Visual tracking sensor for uranium-238 isotope, method for manufacturing the same, and method for visually tracking and extracting uranium using the same.

Abstract

To provide a visual tracking sensor for uranium 238 isotope that is an optical sensor which has specific sensitivity and selectivity for detecting / extracting U(VI) ions of low concentration from different environments, and has speedy performance for optical detection with high selectivity and also has a separation process made efficient.SOLUTION: There is provided a visual tracking sensor for uranium 238 isotope that comprises mesoporous silica having a three-dimensional hexagonal monolith type worm-shaped higher order structure, a chelate compound modified on a surface of the mesoporous silica, and an organic coloring chelate-based probe modified on the chelate compound.SELECTED DRAWING: Figure 17C

Description

[Technical Field]

[0001] The present invention relates to a visual tracking sensor for the uranium-238 isotope, a method for manufacturing the same, and a method for visually tracking and extracting uranium using the same. [Background technology]

[0002] In recent years, with the development of the environment, civilization, industry, and economy, there has been growing interest in energy sources, particularly nuclear power, that offer a compelling solution to the energy crisis, exhibit clear characteristics such as lower greenhouse gas emissions compared to fossil fuels, and contribute to combating global climate change. Against this backdrop, uranium (U(VI)) is used as nuclear fuel in nuclear power generation as a sustainable alternative energy source. Despite relying on nuclear energy as an environmentally friendly energy source, the release of many radioactive contaminants into the environment poses a threat to human health and the environment due to their chemical toxicity and radioactivity. Therefore, effectively and selectively separating and removing radioactive elements such as uranium from various resources such as water environments and raw materials faces increasingly significant challenges and concerns.

[0003] Generally, uranium (U(VI) or 238 Interest in U(VI) is growing. According to the World Health Organization (WHO), the maximum tolerable level of U(VI) ions is 30 ppb, and excessive intake can cause many diseases, including lung cancer, pancreatic cancer, liver cancer, and kidney and bone poisoning. Current estimates suggest that U (VI)Onshore reserves of uranium are sufficient for nuclear power generation for the next 100 years, and research has confirmed that ocean water contains approximately 4.5 billion tons of uranium, equivalent to 1,000 times the onshore reserves. Therefore, there is growing interest in utilizing unconventional U(VI) resources, such as ocean water containing low concentrations of U(VI) ions (3.3 μg / L) with long half-lives and stable oxidation states. In this context, the need to utilize uranium ions is increasing, and there is a pressing need to provide effective strategies that can be used efficiently to extract uranium from various common sources and to recover uranium from contaminated environments such as nuclear waste.

[0004] Uranium exists in nature and is formed in various forms. The three oxidation states of uranium (IV, V, VI) exist as solid oxides, but the existence of U(V) is rare. U(IV)O2 is widely used as commercial nuclear fuel, and because it readily incorporates oxygen into the framework of uranium compounds, many crystalline phases have been distinguished (U (IV) O2-U (VI) (O3). Furthermore, uranium is found in primary uranium minerals such as uraniumite (UO2) and pitchblende, and in secondary minerals such as carnotite, thorbellite, salleite, autonite, uranophene, ullicite, and uranosilcite.

[0005] Therefore, for the advancement of nuclear technology and for the sake of human health, there is a strong need to extract and remove U(VI) from various environments and ores in an efficient and safe manner. For this reason, various removal and recovery technologies such as solvent extraction, precipitation, ion exchange, membrane filtration, nanofiltration, coprecipitation, and adsorption have been relied upon to recover U(VI). Adsorption technology is a promising technique for removing and extracting U(VI) from contaminated industrial wastewater, seawater, and ores due to its valuable characteristics, including low cost, high efficiency, ease of operation, remarkable adsorption capacity, and the potential to provide selective adsorbents. From this perspective, much effort has been devoted to the development and testing of various categories of adsorbent materials for efficiently recovering and removing U(VI), including metal oxides, metal-organic frameworks (MOFs), layered metal sulfides, clay, zeolites, mesoporous materials, chitosan, carbon nanofibers, mesoporous carbon, and carbon nanotubes.

[0006] In recent years, nanomaterials have been widely adopted as effective absorbents due to their unique properties, including high surface area, abundant active and catalytic sites on the surface, stability, low cost, and environmental friendliness. In terms of improving the U(VI) adsorption process, phosphate compounds showed good efficiency due to their high U(VI) binding affinity. Thus, by impregnating the adsorbent skeleton with phosphate groups, the surface of the adsorbent is activated, and the U(VI) recovery process is promoted. Mesoporous materials are attracting considerable attention as adsorption platforms due to their excellent properties. Mesoporous silica substrates such as HOM, SBA-15, KIT-6, and MCM-41 have advantages such as chemical stability, high surface area, and easy functionalization, making them suitable for the extraction and recovery of contaminants and radioactive materials. Mesoporous silica materials such as MCM-41 and SBA-15 have been modified with 5-nitro-2-flualdehyde (fural), amino, dihydroimidazole, and phosphonate groups to improve the U(VI) adsorption capacity. Similarly, modification of MCM-41 with hydroxypyridinone, acetamide-phosphonate, salicylamide, and glycinylurea improves the uptake time and selectivity of actinide recovery. 5-azacytosine, as an N-donor chelating agent, was used to modify hydrothermal carbon materials for selective recovery of U(VI).

[0007] The combination of organic and inorganic materials has improved physical, chemical, and morphological properties, and has actively contributed to the synthesis of new materials with modified specifications. Against this backdrop, organic-inorganic materials possess unique characteristics such as high surface area, thermal and chemical stability, low toxicity, high sensitivity, and selectivity, offering potential candidates as active materials that can be used to efficiently separate and recover target species such as U(VI) from complex environments. Numerous efforts have been made to design organic-inorganic hybrid materials for recovering / removing rare earth elements and hazardous species using porous silica-based materials as a platform to improve the adsorption and sensing performance of designed adsorbents [Patent Documents 1-4, Non-Patent Document 1]. The field of optical sensors, primarily aimed at the early detection and monitoring of contaminants including radioactive materials, has attracted significant attention as a field of organic-inorganic materials. Therefore, efforts continue to develop and utilize optical sensors for monitoring, removing, and extracting radioactive materials with high sensitivity and selectivity. Arsenazo III and Alizarin Red S have been used as optical materials for U(VI) detection. Furthermore, carbon dots (CDs) are used to modify zeolite imidazolate frameworks (ZIF-8) for the separation and detection of U(VI) from aqueous solutions. Therefore, designing optical sensors with specific sensitivity and selectivity to detect / extract low concentrations of U(VI) ions from different environments presents a challenge. Such optical sensor design requires rapid performance of highly selective optical detection and efficient separation processes. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2011-201731 [Patent Document 2] International Publication No. 2011 / 090086 [Patent Document 3] Special Publication No. 2014-514433 [Patent Document 4] Japanese Patent Publication No. 2016-035109 [Non-patent literature]

[0009] [Non-Patent Document 1] Sherif A. El-Safty, Yukiaki Harada, et al., "Research on Highly Selective and Highly Efficient Extraction Technology for Rare Metals Using Nano-Ordered Structures," FY2011 Comprehensive Research Report, Environmental Research Promotion Grant, K22005, K2361. [Overview of the project] [Problems that the invention aims to solve]

[0010] The object of the present invention is to provide an optical sensor with specific sensitivity and selectivity for detecting / extracting low concentrations of U(VI) ions from different environments, offering rapid performance of highly selective optical detection and a visual tracking sensor for uranium-238 isotopes with an efficient separation process. [Means for solving the problem]

[0011] [1] The visual tracking sensor of the present invention is a mesoporous silica having a three-dimensional hexagonal monolithic worm-like higher-order structure, The surface of the mesoporous silica is modified with a chelate compound, An organic chromogenic chelate probe modified with the chelate compound, It is equipped with these features.

[0012] [2] In a visual tracking sensor for uranium-238 isotope [1], preferably the surface and pores of the mesoporous silica are modified with a chelate compound represented by formula 1 or formula 2. [ka] Here, L is a divalent group, "·" represents a radical, R1 is selected from the group consisting of a hydrogen atom, alkyl group, cycloalkyl group, aryl group, monovalent heterocyclic group, substituted amino group, halogen atom, and cyano group, R2 and R3 are the same or different alkyl groups having 1 to 5 carbon atoms, R4 is an alkyl group having 1 to 5 carbon atoms, n is a natural number between 1 and 3, and * represents the bonding site with the porous silica. [3] In a visual tracking sensor for uranium-238 isotopes [2], preferably, L is an alkylene group having 2 to 4 carbon atoms, R1 to R4 are the same or different alkyl groups having 1 to 3 carbon atoms, and n is 2 or 3. [4] In a visual tracking sensor for uranium-238 isotope [3], preferably the chelate compound is a polyoxyethylene aliphatic ether represented by any of the following: phosphonic acid [2-(triethoxysilyl)ethyl]-dimethyl ester, 2-dimethoxyphosphorylethyl (triethoxy)silane, (2-diethylphosphatoethyl)triethoxysilane, 3-diethoxyphosphorylpropyl (trimethoxy)silane, or dimethyl{2-[diethoxy(methyl)silyl]ethyl}phosphonate, as shown in Formula 2. [ka]

[0013] [5] In the visual tracking sensors for uranium-238 isotope [2] to [4], preferably the mass ratio of the chelate compound to the porous silica is in the range of 0.1 to 0.5. [6] In the visual tracking sensor for uranium-238 isotope [5], preferably the mass ratio of the chelate compound to the porous silica is in the range of 0.15 to 0.25. [7] In the visual tracking sensors for uranium-238 isotopes [2] to [6], preferably the porous silica contains at least silicon (Si), oxygen (O), carbon (C), and phosphorus (P), and when the total is 100% by mass, the mass percentage concentration of each element is: 45 ≤ Si ≤ 55 40 ≤ 0 ≤ 45 3 ≤ C ≤ 7, and, 1 ≤ P ≤ 3 It would be good if these conditions were met. [8] In a visual tracking sensor for uranium-238 isotope [2] to [6], preferably the mesoporous silica comprises an aggregate of particles made of porous silica having a hexagonal crystal structure, The aggregate has a hierarchical structure comprising micropores, mesopores, and macropores, The aggregate is 250m 2 / g or more 300m 2 It has a BET method specific surface area in the range of less than or equal to / g, and 0.3cm² 3 / g or more 0.5cm 3 Having a pore volume in the range of less than or equal to / g, The surface of the aggregate has a plurality of grooves between the particles, It would be ideal if uranium were selectively adsorbed and colored.

[0014] [9] In the visual tracking sensors for uranium-238 isotope [2] to [8], preferably the organic chromogenic chelate probe is a chelate probe of an azo compound represented by any of the formulas 3 to 6. [ka] [ka] [ka] [ka]

[0015]

[10] The method for manufacturing the visual tracking sensor of the present invention involves producing a three-dimensional (3D) hexagonal monolithic worm-like higher-order structure mesoporous silica (WHM) by a direct template method using a polyoxyethylene aliphatic ether surfactant as described in [4], By controlling the structure, shape, and size of pores in mesoporous silica modified with polyoxyethylene aliphatic ethers, The WHM platform described above is modified with a chelate probe of an azo compound as described in [9].

[0016]

[11] A method for using the visual tracking sensor of the present invention is a method for extracting uranium from a test aqueous solution, wherein the visual tracking sensor for uranium-238 isotope described in any of [1] to [9] is brought into contact with the test aqueous solution, and the uranium in the test aqueous solution is adsorbed and colored. It is a method that encompasses this.

[12] The present invention provides a method for visually tracking uranium contained in uranium-containing ore, The uranium-containing ore is added to an acid solution selected from the group consisting of hydrochloric acid, nitric acid, and sulfuric acid to prepare the uranium-containing solution. The visual tracking sensor for uranium-238 isotope described in any of [1] to [9] is brought into contact with the uranium-containing solution, and the uranium in the uranium-containing solution is adsorbed onto the visual tracking sensor for uranium-238 isotope, causing it to develop color. It is a method that encompasses this.

[13] In the method for visually tracking uranium contained in uranium-containing ore of the present invention

[12] , preferably the pH of the uranium-containing solution is in the range of 3 to 6.5.

[14] In the method for visually tracking uranium contained in uranium-containing ore of the present invention

[12] , preferably, hydrogen peroxide is further added in addition to the acid solution. [Effects of the Invention]

[0017] The present invention provides a visual tracking sensor for uranium-238 isotopes, an optical sensor with specific sensitivity and selectivity for detecting / extracting low concentrations of U(VI) ions from different environments, offering rapid performance of highly selective optical detection and streamlining the separation process. According to the method for manufacturing a uranium-238 isotope visual tracking sensor of the present invention, the above-mentioned uranium-238 isotope visual tracking sensor can be manufactured. According to the method of using the uranium-238 isotope visual tracking sensor of the present invention, low concentrations of U(VI) ions can be detected / extracted from different environments. [Brief explanation of the drawing]

[0018] [Figure 1] These are representative TEM micrographs (A, C, E) and 3D surface images (B, D, F) of WHM-4 monoliths with worm-like pores synthesized using nonionic surfactants B56, B58, and B78, respectively. All WHM-4 monolith surfaces were recorded at a 35-degree tilt. [Figure 2] This image shows a representative TEM micrograph of a synthesized hexagonal WHM silica monolith. [Figure 3] STEM images and STEM-EDS mapping of a two-dimensional hexagonal mesoporous WHM-2-L nanosensor: (A) STEM image, (B) O, (C) Si, (D) C, (E) P, (F) N, (G) EDS analysis and calculated atomic abundances of species present in the solid capsule. [Figure 4] The FE-SEM images (A, B) and corresponding EDX spectra (C, D, E) of hexagonal P6mm mesoporous HOM-2 synthesized using the lyotropic phase, and the EDX spectrum (F) of hexagonal mesoporous HOM-2-L1 are shown. [Figure 5] The XRD patterns (A) of the wormhole 2D-WHM-2 hexagonal structure synthesized using different surfactants in a microemulsion liquid crystal system, and the XRD pattern (B) of the mesoporous hexagonal WHM-3-(B56) monolithic carrier used in the design of an optical sensor for U(VI) detection are shown. [Figure 6]This shows the N2 adsorption / desorption isotherms of mesoporous hexagonal WHM-2 monolithic materials synthesized using different surfactants (bridge type 56 (B56), bridge type 58 (B58), bridge type 76 (B76), bridge type 78 (B78), Triton X-114 (TX-114), bridge type 35 (B35)). [Figure 7A] This shows the N2 adsorption / desorption isotherms of different monolithic mesoporous WHM carriers synthesized in a microemulsion system using bridge-type 76. [Figure 7B] This shows the N2 adsorption / desorption isotherm of a WHM-3(B56)-L optical supermesocapter sensor synthesized by incorporating four types of chelating agents (L1-L4) into a WHM-3(B56)-L carrier. [Figure 7C] This table shows the pore shapes of a WHM-3(B56)-L optical supermesocaptor sensor synthesized by incorporating four types of chelating agents (L1-L4) into a WHM-3(B56)-L carrier, and different monolithic mesoporous WHM carriers synthesized in a microemulsion system using bridge-type 76. [Figure 7D] The chemical formulas and trade names of the four types of chelating agents L1 to L4 are shown. [Figure 8] (A) shows the 29Si MAS-NMR spectra of the WHM-2(B56, bridged 56) and WHM-2(B56)-L sensors, and (B) shows the 29Si MAS-NMR spectra of the WHM-2(B76, bridged 76) and WHM-2(B76)-L sensors. The spectral decomposition of the obtained component peaks is shown below the main spectrum in regions of different intensity. (C) shows the 13C CP-MAS analysis results for WHM-2(B56, bridged 56). [Figure 9] The TG and DTA curves of WHM-2 (A), fabricated using Brij76, and WHM-2-L super mesocaptain photosensor (B), fabricated by integrating WHM-2 and a Mordant Black 38 (MB38) probe, are shown. [Figure 10](a) Mesoporous silica, (b) WHM-2 prepared using bridge-type 76, (c) WHM-2-L sensor, (d) U(VI) / WHM-2-L composite, and (e) Fourier transform infrared (FT-IR) spectra of the WHM-2-L sensor after 5 cycles used to confirm chemical stability are shown. [Figure 11] (A) pH dependence of U(VI) ion adsorption using WHM-2 adsorbent. 20 mg of WHM-2 adsorbent was added to 100 mL of initial [U(VI)] at 10 ppm, contact time 60 minutes, 25°C. B) The effect of the morphology of the mesoporous WHM monolith synthesized in B56 on the adsorption of 10 ppm [U(VI)] is shown. [Figure 12] (A) shows the pH dependence of visual U(VI) ion detection using the WHM-1-MB38 sensor, where 20 mg of the sensor was placed in 100 mL, the initial [U(VI)] concentration was set to 10 ppm, and the contact time was 60 minutes at 25°C. (B) shows the effect of the type of chelate probe used with the WHM-1-L sensor on the detection of U(VI) ions under optimal conditions using a batch contact adsorption system. (C) shows the effect of the design of various optical sensors using MB38-modified WHM monoliths on the detection performance of U(VI) ions under optimal conditions using a batch contact adsorption system. (D) shows the effect of contact time on the adsorption of 10 ppm U(VI) from an aqueous solution. [Figure 13] The selectivity of mesoporous silica WHM-1 for U(VI) ions is shown under optimal conditions in (A) a single separation system and (B) a binary system. (C) and (D) show the selectivity for detection and extraction of coexisting U(VI) ions in the WHM-1-MB38 sensor in a single separation system and a binary system. Batch adsorption (E) and fixed-bed columnar (F) are shown for the selectivity of U(VI) ions in complex systems. [Figure 14] (A) shows the color change image for detecting U(VI) as a relationship to pH for visually disclosing the element's color. (B) shows the effect of U(VI) concentration on the UV reflectance spectrum using WHM-1-MB38 at pH 3.9. [Figure 15] (A) shows the U(VI) uptake in mg / L using WHM-1, WHM-2, and WHM-1-MB38 adsorbents, (B) shows the effect of the initial U(VI) concentration on the adsorption capacity (qe, mg / g), (C) is a fitted linear graph of the Langmuir isotherm model for U(VI) adsorption to determine the maximum adsorption capacity of the applied adsorbent, and (D) shows the parameters of the Langmuir adsorption isotherm model used for U(VI) adsorption. In all experiments, 0.5 g of adsorbent was added to 500 ml of solution and allowed to stand at room temperature for 30 minutes, after which the results were confirmed using ICP-MS. [Figure 16] The breakthrough curves for U(IV) extraction using a fixed-bed column system are shown when the flow rate, adsorbent amount, and initial U(VI) concentration are varied, using WHM-1(A, C, E) and WHM-1-MB38(B, D, F) bioadsorbents. [Figure 17A] In the diagram, (A) on the left shows the atomic arrangement diagram of the WHM-2 platform. (B) in the center shows the atomic arrangement diagram of the WHM-2 platform with the MB38 probe attached by the graft method. The diagrams to the right of the arrows in (C) and (D) are atomic arrangement diagrams of the WHM-2-L sensor that optically detects U(VI) ions. Arrow (C) shows the process in which U(VI) ions act on the WHM-2-L sensor, and arrow (D) shows the process in which the U(VI) ions are dissociated by a chemical treatment process, returning the sensor to the state in (B). [Figure 17B] In the figure, the left image (A) shows FE-SEM and TEM micrographs of the WHM-2 platform, the center image (B) shows FE-SEM and TEM micrographs of WHM-2-L, the right image (C) shows the atomic arrangement diagram of the WHM-2-L sensor, and the atomic arrangement diagram (E) shows the complex [UO2L(H2O)].(NO3)]. [Figure 17C]In the figure, the left-hand three-layer planar perspective view (A) shows the phosphorus atom P of the WHM-2 platform. The center three-layer planar perspective view (B) shows the state in WHM-2-L where the MB38 probe is bound to the phosphorus atom P. The right-hand three-layer planar perspective view shows the state in the WHM-2-L sensor where the MB38 probe is bound to the phosphorus atom P, and a U(VI) ion is also bound. [Figure 18] (A) shows the effect of EDTA concentration as a stripping agent on the recovery of U(VI) ions by the decomposition process of the WHM-2-MB38 sensor. (B) shows multiple reuse cycles for U(VI) ion extraction and detection of WHM-2-MB38. [Figure 19] The chemical composition of altered granite (AGR) collected from the Gabal El Sela region in the southern part of the eastern desert of Egypt is shown. (B) shows the effects of H2SO4 concentration (M), leaching / stirring time, and temperature, and (C) shows the effect of H2O2 concentration (v / v%) as an oxidizing agent. The optimal conditions affecting 238U leaching from AGR material were investigated. [Figure 20] The images show the gamma-ray spectra associated with the detection and extraction of the 238U isotope from the actual eluate of AGR. (A) shows the WHM-2-MB38 sensor before 238U isotope adsorption, (B) shows the WHM-2-MB38 sensor after 238U isotope adsorption, (C) shows the WHM-2-MB38 / 238U isotope after stripping, and (D) shows the gamma-ray spectrum obtained with WHM-2 after 238U isotope adsorption. The images also show the gamma-ray spectra obtained with a high-purity germanium (HPGe) detector of MMSM after 238U adsorption from the eluate and after 238U desorption using H2SO4 as a stripping / eluting agent. [Figure 21] The images show the gamma rays from the leachate of WHM-2 and WHM-2-MB38 after 238U adsorption and 238U desorption, as measured by a high-purity germanium (HPGe) detector. [Figure 22] This shows the extraction of U(VI) ions from a monazite-simulating solution under optimal conditions using the WHM-MB38 sensor. [Figure 23]It shows the extraction of U ions from an EMM actual monazite sample under optimal conditions using the WHM-MB38 sensor. [Figure 24] It is a schematic diagram showing the uranium adsorbent as a precursor of the present invention. [Figure 25] It is a schematic diagram showing another uranium adsorbent as a precursor of the present invention. [Figure 26] It is a schematic diagram showing the adsorption mechanism using a uranium adsorbent modified with a chelate compound as a precursor of the present invention.

Embodiments for Carrying Out the Invention

[0019] Before explaining the details of the embodiments of the present invention, an overview of the overall structure in the "Embodiments for Carrying Out the Invention" will be described. First, three-dimensional (3D) hexagonal monolith-type worm-like hierarchical mesoporous silica (WHM) was fabricated by a direct templating method using a bridged (CxEOy) surfactant, and a pore shape with a controlled bridged / silica mesophase structure, shape, and size was realized. Here, WHM (worm-like highly ordered mesoporous silica) is an abbreviation for worm-like hierarchical mesoporous silica. WHM is of a three-dimensional (3D) hexagonal monolith type. By modifying the WHM platform with a chelating agent of the mordant family, photo-sensing of U(VI) species becomes possible. These optical sensors can 238 extract, capture, and trap U isotopes from an actual sample with high sensitivity and selectivity. U(VI) ions from a simulated solution and 238 U isotopes from the actual leachate of a metamorphic granite (AGR) raw material were captured by batch contact and fixed-bed column tests. As a result, WHM optical sensors were found to offer a promising candidate with excellent features such as (i) a simple, efficient, low-cost, and environmentally friendly process, (ii) selective extraction of 238U, (iii) economic cost due to regeneration and multiple uses, and (iv) appropriate utilization of agricultural waste. The designed WHM sensor can be used from AGR without placing a significant burden on the environment. 238 We were able to recover and extract U with high selectivity. [Examples]

[0020] [Chemical substances] All materials were used in their original, unrefined state. Tetramethyl orthosilicate (TMOS) is used as the silica compound. Examples of phosphonic acid silane compounds include 3-(trihydroxysilyl)propyl methylphosphonate, monosodium salt (CH3P(O)(ONa)O(CH2)3Si(OH)3), and 3-diethoxyphosphorylpropyl(triethoxy)silane (C 13 H 31 O6Psi) and 2-diethoxyphosphorylethyldiethoxymethylsilane are used. Precursors used for phosphonic acid silane compounds include 3-aminopropyltriethoxysilane (APTES, 99%), ethanol (99.7%), diphenylphosphinate chloride, 1-naphthylphosphate (NPA), and benzylphosphonic acid (BPA).

[0021] A typical commercially available polyoxyethylene aliphatic ether is the one sold under the trademark name Brij (registered trademark) by Uniqema (Wilmington, Delaware), but is not limited to this. 18 H 37 (OCH2CH2) 10 OH, MWav=711), Brij(registered trademark) 78 (eicosaethylene glycol octadecyl ether, C 18 H 35(OCH2-CH2) 20 OH, MWav=1152), Brij(registered trademark)97(29-[(Z)-9-octadecenyloxy]-3,6,9,12,15,18,21,24,27-nonoxanonacosan-1-ol, C 18 H 35 (OCH2CH2) 10 OH, MWav=709). Brij(registered trademark)98(polyoxyethylene(20) oleyl ether, C 18 H 35 (OCH2CH2) 20 OH, MWav=1150, Brij(registered trademark)35(polyoxyethylene 23-lauryl ether, C 12 H 25 (OCH2-CH2) 23 OH, MWav=1198), Brij(registered trademark) 58 (polyethylene glycol hexadecyl ether, C 16 H 33 (OCH2CH2) 20 OH, MWav=1124), and Brij(registered trademark) 56 (polyoxyethylene(10) cetyl ether, C 16 H 33 (OCH2CH2) 10 OH, MWav=683) is used. In addition, Triton(registered trademark) X-114 (TX-114(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol, polyethylene glycol tert-octylphenyl ether, (C2H4O)nC), which is commercially available from Sigma-Aldrich, is used. 14 H 22 O, n=7 or 8) is also used.

[0022] We used Mordant Black 38 (MB38, Omega Chrome Black Blue G), Mordant Black 17 (MB17), Mordant Blue 79 (MB79), and Mordant Black 11 (MB11) from Tokyo Chemical Industry Co., Ltd. MB38 is the compound shown in Chemical Formula 3, and is called benzenesulfonic acid, 3-[[8-(acetylamino)-2-hydroxy-1-naphthalenyl]azo]-5-chloro-2-hydroxy-, monosodium salt. MB17 is the compound shown in Chemical Formula 4, and is called 2-Hydroxy-1-(2-hydroxy-1-naphthylazo)naphthalene-4-sulfonic acid sodium salt. MB79 is the compound shown in Chemical Formula 5, and is called disodium;(3E)-4-oxo-3-[(4-sulfonatonaphthalen-1-yl)hydrazinylidene]naphthalene-1-sulfonate. MB11 is the compound shown in Chemical Formula 6, and is called 3-hydroxy-4-[(1-hydroxynaphthalen-2-yl)diazenyl]-7-nitronaphthalene-1-sulfonic acid. [ka] [ka] [ka] [ka]

[0023] [Fabrication of Monolithic Silica WHMS] To design monolithic silica WHMS materials, a direct templating strategy is used to generate a homogeneous mesophase of translucent silica / surfactant, as previously reported. In particular, to ensure control over the formation of this translucent monolith, the lyotropic system fixes the weight ratio of a specific surfactant to the TMOS compound at 1:2. However, the mass ratio of the silica compound used, including TMOS, to the various phosphosilane compounds is maintained at 3(TMOS):1(phosphosilane). For the synthesis of typical monolithic silica, a sol-gel synthesis method is used. 8.0 g of the silica compound (phosphosilane, TMOS) and 4.0 g of the surfactant were placed in a flask and gently shaken in a water bath (50°C) until a homogeneous solution was obtained. Next, 4.0 g of acidified water / HCl (pH 1.3) was added to promote the exothermic hydrolysis and condensation of silica. The final mass ratio of the mixed composition was found to be surfactant (1):TMOS (1.5):phosphonic acid silane (0.5):H2O / HCl (1). To prevent disruption of the crystal arrangement of the product, methanol generated during the hydrolysis process was removed using a rotary evaporator. Finally, a gel-like optical material was formed, acquiring the shape and size of the flask.

[0024] Subsequently, the resulting gel-like substance was gently dried at 45°C for 24 hours. The as-synthesized WHMS material was refluxed in an ethanoic acid solution containing hydrochloric acid for 16 hours to remove the surfactant. This WHMS material was washed with Milli-Q water (registered trademark) and dried at 45°C for 24 hours. The resulting material was pulverized, stored in an isolated container, and the properties of the prepared sample were analyzed for use as a carrier for the manufacture of adsorbents / porous sensors in the next step. According to our protocol, the characteristics of the monolithic silica WHM material can be controlled by using multiple types of phosphonic acid silane compounds and surfactants in the final mixture (see Scheme 1). Formula 7 in Scheme 1 shows five types of WHM-1 to 5 along with their chemical structures. WHM-1 is phosphonic acid, [2-(triethoxysilyl)ethyl]-dimethyl ester. WHM-2 is 2-dimethoxyphosphorylethyl (trietoxy) silane. WHM-3 is (2-diethylphosphatoethyl)triethoxy silane. WHM-4 is 3-diethoxyphosphorylpropyl (trimethoxy) silane. WHM-5 is dimethyl{2-[diethoxy(methyl)silyl]ethyl}phosphonate.

[0025] The protocol design of the present invention is constructed through two pathways: the first involves immobilizing phosphonic acid silane by varying the type of surfactant, and the second involves immobilizing various phosphonic acid silane compounds by varying the type of surfactant. Consideration must be given to maintaining the weight ratio of the final mixture consisting of surfactant (1):TMOS (1.5):phosphonic acid silane (0.5):H2O / HCl (1). [ka] Scheme (1). Chemical structures of various organophosphates used to control the mesoporous structure of WHMS.

[0026] [Manufacturing of an optical mesocaptor sensor using WHMS] WHM-based optical mesocaptor sensors are designed by directly grafting various organic chelate probes, including MB38, onto a WHM-based platform. A simple method involves adding 1 g of WHM to 200 mg of chelate probe (MB38) dissolved in 100 mL of acetone in a round-bottom flask connected to a rotary evaporator. This mixture was held at 30°C for 4 hours while rotating (without vacuum) to ensure the MB38 chelate probe was thoroughly impregnated into the WHM platform, after which the solvent was removed under vacuum. The resulting mesoporous WHM-ligand (WHM-L) captor / sensor was dried in an oven for 3 hours. The dried mesoporous WHM-L was then washed several times with deionized water to ensure the removal of excess and unreacted probe molecules until saturated. This saturation process, which does not involve probe molecule elution, was confirmed by spectrophotometric analysis. The washed mesoporous WHM-L capsules / sensors were dried in a vacuum oven at 55°C for 6 hours, then stored in insulated darkroom bottles and used for U(VI) ion detection and removal.

[0027] [Leaching procedure for Egyptian metamorphic granite (EAGR)] First, the EAGR ore was crushed to a small size (200 mesh). In the leaching process for U(VI), 1 kg of the crushed EAGR was treated with a mixture of 5% H2O2 and a 0.5 M acidic solution as an oxidizing agent, under continuous stirring at high temperature. From the obtained concentration data, the efficiency (L%) of the leaching process was confirmed according to Equation 3 below.

number

[0028] [Recovery of U(VI) ions] To ensure the cleanliness of the glassware, all glassware used in this process was washed with a 5% HNO3 solution and then with Milli-Q water (registered trademark). Standard stock solutions of U(VI) were prepared at various concentrations at room temperature immediately before use. The adsorption and recovery of U(VI) ions from aqueous solutions and actual rock samples were investigated using batch and fixed-bed columnar methods.

[0029] In the batch system, 20 mg of synthesized WHM or WHM sensor was added to 40 mL of a tested U(VI) solution or leachate in the pH range of 1 to 10. U(VI) recovery and removal performance was evaluated under shackling (vibration) conditions at 25°C for a planned period. The amount of U(VI) uptake and recovery was detected using an inductively coupled plasma mass spectrometer (ICP-MS-PerkinElmer, Elan-6000). The amount of U(VI) uptake (qe mg / g) and adsorption efficiency (Ads.%) can be calculated using Equations 1 and 2.

number

[0030] [Results and Discussion] A wide range of hexagonal monolithic WHM mesoporous structures were designed using microemulsion liquid crystal phases (direct template method) of numerous nonionic bridge-type (CxEOy) and Triton-X114 surfactants. These hexagonal monolithic WHM mesoporous structures are designed to be used as solid support carriers for designing optical nanosensors for sensing U(VI) ions. Under acidic synthesis conditions, within the field of view of the nonionic surfactant, the polymerization process of silica species occurs around the surfactant phase aggregate group. 29 It forms a rigid, cross-linked silica matrix with ordered and disordered pores, which can be confirmed using Si-NMR spectroscopy. Generally, surfactant-silica systems, as direct template systems, play a crucial role in designing ordered or disordered mesophase structures by controlling their shape, size, and pore configuration depending on their type and ratio to silica. Furthermore, by immobilizing chelating agents on a monolithic WHM silica platform, chemical-optical nanosensors can be designed in a simple manner to detect U(VI) ions. We successfully immobilized commercially available organic chromophore probes with active functional groups, such as Mordant Black (MB38), onto WHM silica material, leading to the creation of a wide range of optical-chemical nanosensors for effective detection of U(VI) ions.

[0031] [Structural Engineering and Morphological Design Control of WHM Silica Materials] In this study, a rigid monolithic mesoporous silica network was formed by polymerizing silica compounds using a nonionic surfactant as a direct template, in addition to hydrochloric acid as an acid catalyst. In this example, two key factors, including the type of surfactant and organophosphates, were used to control the hierarchical 3D mesoporous structure of the WHM platform. Various bridging surfactants have a potential role not only in controlling the porous structure of the surface through one-pot synthesis, but also in the process of direction and reconstruction. Therefore, the hierarchical 3D-WHM mesoporous structure was investigated using various analytical tools such as high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), nitrogen adsorption / desorption isotherm, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), and differential thermal analysis (DTA). As shown in the results (Figures 1-4), it was demonstrated that the particle morphology of the WHM silica monolith can be controlled by using a series of direct template nonionic surfactant systems.

[0032] TEM analysis highlights the porous uniformity and structural integrity of the synthesized WHM silica mesoporous material (Figures 1-3). TEM and 3D surface TEM micrographs of synthesized hexagonal WHM silica monoliths of 3D P63 / mmc WHM-3, 2D P6mm HOM-2, and WHM-4 clearly demonstrate the control of particle morphology from these WHM monoliths using direct stenography of nonionic surfactants (Figures 1 and 2).

[0033] To investigate the effect of surfactant type on the homogeneity and organization of the porous structure of synthesized WHM silica, numerous nonionic bridge-type (CxEOy) surfactants, including B35, B58, and B78, were applied to control WHM-4 monoliths (Figures 1A-1F). TEM images show that the fabricated WHM-4 monoliths possess stable, large-domain worm-like mesoporous channels. The formation of disordered pore structures is related to the type of surfactant used, reflecting the importance of the interaction and aggregation of surfactants and silica procuring agents during the polymerization of the silica network matrix. TEM micrographs of the synthesized WHM-4(B35) monoliths clearly demonstrate the control of particle morphology from the WHM-4(B35) monoliths (Figure 1A). Furthermore, irregular matrices were also observed in 3D images of the WHM-4(B35) monoliths taken at a 35-degree tilt (Figure 1B). When WHM-4 was synthesized using B58 instead of B35, several surface defects (indicated by arrows) occurred, and a non-uniform arrangement (indicated by arrows) was formed, as shown in Figures 1C and 1D. However, when a microemulsion system using B78 directly as a template was applied, porous holes and grooves (indicated by arrows) appeared on the surface, and gaps were formed on the surface, affecting the surface topology (Figures 1E and 1F).

[0034] Figure 2(A) shows a three-dimensional hexagonal P63 / mmc WHM-3 synthesized using Brij 56 (Brij 56: silica precursor ratio 50 wt%), Figure 2(B) is a three-dimensional surface image of WHM-3 taken with a 35-degree tilt using a TEM microscope, and Figure 2(C) is a three-dimensional surface image of WHM-3-L1 nanosensor taken with a 40-degree tilt using a TEM microscope. Figure 2(D) shows a two-dimensional hexagonal P6mm WHM-2 formed with a Brij 76 phase domain (Brij 76: silica precursor ratio 50 wt%), Figure 2(E) is a three-dimensional surface image of WHM-2 taken with a 35-degree tilt using a TEM microscope, and Figure 2(F) is a three-dimensional surface image of WHM-2-L1 nanosensor taken with a 35-degree tilt using a TEM microscope. TEM micrographs of WHM-3 synthesized using the B56 surfactant show clear evidence related to the irregular arrangement of the porous structure (Figure 2A). Figure 2D shows the TEM analysis results of WHM-2, which reveal an ordered mesoporous worm-like structure with a uniform and narrow size distribution, leading to a large region of cylindrical two-dimensional hexagonal P6mm structure domains. The uniform distribution of pores is important for the material's mechanical stability and ease of use as a catalyst support.

[0035] To design an optical sensor for visually detecting U(VI) ions, four chelate molecules were grafted onto WHM silica hexagonal monolith carriers. The four types of hexagonal WHM silica monoliths were tested using 3D surface topography of microscope TEM patterns (Figure 2B, C, E, F). (A, B)WHM-3(B56)3D The notation for the 3D space group is on page 63 / mmc. (D, E)WHM-2(B76) The 3D space group is denoted as P6mm, and it is a 2D structure synthesized with a bridge-type 76 phase domain, with a bridge-type 76:silica precursor ratio of 50 wt%. (C)WHM-3(B56)-L1 nanosensor, (F)WHM-2(B76)-L1 nanosensor. As a result, analysis of the experimental conditions and materials revealed that a large number of chelate molecular probes were embedded not only on the surface of the outer pores of the WHM silica material, but also in the inner pores.

[0036] TEM micrographs of 3D P63 / mmc WHM-3(B56) carriers taken at a 35-degree angle revealed a highly random and irregular matrix, as indicated by the arrows (Figure 2B). TEM images of the designed WHM-3(B56)-L1 nanosensor taken at a 40-degree angle show a randomly dispersed interconnection network, indicating the worm-like material surface (indicated by the arrows) of the WHM-3(B56) carriers modified with the L1 probe (Figure 2C). TEM images of hexagonal 2D P6mm WHM-2(B76) show a worm-like structure with a discontinuous matte, while images of the WHM-2(B76)-L1 nanosensor taken at a 35-degree angle show a worm-like structure with a rough surface (Figures 2E, 2F).

[0037] Furthermore, information regarding the formation and localization of all elements in the WHM monolithic silica material was confirmed by primary mapping using STEM (Figure 3). The results of STEM mapping and EDS elemental analysis revealed the composition and relationships of the constituent elements of WHM-3-L1, showing that these elements were very homogeneously distributed within the framework of the test material. Notably, this uniform distribution consisted of Si, O, C, P, and N (Figures 3B-F). To confirm the proportions of these elements, EDS spectra were measured in the same test area, and the presence of these elements was confirmed, similar to the STEM data (Figure 3G).

[0038] Figure 4 shows FE-SEM micrographs of hexagonal WHM-2 and WHM-2-L1 monoliths. The synthesized WHM-2 monoliths exhibited large particle sizes (50–150 μm in diameter) and crystalline structures of varying sizes and shapes. SEM micrographs revealed that all WHM silica materials in the WHM-2 and WHM-2-L1 monolith particles exhibited specific characteristics, including a perfectly smooth surface structure, supporting the crystallization process of mesoporous silica materials. Furthermore, clear striplines were observed in the structures, suggesting the presence of long-range internal channels (Figure 4). As a result, it was confirmed that hexagonal WHM mesoporous silica monoliths can be fabricated and functionalized with controlled particle shape and size using a microemulsion system of nonionic surfactants. The good dispersion composition of the WHM silica monolith material was confirmed using EDX (Figures 4C, F). In addition, the EDX results regarding the constituent element content of WHM-2 and WHM-2-L1 were consistent with the content analyzed according to STEM analysis. EDX analysis revealed that the WHM monolith material contains Si, O, C, P, and N particles (Figure 4C, F). Furthermore, EDX analysis of the superloading level on the surface of the chelated probe clearly confirmed the stability of the nanosensor's shape.

[0039] XRD analysis is a reliable tool for investigating and evaluating the structural regularity of porous materials. In the XRD pattern, the peak corresponding to the (100) plane is well separated, indicating a 2D-WHM-2 hexagonal structure with a p6 mm plane and a d spacing of 4.4 nm (Figure 5A). The XRD patterns of all WHM-2 materials tested showed a uniformly arranged channel-like pore arrangement. This data demonstrates the successful design of hexagonal mesoporous 2D-WHM-2 using a microemulsion liquid crystal phase by applying different types of surfactants. Furthermore, Figure 5B shows the effect of an organic chelating agent grafted onto a three-dimensional hexagonal mesoporous P63 / mmc WHM-3 synthesized from a bridge-type 56 liquid crystal phase. Results for three-dimensional hexagonal P63 / mmc WHM-3 showing a mesophase structure. In addition, XRD analysis of the modified WHM-3 clearly showed ordered channels and a highly uniform texture. Despite the level of chelating agent overload on the surface, the characteristic resolved Bragg diffraction peaks clearly confirm the hexagonal mesoporous P63 / mmc nanosensor shape. These results confirm that the rigid array of the final product contributes to the high flux and transport of target ions in the sensing process.

[0040] To identify important factors influencing the mesoscopically ordered worm-like structure and surface parameters of the microemulsion formulation, the mesoporous pore morphology of WHM-2 synthesized using different surfactants—bridge type 56 (B56), bridge type 58 (B58), bridge type 76 (B76), bridge type 78 (B78), Triton X-114 (TX-114), and bridge type 35 (B35)—was examined using N2 adsorption / desorption isotherms (Figure 6).

[0041] N2 isotherm measurements revealed that the type of surfactant in the microemulsion solution plays a role in designing and controlling pore formation and the uniform structural morphology of the two-dimensional hexagonal WHM monolithic mesoporous material. As a result, the WHM-2 material exhibited type IV behavior with a uniform pore size distribution and H1 hysteresis loops indicating that pores converge to form large channel-like pores (Figure 6). This curve shows that as the size of the surfactant increases, the adsorption branches shift clearly toward higher relative pressures. Furthermore, it was found that the selection of the type of surfactant to be directly templated plays an effective role in improving and controlling the characteristics of large, regular, thick-walled mesoporous domains. Nonlocal density functional theory (NLDFT) analysis of all WHM-2 samples confirmed the uniform mesoporous properties shown in Figure 6.

[0042] In fact, direct templating is a crucial element in controlling the structure of mesophase domains and mesopores in microemulsion synthesis techniques. As mentioned earlier, different surfactants were used as template agents to design the two-dimensional hexagonal morphology of WHM-2. Furthermore, multi-WHM morphological structures can be generated using a single surfactant such as bridge-type 76 (B67) (Figure 7A). The synthesis of different types of WHM structures using bridge-type 76 is related to the molecular packing of the bridge-type 76 surfactant, the procurement ratio of bridge-type 76 to silica in the microemulsion liquid phase, and the pH value. Using N2 adsorption / desorption isotherms, the mesoporous pore morphology of different WHM materials designed using bridge-type 76 (B67) as a template was confirmed, and lyotropic and microemulsion systems were designed (Figures 7A, C). As a result, it was found that the hydrophobicity and hydrophilicity of the surfactants influenced the generated microstructure, and long-range order was formed within the monolithic WHM structure. Using N2 adsorption / desorption isotherms, we confirmed the grafting of four chelating agents (L1-L4) onto the WHM platform and evaluated their effects on surface coverage and surface properties (Figure 7B-D).

[0043] As a result, it was found that the total surface area of ​​all WHM-3(B56)-L optical supermesocaptor sensors decreased due to the embedding of chelate sites in the WHM-3(B56) platform. In addition, a decrease in surface parameters related to the amount of grafted chelate sites was observed. These results confirm that in WHM-3(B56)-L sensors, chelate sites diffuse into the pores and are mainly fixed in large quantities on the pore surface, demonstrating the uniform shape and geometric characteristics of the worm-like sensor pores (see Figures 7B and 7C). The amount of chelate probes grafted onto WHM-3(B56) depends on the ability of these probes to access and interact with the worm-like carriers of WHM-3(B56) (Figure 7D).

[0044] We investigated the composition and chemical inoculation of organosiloxane compounds within the silica network. 29 Confirmed by Si MAS-NMR measurement. Here, "Q" is [(SiO) n Si(OX) 4-n The repeating unit is "n", where "n" represents the number of oxygen atoms bonded around the central silicon atom. A triple silicon center is also called "Tm", where "T" represents the unit "(SiO₂) m RSi(OX) 3-m The letter "m" represents the number of oxygen atoms surrounding the central silicon atom. 29 The relative population around silicon was evaluated by analyzing the Si NMR spectra into individual Gaussian peaks. Two types of WHM-2 platforms synthesized by B56 and B76, and their super-WHM-2-(B56)-L and WHM-2-(B76)-L mesocaptors were analyzed. 29 The Si NMR survey spectra were examined for each sample (Figure 8A, B). The results showed that all samples exhibited resonances of approximately -110.9, -101.5, and -98.2 ppm, corresponding to the Q4, Q3, and Q2 environments of silicon atoms, respectively (Figure 8A, B). Furthermore, 29The Si MAS NMR spectrum includes additional peaks at approximately -58.79, -73.6, and -67.23 ppm, corresponding to T1, T2, and T3 of the organic siloxane species, respectively. This result indicates the presence of organic siloxane species in the WHM material and a high degree of self-condensation. As a result, the intensities of Q4 and T3 are increased compared to the other peaks, confirming the strength of the organic siloxane compound bond within the silica framework.

[0045] To confirm the presence of organosiloxane species in the anatomical formation of WHM materials, 13 ¹³C NMR spectral analysis was performed (Figure 8C). 13 The 13C NMR spectrum is expected to show many resonance signals of varying intensities associated with 2-dimethoxyphosphorylethyl(triethoxy)silane on the WHM-2 platform, consistent with the preparation method and TG-DTA thermal analysis. The WHM-2 results reveal several signals attributable to different carbon atoms of 2-dimethoxyphosphorylethyl(triethoxy)silane (Figure 8C). Two resonance signals at 10.8 ppm and 22.3 ppm are directly linked to silicon (C1) and phosphorus (C2) carbon atoms of the ethyl group, respectively. However, two other resonance peaks at 28.13 and 67.4 ppm can be attributed to C4 and C3 of the ethoxy group of (-PO(OC2H5)2), respectively. The absence of a resonance peak around 30 ppm indicates that surfactant molecules were successfully removed during the solvent extraction process. This result demonstrates the high chemical stability of the organosiloxane compound designed within the silica backbone.

[0046] [Thermal stability of WHMS and optical mesocaptor sensors using WHMS] Using a TG-60 (Shimadzu Corporation), thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were performed in the range of 25°C to 900°C to investigate the thermal stability of Super WHMS Mesocaptor. This analysis confirmed the amount of organic molecules present in the WHMS skeleton after the solvent extraction process in relation to weight loss (Figure 9). These tests also contributed to confirming the presence and proportion of chelating agents in optical mesocaptor sensors using WHMS. The TG curve of WHM-2 shows two regions: weight loss and thermal conduction (Figure 9A). The first weight loss region, appearing below 200°C, indicates the release of absorbed water, chemiadsorbed water of crystals, and volatile molecules. Measurement results in this region showed a weight reduction of 10.7%. In the second region, from 200°C to 580°C, a weight reduction of 21.15% was achieved. This weight reduction is related to the organic particles present in the material skeleton (Figure 9A). Furthermore, the thermal effect on weight loss can be used as an important tool to confirm the surface functionalization and proportion of chelating agents immobilized on the WHMS platform in order to design optical mesocaptor sensors (Figure 9B). It should be emphasized that when the WHM platform is functionalized, the inclusion of chelating agents advances the study of thermal effects. As a result, a significant weight loss due to the thermal decomposition of the new organic layer covering the WHM platform was confirmed. From the TGA / DTA analysis, it was determined that the organic content increased to 29.96 wt.% after the WHM platform was functionalized, and the probe grafted onto the WHM surface was quantified to be approximately 9 wt% (Figure 9B).

[0047] After confirming the ordered porous composition of the prepared WHM material, the chemical composition of the successfully fabricated surface was verified by FTIR spectroscopy (Figure 10). Figure 10 shows all samples under 3400 cm⁻¹. -1 This indicates the presence of a broad band in the vicinity, which is attributed to the OH stretching band resulting from hydrogen bonding between SiO-H and water molecules. Detected values ​​are 459.2, 726.4, and 1066 cm⁻¹. -1 The bands are due to Si-O-Si bending, symmetrical stretching of Si-O-Si, and asymmetrical stretching of Si-O-Si, respectively. 577cm -1The energy band at 959.4 cm² represents a Si-O stretching defect in the silica matrix. -1 In-plane stretching of the Si-O group of the silanol group (Si-OH) was detected, which is thought to indicate the relative degree of polymerization of the silica matrix. The 2931 and 2846.3 cm² values ​​are attributed to the asymmetric and symmetric CH stretching of the phosphonic acid group of the organosiloxane (Si-(CH2)2-PO(OC2H5)2). -1 The bands were seen in each of these locations. Also, 1463cm -1 A deformed band of CH3 has been detected at 1167 and 1066 cm. -1 The two adsorption bands are assigned to CO oscillations: 1774, 1647 cm². -1 The peak is thought to be due to the ligand (chelating agent) or the C=O group of the U-WHM-L complex. 1243 cm -1 The band detected is characteristic of the stretching vibration at P=O. Furthermore, 949 cm -1 The peak showed a stretching oscillation of O=U=O.

[0048] [Extraction and adsorption of U(VI) ions using WHM mesoporous silica support] It is recognized that there are many efforts to rely on environmentally friendly materials with specific surface activity for the removal and extraction of radioactive materials. Porous materials contribute as an effective platform in this field. According to our protocol, it was possible to control the preparation of five monolithic WHM mesoporous silica supports with special properties by using several types of phosphonic acid silane compounds (see Scheme 1 shown in Chemical Formula 7). Using various phosphonic acid ([2-(triethoxysilyl)ethyl]-dimethyl ester) phosphonic acid-silane compounds, 2-dimethoxyphosphorylethyl(triethoxy)silane, (2-diethylphosphatoethyl)triethoxysilane[DEPETS], 3-diethoxyphosphorylpropyl(trimethoxy)silane; and dimethyl{2-[diethoxy(methyl)silyl]ethyl}phosphonate, WHM-1, WHM-2, WHM-3, WHM-4, and WHM-5 were prepared, respectively. The removal and extraction of U(VI) ions from aqueous solutions were evaluated using batch-type contact adsorption experiments. In the batch-type contact adsorption experiment, 20 mg of WHM adsorbent and 20 mL of a specific concentration (10 ppm) U(VI) solution were mixed at room temperature (27°C ± 2°C) for 30 minutes.

[0049] To determine the optimal pH value for effective adsorption and extraction of U(VI) ions using a WHM mesoporous silica monolith support, the effect of a wide range of pH values ​​(1.1 to 10) on the adsorption process was investigated. Figure 11A shows the results of an effective pH test conducted using a WHM-2 adsorbent synthesized from B56 as the adsorbent, with the U(VI) concentration fixed at 10 ppm. The results indicate that changes in pH affect the U(VI) adsorption process due to activation of the adsorbent surface by protonation and ionization processes. Figure 11A shows the increase in U(VI) adsorption when the pH increases from 1 to 6. Furthermore, the maximum U(VI) ion uptake occurs when the dominance of U species in an acidic medium is UO2 2+This was achieved at pH 4.3. The low uptake of U(VI) at lower pH values ​​is thought to be due to electrostatic repulsion between the protonated active WHM-2 surface and the U species. This behavior facilitated the possibility of surface reactivation and regeneration of the spent WHM adsorbent after the adsorption process under acidic conditions. Furthermore, the adsorption and extraction rates of U(VI) decreased as the pH increased, and [UO2]2[OH]2) +2 Ya ([UO2]3[OH]5) + It was found that insoluble and stable hydroxides such as those mentioned above are formed.

[0050] Furthermore, under the same conditions, the influence of the adsorbent composition and its surface properties on the U(VI) adsorption process was investigated. Figure 11B shows the results of adsorbing U(VI) ions at pH 4.3 using all the synthesized mesoporous WHM monoliths (WHM-1, WHM-2, WHM-3, WHM-4, WHM-5). The results indicate the possibility of using WHM hollow porous silica stones with high efficiency in the adsorption of U(VI) ions from aqueous solutions. As a result, it was found that the efficiency of the WHM materials used in the U(VI) ion absorption process from aqueous solutions can be ranked in the order of WHM-1 > WHM-2 > WHM-3 > WHM-4 > WHM-5 (Figure 11B).

[0051] [Extraction and adsorption of U(VI) ions using WHM nanosensors] The design of optical / visual sensors occupies a crucial position in environmental applications, especially when those applications involve tracking or extracting rare or highly hazardous elements. Therefore, there is growing interest in designing environmentally friendly and user-friendly optical sensors for detecting and extracting radioactive materials such as U(VI). In this embodiment, we design an optical sensor based on WHM mesoporous silica with the aim of tracking and extracting U(VI) from aquatic environments with high sensitivity and selectivity. As shown in Figure 7D, four types of chelating agents were used as sensing materials to modify a WHM mesoporous silica support synthesized by a grafting process.

[0052] [Optimal pH conditions for selective adsorption and extraction of U(VI) ions] To evaluate the efficiency of an optical sensor designed to detect U(VI) ions, and to assess the possibility of complex formation between U(VI) ions and a chelate probe, a WHM carrier was used to create optical signals and visible color changes with changes in pH. Figure 12A shows the effect of using a wide range of pH values ​​(1.1-9) for the adsorption / extraction of U(VI) ions with a WHM-1-MB38 mesoporous nanosensor. In all experiments, 20 mg of the WHM-1-MB38 nanosensor was used to adsorb / extract 10 ppm of U(VI) in 100 ml of solution at room temperature for 60 minutes, and the results were confirmed using ICP-MS and UV tools. As a result, significant changes in the U(VI) adsorption process and changes in the sensor's color were observed between pH values ​​of 3.3 and 5.9. The efficiency of this sensor for U(VI) was highest at pH 3.9. As previously mentioned, changes in pH value are associated with UO2 in acidic media below 5.2. 2+ It contributes to the formation of various types of uranium species, including [specific species]. Generally, pH 3.9 is recommended as the optimal condition for visually detecting / removing U(VI) ions from aqueous solutions using the WHM-1-MB38 nanosensor.

[0053] [Effects of chelate probes on selective adsorption and extraction of U(VI) ions] To design an optical sensor for U(VI) ion detection, the efficiency of different chelate probes used to improve the WHM monolithic material was tested under optimal conditions using a batch contact adsorption system. In all experiments, 20 mg of WHM-1-L (L is the chelating agent) and 10 ppm of U(VI) were placed in 100 ml of solution and contacted at room temperature for 60 minutes, and the adsorption process was confirmed using ICP-MS and UV tools. Figure 12B shows that WHM-1-MB38 has high U(VI) uptake performance among the other sensors. As a result, the WHM-1-based sensors used for detecting and extracting U(VI) ions from aqueous solutions were ranked in the following order: WHM-1-MB38 > WHM-1-MB17 > WHM-1-MB79 > WHM-1-MB11 (Figure 12B).

[0054] [Effect of contact time on the performance of U(VI) ion sensors] In addition to ease of use, one of the key features that must be met through visual design is high-speed response. Regarding this point, the effect of contact time on the adsorption and extraction of U(VI) ions at different times (1-90 minutes) at the optimal pH was investigated using the WHM-1-MB38 (Figure 12D). The results showed that U(VI) ion uptake increased rapidly during the first 15 minutes, reflecting the rapid reaction of target ion uptake. After this stage, a negligible slight increase continued, reaching a plateau (i.e., equilibrium) after 13 minutes (Figure 12D). In fact, the visual detection efficiency of the target U(VI) ions is related to the probe type's active site, the surface area of ​​the WHM carrier, and the pH conditions. Furthermore, the WHM-1-MB38 sensor allows for the visual confirmation of the presence of low concentrations of U(VI) ions through a faint red-to-blue color change (see color change in Figure 12d). Generally, depending on the results obtained, U(VI) ions can be efficiently detected / extracted from aqueous solutions using a WHM-L sensor under appropriate conditions of pH 3.9 and a time of 13 minutes.

[0055] [Selective extraction of U(VI) ions] One of the biggest challenges in adsorption, extraction, and sensing processes is selectivity when separating elements, even after obtaining a proper adsorbent platform design. A lack of selectivity in the separation process raises the problem that, in either the tested solution or the inclusion element, other treatments are required to circumvent this process. In the case of optical sensor design, selectivity is essential for successful sensor design. From this perspective, the efficiency of selective processing of synthesized materials in capturing / extracting U(VI) ions more efficiently than other competing ions under optimal conditions was evaluated using batch adsorption and fixed-bed columnar processes.

[0056] The single coexisting ions used were Cu(II)(1), Ni(II)(2), Zn(II)(3), Pb(II)(4), Sr(II)(5), Ba(II)(6), Al(III)(7), Cr(III)(8), Fe(III)(9), V(III)(10), Dy(III)(11), Pr(III)(12), Yb(III)(13), Nd(III)(14), Ce(III)(15), Er(III)(16), Sm(III)(17), and Yb(III)(18). Here, the numbers in parentheses following the element symbols correspond to the numbers on the horizontal axis in Figures 13A to 13D.

[0057] Figure 13A shows the effects of competing elements normally present with U(VI) ions under different conditions in a selective separation and detection process using the WHM-1 adsorbent under optimal conditions. The results obtained by adsorbing each competing ion onto the WHM-1 adsorbent in a single separation system indicate that these elements may be adsorbed in small amounts, but this can be overcome by using a masking agent (Figure 13A). Furthermore, Figure 13B shows the evaluation of a binary system constructed for U(VI) ion adsorption testing in the presence of all ions used in the single separation system test. This data shows that these competing ions do not have a significant effect on the adsorption performance of U(VI) ions using the WHM-1 adsorbent.

[0058] Furthermore, the efficiency of the selective performance of the designed WHM-1-MB38 visual sensor for the adsorption of U(VI) ions in the presence of all ions was evaluated under optimal conditions for the adsorption process. Figure 13C shows the effect of interfering ions as a single separation system on the visual selective separation and detection of U(VI) ions under optimal conditions using the WHM-1-MB38 sensor. As a result, the color of the WHM-1-MB38 sensor clearly changed from a faint red to blue in the presence of U(VI) ions alone, while no clear change in the sensor's color was observed when other interfering ions were examined. To investigate the effect of these interfering ions on the selective adsorption efficiency of U(VI) ions using the WHM-1-MB38 optical sensor, a binary system was designed to evaluate the efficiency of the detection and adsorption process in the presence of these elements (Figure 13D).

[0059] Indeed, the main advantage of adsorbents and sensors lies in their efficiency in separating and identifying target ions in the presence of complex systems that affect the sensitivity and selectivity of the separation process for the target element. Here, we investigated the adsorption and detection efficiency of WHM materials such as WHM-1 and the designed sensor WHM-1-MB38 for U(VI) ions in complex systems (Figures 13E, F). Figure 13E shows the effect of mixing of competing cations on the adsorption and detection of U(VI) using a batch adsorption system. As a result, it was found that multiple competing ion groups in a complex system are highly efficient at selectively adsorbing and detecting U(VI) ions in the presence of the following G1-G6 groups. The complex ion coexisting groups are G1 to G6 as follows. G1 [Cu(II);Ni(II);Zn(II);Pb(II);Sr(II);Ba(II);Na(I), Ca(II)]; G2 [Al(III);Cr(III);Fe(III);V(III);Cs(I);K(I);Mg(II)]; G3 [Dy(III);Pr(III);Yb(III);Nd(III);Ce(III)]; G4 [Er(III);Sm(III);Yb(III)]; G5 [Cu(II);Ni(II);Zn(II);Pb(II);Sr(II);Mg(II);Ba(II);Er(III);Sm(III);Yb(III)], G6 [Dy(III);Pr(III);Yb(III);Nd(III);Ce(III);Al(III);Cr(III);Fe(III);V(III);Cs(I), Na(I)].

[0060] Furthermore, the selective extraction and detection of U(VI) ions in complex systems with multiple competing ion groups was evaluated using the fixed-bed columnar method (Figure 13F). Using WHM-1 (adsorbent) and WHM-1-MB38 (sensor), 1 L of a U(VI) ion composite solution with an optimal pH value was passed through at a flow rate of 2.5 mL / min, and fixed-bed columnar extraction was performed. As a result, it was found that using WHM-1 (adsorbent) and WHM-1-MB38 (sensor) effectively contributes to reducing contamination by U(VI) ions in the columnar process. The adsorption efficiencies of U(VI) ions from simulated solutions of WHM-1 (adsorbent) and WHM-1-MB38 (sensor) were 70.5-74% and 88.7-95.1%, respectively.

[0061] [Adsorption kinetic characteristics of U(VI) ions] To evaluate the efficiency of adsorbents and sensors, it is necessary to consider whether they can efficiently capture target species at different concentrations. Therefore, it is considered necessary to evaluate the efficiency of optical sensors in the presence of different concentrations of U(VI) and determine their capture capabilities in batch adsorption systems and fixed-bed column bar systems.

[0062] [Visual detection and removal of U(VI) ions using a batch-type adsorption system] The effectiveness of visual detection and removal of U(VI) ions was quantitatively and qualitatively evaluated at different pH values. The results showed the possibility of visually detecting and removing U(VI) ions in acidic media from 3.3 to 5.9 (Figure 14). Figure 14A shows the color change of the WHM-1-MB38 sensor in response to changes in pH, reflecting the complex formation due to the interaction between U(VI) ions and the MB38 probe. The results showed that U(VI) ions were better detected and extracted at pH 3.9, and the formation of insoluble, stable hydroxides could be avoided at higher pH levels. The effect of U(VI) ions on the detection and extraction capability of the WHM-1-MB38 sensor was investigated using different U(VI) concentrations under the optimal condition of pH 3.9 (Figure 14B). The results showed a clear increase in peak intensity associated with complex formation around 530 nm and a gradient in the sensor's color change with increasing U(VI) concentration. Furthermore, UO2 2+ By tracking the color change of the sensor caused by the complex coordination of the MB38 probe's donor atoms, the concentration of hexavalent chromium can be predicted with the naked eye (Figure 14B).

[0063] [Kinetic properties of U(VI) ions using a batch-type adsorption system] The uptake capacity of prepared WHM optical sensors, such as the WHM-1-MB38 mesoporous sensor, for U(VI) ions was investigated as a function of initial concentration. A series of batch contact experiments were conducted to evaluate the effect of the initial concentration of U(VI) on the adsorption capacity of WHM-1, WHM-2, and WHM-1-MB38 under optimal conditions. Figure 15A shows the uptake rate of U(VI) ions over a wide range of initial concentrations, where U(VI) uptake rate = C o -C qThe calculations were performed using the relationship (mg / L). Figure (15A) confirms that all tested adsorbents have the ability to rapidly adsorb the low concentrations of U(VI) ions tested. This is thought to be due to the presence of a large number of active surface sites in addition to the high surface area that functions as a host for the target ions. As the concentration of U(VI) ions increases, the affinity of the adsorbent reaches its maximum saturation capacity, and the ability to detect or extract more U(VI) ions decreases. From the results of U(VI) ion uptake at the plateau stage, the maximum saturation capacities of WHM-1, WHM-2, and WHM-1-MB38 were approximately 150 mg / L, 85 mg / L, and 71 mg / L, respectively (Figure 15A).

[0064] On the other hand, the adsorption capacity (q) at equilibrium U(VI) concentration (Ce mg / L) e mg / g) is

number

[0065] On the other hand, to evaluate the interaction between the U(VI) ion and the designed WHM-1-MB38, the Langmuir isotherm model was applied, resulting in the following linear relationship of the Langmuir equation:

number

[0066] [Visual detection and extraction of U(VI) ions using a fixed-bed columnar system] While batch extraction is relied upon for small-scale laboratory experiments due to its simplicity, effectiveness, and the need for small amounts of adsorbent, fixed-bed columnar extraction is preferred for industrial applications due to its potential for large-scale use, the ease of reuse of used adsorbent by washing without the need for mechanical stirring, and the ability to regenerate and reuse adsorbent. In this example, a series of fixed-bed columnar experiments were conducted by filling a fixed amount of WHM-1 adsorbent and an optical WHM-1-MB38 mesoporous monolith sensor, and then passing 2000 ml of U(VI) solution through it at a constant flow rate under optimal pH conditions. The effects of flow rate, the amount of extractor packed, and the initial concentration of U(VI) were investigated (Figure 16).

[0067] Figure 16 shows the breakthrough curve of U(VI) ion uptake in the columnar, C eff / C oThis is expressed as a function of the supply rate (BV) of the U(VI) solution. This method represents the ability of the absorbent in the column to capture U(VI) ions, depending on the shape of the breakthrough curve and the supply rate. The adsorption capacity (qe, mg / g) of the WHM-1 and WHM-1-MB38 adsorbents is expressed using the following formula to determine the breakthrough point (C eff / C o It was calculated using the values ​​detected according to the relationship = 0.01.

number

[0068] Here, C o and C eff The values ​​are the initial and wastewater U(VI) concentrations, respectively, VB is the volume (L) of the supply solution at the breakthrough point, and m is the mass of WHM-1 and WHM-1-MB38 adsorbents. Figure 16 shows the evaluation of various parameters (flow rate, initial concentration of the target substance, and adsorbent dosage) that affect the adsorption capacity of a fixed-bed columnar system at pH 3.9. Regarding the flow rate, an inverse relationship was observed between the flow rate and the absorption / extraction efficiency and the breakthrough point (Figures 16A and B). As a result, it was found that the adsorption efficiency and breakthrough point decreased with increasing flow rate. This is thought to be due to the shorter contact time with the material and the decrease in the diffusion rate to the internal and external active sites. The effect of the amount of adsorbent was evaluated by fixing different amounts of adsorbent (0.5, 1.0, and 2.0 g) in the column system under optimal pH, flow rate of 5 mL / min, initial [U(VI)] value of 50 mg / L, and room temperature conditions (Figures 16C and D). In this example, an increase in the amount of adsorbent resulted in the acquisition of a more active surface area, thus improving adsorption efficiency. Furthermore, examining the effect of the initial concentration of U(VI), it was found that the adsorption capacity increased as the initial concentration of U(VI) increased (Figures 16E, F). From this data, it was confirmed that the WHM-1-MB38 mesoporous sensor is more efficient than the WHM-1 adsorbent.

[0069] [Mechanism for visual detection and extraction of U(VI) ions] Figure 17 is a schematic diagram illustrating the design of the visual sensor on the WHM-2 platform, the U(VI) ion capture mechanism, and its interaction with the chelated organic probe (MB38). The possibility of U(VI) interacting with specific locations on the sensor depends on the minimum potential energy of the surface. To explain the mechanism of the sensor's sensitivity and selectivity, we succeeded in simplifying the evaluation process by focusing on the MB38 molecule rather than the entire surface, and concentrating on the active site that enables the binding process. Because the MB38 probe contains various donor atoms such as nitrogen, oxygen, and sulfur, there are many locations where the target ion can bind.

[0070] Organic monoazo dyes like MB38 are systematically known as chromophores containing aromatic azo groups. Furthermore, the keto form is more stable than the enol form, and tautomerism due to proton exchange and electron density rearrangement significantly influences the probe's behavior. In this respect, the keto form of MB38 organic probe is the most stable among the enol forms and is the preferred form for binding. Therefore, the nitrogen and oxygen atoms of keto MB38 are expected to be more electronegative than the nitrogen atom of the azo group. Thus, the appropriate chelate mode position of the U(VI) compound can be established by forming a complex [UO2L(H2O)](NO3) by attaching to the N and O atoms of the keto group, then forming a coordinate bond with the two N atoms of the azo group, one O from one HNO3, and one H2O molecule [Figure 17A(A,B) shows the atomic arrangement of the sensor design, Figure 17A(C) shows the atomic arrangement of the complex formation as shown in small scale, Figure 17B(C) shows the atomic arrangement of the complex formation on the right, Figure 17C(E) shows the atomic arrangement of the complex [UO2L(H2O)](NO3) (see (E)), and Figure 17C(C) shows the atomic arrangement on the right in the multilayer film]. Furthermore, the selective visual capture of U(VI) ions under acidic pH conditions is possible because hydrogen ions are available, which facilitates the binding process with the MB38 probe and the efficient absorption of the formed U(VI) ions. The formation of this complex was confirmed by FTIR and UV analysis (see Figures 10 and 14).

[0071] [Unlimited recyclability / reusability of WHM light sensors] Sensor recycling and reuse processes have gained a privileged position in terms of reducing economic costs, saving time, and streamlining waste management processes. The importance of designing optical sensors that can be efficiently recycled and reused multiple times is evident. (i) To conserve raw materials needed to manufacture new sensors and reduce costs, (ii) Saving time and effort by continuously adsorbing the target species without interruption, (iii) The sensor may be activated by adding a chelating agent or by extracting and refunctionalizing the platform. (iv) Reduce the release of solid waste, It is located in this position. From this perspective, work was done to provide an efficient chemical method for recycling U(VI) sensors without affecting their efficiency or characteristics (Figure 18).

[0072] The recyclability of WHM-2-L after adsorption of U(VI) ions was achieved by a simple chemical treatment using a suitable stripping solvent, releasing U(VI) ions according to a decomplexing process. The efficiency of this stripping process was determined by evaluating the obtained filtrate and solid sensor using UV-Vis and ICP-MS instruments (Figure 18). Several solvents, including hydrochloric acid, H2SO4, NaOH, EDTA, and organic solvents, were used to identify the optimal stripping agent for U(VI) extraction and sensor reuse. This study showed the effect of acidic solvents on extraction potential, but the EDTA solution yielded the best results. Figure 18A shows the effect of EDTA concentration on the stripping / release / elution process of WHM-2-MB38. As a result, it was found that the optimal EDTA concentration for U(VI) ion recovery is 0.015 M. Furthermore, during the uranium release process, the sensor's color returned from blue to a faint red, representing its original color before use, indicating the successful regeneration of the sensor platform. To confirm complete recovery and the efficiency of the detachment / recovery process, the concentration of U(VI) ions in the filtrate obtained from the recovery process was detected by ICP-MS. The detachment / recovery efficiency %(E%; U(VI) release rate) was:

number

[0073] Using the results obtained by UV-Vis spectroscopy and ICP-MS, the reusability of the WHM-2-MB38 sensor after multiple recycling processes was evaluated (Figure 18B). In the results of the 10th cycle, the sensor still functions efficiently to remove U(VI) under optimal conditions, but it has decreased by 18% compared to the 1st cycle. This decrease can be explained by the removal of a part of the active probe from the surface due to multiple peeling and reuse processes. This problem can be solved by increasing the amount of the sensor used at an advanced stage or by reactivating the sensor. For example, after the peeling process, the sensor surface can be reactivated in two systems. The first method is related to compensating for the loss amount of the probe by adding the WHM-2 sensor to the MB38 probe solution. The second method is related to removing the maximum amount of the MB38 probe from the surface by adding the sensor to an acetone solution and gently stirring for 30 minutes, and then reactivating the surface by grafting with the MB38 probe according to the previously demonstrated design steps of the optical sensor. From the perspectives of economic cost, environmental efficiency, recycling efficiency, and time saving, it is preferable to apply the first method and rely on the second method when necessary.

[0074] [Extraction of 238U Isotope from AGR Raw Material] [Leaching of AGR Raw Material] In this example, one of the main purposes is to use real or simulated samples to verify the efficiency of the designed sensor and ensure a realistic application process. Here, the altered granite (AGR) collected from Gabal El-Sela in the southeastern desert of Egypt and the U isotopes present in ores such as its components 238 Our extraction / detection protocol was applied to capture the (Figure 19A). 238U isotopes were obtained from AGR ore through a leaching process, which uses appropriate reagents to separate the constituent elements of a substance and facilitate the extraction of elements from a solution. To facilitate the leaching process for uranium extraction, the ore was crushed and sorted into different sizes (200 mesh, 0.075 mm). A series of experiments were conducted using different acids such as H2SO4, HCl, and HNO3 at different concentrations to select the conditions best suited to completing the leaching process of the AGR ore. The results of the leaching processes with H2SO4, HCl, and HNO3 acids were 70%, 50%, and 35%, respectively, indicating that H2SO4 was more efficient in the filtration process compared to the others.

[0075] While the tested acids can be used in the leaching process, H2SO4 is preferable. If HCl is used, a large quantity is required to complete the leaching. Using HNO3, a strong oxidizing agent, contributes to an increase in dissolved oxides in the extract. Therefore, H2SO4 is relied upon as a leaching agent for uranium leaches from AGR due to its high leaching efficiency and moderate metallic impurities (Figure 19B).

[0076] To obtain the most suitable conditions for the success of this process, several settings affecting the use of H2SO4 in the leaching process are trusted. These settings relate to the concentration of the H2SO4 acid used, the time, and the temperature (Figure 19B). 238 To investigate the effect of H2SO4 concentration on U elution, different concentrations of H2SO4 (0.1-2M) were used at different temperatures (25°C ± 2°C), stirring times (120 minutes), H2O2 concentrations (2.5% (v / v)~), and AGR dosage (1g). The results showed that elution was best when using 0.5M H2SO4 acid. 238 The amount of U was approximately 70% (Figure 19B). The decrease in elution efficiency at high concentrations is thought to be due to the initiation of gypsum (calcium sulfate) formation, which promoted the adsorption of U ions onto the gypsum surface. Furthermore, since the AGR sample contains a large amount of insoluble U(IV), the isotopes... 238To facilitate the extraction of U, U(IV) was oxidized to U(VI) using an oxidizing agent such as H2O2 that dissociates easily at low cost. The H2O2 concentration (0% - 15%) was 238 As a result of investigating the effect of the H2O2 concentration on the elution efficiency of U isotopes, it was confirmed that as the H2O2 concentration increased from 2.5% to 5%, the elution efficiency increased from 70% to 78.9% (Figure 19C).

[0077] 238 To determine the optimal time to achieve a high elution rate of U, the time-dependence of the elution process was verified at 5 - 120 minutes (Figure 19B). This procedure was adopted with other leaching parameters fixed, such as H2SO4 acid (0.5M), H2O2 concentration (5%), temperature (25°C ± 2°C), and AGR dosage (1g). According to Figure 19B, 238 the elution rate of U increased with the stirring time, reaching a maximum at 45 minutes, and then a negligible slight increase was observed with the increase in the experimental time. Therefore, the optimal leaching time was 45 minutes. Furthermore, when the effect of temperature was investigated in the range of 25°C - 70°C ± 2°C, it was found that 238 the elution amount of U increased with the increase in temperature (Figure 19B). As a result, at 70°C ± 2°C, the elution of U ions into the solution was promoted, and 99.5% of 238 U was obtained. This data confirmed that the elution of U isotopes from AGR was endothermic. Therefore, 70°C ± 2°C was selected as the optimal temperature for the leaching process. According to the analysis data of AGR obtained using an ultra-high purity germanium spectrometer, the 238 U isotope content of the AGR raw material was 3445.5 Bq / kg. Generally, from the results of this study, to extract 99.5% (≈3428 Bq / kg) of the 238 U contained in 1g of the AGR sample, it was necessary to stir 1g of the AGR material with 4 mL of H2SO4 (0.5M) and H2O2 (5%) at 70°C ± 2°C for 45 minutes or more. 238 U was obtained. This data confirmed that the elution of U isotopes from AGR was endothermic. Therefore, 70°C ± 2°C was selected as the optimal temperature for the leaching process. According to the analysis data of AGR obtained using an ultra-high purity germanium spectrometer, the

[0078] [Extraction of U isotopes from the actual leachate] 238 U isotopes] Based on laboratory results and the fact that the visual tracking sensor for uranium-238 isotope of the present invention can be used for the separation and detection of U(VI) ions, this sensor can be used in actual AGR leachates. 238 It is necessary to confirm that it can be applied to the detection and extraction of U. Figures 20(A) and (B) show the gamma-ray spectra of the WHM-2-MB38 sensor and WHM-2, confirming the processes of adsorption, selectivity, and regeneration. Figure 20(A) is the gamma-ray spectrum of the WHM-2-MB38 sensor stirred under the same optimal conditions as used in the extraction process, and it can be seen that there are no peaks characteristic of complex formation. Figure 20(A) shows the isotope from the AGR leachate. 238 The gamma-ray spectrum of the WHM-2-MB38 sensor after extracting U species is shown. From this result, 23 A clear peak is observed indicating that the 8U isotope forms a complex with the sensor's active site. Furthermore, there are no other peaks associated with complex formation with other elemental isotopes present in the AGR leachate. As a result, high selectivity can be obtained from the AGR leachate aqueous solution. 238 We confirmed that uranium isotopes could actually be removed. The stability and reuse efficiency after stripping uranium ions from the sensor were confirmed using gamma-ray spectroscopy (Figure 20(C)). As a result, after the stripping process... 238 It was found that the peak for the U complex had disappeared.

[0079] Furthermore, it was found that there was no clear difference in the results before and after the uranium-238 isotope visual tracking sensor. Figure 20(D) shows the gamma-ray spectrum of the WHM-2 carrier after extraction. This result indicates the presence of multifunctional peaks related to the adsorption of multiple elements from the AGR leachate aqueous solution. This data shows that WHM-2 can be used to extract from the aqueous leachate of the AGR under study. 238 This provides evidence that U isotopes and radioactive materials were actually removed without selectivity. Based on these results, the WHN-2-MB38 sensor can remove actual samples from a real sample. 238 It was confirmed that U isotope species can be visually detected and extracted with high sensitivity, high selectivity, and high volume. Adsorbed uranium ions from the leachate are solid. 238The adsorbent was eluted / recovered / pre-concentrated from the U extractor (over 92.5%), and subsequently could be reused on another occasion (Figure 21).

[0080] [U from Egyptian monazite mineral (EMM)] (VI,238) Visual detection and recovery of ions. Monazite, a mineral used as a single-phase ceramic host, certainly depends in its natural composition on mixed rare-earth orthophosphates, which have contained significant amounts of the radioactive elements uranium and thorium for billions of years. To achieve the practical aspects and economic importance of the designed WHM sensor, investigations were conducted to track and extract U ions from the primary uranium source from monazite sources in Egypt. From this perspective, the efficiency of the WHM-MB38 sensor, designed to extract and detect uranium in monazite rock samples, was evaluated in two stages: (i) using a simulated monazite solution, and (ii) using an EMM leachate.

[0081] [U from simulated monazite solution] (VI) Visual detection and recovery of ions. Simulated solutions for synthesizing monazite were prepared by mixing specific amounts of most elements expected to be present in the actual sample (Table 1, Figure 22). Table 1 shows the visual detection and recovery of U(VI) ions from the simulated solutions under optimal conditions of room temperature and pH 3.9. To evaluate the extraction and traceability of U(VI) ions from the monazite-simulating solution, after setting the optimal extraction conditions to pH 3.9, a batch extraction process was performed using a 40 mg WHM-MB38 sensor in 1 L of solution with stirring at room temperature for 30 minutes. ICP-MS was used as the primary tool to evaluate the different ion concentrations in the simulated solution before and after the extraction process. As a result, the optical meso-sensor using WHM-MB38 was able to track and extract U(VI) ions with high efficiency, sensitivity, and selectivity of 97.35%, even in the presence of high concentrations of competing ions. [Table 1]

[0082] [U from EMM leachate solution (238) Visual detection and recovery of ions. To practically evaluate uranium extraction from monazite ore, actual nitrate samples of uranyl and thorium ions contained in rosetta monazite concentrate were provided. Component analysis of EMM (97% purity) revealed the presence of ThO2 (5.8%), U3O8 (0.52%), Ce2O3 (28.65%), and other rare earth elements (REE 28.76%). Simply put, alkaline leaching is preferable for monazite leaching due to its simple procedure and economic aspects, such as the use of trisodium phosphate (a by-product) in the fertilizer industry. The resulting hydrated oxide solution is then treated with a high-temperature hydrochloric acid solution at 80°C and diluted with water. Furthermore, by selectively neutralizing the solution with ammonia water at pH 5.8-6, uranium and thorium ions can be separated from lanthanides. UO2(NO3)2·6H2O and Th(NO3)4·5H2O were obtained by dissolving thorium uranium cake concentrate in 1 L of 4 M HNO3. Next, selective extraction of U ions was performed at pH 3.9 using a WHM-MB38 meso sensor in both column and batch systems. As a result, it was found that U ions were selectively extracted in the presence of Th ions (Figure 23). Furthermore, the extraction rates of U ions in the batch and column systems were found to be 97.5% and 93.4%, respectively (Figure 23).

[0083] [Visual detection and extraction of U-ions from seawater] Extracting uranium from seawater is considered a crucial challenge not only for removing the most harmful heavy metals but also for conserving energy resources. From this perspective, a sensor designed as an adsorbent to track and extract low concentrations (3.3 ppp) of radioactive U-ions in seawater is a key solution to overcome these challenges. After collecting seawater and removing suspended solids through a filtration process, the concentrations of the main components constituting the seawater were measured at different levels before the processing steps (Table 2). Effective extraction of radioactive U-ions using the WHM-MB38 meso sensor was performed using 1 L of seawater under optimal detection conditions. Furthermore, to confirm the accuracy of the proposed method for recovering U-ions from seawater, an additional concentration of uranium (0.1 mg) was injected into the analyzed seawater matrix. To evaluate the efficiency of the WHM-MB38 sensor in detecting and extracting U-ions from seawater (0.1033 ppm), a batch method was performed after adjusting the pH to 35. Analysis of the solution obtained in the filtration process by ICP-MS revealed that the U ion extraction process performed with high selectivity and a high loading rate of 97% even in the presence of high concentrations of competing ions (Table 2). Table 2 shows the optical detection / extraction of U ions from seawater samples under optimal extraction conditions using a WHM-MB38 photosensor. [Table 2]

[0084] [Visual detection and extraction of U-ions from brackish water wastewater] Furthermore, the detection and extraction of U ions from low-salinity wastewater collected from wells as a natural water source were evaluated. Table 3 shows the ICP-MS analysis results of brackish water wastewater before and after U ion extraction treatment using the WHM-MB38 meso sensor under optimal extraction conditions. To ensure the accuracy of the effective U ion recovery procedure using the WHM-MB38 meso sensor, a certain amount of U(VI) ions (0.1 mg / L) was added to an existing brackish water matrix, and 1 L of well water was used under optimal detection conditions (Table 3). As a result, a highly sensitive and selective extraction process of U ions was confirmed with a high loading rate of 98.03% in the presence of competing ions of different concentrations (Table 3). Table 3 shows the optical detection / extraction of U-ions from a brackish water source under optimal extraction conditions using the HM-MB38 photosensor. [Table 3]

[0085] [Visual detection and extraction of U-ions from well water sources] Furthermore, the detection and extraction of U ions from low-salinity wastewater collected from wells as a natural water source were evaluated. Table 4 shows the ICP-MS analysis results of water collected from the wells before and after U ion extraction treatment using the WHM-MB38 meso sensor. Based on previous experimental results, and by adding a certain amount (0.1 mg / L) of uranium to the existing well water matrix, the accuracy of an effective U-ion recovery procedure using the WHM-MB38 meso sensor in 1 L of well water was ensured under optimal sensing conditions (Table 4). Table 4 shows the optical detection / extraction of U ions from the well water source using the WHM-MB38 photosensor (optimal extraction conditions). As a result, a highly sensitive and selective extraction process of U ions was confirmed with a high loading rate of 98.9% in the presence of competing ions of different concentrations. [Table 4]

[0086] [Conclusion] In this embodiment, U(VI) and238 We successfully designed a super-adsorbent optical sensor on an organic-inorganic worm-like hexagonal mesoporous silica (WHM) monolith platform prepared with a bridge-type (CxEOy) surfactant to track / detect / extract U(VI) isotopes. We designed a highly sensitive and selective optical sensor to extract U(VI) from real samples. 238 To detect and extract U isotopes, the WHM platform was directly grafted with Moldanto Black 38 (MB38) as a chelating probe. U(VI) ions and 238 The optimal conditions for detecting and extracting U isotopes were determined at pH 3.9 using batch and permanent-bed column approaches. The designed WHM-1-MB38 sensor detects trace amounts of U(VI) and in the test solution. 238 It demonstrated the ability to rapidly and visually sense / detect U isotope ions, with a maximum loading capacity of 146.41 mg / g. As a result, it was found that the leachate of the AGR sample contained 238 More than 93% of the U isotope ions could be recovered visually. The WHM-L sensor was regenerated using a simple chemical processing process, and U(VI) ions and 238 Reusing the optical sensor over multiple cycles (>>10 times) without affecting the performance of highly sensitive and selective visual extraction of U isotopes is a major factor from an economic and waste management perspective. The optical sensor developed in this invention provides an environmentally friendly and chemically stable extractor, and through an efficient and simple protocol, extracts U(VI) ions and 238 U ions can be selectively detected and extracted from the raw material. This technical structure allows for the detection and extraction of U(VI) and U(VI) from the actual sample. 238 This represents a promising candidate for applying a rapid and convenient approach to the discovery / extraction of U.

[0087] [Mesoporous silica with a chelate-modified 3D hexagonal monolithic worm-like higher-order structure] As an addendum, we describe a mesoporous silica with a chelate compound-modified three-dimensional hexagonal monolithic worm-like higher-order structure, which is not modified with an organic chromogenic chelate probe, as a precursor of the present invention.

[0088] Figure 24 is a schematic diagram showing a uranium adsorbent as a precursor of the present invention. The uranium adsorbent of the present invention comprises an aggregate 100 of particles made of porous silica 110 having a hexagonal crystal structure. The aggregate 100 has a hierarchical structure comprising micropores (pore diameter: 0.5 nm or more and less than 2 nm), mesopores (pore diameter: 2 nm or more and less than 50 nm), and macropores (pore diameter: 50 nm or more and 10 μm or less). By having pores of various sizes, a hierarchical structure is formed, which can promote the uptake, diffusion, and adsorption of uranium. In particular, the inventors of the present invention have found that the aggregate 100 is 250 m 2 / g or more 300m 2 It has a BET method specific surface area in the range of less than or equal to / g, and 0.3cm² 3 / g or more 0.5cm 3 It was found that the material has a pore volume in the range of less than / g, selectively adsorbs or releases uranium in mesopores and channels, and functions as a uranium adsorbent. Furthermore, the surface of the aggregate 100 constituting the uranium adsorbent of the present invention has a plurality of grooves 120 between the particles, and uranium can be selectively adsorbed and released in mesopores and channels through these grooves.

[0089] The hexagonal crystal structure of porous silica particles can be determined from the diffraction patterns obtained by powder X-ray diffraction measurements. The presence of micropores (diameter 0.5 nm to less than 2 nm), mesopores (diameter 2 nm to less than 50 nm), and macropores (diameter 50 nm to 10 μm) in aggregate 100 can be determined by the NLDFT method (Non-Local Density Functional Theory) based on nitrogen adsorption / desorption isotherms. Simply put, the adsorption / desorption isotherms should be a mixture of IUPAC type I, type II or III, and type IV or V. In this specification, the presence of micropores, mesopores, and macropores in the aggregate is referred to as having a hierarchical structure.

[0090] In aggregate 100, mesopores between 2 nm and 50 nm mainly function as spaces for adsorbing and retaining uranium, preferably the pore volume of the mesopores is 0.358 cm³. 3 / g or more 0.4383cm 3 It has a range of less than / g. Mesopores act as active sites for uranium, promoting uranium capture and enabling efficient uranium adsorption.

[0091] Figure 25 is a schematic diagram showing another uranium adsorbent as a precursor of the present invention. Figure 26 is a schematic diagram showing the adsorption mechanism using a uranium adsorbent modified with a chelate compound as a precursor of the present invention, illustrating the schematic state of uranium adsorption when the uranium adsorbent of the present invention is used in a column system. The uranium adsorbent of the present invention may preferably comprise aggregates 200 of particles in which the surface and pores of porous silica are modified with a chelate compound 210 represented by formula 1 or 2. [ka]

[0092] Here, L is a divalent group, "·" represents a radical, R1 is selected from the group consisting of a hydrogen atom, alkyl group, cycloalkyl group, aryl group, monovalent heterocyclic group, substituted amino group, halogen atom, and cyano group, R2 and R3 are the same or different alkyl groups having 1 to 5 carbon atoms, R4 is an alkyl group having 1 to 5 carbon atoms, n is a natural number between 1 and 3, and * represents the bonding site with porous silica.

[0093] As shown in Figure 26, the R2 and R3 groups of the phosphoryl group, or the R4 group of the carboxyl group in such a chelate compound 210, can selectively adsorb and release uranium. Specifically, R2 to R4 surround and hold the uranium. As a result, the uranium adsorbent shown in Figure 25 can adsorb more uranium than the uranium adsorbent shown in Figure 1.

[0094] L is not particularly limited as a divalent group, but examples include divalent hydrocarbon groups which may have heteroatoms. Examples of divalent hydrocarbon groups which may have heteroatoms include alkylene groups (preferably with 1 to 10 carbon atoms), cycloalkylene groups (preferably with 3 to 10 carbon atoms), alkenylene groups (preferably with 2 to 10 carbon atoms), alkylylene groups (preferably with 2 to 10 carbon atoms), and combinations thereof, as well as combinations of the above with -C(O)-, -C(O)O-, -OC(O)-, -O-, -S-, and -NR- (where R represents a hydrogen atom or a monovalent organic group).

[0095] In particular, L is preferably an alkylene group having 1 to 10 carbon atoms. This promotes the modification of porous silica with the chelate compound 210. More preferably, L is an alkylene group having 1 to 5 carbon atoms. This allows more chelate compound 210 to be modified onto the porous silica, thus enabling the adsorption of more uranium. Still more preferably, L is an alkylene group having 2 to 4 carbon atoms. n is not particularly restricted as long as it is a natural number between 1 and 3, but preferably n is 2 or 3. This allows the porous silica to be firmly modified with compound 210. R1 is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group. This promotes the modification of compound 210 to porous silica.

[0096] R2 and R3 may be the same or different, but from the viewpoint of manufacturing efficiency, they are preferably the same. R2 and R3 are preferably alkyl groups having 1 to 3 carbon atoms. Shortening the alkyl chain makes it easier to selectively incorporate uranium. Experimentally, it has been confirmed that R2 and R3 selectively adsorb uranium, especially when they are methyl or ethyl groups. R4 is preferably an alkyl group having 1 to 3 carbon atoms. Shortening the alkyl chain makes it easier to selectively incorporate uranium. Experimentally, it has been confirmed that R4 selectively adsorbs uranium, especially when it is a methyl or ethyl group. The combinations of L, R1-R4, and n can be arbitrarily set from the above, but preferably, L is an alkylene group having 2-4 carbon atoms, R1-R4 are the same or different alkyl groups having 1-3 carbon atoms, and n is 2 or 3.

[0097] Examples of such chelate compounds 210 include the following. These are easily modified onto porous silica and can selectively adsorb uranium. [ka]

[0098] When the chelate compound 210 is modified, the aggregate 200 is preferably 250 m 2 / g or more 270m 2 It has a BET method specific surface area in the range of less than or equal to / g, and 0.3cm² 3 / g or more 0.4cm 3 It has a pore volume in the range of less than / g. Although the specific surface area and pore volume are slightly reduced by modification with chelate compound 210, the uranium adsorption efficiency can be improved due to the uranium adsorption capacity of chelate compound 210 itself.

[0099] The uranium adsorbent used as a precursor in the present invention preferably satisfies a mass ratio of the chelate compound to porous silica in the range of 0.1 to 0.5. This allows for efficient adsorption of uranium while maintaining the specific surface area and pore volume. The uranium adsorbent used as a precursor in the present invention more preferably satisfies a mass ratio of the chelate compound to porous silica in the range of 0.15 to 0.25. This allows for more efficient adsorption of uranium while maintaining the specific surface area and pore volume. In the uranium adsorbent modified with chelate compound 210 as a precursor of the present invention, preferably, the porous silica contains at least silicon (Si), oxygen (O), carbon (C), and phosphorus (P), and when the total is 100% by mass, the mass percentage concentration of each element is: 45 ≤ Si ≤ 55 40 ≤ 0 ≤ 45 3 ≤ C ≤ 7, and, 1 ≤ P ≤ 3 This satisfies the requirements, allowing for more efficient adsorption of uranium.

[0100] In a uranium adsorbent modified with chelate compound 210 as a precursor of the present invention, more preferably, the mass percentage concentration of each element is 47 ≤ Si ≤ 50 42 ≤ 0 ≤ 45 3 ≤ C ≤ 5, and, 1 ≤ P ≤ 2 This satisfies the requirements, allowing for more efficient adsorption of uranium. [Industrial applicability]

[0101] The visual tracking sensor for uranium-238 isotope according to the present invention can detect / extract low concentrations of U(VI) ions from different environments. According to the method for manufacturing a uranium-238 isotope visual tracking sensor of the present invention, the above-mentioned uranium-238 isotope visual tracking sensor can be manufactured. The present invention provides a method for visually tracking uranium, which allows for the detection and extraction of low concentrations of U(VI) ions from different environments.

Claims

1. Mesoporous silica with a three-dimensional hexagonal monolithic worm-like higher-order structure, The chelate compound modified on the surface of the mesoporous silica, An organic chromogenic chelate probe modified with the chelate compound, A visual tracking sensor for the uranium-238 isotope, comprising: A visual tracking sensor for uranium-238 isotopes, wherein the surface and pores of the mesoporous silica are modified with a chelate compound represented by formula 1 or formula 2. 【Chemistry 1】 Here, L is a divalent group, "•" represents a radical, R1 is selected from the group consisting of a hydrogen atom, alkyl group, cycloalkyl group, aryl group, monovalent heterocyclic group, substituted amino group, halogen atom, and cyano group, R2 and R3 are the same or different alkyl groups having 1 to 5 carbon atoms, R4 is an alkyl group having 1 to 5 carbon atoms, n is a natural number between 1 and 3, and * represents the bonding site with the mesoporous silica.

2. The aforementioned L is an alkylene group having 2 to 4 carbon atoms. The above R1 to R4 are the same or different alkyl groups having 1 to 3 carbon atoms. The uranium-238 isotope visual tracking sensor according to claim 1, wherein n is 2 or 3.

3. The chelating compound is a polyoxyethylene aliphatic ether represented by any of the following: phosphonic acid [2-(triethoxysilyl)ethyl]-dimethyl ester, 2-dimethoxyphosphorylethyl (triethoxy)silane, (2-diethylphosphatoethyl)triethoxysilane, 3-diethoxyphosphorylpropyl (trimethoxy)silane, or dimethyl{2-[diethoxy(methyl)silyl]ethyl}phosphonate, as shown in Formula 2, as a visual tracking sensor for uranium-238 isotopes according to claim 2. 【Chemistry 2】

4. The uranium-238 isotope visual tracking sensor according to any one of claims 1 to 3, wherein the mass ratio of the chelate compound to the mesoporous silica is in the range of 0.1 to 0.

5.

5. The uranium-238 isotope visual tracking sensor according to claim 4, wherein the mass ratio of the chelate compound to the mesoporous silica is in the range of 0.15 to 0.

25.

6. The mesoporous silica contains at least silicon (Si), oxygen (O), carbon (C), and phosphorus (P), and when the total is 100% by mass, the mass percentage concentration of each element is: 45 ≤ Si ≤ 55 40 ≤ 0 ≤ 45 3 ≤ C ≤ 7, and, 1 ≤ P ≤ 3 A visual tracking sensor for uranium-238 isotope according to any one of claims 1 to 5, satisfying the requirements.

7. The mesoporous silica comprises an aggregate of particles made of porous silica having a hexagonal crystal structure. The aggregate has a hierarchical structure comprising micropores, mesopores, and macropores, The aggregate has a BET specific surface area in the range of 250 m² / g to 300 m² / g, and a pore volume in the range of 0.3 cm³ / g to 0.5 cm³ / g. The surface of the aggregate has a plurality of grooves between the particles, A visual tracking sensor for uranium-238 isotopes according to any one of claims 1 to 5, which selectively adsorbs uranium and produces color.

8. The uranium-238 isotope visual tracking sensor according to any one of claims 1 to 7, wherein the organic color-developing chelate probe is a chelate probe of an azo compound represented by any one of formulas 3 to 6. 【Transformation 3】 【Chemistry 4】 【Transformation 5】 【Transformation 6】

9. A three-dimensional (3D) hexagonal monolithic worm-like higher-order structure mesoporous silica (WHM) is prepared by a direct template method using a polyoxyethylene aliphatic ether surfactant as described in claim 3. By controlling the structure, shape, and size of pores in mesoporous silica modified with polyoxyethylene aliphatic ethers, A method for producing a visual tracking sensor for uranium-238 isotope, wherein the WHM platform is modified with a chelate probe of an azo compound as described in claim 8.

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