Adsorbing material and method for manufacturing the same, adsorbing sheet, separation membrane, and artificial dialysis device

Abstract

Provided is an adsorbent material containing MXene, which is excellent in adsorption properties with respect to polar organic compounds, for example. The adsorbent material contains: particles of a layered material including one or more layers; one or more metal atoms selected from the group consisting of Al, Mg, Ca, Ba, Fe, Zn, Mn, and Cu, the layer including: a layer main body represented by the following formula: M m X n (n is 1 or more and 4 or less, and m is greater than n and 5 or less), and a modification or a terminal T (T is at least one selected from the group consisting of a hydroxyl group, a fluorine atom, a chlorine atom, an oxygen atom, and a hydrogen atom) present on the surface of the layer main body, the M of the layer being combined with at least one selected from the group consisting of a chlorine atom, a phosphorus atom, an iodine atom, and a sulfur atom.

Description

Technical Field

[0001] This invention relates to adsorption materials and their manufacturing methods, adsorption sheets, separation membranes, and artificial dialysis equipment. Background Technology

[0002] In recent years, MXene has attracted attention as a novel material. MXene is a type of so-called two-dimensional material, as described later, which is a layered material with one or more layers. Generally, MXene exists in the form of particles of this layered material (also called MXene particles, which can include powders, flakes, nanosheets, etc.).

[0003] Currently, various researches are underway regarding the application of MXene in various fields such as electronic devices and medical equipment. For example, non-patent literature 1 and non-patent literature 2 show methods to use Li... + With Mg 2+ Ca 2+ Ion exchange is performed by inserting Mg into the interlayer of MXene. 2+ Ca 2+ Furthermore, Non-Patent Document 2 shows the intercalation of Na and K, and the use of MXene electrodes. Additionally, Patent Document 1 demonstrates the addition of MgF2 and CaF2 during etching, thereby enabling Mg... 2+ Ca 2+ Intercalation methods. For the aforementioned applications, there is a need to improve the adsorption performance of MXene. Additionally, as an application beyond electrodes, Non-Patent Document 3 discloses the use of MXene for urea removal in dialysis.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent documents US Patent 10,683,208 B2

[0007] Non-patent literature

[0008] Non-patent literature :Michael Ghidiu et al., Ion-Exchange and Cation SolvationReactions in Ti3C2 MXene, Chem. Mater. 2016, 28, 3507-3514

[0009] Non-patent literature :Shuo Li et al., Intercalation of Metal Ions into Ti3C2TxMXene Electrodes for High-Areal-Capacitance Microsupercapacitors withNeutral Multivalent Electrolytes, Adv. Funct. Mater. 2020. 30. 2003721

[0010] Non-patent literature :Fayan Meng et al., MXene Sorbents for Removal of Ureafrom Dialysate: A Step toward the Wearable Artificial Kidney, ACS Nano 2018,12, 10518-10528 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] As described in Non-Patent Document 3, research on the use of MXene in adsorption materials has been ongoing in recent years, but in the prior art, it is difficult to say that the adsorption performance is sufficient. In view of the above, the present invention is proposed to provide an adsorption material with excellent adsorption performance.

[0013] 1. Problem-solving methods

[0014] According to one aspect of the present invention, an adsorbent material is provided, comprising:

[0015] Particles comprising one or more layers of layered material; one or more metal atoms selected from the group consisting of Al, Mg, Ca, Ba, Fe, Zn, Mn, and Cu.

[0016] The layer comprises: M m X n The layer body (where M is at least one group 3, 4, 5, 6, or 7 metal, X is a carbon atom, a nitrogen atom, or a combination thereof, n is 1 or more and 4 or less, and m is greater than n and 5 or less); and the modification or terminal T present on the surface of the layer body (T is at least one selected from the group consisting of hydroxyl, fluorine, chlorine, oxygen, and hydrogen atoms).

[0017] The M of the layer is combined with at least one selected from the group consisting of chlorine atoms, phosphorus atoms, iodine atoms and sulfur atoms.

[0018] According to another aspect of the present invention, a method for manufacturing an adsorbent material is provided, comprising:

[0019] (a) Prepare from the following formula: M m AX n The precursor is represented by the formula (where M is at least one metal from Group 3, 4, 5, 6, or 7, X is a carbon atom, a nitrogen atom, or a combination thereof, A is at least one element from Group 12, 13, 14, 15, or 16, n is 1 or more and 4 or less, and m is greater than n and 5 or less).

[0020] (b) Perform an etching process using an etching solution containing one or more of HCl, H3PO4, HI and H2SO4 to remove at least a portion of the A atoms from the precursor;

[0021] (c) The etched product obtained by pickling the etching process described above;

[0022] (d) Wash the pickled product obtained by the pickling process with water and adjust the pH value of the pickled product;

[0023] (e) Performing a metal atom intercalation process, comprising a step of mixing the water-washed product obtained by the water washing with a compound containing one or more metal atoms selected from the group consisting of Al, Mg, Ca, Ba, Fe, Zn, Mn and Cu; and

[0024] (f) Wash the metal atom intercalation treated material obtained by the metal atom intercalation treatment with water to obtain the adsorbent material.

[0025] 2. Effects of the invention

[0026] According to the present invention, the adsorbent material is formed from a defined layered material (also referred to as "MXene" in this specification) containing one or more metal atoms selected from the group consisting of Al, Mg, Ca, Ba, Fe, Zn, Mn and Cu, wherein the M in MXene is combined with at least one selected from the group consisting of chlorine atoms, phosphorus atoms, iodine atoms and sulfur atoms, thereby providing an adsorbent material containing MXene with excellent adsorption performance.

[0027] Furthermore, according to the present invention, by (a) preparing a specified precursor; (b) performing an etching process using a specified etching solution to remove at least a portion of the A atoms from the precursor; (c) acid washing the etched product obtained by the etching process; (d) water washing the acid-washed product obtained by the acid washing process and adjusting the pH value of the acid-washed product; (e) performing a metal atom intercalation process, which includes a step of mixing the water-washed product obtained by the water washing process with a compound containing one or more metal atoms selected from the group consisting of Al, Mg, Ca, Ba, Fe, Zn, Mn and Cu; and (f) water washing the metal atom intercalation product obtained by the metal atom intercalation process, it is possible to manufacture an adsorbent material containing the aforementioned metal atoms, M in MXene, combined with at least one selected from the group consisting of chlorine atoms, phosphorus atoms, iodine atoms and sulfur atoms, for example, an adsorbent material with excellent adsorption performance of polar organic compounds. Attached Figure Description

[0028] Figure 1 This is a schematic cross-sectional view of MXene, a layered material that can be used as the adsorbent material of the present invention. (a) shows a single-layer MXene, and (b) shows a multi-layer (e.g., double-layer) MXene.

[0029] Figure 2 This is a diagram illustrating the interlayer distance in the adsorbent material of the present invention.

[0030] Figure 3 This is a schematic illustration of an artificial dialysis apparatus using the adsorbent material of the present invention.

[0031] Figure 4 This is a graph showing the X-ray diffraction measurement results in the embodiment. Detailed Implementation

[0032] (Implementation Method 1: Adsorbent Material)

[0033] The adsorption material of one embodiment of the present invention will be described in detail below, but the present invention is not limited to this embodiment.

[0034] The adsorbent material in this embodiment includes:

[0035] Particles comprising one or more layers of layered material; one or more metal atoms selected from the group consisting of Al, Mg, Ca, Ba, Fe, Zn, Mn, and Cu.

[0036] The layer comprises: M m X nThe layer body (where M is at least one group 3, 4, 5, 6, or 7 metal, X is a carbon atom, a nitrogen atom, or a combination thereof, n is 1 or more and 4 or less, and m is greater than n and 5 or less); and the modification or terminal T present on the surface of the layer body (T is at least one selected from the group consisting of hydroxyl, fluorine, chlorine, oxygen, and hydrogen atoms).

[0037] The M of the layer is combined with at least one selected from the group consisting of chlorine atoms, phosphorus atoms, iodine atoms and sulfur atoms.

[0038] The aforementioned layered material can be understood as a layered compound, or it can be represented as "M". m X n T s s is any number; previously, x or z were sometimes used instead of s. Typically, n can be 1, 2, 3, or 4, but is not limited to these.

[0039] In the above formula of MXene, M is preferably at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and Mn, and more preferably at least one selected from the group consisting of Ti, V, Cr and Mo.

[0040] In MXene, we know the above equation: M m X n The expression is as follows.

[0041] Sc2C, Ti2C, Ti2N, Zr2C, Zr2N, Hf2C, Hf2N, V2C, V2N, Nb2C, Ta2C, Cr2C, Cr2N, Mo2C, Mo 1.3 C, Cr 1.3 C, (Ti,V)2C, (Ti,Nb)2C, W2C, W 1.3 C, Mo2N, Nb 1.3 C, Mo 1.3 Y 0.6 C (In the above formula, "1.3" and "0.6" mean approximately 1.3 (=4 / 3) and approximately 0.6 (=2 / 3), respectively.)

[0042] Ti3C2, Ti3N2, Ti3 (CN), Zr3C2, (Ti, V) 3C2, (Ti2Nb) C2, (Ti2Ta) C2, (Ti2Mn) C2, Hf3C2, (Hf2V) C2, (Hf2Mn) C2, (V2Ti) C2, (Cr2Ti) C2, (Cr2V) C 2. (Cr2Nb)C2, (Cr2Ta)C2, (Mo2Sc)C2, (Mo2Ti)C2, (Mo2Zr)C2, (Mo2Hf)C2, (Mo2V)C2, (Mo2Nb)C2, (Mo2Ta)C2, (W2Ti)C2, (W2Zr)C2, (W2Hf)C2,

[0043] Ti4N3, V4C3, Nb4C3, Ta4C3, (Ti, Nb) 4C3, (Nb, Zr) 4C3, (Ti2Nb2) C3, (Ti2Ta2) C3, (V2Ti2) C3, (V2Nb2) C3, (V2Ta2) C3, (Nb2Ta2) C3, (Cr2Ti2) C3, (Cr2V 2) C3, (Cr2Nb2)C3, (Cr2Ta2)C3, (Mo2Ti2)C3, (Mo2Zr2)C3, (Mo2Hf2)C3, (Mo2V2)C3, (Mo2Nb2)C3, (Mo2Ta2)C3, (W2Ti2)C3, (W2Zr2)C3, (W2Hf2)C3, (Mo 2,7 V 1.3 C3 (In the above formula, "2.7" and "1.3" mean approximately 2.7 (=8 / 3) and approximately 1.3 (=4 / 3), respectively.)

[0044] Representatively, in the above formula, M is titanium or vanadium, and X can be a carbon atom or a nitrogen atom. For example, the MAX phase is Ti3AlC2, and MXene is Ti3C2T. s (In other words, M is Ti, X is C, n is 2, and m is 3).

[0045] Furthermore, in this invention, MXene may contain a relatively small amount of residual A atoms, for example, less than 10% by mass relative to the original A atoms. The residual amount of A atoms is preferably less than 8% by mass, more preferably less than 6% by mass. However, even if the residual amount of A atoms exceeds 10% by mass, there may be cases where this is not a problem, depending on the application and conditions of use of the adsorbent material.

[0046] The following uses Figure 1 The MXene particles, which are equivalent to the framework of the adsorbent material in this embodiment, will be described. Figure 1 The layer M, not shown, contains a specific metallic element and is combined with at least one element selected from the group consisting of chlorine, phosphorus, iodine and sulfur atoms.

[0047] The adsorbent material in this embodiment contains Figure 1 (a) schematically illustrates an assembly of a single layer of MXene10a (a monolayer of MXene). MXene10a, more specifically, is an assembly having M m X n The layer body (M) is represented m X n The MXene layer 7a comprises a layer 1a, and modifications or ends T3a, 5a present on the surface of the layer body 1a (more specifically, at least one of the two opposing surfaces of each layer). Therefore, the MXene layer 7a is also referred to as "M". m X n T s “s” is any number.

[0048] The adsorbent material in this embodiment may include one layer or multiple layers. For example, MXene (multilayer MXene) can be a multilayer material. Figure 1 (b) Schematic illustrations show that MXene10b with two layers can be listed, but are not limited to these examples. Figure 1 (b) 1b, 3b, 5b, and 7b are the same as those mentioned above. Figure 1 (a) 1a, 3a, 5a, and 7a are the same. Two adjacent MXene layers (e.g., 7a and 7b) of a multilayer MXene are not necessarily completely separated, but can be in partial contact. The MXene 10a can be a single layer formed by the separation of each of the aforementioned multilayer MXene 10b, or it can be a mixture of unseparated multilayer MXene 10b and the aforementioned single-layer MXene 10a and multilayer MXene 10b. The adsorbent material of this embodiment is preferably formed from particles of a layered material comprising multiple layers, i.e., multilayer MXene. By forming it from particles of a layered material comprising multiple layers, a large amount of the target substance can be adsorbed between the layers, thereby improving the adsorption performance.

[0049] While not limiting this embodiment, the thickness of each layer of MXene (corresponding to MXene layers 7a and 7b described above) is, for example, 0.8 nm or more and 5 nm or less, particularly 0.8 nm or more and 3 nm or less (mainly due to the number of M-atom layers contained in each layer). In each stack of multilayer MXenes, the interlayer spacing (or void size, Figure 1 (b) is represented by Δd, for example, 0.8 nm or more and 10 nm or less, especially 0.8 nm or more and 5 nm or less, and even more specifically about 1 nm, and the total number of layers can be 2 or more and 20,000 or less.

[0050] The adsorbent material of this embodiment contains one or more metal atoms selected from the group consisting of Al, Mg, Ca, Ba, Fe, Zn, Mn, and Cu. To distinguish this metal atom from the metal atoms constituting MXene, it is referred to as a "specific metal atom," and to distinguish MXene containing layered material particles and specific metal atoms from MXene without specific metal atoms, it is referred to as "MXene containing specific metal atoms."

[0051] The aforementioned specific metal atom may originate from an intercalating agent used for intercalation of the specific metal atom. Preferably, the specific metal atom exists through intercalation, and more preferably, it exists in the interlayer of MXene. The specific metal atom in MXene can be in the state of a metal ion, i.e., it exists as a divalent metal ion in the interlayer of MXene. The presence of the specific metal atom in the interlayer of MXene acts as a support structure for the wide interlayer, facilitating the insertion of the target substance into the MXene interlayer. As a result, a large amount of the target substance can be adsorbed, improving adsorption performance, which is therefore preferred. For example, when the target substance is urea, the adsorption characteristics of the adsorbent material for urea become high, making it an excellent material for artificial dialysis. Furthermore, when the target substance is a representative dye such as methylene blue, it can serve as an excellent adsorbent material for removing dyes from industrial water. In addition, specific metal atoms such as Mg or Ca exist in the interlayer of MXene, which widens the interlayer of MXene. As a result, impurities in the interlayer of MXene, such as acidic substances used in manufacturing, are easily removed during the manufacturing stage. This can suppress changes in the pH value of the solution caused by acidic substances in the adsorbent material when the obtained adsorbent material comes into contact with the solution.

[0052] In the manufacture of adsorbent materials, by intercalating the aforementioned specific metal atoms into the interlayer space of MXene, the interlayer distance is widened, making it more suitable for the size of the target adsorbate, thus improving adsorption performance. The aforementioned specific metal atoms are elements with a charge of 2 or higher and capable of forming water-soluble compounds.

[0053] The content of specific metal atoms (when there are two or more, it is considered as the total content) can be above 0.001% by mass and below 3.0% by mass.

[0054] The specific metal atom, considering biocompatibility, preferably contains one or more selected from the group consisting of Mg, Ca, Fe, Zn, and Mn. More preferably, the specific metal atom consists of one or more selected from the group consisting of Mg, Ca, Fe, Zn, and Mn. The aforementioned specific metal atom includes one or more of Mg and Ca, which is further preferred from the viewpoint of further improving biocompatibility. The aforementioned specific metal atom is particularly preferred to be Mg and / or Ca.

[0055] The total content of one or more of Mg and Ca in the specific metal atom is preferably 0.001% by mass or more and 1.5% by mass or less. From the viewpoint of further improving biocompatibility, it is preferable to have fewer specific metal atoms.

[0056] For example, as described later, in the case of an adsorbent material that does not contain Li but contains one or more of Mg and Ca as specific metal atoms, Mg and Ca exist as ions, resulting in higher biocompatibility, and is therefore preferred, and Mg 2+ and Ca 2+ Increasing the interlayer distance results in an interlayer distance suitable for the size of urea molecules, thus facilitating urea entry into the MXene interlayer, which is therefore preferred.

[0057] In the adsorbent material of this embodiment, the M of the layer is bonded to at least one selected from the group consisting of chlorine atoms, phosphorus atoms, iodine atoms, and sulfur atoms. The chlorine atoms, phosphorus atoms, iodine atoms, and sulfur atoms may be derived from HCl (hydrochloric acid), H3PO4 (phosphoric acid), HI (hydrogen iodide), and H2SO4 (sulfuric acid) contained in the etching solution used to etch the MAX phase, the precursor of MXene. In other words, the chlorine atoms in the adsorbent material of this embodiment are preferably Cl atoms bonded to the M of the layer. - The phosphorus atoms, preferably those bonded to M in the layer, constitute PO4. 3- The phosphorus atoms in the adsorbent material of this embodiment, and the iodine atoms therein, are preferably I atoms bonded to M in the layer. Furthermore, the sulfur atoms in the adsorbent material of this embodiment are preferably SO4 atoms bonded to M in the layer. 2- The sulfur atom.

[0058] (Li content of the adsorbent material)

[0059] The adsorbent material of this embodiment preferably has a Li content below the limit of quantitation, for example, a Li content of 0.0001% by mass or less (including 0% by mass). By suppressing the Li content of the adsorbent material within the above range, the adsorbent material of this embodiment can be used in applications requiring biocompatibility, such as separation membranes in artificial dialysis devices. The Li content can be measured, for example, by using inductively coupled plasma atomic emission spectrometry (ICP-AES).

[0060] (Interlayer distance of the adsorbent material)

[0061] In this embodiment, the adsorbent material, as described above, preferably widens the interlayer by inserting specific metal atoms into the interlayer of MXene. m X n When Ti3C2 is represented as Ti3C2O2 (O-term), the crystal structure is as follows: Figure 2 Schematic illustration ( Figure 2 In the diagram, 20 represents titanium atoms, 21 represents oxygen atoms, and other constituent atoms are not shown. This can be considered as such. Figure 2 The distance between layers, indicated by the two arrows, is widened. This distance can be determined by observing the position of a low-angle peak (below 10°) on the (002) plane of MXene in the XRD pattern obtained by X-ray diffraction measurement. The lower the peak angle in the XRD pattern, the wider the interlayer distance. In this embodiment, the adsorbent material preferably has a peak on the (002) plane below 8.0° obtained by X-ray diffraction measurement. More preferably, the peak is below 7.0°. Furthermore, the lower limit of the peak position is approximately 5.0°. The peak refers to the apex of the peak. The X-ray diffraction measurement can be performed under the conditions shown in the embodiments described later.

[0062] The adsorbent material of this embodiment has M m X n When MXene, represented by Ti3C2, and specific metal atoms are used, the interlayer distance obtained from the XRD results described above is, for example, 12.0 Å or more, preferably 12.5 Å or more, more preferably 13.0 Å or more, and the upper limit of the interlayer distance can be, for example, about 17.5 Å. Due to the widening of the interlayer distance, it is considered that the interlayer distance becomes an appropriate value relative to the size of the urea molecule, thus improving the adsorption performance. In particular, interlayer distances within the above range are suitable for urea toxins that need to be removed by artificial dialysis, and are especially suitable for urea adsorption. Therefore, the adsorbent material of this embodiment is suitable for the adsorption of urea.

[0063] (Adsorbent materials formed from composite materials)

[0064] As an adsorbent material in this embodiment, one or more materials selected from ceramics, metals, and resins may also be included. For example, as illustrated later, when the adsorbent material of this embodiment is used for urea adsorption in artificial dialysis, the MXene containing specific metal atoms of this embodiment, together with one or more materials selected from ceramics, metals, and resins, forms a composite material, which can achieve stable adsorption performance, such as the adsorption performance of urea.

[0065] Examples of ceramics mentioned above include metal oxides such as silicon dioxide, aluminum oxide, zirconium oxide, titanium dioxide, magnesium oxide, cerium oxide, zinc oxide, barium titanate, hexagonal ferrite, and mullite; and non-oxide ceramics such as silicon nitride, titanium nitride, aluminum nitride, silicon carbide, titanium carbide, tungsten carbide, boron carbide, and titanium boride. Examples of metals mentioned above include iron, titanium, magnesium, aluminum, and alloys based on them.

[0066] Furthermore, cellulose-based and synthetic polymer-based resin materials can be cited as examples. Examples of such polymers include hydrophilic polymers (including hydrophilic polymers that have been formulated with hydrophilic additives to exhibit hydrophilicity, and hydrophilic polymers whose surfaces have been treated to be hydrophilic). More preferably, hydrophilic polymers include one or more selected from the group consisting of polysulfone, cellulose acetate, regenerated cellulose, polyethersulfone, water-soluble polyurethane, polyvinyl alcohol, sodium alginate, acrylic water-soluble polymers, polyacrylamide, polyaniline sulfonic acid, and nylon.

[0067] The hydrophilic polymer is, for example, a hydrophilic polymer having polar groups, preferably groups that form hydrogen bonds with the modification of the layer or the terminal T. As such a polymer, it is preferred to use one or more polymers selected from the group consisting of water-soluble polyurethane, polyvinyl alcohol, sodium alginate, acrylic water-soluble polymers, polyacrylamide, polyaniline sulfonic acid, and nylon. More preferably, it is a polymer selected from the group consisting of water-soluble polyurethane, polyvinyl alcohol, and sodium alginate, and even more preferably, it is water-soluble polyurethane.

[0068] Furthermore, when the adsorbent material formed by the composite material is used for biological applications, the polymer constituting the composite material can be, for example, a polymer used in hemodialysis or hemofiltration. Specifically, examples include polymethyl methacrylate, polyacrylonitrile, cellulose, cellulose acetate, polysulfone, polyvinyl alcohol, or a copolymer of polyvinyl alcohol and ethylene, etc. Preferably, one or more of polysulfone, polymethyl methacrylate, and cellulose acetate are used. More preferably, polysulfone or polymethyl methacrylate is used.

[0069] The proportion of the polymer contained in the composite material can be appropriately set according to the application. For example, the proportion of the polymer, based on its proportion in the adsorbent material (when dry), is higher than 0% by volume, for example, it can be 80% by volume or less, further 50% by volume or less, further 30% by volume or less, further 10% by volume or less, and even further 5% by volume or less.

[0070] The method for manufacturing the adsorbent material formed from the composite material is not particularly limited. In this embodiment, when the adsorbent material contains a polymer and is a sheet-like adsorbent, for example, as illustrated below, MXene containing specific metal atoms can be mixed with the polymer to form a coating film.

[0071] First, the polymer is mixed with an MXene aqueous dispersion containing MXene atoms (which contains particles formed from MXene atoms containing specific metal atoms), an MXene organic solvent dispersion containing specific metal atoms, or an MXene powder containing specific metal atoms. Water is a representative example of the dispersion medium for the aforementioned MXene aqueous dispersion containing specific metal atoms. Depending on the circumstances, other liquid substances may be included in small amounts (e.g., 30% by mass or less, preferably 20% by mass, on a total basis).

[0072] The above-mentioned stirring of MXene particles containing specific metal atoms with polymers can be carried out using dispersion devices such as homogenizers, propeller mixers, thin-film gyratory mixers, planetary mixers, mechanical vibrators, and eddy current mixers.

[0073] The slurry containing the mixture of MXene particles with specific metal atoms and polymer is applied to a substrate (e.g., a substrate), and the application method is not limited. Examples include spraying using nozzles such as single-fluid nozzles, dual-fluid nozzles, and air brushes; slot coating using a benchtop coater, comma coater, or bar coater; screen printing; metal mask printing; and coating methods such as spin coating, dip coating, and drip coating.

[0074] The coating and drying process described above can be repeated multiple times as needed until a film of the desired thickness is obtained. Drying and curing can be carried out, for example, using an atmospheric pressure oven or a vacuum oven at a temperature below 400 degrees Celsius.

[0075] When the adsorbent material of this embodiment is a composite material including ceramics or metals, the following methods can be listed as manufacturing methods: mixing, for example, granular MXene containing specific metal atoms with, for example, granular ceramics or metals, and heating at a low temperature to maintain the composition of MXene containing specific metal atoms to form an adsorbent material.

[0076] (The shape of the adsorbent material)

[0077] The shape of the adsorbent material in this embodiment is not limited. In addition to the sheet-like shape of the film or the like, the shape of the adsorbent material can also be a cuboid, sphere, polygon, or the like with thickness.

[0078] (Adsorption tablets)

[0079] As a preferred embodiment of the adsorbent material in this embodiment, an adsorbent sheet can be cited. The adsorbent sheet, besides being formed from the adsorbent material of this embodiment (i.e., an adsorbent sheet containing the specific metal element MXene, or a composite material containing it), can also be formed by the adsorbent material of this embodiment on the surface of a substrate made of one or more materials selected from ceramics, metals, and resins. The ceramics, metals, and resins can be the materials listed in the description of the aforementioned composite materials. Preferably, the adsorbent sheet of the adsorbent material of this embodiment is formed on a substrate made of a resin material, preferably the aforementioned polymer. The adsorbent material of this embodiment on the substrate can be formed, for example, on one side of the substrate by coating, or on at least a portion of the substrate. As a method for forming the adsorbent material on the substrate, commonly used coating methods such as dipping, brushing, rolling, roller coating, air spraying, airless spraying, curtain coating, roller curtain coating, slot coating, and electrostatic coating can be used. The thickness of the adsorbent sheet and the thickness of the substrate can be appropriately set according to the application.

[0080] (Applications of adsorbent materials)

[0081] One application of the adsorbent material in this embodiment is for the adsorption of polar organic compounds. Polar organic compounds are a general term for organic compounds with polarity, referring to compounds having polar groups such as OH, NO2, NH, NH2, and COOH groups, which can form hydrogen bonds between hydrogen atoms in water molecules and these polar groups when mixed with water. Among these polar organic compounds, examples of adsorbable targets include polar solvents such as alcohols containing hydroxyl groups, compounds containing amino groups, and ammonia. The adsorbent material in this embodiment can be used to adsorb compounds containing one or more hydroxyl and amino groups, and ammonia. Examples of compounds containing one or more hydroxyl and amino groups include, for example, monohydric alcohols with 1 to 22 carbon atoms; polyphenols; polyhydric alcohols such as ethylene glycol, propylene glycol, and glycerol; alkanolamines such as triethanolamine; and sugars such as xylose and glucose. In addition, examples of compounds containing an amino group include monoamines such as methylamine and dimethylamine; diamines such as ethylenediamine; polyamines such as diethylenetriamine; aromatic amines such as aniline; amino acids such as valine and leucine; urea, uric acid, urate, and creatine. Examples of compounds containing both hydroxyl and amino groups include ethanolamine and diethanolamine.

[0082] The adsorbent material of this embodiment is preferably used for adsorbing uremic toxins containing urea, uric acid, creatinine, etc. The adsorbent material of this embodiment is particularly suitable for adsorbing urea.

[0083] The adsorbent material of this embodiment can be used to adsorb and remove waste products such as urea in hemodialysis, hemofiltration, hemodiafiltration, peritoneal dialysis, etc. Furthermore, the adsorbent material of this embodiment can be used in artificial dialysis equipment used for performing the aforementioned hemodialysis, hemofiltration, hemodiafiltration, peritoneal dialysis, etc.

[0084] As for the aforementioned artificial dialysis equipment, it can be classified into hemodialysis equipment and peritoneal dialysis equipment, and hemodialysis equipment is further divided into single-pass (single-cycle) and circulating types. In addition, circulating types include REDY systems (recirculating dialysate systems) and other systems. The aforementioned artificial dialysis equipment can also be classified according to the following methods: methods that remove urea by cross-flowing blood from the patient with dialysate without contacting the blood; and methods that directly filter the blood. Peritoneal dialysis equipment is predominantly single-pass. The adsorbent material of this embodiment can be used in both hemodialysis and peritoneal dialysis, and can be used as an adsorbent membrane, separation membrane, adsorbent material filter element, etc., in artificial dialysis equipment such as hemodialysis equipment and peritoneal dialysis equipment. For example, when used in a REDY system (recirculating dialysate system), the adsorbent material of this embodiment can be used as an adsorbent material filter element.

[0085] Figure 3 In this example, a single-pass hemodialysis device is schematically shown as an example of an artificial dialysis device using the adsorbent material of this embodiment. Figure 3 In the hemodialysis apparatus 40, untreated blood introduced through the blood inlet 41 is pumped to the blood purification apparatus 44 by the blood pump 43. Meanwhile, unused dialysate from the dialysate tank 48 is pumped to the blood purification apparatus 44 by the dialysate pump 50. In the blood purification apparatus 44, the blood in the blood purification apparatus passage zone 46 undergoes hemodialysis, hemofiltration, or hemofiltration via the separation membrane 45. Substances to be removed are transferred through the separation membrane 45 to the dialysate passage zone 47 of the blood purification apparatus. The purified blood is then sent to the blood outlet 42. Meanwhile, the dialysate containing the substances to be removed from the dialysate passage zone 47 is transported to the used dialysate tank 49. Figure 3Not illustrated, but during the delivery of blood before and / or after treatment, a device may be installed, as needed, to include a path for replenishing the blood with medications, proteins, etc. Additionally, sensors may be installed to measure blood flow rate, dialysate flow rate, and, as needed, the protein concentration in the blood. Furthermore, switching valves that can open and close the flow path may be installed along the blood and / or dialysate flow path, as needed.

[0086] The separation membrane using the adsorption material of this embodiment is suitable for use in artificial dialysis membranes such as those used in hemodialysis. As materials other than the adsorption material constituting the separation membrane, cellulose-based and synthetic polymer-based materials used in hemodialysis and the like are generally acceptable examples. Specifically, examples include polymethyl methacrylate, polyacrylonitrile, cellulose, cellulose acetate, polysulfone, polyvinyl alcohol, or vinyl alcohol copolymers such as copolymers of polyvinyl alcohol and ethylene. Polysulfone, polymethyl methacrylate, and cellulose acetate are preferred, and polysulfone and polymethyl methacrylate are more preferred. The shape of the separation membrane for artificial dialysis is not particularly limited; for example, porous, hollow fiber, and laminated sheet membrane types are acceptable.

[0087] The adsorbent material of this embodiment, as described above, is also suitable as an adsorbent material for adsorbing dyes. Examples of such dyes include methylene blue. The adsorbent material is suitable, for example, for removing methylene blue dye contained in industrial water. Examples of using the adsorbent material for adsorbing dyes include the aforementioned adsorbent sheet and a separation membrane using the adsorbent material. In the separation membrane used for dye adsorption, the constituent material other than the adsorbent material is not particularly limited and can be one or more materials selected from ceramics, metals, and resins. As these materials, ceramics, metals, and resins that can be used in the aforementioned composite materials can be used.

[0088] (Implementation Method 2: Method for Manufacturing Adsorbent Material)

[0089] Hereinafter, the method for manufacturing the adsorbent material according to the embodiments of the present invention will be described in detail, but the present invention is not limited to such embodiments.

[0090] The method for manufacturing the adsorbent material in this embodiment includes:

[0091] (a) Prepare from the following formula: M m AX n The precursor is represented by the formula (where M is at least one metal from Group 3, 4, 5, 6, or 7, X is a carbon atom, a nitrogen atom, or a combination thereof, A is at least one element from Group 12, 13, 14, 15, or 16, n is 1 or more and 4 or less, and m is greater than n and 5 or less).

[0092] (b) Perform an etching process using an etching solution containing one or more of HCl, H3PO4, HI and H2SO4 to remove at least a portion of the A atoms from the precursor;

[0093] (c) The etched product obtained by pickling the etching process described above;

[0094] (d) Wash the pickled product obtained by the pickling process with water and adjust the pH value of the pickled product;

[0095] (e) Performing a metal atom intercalation process, comprising a step of mixing a water-washed product obtained after the water washing process with a compound containing one or more metal atoms selected from the group consisting of Al, Mg, Ca, Ba, Fe, Zn, Mn, and Cu; and

[0096] (f) The metal atom intercalation product obtained by the aforementioned metal atom intercalation treatment is washed with water to obtain an adsorbent material. According to this manufacturing method, it is possible to manufacture an adsorbent material containing the aforementioned specific metal atom, wherein M in MXene is combined with at least one selected from the group consisting of chlorine atoms, phosphorus atoms, iodine atoms, and sulfur atoms, and exhibits excellent adsorption performance for example, polar organic compounds.

[0097] In the method for manufacturing the adsorbent material of this embodiment, particularly for the intercalation of specific metal atoms, as described above, an etching process is performed using an etching solution containing one or more of HCl, H3PO4, HI, and H2SO4, utilizing the large and three-dimensional (Cl) atoms on the surface. - PO4 3- , I and SO4 2- MXenes are obtained by acid washing before intercalation of specific metal atoms to remove impurities that hinder intercalation. Thus, MXenes with specific metal atoms contained in the interlayer and excellent adsorption performance can be easily obtained.

[0098] The following is a detailed description of each step in the above manufacturing method.

[0099] • Process (a)

[0100] First, a specified precursor is prepared. In this embodiment, the specified precursor used is the MAX phase, which serves as a precursor to MXene.

[0101] From the following formula: M m AX n (where M is at least one metal from Group 3, 4, 5, 6, or 7, X is a carbon atom, a nitrogen atom, or a combination thereof, A is at least one element from Group 12, 13, 14, 15, or 16, n is 1 or more and 4 or less, and m is greater than n and 5 or less).

[0102] The M, X, n, and m mentioned above are as described in MXene. A is at least one element from Group 12, 13, 14, 15, or 16, typically a Group A element, typically Group IIIA or IVA, and more specifically, may include at least one element selected from the group consisting of Al, Ga, In, Tl, Si, Ge, Sn, Pb, P, As, S, and Cd, preferably Al.

[0103] The MAX phase, with layers composed of A atoms located at M... m X n The MAX phase represents a crystal structure between two layers (each X can have a lattice located within an octahedral array of M). A representative example of the MAX phase, in the case of m = n + 1, is a repeating unit where layers of X atoms are arranged one layer at a time between each of the n + 1 layers of M atoms (these layers are collectively referred to as "M"). m X n A layer of A atoms ("layer of A atoms") is configured as the layer below the (n+1)th M atom layer, but is not limited to this.

[0104] The aforementioned MAX phase can be manufactured using known methods. For example, TiC powder, Ti powder, and Al powder are mixed in a ball mill, and the resulting mixed powder is sintered in an Ar atmosphere to obtain a sintered body (bulk MAX phase). Subsequently, the sintered body is pulverized with an end mill to obtain a powdered MAX phase for the next process.

[0105] • Process (b)

[0106] An etching process is performed, i.e., using an etching solution containing one or more of HCl, H3PO4, HI, and H2SO4, to remove at least a portion of the A atoms from the precursor. In the manufacturing method of this embodiment, the aim is to facilitate the intercalation of specific metal atoms in the later step (e), in order to obtain an MXene surface with a large and three-dimensional (Cl... - PO4 3- , I and SO4 2- MXene is etched using an etchant containing one or more of the above-mentioned HCl, H3PO4, HI, and H2SO4. Other etching conditions are not particularly limited and known conditions can be used. As mentioned above, etching can also be performed using an etchant containing F... -The etching solution is applied, for example, in a method using an etching solution that also contains hydrochloric acid in hydrofluoric acid. In these methods, a mixture of hydrofluoric acid and pure water can be used as a solvent. The etched product obtained by the above etching process can be, for example, a slurry. As the etching solution, at least one etchant selected from the group consisting of HCl concentration of 6.0 M or higher, H3PO4 concentration of 5.5 M or higher, HI concentration of 5.0 M or higher, and H2SO4 concentration of 5.0 M or higher can be used. In the etching of the A atom, depending on the situation, a portion of the M atom is also selectively etched along with the A atom.

[0107] After the above etching, it is appropriate to wash with water. For example, water addition and stirring, centrifugation, etc. can be performed. As stirring methods, manual shaker, automatic shaker, shear mixer, can mill, etc. can be used. The stirring speed, stirring time, and other stirring degree can be adjusted according to the amount or concentration of the material to be processed. The water washing is performed once or more. It is preferable to wash with water multiple times. For example, specifically, the following steps (i) to (iii) can be performed in the range of 2 or more, for example, 10 or less: (i) adding water and stirring (in the etched material or the remaining precipitate obtained in (iii) below); (ii) centrifuging the stirred material; (iii) discarding the supernatant after centrifugation.

[0108] • Process (c)

[0109] The etched product obtained by acid etching.

[0110] The acid used for the above pickling is not limited; for example, inorganic acids such as mineral acids and / or organic acids can be used. The acid is preferably an inorganic acid only, or a mixture of inorganic and organic acids. The acid is more preferably an inorganic acid only. As the inorganic acid, one or more of the following can be used: hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, hydroiodic acid, hydrobromic acid, hydrofluoric acid, etc. One or more of hydrochloric acid and sulfuric acid are preferred. As the organic acid, examples include acetic acid, citric acid, oxalic acid, benzoic acid, sorbic acid, etc. The concentration of the acid solution mixed with the etched material can be adjusted according to the amount or concentration of the etched material being processed.

[0111] In the above-mentioned pickling process, the etchant and the acid solution are mixed, for example by stirring. Stirring methods include using a manual shaker, an automatic shaker, a shear mixer, or a grinding mill. The stirring speed, stirring time, and other degrees of stirring can be adjusted according to the amount or concentration of the etchant being processed.

[0112] Whether or not heating is used when mixing the above acid solution is irrelevant. The acid solution can be mixed without heating and stirring, or it can be heated and stirred simultaneously within a liquid temperature range below 80°C.

[0113] Process (d)

[0114] The acid-treated product obtained after the acid pickling is washed with water to adjust its pH value. This washing can be performed using the same method as the washing after etching described above. The pH value after acid pickling is adjusted by performing this washing. For example, the pH value of the acidic region can be set to a range of 5 or higher and 8 or lower. In the aforementioned Patent Document 1, the MgF2 and CaF2 used during etching would remain as insoluble compounds after pH adjustment via washing, which is therefore not preferred.

[0115] • Process (e)

[0116] The process involves a specific metal atom intercalation treatment, which includes a step of mixing the water-washed product obtained from the aforementioned water washing with a compound containing one or more specific metal atoms selected from the group consisting of Al, Mg, Ca, Ba, Fe, Zn, Mn, and Cu. As mentioned above, the specific metal atoms are larger than Na, K, etc., and thus have improved adsorption properties due to their interlayer broadening effect.

[0117] As compounds containing the specific metal atoms, ionic compounds in which the specific metal ion is combined with the cation can be used. Examples include iodides, phosphates, sulfate-containing sulfide salts, nitrates, acetates, and carboxylates of the specific metal ion. Compounds with low solubility, such as MgF2 and CaF2 mentioned above, are not included.

[0118] The content of the compound containing the specific metal atom in the intercalation treatment complex is preferably 0.001% by mass or more. More preferably, it is 0.01% by mass or more, and even more preferably 0.1% by mass or more. On the other hand, from the viewpoint of dispersibility in solution, it is preferable that the content of the compound containing the specific metal atom is 10% by mass or less, and more preferably 1% by mass or less.

[0119] The specific method of intercalation is not particularly limited. For example, for the above-mentioned MXene-based aqueous medium clay, a compound containing the aforementioned specific metal atoms can be mixed and stirred or allowed to stand. Stirring at room temperature is an example. The stirring methods mentioned above include, for example, using a stirring rod such as a stirrer, using stirring blades, using a mixer, and using a centrifuge. The stirring time can be set according to the manufacturing scale of the adsorbent material, for example, between 12 and 24 hours.

[0120] • Process (f)

[0121] The specific metal atom intercalation product obtained by washing with water is a specific metal atom intercalation product to obtain an adsorbent material. This washing can be performed by the same method as the washing after etching described above. For example, centrifuging the slurry-like specific metal atom intercalation product, discarding the supernatant, washing the remaining precipitate with water, and repeating the above process can yield, for example, clay-like MXene with specific metal atom intercalation.

[0122] According to the manufacturing method of this embodiment, during the intercalation treatment of the specific metal atoms and the water washing of the above-mentioned step (f), the protons from the acidic substances used in the etching and pickling that remain in the interlayer are discharged to the outside of the layer and removed. Therefore, the adsorbent material obtained therefrom will not cause the pH value of the solution to decrease when it is immersed in the solution, and has excellent pH stability.

[0123] The adsorbent materials, their manufacturing methods, adsorbent sheets, separation membranes, and artificial dialysis devices according to embodiments of the present invention have been described in detail above, but various modifications can be made. Furthermore, the adsorbent materials of the present invention can also be manufactured by methods different from those described in the embodiments above. It should also be noted that the manufacturing method of the adsorbent materials of the present invention is not limited to providing the adsorbent materials of the embodiments described above.

[0124] Example

[0125] [Preparation of MXene adsorbent materials]

[0126] In this embodiment, the following detailed steps are performed in sequence: (1) preparation of the precursor (MAX), (2) etching of the precursor, (3) water washing after etching, (4) acid washing (to remove Al residues from MAX), (5) water washing after acid washing, (6) intercalation of specific metal atoms, (7) cleaning after intercalation, and (8) freeze drying to produce an adsorbent material formed from MXene containing specific metal atoms.

[0127] (1) Preparation of precursor (MAX)

[0128] TiC powder, Ti powder, and Al powder (all manufactured by High Purity Chemical Research Institute, Ltd.) were mixed in a molar ratio of 2:1:1 in a ball mill containing zirconia balls for 24 hours. The resulting mixed powder was calcined at 1350°C for 2 hours under an Ar atmosphere. The resulting calcined body (block MAX) was then pulverized with an end mill to a maximum size of less than 40 μm. Thus, Ti3AlC2 particles were obtained as a precursor (powdered MAX).

[0129] (2) Etching of the precursor

[0130] Using Ti3AlC2 particles (powder) prepared by the above method, etching was performed under the following etching conditions to obtain a solid-liquid mixture (slurry) containing solid components derived from the Ti3AlC2 powder. In this embodiment, it is assumed that the chlorine atoms originate from the hydrochloric acid (HCl) contained in the etching solution used in the etching process, which combines with the M layer of the MXene.

[0131] (Etching conditions)

[0132] • Precursor: Ti3AlC2 (passed through a sieve with a mesh size of 45μm)

[0133] • Etching solution composition: 49% HF 6mL

[0134] 18mL H2O

[0135] HCl (12M) 36mL

[0136] • Precursor dosage: 3.0g

[0137] • Etched container: 100mL bottle

[0138] • Etching temperature: 35℃

[0139] Etching time: 24 hours

[0140] • Mixer speed: 400 rpm

[0141] (3) Water washing after etching

[0142] Divide the above slurry into three equal parts and insert each part into a 50 mL centrifuge tube. Centrifuge at 3500 G and discard the supernatant. Add 40 mL of pure water to the remaining precipitate in each centrifuge tube and centrifuge again at 3500 G to remove the supernatant. Repeat the above operation 11 times to obtain the slurry as the washing material.

[0143] (4) Pickling (to remove Al residue from MAX)

[0144] After adding 40 mL of 1M hydrochloric acid to the above slurry, stir with a shaker for 5 minutes, then centrifuge at 3500G and discard the supernatant.

[0145] (5) Water washing after pickling

[0146] To the remaining precipitate in each centrifuge tube, (i) 40 mL of pure water was added, (ii) the mixture was centrifuged at 3500 G, and (iii) the supernatant was removed. This process (i) through (iii) was repeated a total of 5 times. After final centrifugation, the supernatant was discarded, yielding Ti3C2T. s - Moisture-rich clay medium.

[0147] (6) Intercalation of specific metal atoms (Mg, Ca, or Al)

[0148] For Ti3C2T prepared by the above method s - For water-medium clay, intercalation of specific metal atoms (Mg, Ca, or Al) is performed using the intercalating agents shown in Table 1. Detailed intercalation conditions are as follows. Furthermore, the stirring time is 18 hours under the following conditions, but the stirring time can be set according to the manufacturing scale of the MXene adsorbent, for example, between 12 and 24 hours.

[0149] (Conditions for Mg, Ca, or Al intercalation)

[0150] ·Ti3C2T s - Moisture-modified clay (MXene after washing): Solid content 1.0g

[0151] • MgCl2: 2.34g (Example 1), or CaCl2: 3.16g (Example 2), or AlCl3: 3.15g (Example 3)

[0152] • Pure water: 20mL

[0153] • Intercalation container: 100mL bottle

[0154] • (Stirring) Temperature: Above 20℃ and below 25℃ (room temperature)

[0155] • (Stirring) Time: 18 hours

[0156] • Mixer speed: 800 rpm

[0157] (7) Water washing after intercalation of Mg, Ca, or Al

[0158] The slurries obtained by intercalation with Mg, Ca, or Al were transferred to centrifuge tubes. (i) 40 mL of pure water was added, (ii) centrifugation was performed at 3500 G, and (iii) the supernatant was removed. This process (i) to (iii) was repeated five times to remove excess Mg, Ca, or Al, yielding MXene clays intercalated with Ma, Ca, or Al. The filter membranes (MXene films) used for XRD measurements described later were obtained by suction filtration of the MXene clays. The MXene films were prepared by vacuum drying at 80°C for 24 hours after filtration. A membrane filter (Merck, Durapore, 0.45 μm pore size) was used for the suction filtration.

[0159] (8) Drying

[0160] The MXene clays were frozen at -40°C for 5 hours, and then dried in a freeze dryer for 24 hours to obtain the MXene dried powders of Examples 1, 2, and 3. These dried powders were used as MXene adsorbents.

[0161] As comparative examples, the following were also prepared: the adsorbent material of Comparative Example 1, which was manufactured in the same manner as described above except for the use of Na; the adsorbent material of Comparative Example 2, which was manufactured in the same manner as described above except for the use of K; and the adsorbent material of Comparative Example 3, which was manufactured by the method described in Non-Patent Document 1, i.e., without the use of hydrochloric acid in etching and without intercalation.

[0162] [Evaluation of MXene Adsorbent Materials]

[0163] [Evaluation of inter-floor distance]

[0164] The interlayer distance of MXene constituting the adsorbent material was measured. More specifically, XRD measurements of the adsorbent materials of Examples 1-3 and Comparative Examples 1 and 2 were performed under the following conditions to obtain two-dimensional X-ray diffraction images of the MXene films. The results of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in... Figure 4 middle.

[0165] (XRD measurement conditions)

[0166] ·Using device: MiniFlex600 manufactured by Rigaku Co., Ltd.

[0167] ·condition

[0168] Light source: Cu tube bulb

[0169] Characteristic X-rays: CuKα = 1.54 Å

[0170] Measurement range: 3 degrees - 20 degrees

[0171] Steps: 50 steps / degree

[0172] The interlayer distance was calculated based on the XRD measurement results above. The results were 13.5 Å for Example 1, 14.9 Å for Example 2, and 13.0 Å for Example 3. The distance for Comparative Example 1 was 11.8 Å, and the distance for Comparative Example 2 was also 11.8 Å.

[0173] according to Figure 4 Based on the above calculation results of interlayer distance, in Examples 1-3, because Mg, Ca, and Al were intercalated respectively, the peak of the (002) plane was located on the low-angle side, and the interlayer distance was broadened. In contrast, Comparative Examples 1 and 2 were intercalated with Na and K respectively, but because these atoms are smaller than Mg and Ca, the interlayer distance was not sufficiently broadened.

[0174] [Measurement of the content of specific metal atoms (Mg, Ca, Al) in MXene]

[0175] MXene was soluble using an alkaline fusion method, and the Mg content in the MXene of Example 1, the Ca content in the MXene of Example 2, and the Al content in the MXene of Example 3 (all equivalent to the intercalator residue) were measured using ICP-AES (using an iCAP7400 manufactured by Thermo Fisher Scientific). The results showed that in Example 1, the Mg content was 0.78% by mass; in Example 2, the Ca content was 1.37% by mass; and in Example 3, the Al content was 0.58% by weight. In any other example, it was also confirmed that the Li content was below the limit of quantitation, i.e., below 0.0001% by mass.

[0176] [Evaluation of the quantity of acidic substances in the interlayer]

[0177] The pH value of the adsorbent material was measured when it was immersed in pure water to evaluate whether acidic substances inserted between the layers during the manufacturing process would flow out. The results showed that in Comparative Example 3 without an intercalating agent, the pure pH value of the adsorbent material was 3.59, compared to 5.34 for Example 1 (intercalating agent: Mg) and 5.15 for Example 2 (intercalating agent: Ca). Additionally, the pH value of Example 3 (intercalating agent: Al) was 5.12. Based on these results, it can be concluded that in Comparative Example 3 without an intercalating agent, acidic substances inserted between the layers during the manufacturing process of the adsorbent material flowed out after the adsorbent material was manufactured, exhibiting strong acidity. In contrast, in Examples 1-3, the interlayer of the adsorbent material was wider, thus the acidic substances used in the manufacturing process were easily removed during manufacturing. As a result, the decrease in pH value when the adsorbent material was immersed in pure water could be suppressed.

[0178] [Evaluation of Adsorption Performance]

[0179] Using the adsorption materials of Examples 1-3 and Comparative Examples 1-3 described above, the adsorption amount of the target substance (urea) was measured in the following manner, and the adsorption performance of the adsorption materials was evaluated.

[0180] (1) Preparation of urea solution

[0181] Weigh 0.5g of urea and add it to 100mL of pure water. Dilute it 100 times to adjust the concentration of urea solution to 5mg / dL.

[0182] (2) Preparation of the test kit solution

[0183] Using the biological detection kit (product name: DIUR-100) manufactured by Funakoshi Co., Ltd., the detection kit solution was prepared by mixing solution A and solution B of the kit in equal volumes.

[0184] (3) Preparation of solution containing adsorbed substance (urea solution)

[0185] Add 250 mL of the urea solution prepared according to step (1) above to a 500 mL beaker. Heat and stir with a hot stirrer at 400 rpm and 37 °C to prepare a solution containing urea as the adsorbent. Prepare 6 of these urea solutions for each example.

[0186] (4) Urea adsorption and sample sampling

[0187] 0.1 g of the adsorbent material from Examples 1-3 and Comparative Examples 1-3 were respectively added to the urea solution prepared in step (3) and stirred with a hot stirrer for 30 minutes. Subsequently, the solutions after standing were extracted with a 10 mL dropper, and the floating adsorbent material was separated by centrifugation at 20000 rpm for 10 minutes, and 250 μL of supernatant was taken as a sample.

[0188] (5) Dropping the test kit solution

[0189] Add 1250 μL of the detection kit solution prepared in step (2) to the supernatant and let it stand for 50 minutes.

[0190] (6) Absorbance measurement

[0191] First, to set the calibration curve, prepare a urea solution without adsorbent material and a urea solution diluted 2 times without adsorbent material. Then, measure the absorbance of each solution to set the calibration curve. Next, measure the absorbance of the sample prepared according to step (5), compare the absorbance of each sample with the calibration curve, and determine the concentration of unadsorbed residual urea in the solution. Based on this urea concentration, calculate the amount of urea adsorbed (the amount of urea per 1g of adsorbent material (mg)). The results are shown in Table 1.

[0192] Table 1

[0193]

[0194] Based on the above results, it can be concluded that when Na and K are used, the interlayer distance is small, and Na and K exist at molecular adsorption sites, thus hindering adsorption. Therefore, the adsorption performance is lower than that of Comparative Example 3 without intercalating agents. In contrast, Examples 1, 2, and 3, which use Mg, Ca, and Al as intercalating agents respectively, can obtain MXene structures with interlayer distances suitable for the size of urea molecules, and therefore can exhibit high adsorption performance for urea.

[0195] Examples 1, 2, and 3 above are respectively Mg 2+ Ca 2+ Al 3＋ The adsorbent is inserted between MXene layers, but Li is not used in the manufacturing process, therefore it is Li-free. While it is difficult to sufficiently reduce the Li content in the techniques of Non-Patent Document 1 and Non-Patent Document 2, the adsorbent according to this embodiment can also meet applications requiring significant Li reduction. Furthermore, as in Patent Document 1, when MgF2 and CaF2 are used during etching, these compounds have low solubility and can remain as impurities in the material. Therefore, for example, if the residue of these compounds is not permissible, further improvement is considered, but the adsorbent according to this embodiment also does not contain poorly soluble impurities such as MgF2 and CaF2. Therefore, it exhibits excellent biocompatibility, especially when using Mg or Ca as an intercalating agent. Furthermore, as mentioned above, the adsorbents of Examples 1-3 do not contain much acidic substance used in manufacturing, thus suppressing the decrease in pH value of the solution when the adsorbent is immersed in the solution, and exhibiting excellent pH stability.

[0196] [Evaluation of the adsorption performance of the dye (methylene blue)]

[0197] Using the MXenes of Examples 1-3 and Comparative Examples 1-3 as examples of dyes, and with methylene blue as the adsorption target, adsorption evaluation was performed.

[0198] (1) Preparation of methylene blue solution

[0199] Weigh 0.1g of methylene blue and add it to 2L of pure water to prepare a urea solution with a concentration of 5mg / L.

[0200] (2) Preparation of solution containing adsorbent (urea solution)

[0201] Add 250 mL of the methylene blue solution prepared in step (7) above to a 500 mL beaker. Use a stirrer to heat and stir at 400 rpm and 20 °C to prepare a solution containing methylene blue as the adsorbent. Prepare 6 of these urea solutions for each example.

[0202] (3) Urea adsorption and sample sampling

[0203] 0.01 g of the adsorbent material from Examples 1-3 and Comparative Examples 1-3 were respectively added to the methylene blue solution prepared in step (8) and stirred for 30 minutes. Subsequently, the solutions after standing were extracted with a 10 mL dropper, and the floating adsorbent material was separated by sedimentation using a centrifuge at 3500 G for 5 minutes, and 1000 μL of the supernatant was taken as a sample.

[0204] (4) Absorbance measurement

[0205] First, to establish the calibration curve, a methylene blue solution without adsorbent material and a solution of methylene blue solution without adsorbent material diluted 2 times were prepared. Then, the absorbance of each solution was measured to generate the calibration curve. Next, the absorbance of the sample prepared according to step (9) was measured, and the absorbance of each sample was compared with the calibration curve to determine the concentration of unadsorbed methylene blue remaining in the solution. Based on this concentration of methylene blue, the amount of methylene blue adsorbed (methylene blue amount per 1g of adsorbent material (mg)) was calculated. The results are shown in Table 2.

[0206] Table 2

[0207]

[0208] Based on the above results, when using Na and K, the interlayer distance is small, and Na and K exist at molecular adsorption sites, thus hindering adsorption. Therefore, the adsorption performance can be considered lower than that of Comparative Example 3 with intercalating agent but without intercalating agent. In contrast, Examples 1, 2, and 3, which used Mg, Ca, and Al as intercalating agents respectively, yielded MXene structures with interlayer distances suitable for the size of methylene blue molecules, and thus can exhibit high adsorption performance.

[0209] This application is accompanied by a priority claim based on Japanese Patent Application Nos. 2021-003541 and 2021-028821, which are incorporated herein by reference.

[0210] Industrial availability

[0211] The adsorbent material of the present invention can be used for any suitable purpose, such as preferably as a separation membrane in an artificial dialysis device.

[0212] Symbol Explanation

[0213] Main body of layers 1a and 1b (M) m X n layer)

[0214] 3a, 5a, 3b, 5b Modifications or terminal T

[0215] 7a, 7b MXene layers

[0216] 10a and 10b MXene particles (particles in layered materials)

[0217] 20 titanium atoms

[0218] 21 oxygen atoms

[0219] 40 hemodialysis devices

[0220] 41 Blood inlet

[0221] 42 Blood discharge port

[0222] 43 Blood Pumps

[0223] 44 Blood purification equipment

[0224] 45 Separation Membrane

[0225] 46 Blood purification equipment blood passes through the area

[0226] 47. Dialysis fluid from the blood purification equipment passes through the area.

[0227] 48. Unused dialysis tanks

[0228] 49. Used dialysis fluid tank

[0229] 50 Dialysis fluid pump

Claims

1. An adsorbent material comprising: particles of layered material including one or more layers; and one or more metal atoms selected from the group consisting of Al, Mg, and Ca as intercalating agents. The layer includes: from the formula: M m X n layer body represented by the formula, In the formula, M is at least one metal from Groups 3, 4, 5, 6, or 7. X is a carbon atom, a nitrogen atom, or a combination of carbon and nitrogen atoms. n is 1 or more and 4 or less m is greater than n and less than 5; Modifications or end-point Ts present on the surface of the main body of this layer. T is selected from at least one of the group consisting of hydroxyl, fluorine, chlorine, oxygen and hydrogen atoms. The M of the layer is combined with at least one selected from the group consisting of chlorine atoms, phosphorus atoms, iodine atoms, and sulfur atoms. The Li content is less than 0.0001% by mass and includes 0% by mass.

2. The adsorbent material of claim 1, wherein, It is formed by particles of layered material comprising multiple layers.

3. The adsorbent material of claim 1 or 2, wherein, The M of the layer and from Cl - PO4 3- I - and SO4 2- At least one of the selected groups is combined.

4. The adsorbent material of claim 1 or 2, wherein, The metal atoms include one or more of Mg and Ca.

5. The adsorbent material of claim 1 or 2, wherein, The total content of one or more of Mg and Ca in the metal atoms is more than 0.001% by mass and less than 1.5% by mass.

6. The adsorbent material of claim 1 or 2, wherein, It has a sheet-like shape.

7. Use of the adsorbent material according to any one of claims 1 to 6 for adsorbing polar organic compounds.

8. Use of the adsorbent material according to any one of claims 1 to 6 for adsorbing compounds having one or more of hydroxyl and amino groups, and ammonia.

9. Use of the adsorbent material according to any one of claims 1 to 6 for adsorbing uremic toxins.

10. Use of the adsorbent material according to any one of claims 1 to 6 for adsorbing urea.

11. Use of the adsorbent material according to any one of claims 1 to 6 for adsorbing dyes.

12. Use according to claim 11, wherein, The dye is methylene blue.

13. An adsorption sheet that uses the adsorption material according to any one of claims 1 to 6.

14. A separation membrane that uses the adsorption material according to any one of claims 1 to 6.

15. An artificial dialysis device that uses the adsorbent material according to any one of claims 1 to 6.

16. A method for producing the adsorbent material as claimed in any one of claims 1 to 6, wherein include: (a) preparing a precursor represented by the following formula: M m AX n ​ In the formula, M is at least one metal from Groups 3, 4, 5, 6, or 7. X is a carbon atom, a nitrogen atom, or a combination of carbon and nitrogen atoms. A is at least one element from groups 12, 13, 14, 15, or 16. n is 1 or more and 4 or less m is greater than n and less than 5; (b) Perform an etching process using an etching solution containing one or more of HCl, H3PO4, HI and H2SO4 to remove at least a portion of the A atoms from the precursor; (c) The etched product obtained by pickling the etching process described above; (d) Wash the pickled product obtained by the pickling process with water and adjust the pH value of the pickled product; (e) Performing a metal atom intercalation process, which includes a step of mixing the water-washed product obtained by the water washing with a compound containing one or more metal atoms selected from the group consisting of Al, Mg and Ca. and (f) Wash the metal atom intercalation treated material obtained by the metal atom intercalation treatment with water to obtain the adsorbent material according to any one of claims 1 to 6.

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