine vapor by MSOFs in Example 1 of the present invention; Figure 6 is the adsorption kinetics diagram of iodine solution by MSOFs in Example 1 of the present invention; Figure 7 The fluorescence emission spectra of MSOF-1 in Example 1 of the present invention for different iodine adsorption amounts; Figure 8 is a powder X-ray diffraction pattern of the non-woven fabric fiber loaded with MSOF-1 in Example 1 of the present invention; Fig. 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; Fig.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.

[0022] Fig.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

[0023] 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 in conjunction with specific embodiments and drawings, but the embodiments are not intended to limit the present invention.

[0024] The first aspect of the present invention provides a method for preparing a luminescent iodine adsorbent, comprising the following steps: 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; Wherein, 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.

[0025] The present invention uses luminescent metal-organic coordination compound-based supramolecular organic framework materials (MSOFs) as adsorbents to adsorb iodine, and monitors the adsorption process in real time in situ fluorescence, thereby preparing a protective mask with iodine adsorption performance, fluorescence detection and antibacterial properties.

[0026] Wherein, the adsorbent is prepared according to the following steps: Silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride are reacted in a mixed solution of methanol, dichloromethane and ultrapure water to obtain a silver-organic coordination compound Ag(4-Mpy) 2 (PPh3 ) 2 , then in 3~5 o C conditions, the MSOF-1 adsorbent was obtained by hierarchical supramolecular self-assembly; The molar ratio of silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride is 1:1:6:1; The volume ratio of the methanol, dichloromethane and ultrapure water is 3:0.2:0.1.

[0027] In one embodiment, a method for preparing a luminescent iodine adsorbent comprises the following steps: At 30 o C and under vigorous stirring conditions, 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 (PPh 3 ) 2 Then in 4 o Ag(4-Mpy) 2 (PPh 3 ) 2 The MSOF-1 adsorbent was prepared by hierarchical supramolecular self-assembly. The white precipitate at the bottom was collected by high-speed centrifugation at a relative centrifugal force of 9000 g. The 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.

[0028] A second aspect of the present invention provides a method for preparing a luminescent iodine adsorbent, comprising the following steps: The MSOF-1 adsorbent prepared above was immersed in dichloromethane, chloroform, N,N -dimethylformamide or N, N -dimethylacetamide solution and soaked for 24 to 48 hours to obtain MSOF-2 adsorbent.

[0029] 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,N -dimethylacetamide solution for 24 h. The 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.

[0030] Wherein, 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 for 8-12 hours, and iodine molecules were slowly diffused into the mixed solution by liquid phase diffusion method. o C environment, the reaction was allowed to stand to generate a silver-organic coordination compound Ag(PPh 3 ) 3 I, continue at 3~5 o C conditions, the MSOF-3 adsorbent was obtained by hierarchical supramolecular self-assembly; The molar ratio of silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride is 1:1:6:1; The volume ratio of methanol, dichloromethane and ultrapure water is 3:0.2:0.1; 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 1~2mM; and the iodine molecules are elemental iodine.

[0031] 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 the iodine molecules were slowly diffused into the mixed solution by liquid phase diffusion method. o C environment to generate a silver-organic coordination compound Ag(PPh 3 ) 3 I. in 4 o C conditions, through Ag(PPh 3 ) 3 The white 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.

[0032] 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).

[0033] The third aspect of the present invention provides a MSOF-1 adsorbent.

[0034] A fourth aspect of the present invention provides a MSOF-2 adsorbent.

[0035] A fifth aspect of the present invention provides a MSOF-3 adsorbent.

[0036] A sixth aspect of the present invention provides a use of an adsorbent in adsorbing radioactive gaseous iodine and liquid iodine.

[0037] The present invention uses fluorescence spectroscopy to monitor the fluorescence changes of MSOFs during the process of iodine adsorption.

[0038] A seventh aspect of the present invention provides a functional fiber, which includes a non-woven fiber and the above-mentioned adsorbent loaded on the non-woven fiber.

[0039] In one embodiment, a method for preparing a protective device loaded with luminescent MSOFs comprises the following steps: The MSOFs powder was ultrasonically dispersed in ultrapure water, and then the non-woven fabric fiber was placed in the dispersed suspension and shaken overnight at 200 rpm. After that, it was taken out, rinsed with ultrapure water and dried to prepare functional fibers. Protective devices such as protective masks, protective clothing, and air purifier filters were prepared based on the functional fibers.

[0040] An eighth aspect of the present invention provides an application of a functional fiber in a protective mask, protective clothing or an air purifier.

[0041] The present invention successfully synthesized a series of porous materials (MSOFs, MSOF-1, -2, -3) based on silver-organic coordination compounds through surface ligand engineering, which have different surface charge properties. The iodine adsorption position of MSOF-1 is located on the nitrogen heterocyclic ring and benzene ring of its surface ligand; the iodine adsorption position of MSOF-2 is located on the nitrogen heterocyclic ring of its surface ligand; and the iodine adsorption position of MSOF-3 is on the benzene ring of its surface ligand. The electron-rich groups on the surface of MSOFs can form charge transfer complexes with electron-deficient iodine molecules, thereby showing excellent adsorption capacity for iodine. After MSOFs adsorb iodine, they induce an efficient charge transfer process from the surface ligand to the iodine molecule, resulting in the gradual quenching of the fluorescence of MSOFs as the amount of iodine adsorption increases. MSOFs were loaded on non-woven fabric fibers by an impregnation method to prepare masks with iodine removal performance, real-time fluorescence sensing and antibacterial properties.

[0042] 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.

[0043] Example 1 The method for preparing the luminescent MSOF-1 adsorbent comprises the following steps: At 30 oC temperature and 1500rpm vigorous stirring conditions, the freshly prepared silver nitrate aqueous solution (1mL, 25mM) was dripped dropwise into the 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. The freshly prepared sodium borohydride aqueous solution (0.1mL, 0.5mg) was immediately added to the above mixed solution. After 10h of reaction, the solution was milky white, and 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, and the final product was placed in a vacuum drying oven for 50 o Dry overnight at C.

[0044] The method for preparing the luminescent MSOF-2 adsorbent comprises the following steps: 5 mg of MSOF-1 single crystal was immersed in 2 mL of dichloromethane solution at room temperature (25 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.

[0045] The method for preparing the luminescent MSOF-3 adsorbent comprises the following steps: At 30 o Under the conditions of temperature of 370 °C and vigorous stirring at 1500 rpm, add freshly prepared methanol solution of silver nitrate (1 mL, 25 mM) dropwise into methanol solution of 4-mercaptopyridine (2 mL, 12.5 mM). While stirring vigorously, quickly add dichloromethane solution of triphenylphosphine (0.2 mL, 40 mg), and the turbid solution immediately becomes clear and transparent. Immediately add freshly prepared aqueous sodium borohydride solution (0.1 mL, 2.1 mg) to the above mixed solution. The dark brown solution becomes a colorless solution after stirring for 10 hours. Filter the colorless solution with a 0.22 μm organic filter membrane into a 20 mL sample bottle, and slowly add an equal volume of methanol solution of iodine (2 mM) on top of the filtrate. At 4 o After standing in a refrigerator at 40 °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.

[0046] The preparation method of the protective mask loaded with luminescent MSOFs comprises the following steps: 5 mg of MSOF-1 powder was ultrasonically dispersed in 5 mL of ultrapure water, and then the middle layer of the medical surgical mask was placed in the dispersed suspension and shaken overnight on a shaker at 200 rpm. It was then taken out, rinsed with ultrapure water, and composited with the upper and bottom layers for the preparation of a protective mask.

[0047] Example 2 The preparation method of the luminescent MSOF-1 adsorbent is the same as that in Example 1.

[0048] The method for preparing the luminescent MSOF-2 adsorbent comprises the following steps: 5 mg of MSOF-1 single crystal was immersed in 2 mL of chloroform solution at room temperature (25 o C) for one day to obtain a yellow long strip powder. The obtained 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.

[0049] The preparation method of the luminescent MSOF-3 adsorbent is the same as that in Example 1.

[0050] The preparation method of the protective mask loaded with luminescent MSOFs is the same as that in Example 1.

[0051] Example 3 The method for preparing the luminescent MSOF-1 adsorbent comprises the following steps: The synthesis conditions and steps were the same as those in Example 1, except that silver nitrate was dissolved in methanol solution and the amount of sodium borohydride was 0.21 mg. 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 and the filtrate was concentrated to 4 o C refrigerator for 2 days to obtain colorless square crystals. The obtained 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.

[0052] The method for preparing the luminescent MSOF-2 adsorbent comprises the following steps: 5 mg of MSOF-1 single crystal was immersed in 2 mL of N,N -dimethylformamide solution. At room temperature (25 o C) for two weeks to obtain yellow long crystals. 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.

[0053] The method for preparing the luminescent MSOF-3 adsorbent comprises the following steps: 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 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.

[0054] The preparation method of the protective mask loaded with luminescent MSOFs is the same as that in Example 1.

[0055] Example 4 The preparation of the luminescent MSOF-1 adsorbent was the same as in Example 3.

[0056] The method for preparing the luminescent MSOF-2 adsorbent comprises the following steps: 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 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.

[0057] The preparation method of the luminescent MSOF-3 adsorbent is the same as that in Example 3.

[0058] The preparation method of the protective mask loaded with luminescent MSOFs is the same as that in Example 1.

[0059] Example 5 The preparation method of the luminescent MSOF-1 adsorbent is the same as that in Example 1.

[0060] The preparation method of the luminescent MSOF-2 adsorbent is the same as that in Example 1.

[0061] The preparation method of the luminescent MSOF-3 adsorbent is the same as that in Example 1.

[0062] The preparation method of the protective mask loaded with luminescent MSOFs comprises the following steps: 5 mg of MSOF-2 powder was ultrasonically dispersed in 5 mL of ultrapure water, and then the middle layer of the medical surgical mask was placed in the dispersed suspension and shaken overnight on a shaker at 200 rpm. It was then taken out, rinsed with ultrapure water, and composited with the upper and bottom layers for the preparation of a protective mask.

[0063] Example 6 The preparation method of the luminescent MSOF-1 adsorbent is the same as that in Example 1.

[0064] The preparation method of the luminescent MSOF-2 adsorbent is the same as that in Example 1.

[0065] The preparation method of the luminescent MSOF-3 adsorbent is the same as that in Example 1.

[0066] The preparation method of the protective mask loaded with luminescent MSOFs comprises the following steps: 5 mg of MSOF-3 powder was ultrasonically dispersed in 5 mL of ultrapure water, and then the middle layer of the medical surgical mask was placed in the dispersed suspension and shaken overnight on a shaker at 200 rpm. It was then taken out, rinsed with ultrapure water, and composited with the upper and bottom layers for the preparation of a protective mask.

[0067] 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 masks loaded with luminescent MSOFs in 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 masks loaded with luminescent MSOFs prepared in Example 1, and the specific results are as follows: The crystal structure of the MSOFs assembly element silver-organic coordination compound in Example 1 is as follows Figure 1 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. Ag(4-Mpy) 2 (PPh 3 ) 2 The structure of [Ag(4-Mpy) 2 ] n Only electron-rich N structure is presented, Ag(PPh 3 ) 3 I only presents a π-electron-rich structure. These results indicate that the three silver-organic coordination compounds all have obvious negative surface potentials, which provide the possibility for the absorption of positively charged iodine through charge transfer.

[0068] The crystal structure of the MSOFs prepared in Example 1 was characterized by powder X-ray diffractometer. Figure 2 As shown, the diffraction peak signals of the prepared MSOFs powder crystals all match the simulated XRD data, indicating the successful synthesis of the material.

[0069] 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.

[0070] The fluorescence emission spectrum of the MSOFs in Example 1 is as follows: Figure 4As shown. 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.

[0071] The adsorption kinetics of iodine vapor by the MSOFs in Example 1 was studied, and the specific test method was as follows: Static iodine adsorption experiments were performed in a custom-made system. Typically, two 3 mL glass bottles 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 samples, and the second vial was an empty bottle 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 its weight reached a stable value. The maximum static capture capacity was determined by the weight gain of the MSOFs sample. The adsorption amount Q was calculated by the following formula e (g / g): Q e =(m e -m 0 ) / m 0 , where m 0 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.

[0072] The experimental results show that the equilibrium adsorption capacities of MSOF-1, MSOF-2 and MSOF-3 are 1.78, 1.86 and 3.62 g / g, respectively. The above results indicate the great potential of MSOFs as adsorbents for iodine adsorption.

[0073] The adsorption kinetics of the MSOFs in Example 1 on the iodine solution was studied, and the specific test method was as follows: 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.

[0074] After adding MSOFs, the color of the iodine solution gradually changed from dark purple to colorless, indicating that MSOFs gradually absorbed the iodine in the solution. Among them, in the adsorption systems containing MSOF-1, -2, and -3, the time for the solution to become colorless was 4, 5, and 2 hours, respectively. The n-hexane solution of iodine has obvious ultraviolet absorption at 522nm. As the adsorption time increases, the ultraviolet absorption intensity at 522nm gradually decreases until it disappears. We plotted the change of the ultraviolet absorption intensity of the n-hexane solution of iodine at 522nm with the adsorption time of MSOFs. The iodine adsorption amount of MSOF-1, MSOF-2, and MSOF-3 within 5, 6, and 2 hours, respectively, was close to 100%. These results show that MSOFs can be used as candidate materials for adsorbing radioactive iodine in nuclear waste water.

[0075] 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 the increase of iodine adsorption. When the adsorption amount is 1 g / g, the fluorescence of MSOF-1 disappears completely. Therefore, at the maximum adsorption amount (1.78 g / g), I 2 @MSOF-1 has no fluorescence signal. Different from traditional adsorbents, the fluorescence response performance of MSOFs during iodine adsorption will be beneficial to establish a fluorescence real-time monitoring system for monitoring the iodine adsorption process.

[0076] 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 fabric fibers loaded with MSOF-1 have characteristic diffraction peaks of both MSOF-1 and non-woven fabric fibers, indicating that MSOF-1 is successfully loaded on the non-woven fabric fibers.

[0077] The morphology of the nonwoven fabric loaded with MSOF-1 prepared in Example 1 was characterized by scanning electron microscopy. Fig. 9 The surface of the nonwoven fabric is smooth, and after being immersed in the dispersion of MSOF-1, a large number of MSOF-1 particles are attached to the surface of the nonwoven fabric, indicating the successful loading of the material.

[0078] The iodine removal rate of the protective mask in Example 1 was studied, and the specific testing method was as follows: The non-woven fabric fiber loaded with MSOF-1 was used as the middle layer and sandwiched between the upper and lower layers of the commercial mask to make a mask with iodine adsorption capacity. 6mL of 1mM iodine KI aqueous solution (KI concentration is 5mM) was used for aerogel emission, and the top layer of the mask was exposed to the side of the microbial aerosol generator, and the airflow rate was controlled to 0.3mL / min. Then each layer of the mask was immersed in a methanol solution for iodine release, and the iodine removal rate was determined by UV-visible absorption spectroscopy. The results are shown in Fig.10 shown.

[0079] Iodine was basically removed by the non-woven fiber layer of the protective mask loaded with MSOF-1 or the commercial mask, and there was no obvious iodine absorption in the other two layers. However, compared with the protective mask loaded with MSOF-1, the iodine removal ability of the commercial mask was much worse. The iodine removal efficiency of the protective mask loaded with MSOF-1 was 99.1%, which was much higher than the iodine removal efficiency of the commercial mask (1.3%), indicating that the prepared protective mask loaded with MSOF-1 had significant iodine adsorption and protection effects.

[0080] The fluorescence emission spectra of the protective mask before and after iodine removal in Example 1 are as follows: Fig.11 As shown in the figure, 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.

[0081] 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, filter elements of air purifiers, 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 the efficient processing and real-time monitoring of iodine; and the preparation method of the present invention has simple steps, convenient operation, and low equipment requirements.

[0082] The present invention describes preferred embodiments and their effects. However, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0083] Although 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 the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a luminescent iodine adsorbent, characterized in that: The following steps are involved: 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; Wherein, 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.

2. The method for preparing the luminescent iodine adsorbent according to claim 1, 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 to obtain a silver-organic coordination compound Ag(4-Mpy)2(PPh3)2. o C conditions, the MSOF-1 adsorbent was obtained by hierarchical supramolecular self-assembly; The molar ratio of silver nitrate, 4-mercaptopyridine, triphenylphosphine and sodium borohydride is 1:1:6:0.5-1.5; The volume ratio of the methanol, dichloromethane and ultrapure water is 2-4:0.2:0.

1.

3. A method for preparing a luminescent iodine adsorbent, characterized in that: The following steps are involved: The MSOF-1 adsorbent prepared in claim 2 is immersed in dichloromethane, chloroform, N,N -dimethylformamide or N,N -dimethylacetamide solution and soaked for 24 to 48 hours to obtain MSOF-2 adsorbent.

4. The method for preparing the luminescent iodine adsorbent according to claim 1, 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 for 8-12 hours, and iodine molecules were slowly diffused into the mixed solution by liquid phase diffusion method. o C environment, the reaction was allowed to stand to generate a silver-organic coordination compound Ag(PPh3)3I. o C conditions, the MSOF-3 adsorbent was obtained by hierarchical supramolecular self-assembly; 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.

5. A MSOF-1 adsorbent prepared by the method according to claim 2.

6. A MSOF-2 adsorbent prepared by the method according to claim 3.

7. A MSOF-3 adsorbent prepared by the method according to claim 4.

8. Use of the adsorbent according to claim 5, 6 or 7 in adsorbing radioactive gaseous iodine and liquid iodine.

9. A functional fiber, characterized in that: The functional fibers include non-woven fabric fibers and the adsorbent according to claim 5, 6 or 7 supported on the non-woven fabric fibers.

10. Use of the functional fiber according to claim 9 in a protective mask, protective clothing or an air purifier.

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