Porous glass material, method for manufacturing porous glass material precursor, method for manufacturing porous glass material, porous structure, substance capturing filter, and method for capturing substance

Abstract

To provide a porous glass material and a porous structure having preferable processing capacity and property exerting capacity, a substance capturing filter using the same and a method for capturing a substance, a method for manufacturing the porous glass material, and a method for manufacturing a porous glass material precursor for acquiring the porous glass material.SOLUTION: Disclosed are: a porous glass material and a porous structure having different pore sizes; a substance capturing filter using the same and a method for capturing a substance; a method for manufacturing the porous glass material; and a method for manufacturing a porous glass material precursor for acquiring the porous glass material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a porous glass material, a method for manufacturing a porous glass material precursor, a method for manufacturing a porous glass material, a porous structure, a substance capture filter, and a substance capture method. [Background technology]

[0002] Porous materials, which allow solutions, suspensions, and gases to pass through and allow reactions and separations to occur using the pores, are widely used in applications such as filters, column packings, adsorbents, catalyst supports, emulsification membranes, and microporous bubbling nozzles. For example, Patent Document 1 describes a filter for capturing minute substances made of a porous glass substrate. Patent Document 2 describes a porous filter substrate containing an inorganic material and having a compound with specific groups attached to its surface. Patent Document 3 describes a porous body having a hydridosilica skeleton produced by a sol-gel process. Patent Document 4 describes a method for producing bimodal glass having macropores and mesopores, which involves pseudomorphic transformation of macroporous glass. Patent Document 5 describes a method for producing a monolithic porous body having a three-stage hierarchical porous structure by a sol-gel process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2016 / 136978 [Patent Document 2] International Publication No. 2023 / 113031 [Patent Document 3] International Publication No. 2014 / 083729 [Patent Document 4] Japanese Patent Application Laid-Open No. 2016-505485 [Patent Document 5] Japanese Patent Application Laid-Open No. 2012-111655 Summary of the Invention [Problem to be solved by the invention]

[0004] When a solution or suspension is passed through a porous material, substances in the solution or suspension are trapped in the pores, gradually making it difficult for the solution or suspension to pass through or causing clogging. Therefore, it is desirable for the porous material to have low pressure loss when passing a solution or suspension, i.e., high processing capacity. In addition, it is also desirable for the porous material to be able to fully exhibit desired properties such as capture, separation, reaction, and emulsification. However, there is generally a trade-off between processing capacity and property-exhibiting ability, and it is difficult to improve both. In light of this situation, one embodiment of the present disclosure relates to a porous glass material having good processing capacity and property-exhibiting ability, a substance-trapping filter and substance-trapping method using the same, a method for manufacturing the porous glass material, and a method for manufacturing a porous glass material precursor for obtaining the porous glass material.

[0005] In addition, there are cases where the porous material is desired to have excellent strength so as to be able to withstand the load of, for example, a solution or suspension that is passed through it. In view of such circumstances, a further embodiment of the present disclosure relates to a porous structure that has good processing ability and the ability to exhibit characteristics and is excellent in strength, as well as a substance capture filter and a substance capture method using the same. [Means for solving the problem]

[0006] Means for solving the above problems include the following aspects. <1> A porous glass material in which two or more types of porous glass particles having different pore sizes are bonded together, wherein two or more of the two or more types of porous glass particles contain pores having a structure derived from phase separation due to spinodal decomposition. <2> Two or more peaks are observed in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, and at least two of the two or more peaks have a peak half-width X and a peak pore diameter Y that satisfy the relationship X / Y<2.0. <1> The porous glass material according to claim 1. <3> the two or more types of porous glass particles are n types of porous glass particles, where n is an integer of 2 or more, and when the n types of porous glass particles are counted in order of pore diameter, the 1st to n / 2nd porous glass particles are defined as porous glass particles L when n is an even number, and the 1st to (n+1) / 2nd porous glass particles are defined as porous glass particles L when n is an odd number, the minor axis of at least one type of porous glass particles L is larger than the pore diameter; <1> or <2> The porous glass material according to claim 1. <4> The two or more types of porous glass particles are n types of porous glass particles, where n represents an integer of 2 or more, and among the n types of porous glass particles, the 1st to n / 2nd porous glass particles when n is an even number, or the 1st to (n+1) / 2nd porous glass particles when n is an odd number, counted in order of increasing pore diameter, are designated as porous glass particles L, and the 1st to n / 2nd porous glass particles when n is an even number, or the 1st to (n+1) / 2nd porous glass particles when n is an odd number, counted in order of decreasing pore diameter, are designated as porous glass particles S, wherein the minor axis of any of the porous glass particles S is 2 to 500 times the pore diameter of any of the porous glass particles L. <1> ~ <3> The porous glass material according to any one of the above. <5> In a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, 2 to 20 peaks are observed. <1> ~ <4> The porous glass material according to any one of the above. <6> In a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, two or more peaks are observed within the pore diameter range of 0.005 to 100 μm. <1> ~ <5> The porous glass material according to any one of the above. <7> Two or more peaks are observed in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, and in any two of the two or more peaks, the ratio of the peak pore diameter on the larger pore diameter side to the peak pore diameter on the smaller pore diameter side is 1.5 or more. <1> ~ <6> The porous glass material according to any one of the above. <8> The peak particle diameters of the two or more types of porous glass particles are each 0.04 to 200 μm. <1> ~ <7> The porous glass material according to any one of the above. <9> the volume fraction of the porous glass particles having the smallest volume fraction among the two or more types of porous glass particles is 5% by volume or more relative to the total volume fraction of the two or more types of porous glass particles; <1> ~ <8> The porous glass material according to any one of the above. <10> In a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, one or more peaks are observed in the pore diameter range of 0.01 to 0.5 μm and in the pore diameter range of more than 0.5 μm and not more than 20 μm. <1> ~ <9> The porous glass material according to any one of the above. <11> The porous glass material comprises SiO2 and Al2O3. <1> ~ <10> The porous glass material according to any one of the above. <12> two or more types of phase-separated glass particles are obtained by microparticulating two or more types of phase-separated glass materials having different structural scales of phase separation due to spinodal decomposition; mixing the two or more types of phase-separated glass particles; the mixed phase-separated glass particles are heated to bond the particles together, thereby obtaining a molded body; A method for producing a porous glass material precursor. <13> two or more types of phase-separated glass particles are obtained by microparticulating two or more types of phase-separated glass materials having different structural scales of phase separation due to spinodal decomposition; mixing the two or more types of phase-separated glass particles; the mixed phase-separated glass particles are heated to bond the particles together to obtain a molded body; the molded body is brought into contact with at least one selected from the group consisting of water at 40°C or higher, an acidic solution, and an alkaline solution, thereby removing the eluted phase from the phase-separated glass particles, thereby obtaining a porous glass material. A method for producing porous glass materials. <14> After obtaining the two or more types of phase-separated glass particles, the two or more types of phase-separated glass particles are classified before being mixed together. <12> or <13> The method described below. <15> After mixing the two or more types of phase-separated glass particles, the mixed phase-separated glass particles are pressure-molded before heating the phase-separated glass particles. <12> ~ <14> 10. The method according to any one of claims 1 to 9. <16> <1> ~ <11> 10. A substance capture filter comprising the porous glass material according to any one of claims 1 to 9. <17> Used to capture extracellular vesicles, <16> The substance capture filter according to claim 1. <18> Further, the coating layer contains a protein adhesion inhibitor. <16> or <17> The substance capture filter according to claim 1. <19> The peak particle diameters of the two or more types of porous glass particles are each 0.5 to 100 μm. <16> ~ <18> 10. The substance trapping filter according to claim 1, wherein: <20> A solution or suspension containing the target substance <16> ~ <19> A method for capturing a substance, comprising contacting a substance with the substance-capturing filter described in any one of claims 1 to 4. <21> In a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, two or more peaks are observed within the pore diameter range of 0.005 to 100 μm, In at least two of the two or more peaks, the peak half width X and the peak pore diameter Y satisfy the relationship of X / Y<2.0; The porosity is 30 to 70%. A porous structure comprising at least one component selected from the group consisting of SiO2 and Al2O3. <22> It is porous glass, <21> The porous structure according to claim 1. <23> Further, the composition contains at least one component selected from the group consisting of MgO, CaO, BaO, Na2O, and KO, <21> or <22> The porous structure according to claim 1. <24> In any two of the two or more peaks, the ratio of the peak pore diameter on the large pore diameter side to the peak pore diameter on the small pore diameter side is 1.5 or more. <21> ~ <23> 1. The porous structure according to any one of claims 1 to 9. <25> Pore ​​surface area: 0.01 to 100 m 2 / g, <21> ~ <24> 1. The porous structure according to any one of claims 1 to 9. <26> In a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, a peak is observed in the pore diameter range of 0.05 μm or more. <21> ~ <25> 1. The porous structure according to any one of claims 1 to 9. <27> In a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, one or more peaks are observed in the pore diameter range of 0.01 to 0.5 μm and in the pore diameter range of more than 0.5 μm and not more than 20 μm. <21> ~ <26> 1. The porous structure according to any one of claims 1 to 9. <28> Contains pores having a structure derived from phase separation due to spinodal decomposition. <21> ~ <27> 1. The porous structure according to any one of claims 1 to 9. <29> Two or more types of porous glass particles with different pore sizes are bonded together. <21> ~ <28> 1. The porous structure according to any one of claims 1 to 9. <30> It is a plate-like structure with a thickness of 5 mm or less. <21> ~ <29> 1. The porous structure according to any one of claims 1 to 9. <31> Used for filtering purposes <21> ~ <30> 1. The porous structure according to any one of claims 1 to 9. <32> <21> ~ <31> A substance-trapping filter comprising the porous structure according to any one of claims 1 to 4. <33> Used to capture extracellular vesicles, <32> The substance capture filter according to claim 1. <34> Further, the coating layer contains a protein adhesion inhibitor. <32> or <33> The substance capture filter according to claim 1. <35> A solution or suspension containing the target substance <32> ~ <34> A method for capturing a substance, comprising contacting a substance with the substance-capturing filter described in any one of claims 1 to 4. [Effects of the Invention]

[0007] According to one embodiment of the present disclosure, there are provided a porous glass material having good processing ability and property-exhibiting ability, a substance capture filter and a substance capture method using the same, a method for manufacturing the porous glass material, and a method for manufacturing a porous glass material precursor for obtaining the porous glass material. According to a further embodiment of the present disclosure, there are provided a porous structure having good processing capacity and property-exhibiting ability, and excellent strength, as well as a substance-trapping filter and a substance-trapping method using the same. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a scanning electron microscope (SEM) photograph of an example of a porous glass material. [Figure 2] 1 shows a graph of Log differential pore volume versus pore diameter for the porous glass substrate of Example 6. [Figure 3] 1 shows a graph of Log differential pore volume versus pore diameter for the porous glass substrate of Example 9. [Figure 4] 1 shows the relative ratios of CD9 luminescence band signals by Western blotting in Test Example 1. [Figure 5] 1 shows the filter resistance per unit thickness of the porous glass substrate in Test Example 2. [Figure 6] 1 shows a graph of filtrate volume versus flow rate in a filter made of a porous glass substrate in Test Example 3. [Figure 7] FIG. 1 is a conceptual diagram of an example of a structure resulting from phase separation due to spinodal decomposition. [Figure 8] 1 is a SEM photograph of an example of a structure resulting from phase separation due to spinodal decomposition. [Figure 9] 1 is a graph plotting the filter resistance per unit thickness of the porous glass substrates prepared in the examples and the CD63 concentration in the filtrate eluted after passing through the porous glass substrate. [Figure 10] 1 is a graph showing the relationship between the pore surface area of ​​a porous glass substrate prepared in an example and the CD63 concentration in the filtrate eluted after passing through the porous glass substrate. [Figure 11] 1 is a graph showing the relationship between the pore surface area and the filter material resistance per unit thickness of the porous glass substrates produced in the examples. [Figure 12] 1 is a graph showing the relationship between the porosity and Young's modulus of the porous glass substrates produced in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, modes for carrying out embodiments of the present disclosure will be described in detail. However, the embodiments of the present disclosure are not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and they do not limit the embodiments of the present disclosure.

[0010] In the present disclosure, the term "process" includes not only a process that is independent of other processes, but also a process that cannot be clearly distinguished from other processes as long as the purpose of the process is achieved. In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, each component may contain multiple substances corresponding to the component. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.

[0011] First Embodiment <Porous glass material> The porous glass material according to the first embodiment is a porous glass material in which two or more types of porous glass particles having different pore sizes are bonded together, and two or more of the two or more types of porous glass particles contain pores having a structure derived from phase separation due to spinodal decomposition.

[0012] In the present disclosure, pores refer to minute pores present on the surface and inside of a solid, and pore diameter refers to the size of the pores. The pore diameter is the value on the horizontal axis corresponding to the peak position on a graph obtained by performing an analysis using mercury intrusion porosimetry and plotting the pore diameter on the horizontal axis and the log differential pore volume on the vertical axis (i.e., a graph of the log differential pore volume versus pore diameter). In this disclosure, a porous material having two or more types of pores with different pore sizes may be referred to as a "hierarchical" material. Whether the pore sizes are different or not can be determined by the peaks in a graph of log differential pore volume versus pore size obtained by mercury intrusion porosimetry, as described below. The "phase separation due to spinodal decomposition" structure is well known to those skilled in the art and has a continuous entanglement structure of two or more phases resulting from phase separation. "Pores having a structure resulting from spinodal decomposition" refers to a structure in which at least one phase in the "phase separation due to spinodal decomposition" structure has been removed to form pores. FIG. 7 is a conceptual diagram of an example of a structure resulting from spinodal decomposition. FIG. 8 is an SEM photograph of an example of a structure resulting from spinodal decomposition. A structure resulting from spinodal decomposition can be obtained, for example, by treating a phase-separated glass with a solution capable of dissolving at least one phase to form pores. Because a structure resulting from spinodal decomposition has the above-described characteristic structure, the presence or absence of the structure can be identified by SEM observation by those skilled in the art.

[0013] In the present disclosure, when two or more peaks overlap in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, peaks that can be separated using the Gaussian function below and have a peak intensity (i.e., Log differential pore volume) of 0.3 mL / g or more after separation are treated as a single peak.

[0014]

number

[0015] A: Peak intensity (mL / g) μ: Peak pore diameter (μm) σ: Standard deviation (μm)

[0016] When fitting a curve graph of Log differential pore volume versus pore diameter, with the horizontal axis being pore diameter and the vertical axis being Log differential pore volume, with multiple Gaussian functions, it is considered to have converged if the following convergence condition is satisfied. Within 2000 iterations of the fitting algorithm, one of the following is satisfied: The relative change in the objective function is 1×10 -8 The following is the result. -Relative change in parameters is 1×10 -8 The following is the result. The absolute value of the gradient of the objective function is 1×10 -8 The following is the result. In addition, the coefficient of determination R is used as an index of accuracy for the model obtained as a result of fitting. 2 is 0.90 or more.

[0017] The porous glass material according to the first embodiment has good processing ability and ability to exhibit properties. In the present disclosure, the processing capacity refers to the ease of fluid passage (i.e., breathability or liquid permeability) regardless of the intended use. As shown in the examples below, the processing capacity can be determined by indicators such as clogging resistance and filter resistance per unit thickness. In the present disclosure, the term "ability to exhibit properties" refers to the ability to exhibit specific properties required for a particular application. Examples of the ability to exhibit properties include capture performance, separation performance, catalytic performance, and emulsification performance. For example, in one embodiment, when a porous glass material is used to collect extracellular vesicles in serum, the capture performance is expressed as the amount of extracellular vesicles collected dispersed in serum, and can be evaluated by ELISA (enzyme-linked immunosorbent assay). The reason why the porous glass material according to the first embodiment exhibits the above-mentioned effects is not entirely clear, but is presumed to be as follows. The porous glass material according to the first embodiment is a porous glass material in which two or more types of porous glass particles with different pore sizes are bonded together. In such a porous glass material, it is believed that pores with relatively large pore sizes (hereinafter also referred to as "large pores") mainly contribute to the high processing capacity for passing liquids, while pores with relatively small pore sizes (hereinafter also referred to as "small pores") mainly contribute to the exhibiting of properties. In the porous glass material according to the first embodiment, two or more types of porous glass particles contain pores with an entangled structure resulting from phase separation due to spinodal decomposition. This ensures the processing capacity through the large pores, and increases the number of contact points between the large pores and the small pores, thereby increasing the amount of access to the small pores. Furthermore, the retention efficiency of substances in the small pores is improved. This is believed to make it easier for the small pores to exhibit the properties. Note that the porous glass material according to the first embodiment is not restricted in any way by the above-mentioned presumed mechanism. The terms "large pores" and "small pores" are used for convenience in comparing two types of pores and do not limit the specific sizes of the pores. In the present disclosure, for the sake of explanation, pores with relatively large pore diameters that mainly allow liquids to pass through are referred to as "large pores," and pores with relatively small pore diameters that mainly contribute to the exhibiting of properties are referred to as "small pores." In addition, the porous glass material according to the first embodiment uses glass, which allows hydroxyl groups to be exposed on the surface, and thus has the advantage of enabling various surface modifications to be performed at high density. Because porous materials have a large surface area, the electrical affinity between the porous material and the fluid when they come into contact with the fluid significantly affects pressure loss and various other properties. Therefore, the high surface modification properties of porous materials are a major advantage. 1 shows an SEM photograph of an example of a porous glass material in which two or more types of porous glass particles with different pore sizes are bonded together. In the porous glass material shown in the figure, a structure in which porous glass particles with small pores and porous glass particles with large pores are bonded together is observed. Note that embodiments of the present disclosure are not limited to the illustrated embodiment.

[0018] The "two or more types of porous glass particles having different pore sizes" may be two types, or three or more types. For example, the number of types of porous glass particles may be 2 to 20 types, 2 to 15 types, 2 to 10 types, 2 to 5 types, or even 2 types. Regardless of the number of types of porous glass particles, it is believed that good processing ability and ability to exhibit properties can be obtained due to the above-mentioned estimated mechanism. The number of "types" of "two or more types of porous glass particles with different pore sizes" is determined by the number of peaks in a graph of Log differential pore volume versus pore size obtained by mercury intrusion porosimetry. That is, if the number of peaks is two, it is determined that two types of porous glass particles with different pore sizes are contained, and if the number of peaks is three, it is determined that three types of porous glass particles with different pore sizes are contained.

[0019] Therefore, the number of peaks observed in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry may be 2 to 20, 2 to 15, 2 to 10, 2 to 5, or even 2.

[0020] In the porous glass material according to the first embodiment, two or more types of porous glass particles having different pore sizes are bonded together. The bonding method is not particularly limited, and may be chemical bonding or physical bonding. Preferably, two or more types of porous glass particles having different pore sizes are physically bonded together, and the physical bonding is achieved, for example, by mixing and sintering two or more types of porous glass particles having different pore sizes.

[0021] In the porous glass material according to the first embodiment, at least two of the two or more types of porous glass particles may contain pores having a structure derived from phase separation due to spinodal decomposition. That is, even if there are three or more types of "two or more types of porous glass particles," at least two of the types may contain pores having a structure derived from phase separation due to spinodal decomposition.

[0022] In one embodiment, two or more peaks are observed in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, and for at least two of the two or more peaks, the peak half-width X and peak pore diameter Y preferably satisfy the relationship X / Y<2.0, more preferably X / Y<1.7, even more preferably X / Y<1.4, and particularly preferably X / Y<1.2. When X / Y satisfies the above relationship, it means that the peak width is relatively small, i.e., the peak is sharp. Since the pore diameters of at least two types of porous glass particles are relatively uniform, the performance of each pore diameter (e.g., the processing ability of large pores or the ability to exhibit characteristics of small pores) can be suitably exhibited.

[0023] In one embodiment, the two or more types of porous glass particles are n types of porous glass particles, where n is an integer of 2 or greater, and when the n types of porous glass particles are counted in order of pore size, the 1st to n / 2nd porous glass particles when n is an even number, or the 1st to (n+1) / 2nd porous glass particles when n is an odd number, are designated as porous glass particles L. It is preferable that the minor axis of at least one type of porous glass particles L is larger than the pore size. The porous glass particles L are particles with a relatively large pore size among the two or more types of porous glass particles, and the fact that the minor axis of at least one of the porous glass particles L is larger than the pore size generally means that the porous glass particles can maintain large pores that are not directly connected to small pores. Maintaining large pores that are not directly connected to small pores is thought to suppress clogging caused by a solution or suspension flowing through the small pores, thereby contributing to improved processing capacity. The minor diameter of porous glass particles can be measured by SEM observation and is the average of values ​​measured at 100 or more points. The "minor diameter" of a glass particle refers to the longest diameter perpendicular to the longest diameter in a single particle image observed by SEM.

[0024] In one embodiment, the two or more types of porous glass particles are n types of porous glass particles, where n is an integer of 2 or greater. Among the n types of porous glass particles, the 1st to n / 2nd porous glass particles are defined as porous glass particles L when n is an even number, and the 1st to (n+1) / 2nd porous glass particles are defined as porous glass particles L when n is an odd number, and the 1st to n / 2nd porous glass particles are defined as porous glass particles S when n is an even number, and the 1st to (n+1) / 2nd porous glass particles are defined as porous glass particles S when n is an odd number, and the short diameter of any of the porous glass particles S is preferably 2 to 500 times, more preferably 2.2 to 350 times, and even more preferably 2.4 to 100 times the pore diameter of any of the porous glass particles L. Among two or more types of porous glass particles, porous glass particles L are particles with a relatively large pore diameter, and porous glass particles S are particles with a relatively small pore diameter. When n is an odd number, porous glass particles corresponding to both porous glass particles L and porous glass particles S exist. However, porous glass particles L and porous glass particles S may be selected so that the porous glass particles L and porous glass particles S, which are compared in terms of the short diameter and the pore diameter, are different. The fact that the short diameter of any of the porous glass particles S and the pore diameter of any of the porous glass particles L satisfy the above relationship generally means that the ratio of the particle diameter of particles having small pores to the pore diameter of large pores (hereinafter also referred to as "ratio R") is within a certain range. It is believed that a small ratio R increases the contact area of ​​large pores with particles having small pores, thereby increasing the amount of access of a solution or suspension to the small pores. As a result, it is believed that the performance of the small pores is more easily exhibited. Conversely, when the ratio R is large, the amount of solution or suspension that can access the small pores is reduced, clogging can be suppressed, and processing capacity can be improved. Therefore, it is believed that by keeping the ratio R within the above range, a good balance between processing capacity and ability to exhibit characteristics can be achieved. The method for measuring the minor axis and pore diameter of the porous glass particles is as described above.

[0025] In one embodiment, in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, two or more peaks are preferably observed within a pore diameter range of 0.005 to 100 μm, more preferably two or more peaks are observed within a pore diameter range of 0.01 to 20 μm, and even more preferably two or more peaks are observed within a pore diameter range of 0.01 to 10 μm. By having the pore diameter within the above range, it is thought that the performance of each pore diameter can be easily exhibited.

[0026] In one embodiment, in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, one or more peaks may be observed in the pore diameter range of 0.01 to 0.5 μm and in the pore diameter range of more than 0.5 μm to 20 μm. For example, when a porous glass material is used for capturing microscopic substances such as extracellular vesicles, pore sizes within the above ranges may provide particularly good performance. One or more peaks may be observed in the pore diameter range of 0.05 to 0.4 μm and in the pore diameter range of 0.5 to 10 μm, and one or more peaks may be observed in the pore diameter range of 0.08 to 0.3 μm and in the pore diameter range of 0.5 to 2 μm.

[0027] In one embodiment, two or more peaks are observed in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, and in any two of the two or more peaks, the ratio of the peak pore diameter on the larger pore side to the peak pore diameter on the smaller pore side is preferably 1.5 or more, more preferably 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, 2.0 or more, 2.1 or more, 2.2 or more, 2.3 or more, 2.4 or more, 2.5 or more, 2.6 or more, 2.7 or more, 2.8 or more, 2.9 or more, or 3.0 or more. When the peak pore diameter ratio is within the above range, the difference between the larger pore diameter and the smaller pore diameter becomes clear, and it is believed that good processing ability and characteristic development ability can be exhibited. The ratio may be, for example, 100 or less.

[0028] In one embodiment, the peak particle diameters of the two or more types of porous glass particles are each preferably 0.04 to 200 μm, more preferably 0.1 to 150 μm, and even more preferably 0.5 to 50 μm. When the peak particle diameters are within the above ranges, a porous glass material with excellent strength can be obtained. The peak particle size is determined by the following method. The image obtained by SEM observation is binarized, a horizontal line is drawn across the binarized image, and the minor axis length of the porous glass particles on the line is measured. Five or more horizontal lines are drawn per image, and 100 or more measurement points are used. Even if the shapes displayed in the image differ, they are analyzed uniformly using the above procedure. The minor axis data of the porous glass particles determined as above is created into a histogram, and the peak value is taken as the peak particle size.

[0029] In one embodiment, the volume fraction of the porous glass particles having the smallest volume fraction among the two or more types of porous glass particles is preferably 5% by volume or more, more preferably 10% by volume or more, and even more preferably 20% by volume or more, based on the total volume fraction of the two or more types of porous glass particles. When the volume fraction is in the above range, it is believed that the small pore characteristics can be particularly well exhibited.

[0030] In one embodiment, the porosity of the porous glass material is preferably 30% or more, more preferably 40% or more, and even more preferably 50% or more, from the viewpoint of improving processing ability. Furthermore, the porosity is preferably within the above range from the viewpoint of improving heat insulating performance. From the viewpoint of improving strength, the porosity is preferably 70% or less, more preferably 60% or less. Furthermore, in heat treatment for purposes such as sterilization, if the porosity is not too high, the material will cool easily and the process time can be shortened. From the viewpoint of shortening the process time for heat treatment, etc., the porosity is preferably within the above range. The porosity is the porosity obtained by mercury intrusion porosimetry, analyzed within a pore diameter range of 0.003 to 200 μm.

[0031] In one embodiment, the pore surface area of ​​the porous glass material is 0.01 m or less from the viewpoint of improving the ability to exhibit properties (for example, the ability to capture substances). 2 / g or more is preferable, and 0.1m 2 / g or more, 1.0m 2 / g or more, 2.0m 2 / g or more, 3.0m 2 / g or more, or 4.0m 2 From the viewpoint of further improving the processing capacity, the pore surface area of ​​the porous glass material is 100 m 2 / g or less is preferable, and 90m 2 / g or less, 80m 2 / g or less, 70m 2 / g or less, 60m 2 / g or less, or 50m 2 From this viewpoint, the pore surface area of ​​the porous glass material is 0.01 to 100 m 2 / g is preferred, and 0.1 to 80m 2 / g is more preferable, and 0.3 to 50m 2 The pore surface area is the pore surface area obtained by mercury intrusion porosimetry and analyzed in the pore diameter range of 0.003 to 200 μm.

[0032] In one embodiment, from the viewpoint of further improving processing capacity, the pore volume of the porous glass material is preferably 0.01 mL / g or more, more preferably 0.05 mL / g or more, 0.1 mL / g or more, 0.2 mL / g or more, or 0.3 mL / g or more. From the viewpoint of strength, the pore volume of the porous glass material is preferably 10 mL / g or less, more preferably 5 mL / g or less, 4 mL / g or less, 3 mL / g or less, 2 mL / g or less, 1 mL / g or less, 0.9 mL / g or less, 0.8 mL / g or less, or 0.7 mL / g or less. The pore volume is the pore volume obtained by mercury intrusion porosimetry and analyzed in the pore diameter range of 0.003 to 200 μm.

[0033] In one embodiment, from the viewpoint of further improving the processing capacity, it is preferable that a peak be observed in the pore diameter range of 0.05 μm or more in a graph of Log differential pore volume vs. pore diameter obtained by mercury porosimetry. From the viewpoint of further improving the processing capacity, it is preferable that a peak be observed only in the pore diameter range of 0.05 μm or more in a graph of Log differential pore volume vs. pore diameter obtained by mercury porosimetry. That is, it is preferable that a peak be observed in the pore diameter range of 0.05 μm or more, and that no peak be observed in the pore diameter range of less than 0.05 μm.

[0034] The shape of the porous glass material is not particularly limited, and may be plate-like, polyhedral, spherical, or the like.

[0035] [Uses of porous glass materials] Porous glass materials can be suitably used for applications such as filters, separation membranes, column packing materials, adsorbents, catalyst supports, emulsification membranes, microporous bubbling nozzles, enzyme supports, DNA synthesis supports, nanocrystal supports, dye units, solid-state dye lasers, bonding materials, water-retaining materials, molecular sieves, ion exchange materials, heat insulating materials, electrode materials, separators, magnets, low-dielectric substrates, soundproofing / sound-absorbing materials, radioactive waste solidification, removal and recovery of hazardous substances such as heavy metal ions, removal and recovery of valuable substances such as rare metals, vacuum chucks, adsorbents, etc. Use of porous glass materials as substance-trapping filters will be described in detail below.

[0036] <Method of manufacturing a porous glass material precursor and method of manufacturing a porous glass material> In one embodiment, a method for producing a porous glass material precursor includes: Two or more types of phase-separated glass materials having different structural scales of phase separation due to spinodal decomposition are microparticulated to obtain two or more types of phase-separated glass particles (hereinafter also referred to as the "microparticulation step"); The two or more types of phase-separated glass particles are mixed (hereinafter also referred to as the "mixing step"); The process includes heating the mixed phase-separated glass particles to bond the particles together and obtain a molded body (hereinafter also referred to as "sintering process").

[0037] In one embodiment, a method for producing a porous glass material includes the steps of: Two or more types of phase-separated glass materials having different structural scales of phase separation due to spinodal decomposition are microparticulated to obtain two or more types of phase-separated glass particles (i.e., the "microparticulation step"); mixing the two or more types of phase-separated glass particles (i.e., the "mixing step"); The mixed phase-separated glass particles are heated to bond the particles together to obtain a molded body (i.e., the "sintering step"); The method includes contacting the molded body with at least one selected from the group consisting of water at 40°C or higher, an acidic solution, and an alkaline solution to remove the eluted phase from the phase-separated glass particles, thereby obtaining a porous glass material (hereinafter also referred to as the "eluted phase removing step").

[0038] The porous glass material described above can be produced by the above-mentioned method for producing a porous glass material precursor and the method for producing a porous glass material. The above and optional steps will be described in detail below.

[0039] (1) Preparation of glass base material Before the microparticulation step, a glass base material may be prepared by mixing desired raw materials. The glass base material can be obtained, for example, by mixing glass raw materials to obtain a desired glass composition, heating and melting the mixture, pouring the resulting molten glass into a mold, and cooling it. Alternatively, a ready-made glass base material may be prepared.

[0040] The glass composition is not particularly limited as long as it is a composition that undergoes phase separation by spinodal decomposition, and examples thereof include silicon oxide-boron oxide-alkali metal oxide; silicon oxide-boron oxide-alkali metal oxide containing at least one selected from the group consisting of alkaline earth metal oxide, zinc oxide, aluminum oxide, and zirconium oxide; silicon oxide-phosphate-alkali metal oxide; silicon oxide-boron oxide-calcium oxide-magnesium oxide-aluminum oxide-titanium oxide, etc. Among these, a glass composition having silicon oxide-boron oxide-alkali metal oxide as its base composition is preferred.

[0041] More specifically, examples of such glass compositions include, on an oxide basis, SiO2 as well as components such as B2O3, Na2O, Al2O3, CaO, MgO, KO, Li2O, ZrO2, and TiO2. In one embodiment, from the viewpoint of material strength, the glass composition preferably contains SiO2 and Al2O3. Examples of glass compositions include SiO2-B2O3-Na2O systems, SiO2-Al2O3-B2O3-Na2O systems, SiO2-Al2O3-B2O3-CaO-MgO systems, SiO2-Al2O3-B2O3-Na2O-K2O-CaO-MgO systems, SiO2-Al2O3-B2O3-Li2O-Na2O-MgO systems, SiO2-Al2O3-B2O3-Li2O-Na2O-CaO systems, SiO2-Al2O3-B2O3-Na2O-K2O-CaO-ZrO2 systems, SiO2-B2O3-Na2O systems, and SiO2-B2O3-CaO-MgO-Al2O3-TiO2 systems.

[0042] The content of silicon oxide in the glass is preferably 45 to 80 mass %, more preferably 50 to 80 mass %, based on the oxide.

[0043] Glass that undergoes phase separation by spinodal decomposition is glass that exhibits phase separation. Phase separation refers to the property of the glass to undergo phase separation into a silicon oxide-rich phase and an alkali metal oxide-boron oxide-rich phase upon heat treatment, for example, in the case of borosilicate glass having silicon oxide-boron oxide-alkali metal oxide.

[0044] (2) Phase separation process Optionally, a phase-separated glass material may be obtained by inducing phase separation through spinodal decomposition in a fabricated or prepared glass preform (also referred to as a "phase separation process"). Typically, the glass preform is heat-treated to cause phase separation of the glass. Because the phase separation state formed varies depending on the heating temperature and heating time, it is preferable to select heating conditions so as to obtain a desired phase-separated state. In other words, by adjusting the heating temperature and heating time, a desired phase-separated state can be obtained, and as a result, a porous glass material with desired pores can be obtained. The higher the heating temperature or the longer the heating time, the more the phase separation progresses, resulting in a porous glass material with larger pore diameters. Furthermore, while changes in heating temperature have a significant effect on the progress of phase separation, changes in heating time have little effect on the progress of phase separation. Therefore, to obtain a desired pore diameter, it is advisable to determine a rough range for the heating temperature and precisely control the heating time. For example, the heating temperature is set within a range of 400 to 800°C, and the treatment is carried out for a range of 10 minutes to 200 hours (preferably 10 minutes to 100 hours). The above conditions are particularly preferable for the borosilicate glass described above. Note that, when producing glass, if phase separation occurs at the molten stage during melting of glass raw materials, the heating during melting includes a phase separation step, and therefore the above-mentioned separate phase-separation heat treatment can be omitted. Note that the phase-separated glass material may be produced as described above, or an available ready-made phase-separated glass material may be prepared.

[0045] (3) Micronization process In the micronization step, two or more types of phase-separated glass materials with different structural scales of phase separation due to spinodal decomposition are micronized to obtain two or more types of phase-separated glass particles. The "structural scale of phase separation" refers to the fineness of the phase-separated structure. For example, as described above, the higher the heating temperature or the longer the heating time, the more advanced the phase separation state, i.e., the coarser (larger structural scale) phase separation state is obtained. The micronization method is not particularly limited as long as it is a method that can obtain particles of the desired size, and examples include pulverization using a ball mill or jet mill.

[0046] (4) Classification process After the micronization step and before the mixing step, the two or more types of phase-separated glass particles prepared as described above may optionally be classified (also referred to as the "classification step"). It is believed that classification allows for more precise adjustment of the particle size of the phase-separated glass particles, allowing the performance of each phase-separated glass particle to be particularly well exhibited. Classification is carried out, for example, using a sieve with openings of the desired size. On the other hand, if phase-separated glass particles having the desired particle size are obtained in the micronization step, classification may not be necessary.

[0047] (5) Mixing process In the mixing step, two or more types of phase-separated glass particles prepared as described above are mixed. The two or more types of phase-separated glass particles have different structural scales of phase separation due to spinodal decomposition. According to this method, by adjusting the types and mixing ratio of the phase-separated glass particles to be mixed, it is possible to precisely control the pore size, number of classes, and their ratio of the porous glass material. The phase-separated glass particles to be mixed may have the same glass composition or different glass compositions. From the viewpoint of simplifying production, it is preferable that the phase-separated glass particles to be mixed have the same glass composition.

[0048] (6) Pressure molding process After the mixing step and before the sintering step, the mixed phase-separated glass particles may optionally be pressure-molded (also referred to as the "pressure molding step"). Pressure molding can efficiently bond the porous glass particles together. For example, pressure molding involves placing the phase-separated glass particles in a mold and applying pressure of 1 to 200 MPa for 1 to 5 minutes. On the other hand, even if pressure molding is not performed, a porous glass material can be produced as long as the phase-separated glass particles can be bonded in the sintering step.

[0049] (7) Sintering process In the sintering step, the mixed phase-separated glass particles are heated to bond the particles together to obtain a molded body. The phase-separated glass particles can be bonded together by heating them at a temperature below their melting point. Heating is carried out, for example, at 600 to 800°C for 1 to 30 hours. This molded body is also referred to as a "porous glass material precursor" in the present disclosure.

[0050] (8) Processing process After the sintering step and before the eluted phase removing step, the compact may be optionally processed by cutting it to a desired size and polishing the cut block (also referred to as a "processing step").

[0051] (9) Elution phase removal process In the eluted phase removal step, the molded body obtained as described above is brought into contact with at least one selected from the group consisting of water at 40°C or higher, an acidic solution, and an alkaline solution (hereinafter also referred to as "dissolving solution") to remove the eluted phase from the phase-separated glass particles. For this purpose, the phase-separated glass is designed so that the phase to be eluted can be dissolved in at least one selected from the group consisting of water at 40°C or higher, an acidic solution, and an alkaline solution. The treatment with the dissolving solution may be carried out once or multiple times, and water at 40°C or higher, an acidic solution, and an alkaline solution may be combined in any order.

[0052] Examples of the acid contained in the acidic solution include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid, organic acids such as acetic acid, and combinations of these. Among these, inorganic acids such as hydrochloric acid and nitric acid are preferred. The acidic solution is preferably an aqueous solution, and the acid concentration can be appropriately set to any pH. In order to prevent cracking, warping, etc. of the glass due to the acid treatment, inorganic salts such as ammonium salts and borax may be added to the acid solution. The temperature of the acidic solution is preferably 20 to 100°C. The treatment time with the acidic solution is preferably 10 minutes to 150 hours. Since the pore size can be adjusted by carrying out the treatment for a long time, the treatment conditions can be appropriately selected so as to obtain pores of the desired size.

[0053] Examples of the alkali contained in the alkaline solution include sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, and ammonia. The alkaline solution is preferably an aqueous solution, and the concentration of the aqueous alkaline solution is preferably 0.01 to 2.0 mol / L, more preferably 0.1 to 2.0 mol / L. The temperature of the alkaline solution is preferably 10 to 60°C. The treatment time with the alkaline solution is preferably 5 minutes to 10 hours, more preferably 5 minutes to 2 hours. Since the pore size can be adjusted by carrying out the treatment for a long time, the treatment conditions can be appropriately selected so as to obtain pores of the desired size.

[0054] As water at 40°C or higher, pure water with few impurities is preferred. The temperature of the water is 40°C or higher, preferably 50 to 90°C. The treatment time with water at 40° C. or higher is preferably 5 minutes to 2 hours. Since the pore size can be adjusted by carrying out the treatment for a longer period of time, the treatment conditions can be appropriately selected to obtain pores of the desired size.

[0055] In one embodiment, after elution with an acidic solution (e.g., elution of an acid-soluble alkali metal oxide-boron oxide-rich phase), a washing treatment is preferably performed with at least one selected from the group consisting of an alkaline solution and water at 40°C or higher. By performing a washing treatment after eluting the acid-soluble phase, residues generated by the acid treatment can be dissolved and removed. In this case, silicon oxide may be removed by hydrolysis or the like, promoting porosity, and the washing treatment can also be used to adjust the degree of porosity. In particular, an alkaline solution is effective for adjusting the degree of porosity, and water at 40°C or higher is effective for dissolving and removing residues. Therefore, when both an alkaline solution treatment and a water treatment at 40°C or higher are performed, it is preferable to perform the alkaline solution treatment followed by water at 40°C or higher. Performing the alkaline solution treatment followed by water at 40°C or higher in this way effectively removes residues, thereby improving the processing capacity of the resulting porous glass material.

[0056] (10) Surface modification process After the elution phase removal step, the resulting porous glass material may optionally be surface-modified (also referred to as the "surface modification step"). Surface modification can impart additional physical and / or chemical functions to the porous glass material. For example, polymers, inorganic substances, biological substances, nucleic acids, etc. may be applied to the surface of the porous glass material by dip coating, spin coating, sputtering, inkjet printing, etc. Examples of surface treatments include surface treatments that improve the hydrophilicity of the surface, surface treatments that impart adsorption specificity for capturing specific substances, and treatments that make it difficult for specific substances to be adsorbed. Examples of surface treatments for improving the hydrophilicity of the surface include treatments using a silane coupling agent having a hydrophilic group, phosphonic acid having a hydrophilic group, titanium oxide, and the like. Examples of surface treatments that impart adsorption specificity for capturing a specific substance include treatments with antibodies, nucleic acids, and the like. Examples of surface treatments that make it difficult for specific substances to be adsorbed include treatments using protein adhesion inhibitors, fluorine-based silane coupling agents, and the like.

[0057] <Substance capture filter> The substance capture filter in one embodiment includes the porous glass material described above. By passing a solution or suspension through the porous glass material, the desired substance can be separated and captured. The substance capture filter can be produced by processing the porous glass material described above into a filter shape (typically, a plate shape). Because the substance capture filter uses the porous glass material described above, it has good processing capacity and the ability to exhibit its characteristics. Furthermore, because the porous glass material according to the first embodiment has good processing capacity, it is possible to increase the thickness of the filter, which makes it less likely to break and increases the amount of sample that can be processed. As a result, for example, a filter that is highly durable and less likely to clog can be obtained.

[0058] The shape of the filter is not particularly limited and is typically a plate, and the planar shape may be, for example, a polygon such as a triangle or a rectangle, or a circle such as a perfect circle or an ellipse. Among these, from the viewpoint of making the load applied from the fluid more uniform, it is preferable that the planar shape is a circle, and particularly a perfect circle. From the viewpoint of improving strength and durability, the thickness of the substance capture filter is preferably 0.01 mm or more, more preferably 0.05 mm or more, 0.10 mm or more, 0.15 mm or more, 0.20 mm or more, 0.25 mm or more, 0.30 mm or more, 0.35 mm or more, 0.40 mm or more, 0.45 mm or more, or 0.50 mm or more. There is no particular upper limit to the thickness of the capture filter, and from the viewpoint of ease of handling and mass production, it is preferably 100.00 mm or less, more preferably 50.00 mm or less, 10.00 mm or less, 9.00 mm or less, 8.00 mm or less, 7.00 mm or less, 6.00 mm or less, 5.00 mm or less, 4.00 mm or less, or 3.00 mm or less. From these viewpoints, the thickness of the substance capture filter is preferably 0.01 to 100.00 mm. The surface area of ​​the substance capture filter is 0.1 to 10.5 cm 2 is preferable, and 0.2 to 6 cm 2 is more preferable, and 0.3 to 6 cm 2 is particularly preferred.

[0059] There are no particular limitations on the target substance to be captured, and examples include asbestos, carbon black, ink, colloidal particles, viruses, biomolecules such as albumin, antibodies, and extracellular vesicles, bacteria, blood cells, aerosol particles, etc. It is desirable to select the pore size of the porous glass material depending on the size of the substance to be captured.

[0060] When the target substance is extracellular vesicles, it is preferable to use a substance capture filter having a coating layer containing a protein adhesion inhibitor, in order to prevent the extracellular vesicles from adhering to the filter and becoming unable to peel off. The coating layer may be formed by applying the protein adhesion inhibitor directly, or by dispersing the protein adhesion inhibitor in a medium such as a solvent or dispersion medium and then removing the medium. Examples of protein adhesion inhibitors include polymers having structural units with biocompatible groups. Specific examples include polyethylene glycol, polymers having structural units of 2-methacryloyloxyethyl phosphorylcholine, and fluorine-containing polymers having biocompatible groups as described in WO 2016 / 002796.

[0061] The preferred ranges of the peak particle diameters of the two or more types of porous glass particles in the porous glass material are as described above. In one embodiment of the substance capture filter, the peak particle diameters of the two or more types of porous glass particles are each preferably 0.5 to 100 μm, more preferably 1 to 50 μm, and even more preferably 2 to 20 μm.

[0062] <Matter capture method> In one embodiment, a substance capture method includes contacting a solution or suspension containing a target substance with the substance capture filter. In this method, the solution or suspension containing the target substance is supplied onto the substance capture filter, which serves as a capture means. The liquid and any uncaptured substances pass through the substance capture filter and are discharged as filtrate. Meanwhile, the target substance is captured on the pore surface and / or within the pores of the substance capture filter.

[0063] It is preferable to adjust the viscosity of the solution or suspension containing the target substance so that separation can be carried out effectively. Examples of liquid components for adjusting the viscosity of the solution or suspension before separation include water, alcohol, etc.

[0064] In the substance capture method, pressure may be applied when the solution or suspension is brought into contact with the substance capture filter. The pressure is preferably 0.1 to 100 MPa. A pressure of 0.1 MPa or higher can promote separation, while a pressure of 100 MPa or lower can prevent damage to the substance capture filter.

[0065] In addition to the above-described embodiments of the porous glass material, it is also possible to prepare porous materials using materials other than glass based on the same concept. That is, by mixing porous materials with different pore sizes and using chemical reactions (thermal reactions, hydrolysis reactions, condensation reactions, oxidation-reduction reactions, acid-base reactions, etc.), it is also possible to prepare porous materials with two or more pore sizes. Here, "porous materials with two or more pore sizes" refers to "porous materials in which two or more peaks are observed in a graph of log differential pore volume versus pore size obtained by mercury intrusion porosimetry." It is preferable that at least two of the two or more peaks satisfy the relationship X / Y<2.0, where X is the peak half-width and Y is the peak pore size. Examples of "materials other than glass" include porous materials made of polymers (resins, plastics, rubber, silk, cotton, fibers, proteins, etc.), ceramics (cement, alumina, sialon, etc.), metals (iron, gold, copper, aluminum, alloys, stainless steel, titanium, nickel, etc.), crystals (zeolites, etc.), other composite materials, covalent organic frameworks (COFs), metal organic frameworks (MOFs), etc. The porous materials to be mixed may be a combination of different materials; for example, new porous materials can be produced by mixing resin and metal and using chemical reactions (thermal reactions, hydrolysis reactions, condensation reactions, oxidation-reduction reactions, acid-base reactions, etc.).

[0066] Second Embodiment <Porous structure> The porous structure according to the second embodiment has two or more peaks observed in a pore diameter range of 0.005 to 100 μm in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, and at least two of the two or more peaks have a peak half-width X and a peak pore diameter Y that satisfy the relationship X / Y<2.0, a porosity of 30 to 70%, and contains at least one component selected from the group consisting of SiO2 and Al2O3. The porous structure according to the second embodiment has good processing ability and ability to exhibit properties, and is excellent in strength. The two or more peaks indicate that the porous structure has at least two types of pores: pores with relatively large pore diameters (i.e., large pores) and pores with relatively small pore diameters (i.e., small pores). In such a porous structure, it is believed that the large pores mainly contribute to high liquid processing capacity, while the small pores mainly contribute to the performance of the properties. It is believed that these at least two types of pores can achieve both processing capacity and the ability to perform the properties. Furthermore, when the peak half-width X and the peak pore diameter Y of any two of the two or more peaks satisfy the relationship X / Y<2.0, this means that the peak width is relatively small. The relatively uniform pore diameters allow the performance of each pore diameter (e.g., processing capacity due to large pores or performance of the properties due to small pores) to be particularly well-functioning. Furthermore, it is believed that a porosity of 30% or more can particularly well maintain processing capacity. In addition, it is believed that a porous structure having a porosity of 70% or less and containing at least one selected from the group consisting of SiO2 and AlO3 can maintain strength particularly favorably.

[0067] The details of the porous structure according to the second embodiment can be applied to the details of the porous glass material according to the first embodiment, unless there is a contradiction. The porous structure according to the second embodiment may be the porous glass material according to the first embodiment. However, the porous structure according to the second embodiment is not limited to a porous glass material in which two or more types of porous glass particles having different pore sizes are bonded, and two or more of the two or more types of porous glass particles contain pores having a structure derived from phase separation due to spinodal decomposition. In addition, in the description of the porous glass material according to the first embodiment, the term "porous glass material" will be read as "porous structure." Some of the features of the porous structure according to the second embodiment will be described in detail below.

[0068] In the porous structure according to the second embodiment, two or more peaks are observed within a pore diameter range of 0.005 to 100 μm in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry. The number of peaks may be 2 to 20, 2 to 15, 2 to 10, 2 to 5, or even 2. Outside the pore diameter range of 0.005 to 100 μm, the presence or absence and number of peaks are not particularly limited.

[0069] In one embodiment, in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, two or more peaks are preferably observed within a pore diameter range of 0.01 to 20 μm, and more preferably within a pore diameter range of 0.01 to 10 μm. By having the pore diameter within the above range, it is believed that the performance of each pore diameter can be easily exhibited.

[0070] In the porous structure according to the second embodiment, in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, for any two of the two or more peaks observed within a pore diameter range of 0.005 to 100 μm, the peak half-width X and peak pore diameter Y satisfy the relationship X / Y<2.0. The peak half-width X and peak pore diameter Y preferably satisfy the relationship X / Y<1.7, more preferably X / Y<1.4, and even more preferably X / Y<1.2. When X / Y satisfies the above relationship, the performance of each pore diameter (e.g., the processing ability of large pores or the property-exhibiting ability of small pores) can be particularly suitably exhibited.

[0071] The porosity of the porous structure according to the second embodiment is 30 to 70%. From the viewpoint of improving processing capacity, the porosity is preferably 40% or more, and more preferably 50% or more. From the viewpoint of improving strength, the porosity is preferably 60% or less. The porosity is the porosity obtained by mercury intrusion porosimetry and analyzed in the pore diameter range of 0.003 to 200 μm.

[0072] The porous structure according to the second embodiment contains, as a chemical component, at least one component selected from the group consisting of SiO2 and Al2O3. From the viewpoints of chemical durability and strength, the porous structure preferably contains SiO2, and from the viewpoint of strength, it is more preferable that the porous structure contains Al2O3. From these viewpoints, it is even more preferable that the porous structure contains SiO2 and Al2O3. From the viewpoint of further improving the strength, the porous structure preferably further contains at least one component selected from the group consisting of MgO, CaO, BaO, Na2O, and K2O. The porous structure may contain other components such as B2O3, ZrO2, Li2O, and TiO2.

[0073] The content of SiO2 in the porous structure is preferably 45 to 80 mass %, more preferably 50 to 80 mass %, and may be 60 to 80 mass %, based on the oxide. The content of Al2O3 in the porous structure is preferably 0.1 to 30 mass %, more preferably 1 to 20 mass %, and even more preferably 1 to 10 mass %, based on the oxide. The total content of SiO2 and Al2O3 in the porous structure is preferably 50 to 95 mass %, more preferably 60 to 90 mass %, based on the oxides.

[0074] Examples of materials for the porous structure include glass, ceramics (cement, alumina, sialon, etc.), resin, and metal. The porous structure may be made of one material or may contain multiple materials. In one embodiment, the porous structure is preferably porous glass. The porous glass may be the porous glass material described in detail in relation to the first embodiment.

[0075] In one embodiment, in any two of the two or more peaks observed in a graph of Log differential pore volume vs. pore diameter obtained by mercury intrusion porosimetry, the ratio of the peak pore diameter on the larger pore side to the peak pore diameter on the smaller pore side is preferably 1.5 or more, more preferably 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, 2.0 or more, 2.1 or more, 2.2 or more, 2.3 or more, 2.4 or more, 2.5 or more, 2.6 or more, 2.7 or more, 2.8 or more, 2.9 or more, or 3.0 or more. When the peak pore diameter ratio is within the above range, the difference between the larger pore diameter and the smaller pore diameter becomes clear, and it is believed that good processing ability and characteristic development ability can be exhibited. The ratio may be, for example, 100 or less.

[0076] The pore surface area of ​​the porous structure is 0.01 m from the viewpoint of improving the ability to exhibit characteristics (for example, the ability to capture substances). 2 / g or more is preferable, and 0.1m 2 / g or more, 1.0m 2 / g or more, 2.0m 2 / g or more, 3.0m 2 / g or more, or 4.0m 2 From the viewpoint of further improving the processing capacity, the pore surface area of ​​the porous structure is 100 m 2 / g or less is preferable, and 90m 2 / g or less, 80m 2 / g or less, 70m 2 / g or less, 60m 2 / g or less, or 50m 2 From this viewpoint, the pore surface area of ​​the porous structure is 0.01 to 100 m 2 / g is preferred, and 0.1 to 80m 2 / g is more preferable, and 0.3 to 50m 2 The pore surface area is the pore surface area obtained by mercury intrusion porosimetry and analyzed in the pore diameter range of 0.003 to 200 μm.

[0077] From the viewpoint of further improving processing capacity, the pore volume of the porous structure is preferably 0.01 mL / g or more, more preferably 0.05 mL / g or more, 0.1 mL / g or more, 0.2 mL / g or more, or 0.3 mL / g or more. From the viewpoint of further improving strength, the pore volume of the porous structure is preferably 10 mL / g or less, more preferably 5 mL / g or less, 4 mL / g or less, 3 mL / g or less, 2 mL / g or less, 1 mL / g or less, 0.9 mL / g or less, 0.8 mL / g or less, or 0.7 mL / g or less. The pore volume is the pore volume obtained by mercury intrusion porosimetry and analyzed in the pore diameter range of 0.003 to 200 μm.

[0078] In one embodiment, from the viewpoint of further improving the processing capacity, it is preferable that a peak be observed in the pore diameter range of 0.05 μm or more in a graph of Log differential pore volume vs. pore diameter obtained by mercury porosimetry. From the viewpoint of further improving the processing capacity, it is preferable that a peak be observed only in the pore diameter range of 0.05 μm or more in a graph of Log differential pore volume vs. pore diameter obtained by mercury porosimetry. That is, it is preferable that a peak be observed in the pore diameter range of 0.05 μm or more, and that no peak be observed in the pore diameter range of less than 0.05 μm.

[0079] In one embodiment, in a graph of Log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, one or more peaks may be observed in the pore diameter range of 0.01 to 0.5 μm and in the pore diameter range of more than 0.5 μm to 20 μm. For example, when the porous structure is used to capture micromaterials such as extracellular vesicles, pore sizes within the above ranges may provide particularly good performance. One or more peaks may be observed in the pore diameter range of 0.05 to 0.4 μm and in the pore diameter range of 0.5 to 10 μm, and one or more peaks may be observed in the pore diameter range of 0.08 to 0.3 μm and in the pore diameter range of 0.5 to 2 μm.

[0080] In one embodiment, the porous structure preferably includes pores having a structure derived from phase separation due to spinodal decomposition. The details of the pores having a structure derived from phase separation due to spinodal decomposition are as described above.

[0081] In one embodiment, the porous structure may be a porous structure in which two or more types of porous glass particles with different pore sizes are bonded together. Details of the embodiment in which "two or more types of porous glass particles with different pore sizes are bonded together" are as described above.

[0082] The shape of the porous structure is not particularly limited and may be plate-like, polyhedral, spherical, or the like. In one embodiment, the porous structure may be plate-like. When the porous structure is plate-like, the thickness may be, for example, 5.00 mm or less, 4.00 mm or less, or 3.00 mm or less. Even if the thickness is less than the above upper limit, the porous structure has excellent strength and is therefore highly practical. The thickness may be 0.01 mm or more.

[0083] [Uses of porous structures] The use of the porous structure is not particularly limited. For example, the porous structure can be suitably used for applications such as filters (including substance capture filters), separation membranes, column packing materials, adsorbents, catalyst carriers, emulsification membranes, microporous bubbling nozzles, enzyme carriers, carriers for DNA synthesis, nanocrystal carriers, dye units, solid-state dye lasers, bonding materials, water-retaining materials, molecular sieves, ion exchange materials, heat insulating materials, electrode materials, separators, magnets, low-dielectric substrates, soundproofing / sound-absorbing materials, radioactive waste solidification, removal and recovery of hazardous substances such as heavy metal ions, removal and recovery of valuable substances such as rare metals, vacuum chucks, and adsorbents.

[0084] <Method of manufacturing porous structure> The method for producing the porous structure is not particularly limited. For example, the porous structure may be produced by mixing porous materials having different pore sizes and using a chemical reaction (thermal reaction, hydrolysis reaction, condensation reaction, oxidation-reduction reaction, acid-base reaction, etc.). The porous material may contain, for example, at least one component selected from the group consisting of SiO2 and Al2O3, and may contain other components as desired. The pore diameter, peak half width, porosity, pore surface area, and pore volume can be adjusted by appropriately selecting the respective porous materials used as raw materials. The pore diameter, peak half-width, porosity, pore surface area, and pore volume of the raw material may be adjusted by the manufacturing conditions. For example, when phase separation is performed by spinodal decomposition, the pore diameter, peak half-width, porosity, pore surface area, and pore volume can be adjusted by adjusting the heating temperature and / or heating time in the phase separation process. Alternatively, the parameters can be controlled by adjusting the particle size distribution of the powder obtained in the atomization process and classification process, adjusting the mixing ratio of the mixed powder species in the mixing process, adjusting the conditions in the pressure molding process, adjusting the heating temperature and / or heating time in the sintering process, etc.

[0085] <Substance Capture Filter and Substance Capture Method> The details of the substance-trapping filter and substance-trapping method described in detail in relation to the porous glass material according to the first embodiment can also be applied to the porous structure according to the second embodiment, provided that the "porous glass material according to the first embodiment" or "porous glass material" is read as "porous structure." [Example]

[0086] Next, embodiments of the present disclosure will be described in detail using examples, but the embodiments of the present disclosure are not limited to these examples. In the following examples, Examples 1 to 6 are examples, and Examples 7 to 13 are comparative examples. In addition, Examples 2-1 to 2-27 are examples, and Examples 2-28 to 2-31 are comparative examples.

[0087] <Examples 1 to 13> [Production of Porous Glass Material] 1. Preparation of glass base material The raw materials, SiO2, Al2O3, BO3, MgO, CaCO3, BaCO3, and Na2CO3 particles, were mixed to obtain 800 g of a seven-component glass raw material (SiO2-Al2O3-BO3-MgO-CaO-BaO-Na2O) with a mass percentage of 51% SiO2, 4% Al2O3, 25% BO3, 5% MgO, 6% CaO, 2% BaO, and 7% Na2O. The glass raw material was placed in a platinum crucible and heated to 1500°C in a resistance-heated electric furnace. After degassing and homogenization for 4 hours, the resulting molten glass was poured into a mold and cooled from a temperature of glass transition temperature (Tg: 580°C) + 50°C to room temperature (approximately 25°C) at a rate of 1°C / min to obtain a glass block (glass base material).

[0088] 2. Phase separation The glass block was heat-treated under the conditions shown in Table 1 to carry out a phase-separation treatment so as to obtain a desired pore size, thereby obtaining a phase-separated glass block (phase-separated glass material).

[0089] 3. Micronization The phase-separated glass block was crushed into cullets, and then crushed to a desired particle size by the method shown in Table 1 to obtain phase-separated glass particles.

[0090] 4. Classification The phase-separated glass particles were classified to obtain phase-separated glass particles having a desired particle size.

[0091] 5. Mixing Phase-separated glass particles with different pore sizes were blended in the proportions shown in Table 2, and the mixture was mixed by hand shaking 100 times.

[0092] 6. Pressure molding 50g of the mixed phase-separated glass particles was placed in a 55mm x 40mm mold and subjected to a pressure of 67.4kgf / cm 2 After preforming by applying a pressure of 150 MPa (approximately 6.6 MPa) for 5 minutes, the final forming was carried out by applying a pressure of 150 MPa by cold isostatic pressing for 1 minute.

[0093] 7. Sintering The molded body of the phase-separated glass particles was sintered by heat treating it at 640°C for 10 hours, to obtain a phase-separated glass sintered block (a porous glass material precursor).

[0094] 8.Processing The phase-separated glass block or the phase-separated glass sintered body block was cut and ground, and finally both surfaces were polished to a mirror finish to obtain plate-shaped glass having the dimensions shown in Table 4.

[0095] 9. Acid treatment The glass plates were immersed in 1N HCl for the times shown in Table 2 to carry out a leaching treatment.

[0096] 10.Alkaline treatment The glass substrate was washed with 0.1 N NaOH and water at 80° C. to obtain a porous glass substrate (porous glass material).

[0097] 11.Surface modification The porous glass substrate was immersed in an isopropyl alcohol (IPA) solution containing a silane coupling agent at 50°C for 24 hours, and then washed with IPA to coat the surface.

[0098] 12. Assembly to the housing The obtained porous glass substrate was fixed inside a cylindrical tube so that the inside could be sealed, thereby producing a capturing means capable of processing 500 μL of dispersion solution.

[0099] Phase-separated glass particles A to J were produced by steps 1 to 4, and these were used to produce samples of Examples 1 to 13 by the above-mentioned steps. In Examples 1 to 13, some steps were omitted, and whether or not a step was performed is indicated in Tables 1 and 2. Table 1 shows the conditions for producing phase-separated glass particles in steps 1 to 4. In Table 1, "-" indicates that the step was not performed or that the item did not apply. Table 2 shows the conditions for producing the porous glass substrate in steps 5 to 12. In Table 2, "-" indicates that the step was not performed or that the item did not apply. "P1" represents particles on the small pore diameter side of the phase-separated glass particles used (however, if only one type of phase-separated glass particle was used, then that particle), and "P2" represents particles on the large pore diameter side of the phase-separated glass particles used, and the same applies to the following tables.

[0100] [Table 1]

[0101] [Table 2]

[0102] [Measurement of pore size and particle size] The pore size and particle size of the porous glass substrate after surface modification were measured by the following method.

[0103] (pore diameter) The pore size distribution was determined by mercury intrusion porosimetry using a Micromeritics Autopore V9620 pore size distribution analyzer, as a graph of log differential pore volume versus pore size. Approximately 0.2 g of sample was placed in a 5 cc standard cell (stem volume 0.4 cc) and measured under an initial pressure of 7 kPa (approximately 1 psia, equivalent to a pore diameter of approximately 210 μm). The mercury parameters were set to a mercury contact angle of 140 degrees and a mercury surface tension of 480 dynes / cm. The median diameter (D50 value) was determined from the obtained pore size distribution. The peak pore size value refers to the pore size at the peak top (i.e., the peak pore size) determined based on the obtained pore size distribution. The peak half-width refers to the width of the pore size at half the peak top.

[0104] (particle size) The surface and cross section of each sample were observed by SEM to obtain image data, which were then processed and analyzed using image analysis software (National Institutes of Health [NIH] open source, named "Image J").

[0105] Image processing First, the images obtained by SEM observation were binarized using "Image J." Brightness and contrast were corrected to highlight the glass structure, and an appropriate threshold was set to clearly show the differences in appearance between porous glass particles with different pore sizes, resulting in a binarized image. The threshold was selected using the Kittler method.

[0106] Image analysis Next, horizontal lines were drawn across the resulting binarized image, and the minor axis lengths of the porous glass particles along the lines were measured. At least five horizontal lines were drawn per image, and at least 100 measurement points were used. Because the structure of each glass sample was random due to the nature of phase separation caused by spinodal decomposition, it is believed that the areas displayed in the images may differ. However, in this method, the analysis was performed uniformly using the above procedure, regardless of the particle shape. The minor axis data of the porous glass particles obtained by image analysis under the conditions set above were plotted as a histogram, and the peak value was determined as the particle diameter.

[0107] The measured peak half widths and peak half width X / peak pore diameter Y (X / Y) for the phase-separated glass particles A to J are shown in the table below.

[0108] [Table 3]

[0109] (※1) This item was substituted with the D50 value, which is approximately equal to the peak pore diameter. (※2) This item was substituted with an estimated value using the D50 value and the relationship between pore diameter and peak value / peak width.

[0110] The table below summarizes the dimensions, pore diameter, particle diameter, and characteristic values ​​of the obtained plate-shaped glass for the porous glass substrates of Examples 1 to 13. In the table, "-" indicates that the measurement was not performed or is not applicable. Details of each characteristic value in the table are as follows. A value: Peak half-width X / peak pore diameter Y B value: Minor diameter / pore diameter of the large pore diameter porous glass particle (P2) C value: Minor axis of the porous glass particle (P1) on the small pore diameter side / Pore diameter of the porous glass particle (P2) on the large pore diameter side D value: The number of peaks in the pore diameter range of 0.005 to 100 μm in a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry E value: The ratio of the peak pore diameter on the larger pore diameter side to the peak pore diameter on the smaller pore diameter side of the two peaks in a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry. F value: Peak particle size

[0111] [Table 4]

[0112] (※1) This item was substituted with the D50 value, which is approximately equal to the peak pore diameter. (※2) This item was substituted with an estimated value using the D50 value and the relationship between pore diameter and peak value / peak width. (※3) This item is an estimated value based on Example 2. (※4) In this measurement system, the peak pore diameter on the large pore diameter side (P2) is calculated to be smaller when the porous glass substrate is sintered than when it is a phase-separated glass ingot. The value described in this section is an estimated value based on the rate of change when the porous glass substrate of Example 6 was produced by sintering phase-separated glass particle J. (*5) The number of peaks listed in this section is an estimate based on the number of types of phase-separated glass particles with different pore sizes. As shown in Example 6, the number of peaks is considered to be the same as the number of types of phase-separated glass particles with different pore sizes.

[0113] 2 and 3 show graphs of the Log differential pore volume versus pore diameter for Examples 6 and 9. Two peaks were observed in Example 6, and one peak was observed in Example 9.

[0114] [Characteristics evaluation] The following characteristic evaluations were carried out using a sample in which the porous glass substrate was fixed in a cylindrical tube after assembly into a housing and which was capable of processing a dispersion solution.

[0115] (Test Example 1: Recovery amount of extracellular vesicles dispersed in serum) As an example of the individual properties of porous glass materials, we evaluated the recovery performance of extracellular vesicles (EVs) dispersed in human serum when using porous glass substrates as filters. CD9 (molecular weight 24 kDa), a protein characteristic of extracellular vesicles, was used as an indicator of recovery amount. CD9 was recovered as a filtrate from a porous glass substrate through which human serum had been passed. The filtrate was then evaluated by Western blotting, and image data for CD9 luminescence detection was obtained. Furthermore, this image data was analyzed using image analysis software (Image J, open source software from the National Institutes of Health [NIH]). The signal value of the resulting luminescence band was used as an indicator of CD9 recovery amount, and relative comparison data for CD9 recovery amount were obtained. The above procedure was also performed on three samples of human serum from different lots. The detailed procedure is described below.

[0116] -Recovery of CD9 using porous glass substrate 500 μL of human serum pretreated with a 0.2 μm cellulose acetate filter was placed in the tube and centrifuged at 6000 G for 10 minutes. Next, 100 μL of buffer solution was placed in the tube and centrifuged at 3000 G for 5 minutes. Then, 100 μL of surfactant-containing solution was placed in the tube and centrifuged at 300 G for 1 minute, held for 5 minutes, and then centrifuged at 6000 G for 5 minutes. This dissolved the lipid membrane of the extracellular vesicles captured on the porous glass substrate, and proteins contained in the extracellular vesicles, including CD9, were recovered in the filtrate.

[0117] - Obtaining image data of CD9 luminescence detected by Western blotting The resulting filtrate was heated at 75°C for 5 minutes, then loaded into the wells of an SDS-PAGE gel and electrophoresed at 150V for 80 minutes. SDS-PAGE was then performed. A current of 1.3A and 25V was applied to the membrane overlying the gel for 7 minutes to transfer the data. The resulting membrane was reacted with a CD9 antibody as the primary antibody, followed by a secondary antibody. Luminescence was then detected by adding a luminescence reagent using an Amersham ImageQuant 800 series (IQ800) CCD imager from Cytiva, and image data for CD9 luminescence detection were obtained.

[0118] Analysis of CD9 luminescence detection image data Images obtained by Western blotting were inverted using the image analysis software "Image J." The measurement range was then specified by drawing a rectangular frame around the luminescent band observed around 24 kDa. The luminescent band was then quantified using an Image J band quantification macro (Ochanomizu University Open Macro, named "Quantification of Gel Bands by an Image J Macro, Band / Peak Quantification Tool"). The signal value of the obtained luminescent band was used as an index of CD9 recovery, and relative comparison data between samples was calculated.

[0119] The relative ratios of CD9 emission band signals by Western blotting are shown in Table 5 and Figure 4. The filter made with the hierarchical porous glass substrate showed a recovery amount of extracellular vesicles equal to or greater than that of a filter made with a porous glass substrate with only one pore size peak (a comparative example). Furthermore, the high recovery amount of extracellular vesicles in the hierarchical porous glass was characterized by a smaller peak pore size on the small pore size side and a high mass ratio of porous glass particles with pore sizes on the small pore size side.

[0120] (Test Example 2: Filter material resistance per unit thickness) The filter resistance per unit thickness, which is an indicator of the fluid passage performance within the porous material, was evaluated as the processing capacity of an example of a porous glass material. The lower the filter resistance per unit thickness, the higher the fluid passage capacity and the less likely it is to clog. First, water was passed through the porous glass substrate, and the pressure, time, and filtrate volume data were measured during the water passage. Next, a graph of u×μ×l vs. P was created from the data using the relationship "P=r×u×μ×l" obtained from Ruth's filtration rate equation "u=P / (μ×r×l)" (u: flow rate, P: pressure, μ: filtrate viscosity, r: filter resistance per unit thickness, l: filter thickness). The slope of the resulting graph was used to calculate the filter resistance per unit thickness, r. Furthermore, a graph of peak pore size vs. filter resistance was created by plotting the filter resistance r values ​​for each pore size of the porous glass substrate. Here, the smallest peak value among multiple peak values ​​was used as the peak pore size for the layered porous glass substrate. The detailed procedure is described below.

[0121] ·Water flow through porous glass substrate 500 μL of pure water was placed in the tube and centrifuged in a centrifuge adjusted to 20°C, after which the mass of the resulting filtrate was measured. Data was obtained at five points with different centrifugal forces and centrifugation times, thereby obtaining data for varying pressure P and flow rate u.

[0122] Calculation of filter resistance per unit thickness A graph of u x μ x l vs. P was created from the data obtained above. The viscosity of the filtrate μ was calculated using the viscosity of water at 25°C, 1.002 mPa·s. The thickness of the filter material l was calculated using the thickness of the porous glass substrate. The flow rate u and pressure P were calculated using the following formulas. Flow rate u = filtrate mass / density of water at 20°C [0.998 g / cm 3 ] / area of ​​porous glass substrate / centrifugation time Pressure P = (centrifugal force × gravitational acceleration × (volume of pure water contained in the tube [500 μL] × density of water at 20 °C [0.998 g / cm 3 ]-filtrate mass / 2) / area of ​​porous glass substrate Next, from the relationship "P=r×u×μ×l" obtained from Ruth's filtration rate formula "u=P / (μ×r×l)", the slope of the resulting u×μ×l vs. P graph was calculated as the filter material resistance r per unit thickness.

[0123] Graphing peak pore size vs. media resistance The data on the filter resistance r was plotted for each pore size of the porous glass substrate to create a graph of peak pore size versus filter resistance. Here, the peak pore size of the layered porous glass substrate was the smallest of the multiple peaks that were expected to exhibit the properties of the porous material.

[0124] The filter resistance per unit thickness is shown in Table 5 and Figure 5. The filter fabricated using the multilayered porous glass substrate exhibited a significant reduction in filter resistance compared to the comparative example, a filter fabricated using a porous glass substrate with only one pore diameter peak. Furthermore, the characteristics of the multilayered porous glass substrate that result in low filter resistance are a large pore diameter on the small pore diameter side and a high mass ratio of porous glass particles with pore diameters on the large pore diameter side.

[0125] (Test Example 3: Clogging resistance to serum) As an example of the processing capacity of a porous material, the resistance to clogging when human serum is passed through a porous glass substrate used as a filter was evaluated. First, in operation (1), 500 μL of human serum pretreated with a 0.2 μm cellulose acetate filter was placed in the tube. Next, in operation (2), the tube was centrifuged at 4000 G for 1 to 60 minutes in a centrifuge adjusted to 20°C, and the mass of the filtrate was measured. Furthermore, in operation (3), additional human serum pretreated with a 0.2 μm PTFE filter was placed in the tube so that the total amount of human serum contained in the tube was 500 μL. Next, operations (2) and (3) were repeated multiple times to investigate the change in flow rate versus filtrate volume under semi-constant pressure conditions.

[0126] The filtrate volume and flow rate were calculated from the centrifugal separation conditions and filtrate mass data obtained in the above test. Assuming that the density of human serum is equivalent to that of water, the flow rate was calculated as follows: Flow rate = filtrate mass / density of water at 20°C [0.998 g / cm 3 The filtrate volume was calculated using the formula: "Filtrate volume after nth repetition = total filtrate volume up to (n-1)th repetition + filtrate volume after nth repetition / 2", where n is the number of repetitions. A graph was created plotting the flow rate and filtrate volume obtained above, and the decrease in flow rate with increasing filtrate volume was evaluated as an indicator of the clogging resistance of the porous glass substrate to human serum.

[0127] As an index of clogging resistance, we focused on the resistance of the flow rate to decrease when the amount of filtrate increased. In other words, when the amount of filtrate calculated using the above method was plotted on the horizontal axis and the flow rate on the vertical axis, the smaller the change in flow rate relative to the amount of filtrate, the higher the clogging resistance was determined to be. The clogging characteristics were evaluated according to the following criteria A to D. A: The flow rate is maintained at 10 μl / min or more when the serum flow rate exceeds 1000 ml. B: Does not meet the A rating, but maintains a flow rate of 10 μl / min or more when the serum flow rate exceeds 800 ml C: Does not meet the A and B criteria, but maintains a flow rate of 10 μl / min or more when the serum flow rate exceeds 600 ml D: Does not meet the A-C grades

[0128] Table 6 shows the test results for the filters made with the porous glass substrates of Examples 2, 4, 5, and 7, and Figure 6 shows a graph of filtrate volume versus flow rate. The filter made with the comparative porous glass substrate, which has only one pore size peak, exhibited a significant decrease in flow rate as the filtrate volume increased. In contrast, the filter made with the multilayered porous glass substrate exhibited a relatively gradual decrease in flow rate as the filtrate volume increased. Furthermore, in the multilayered porous glass substrate, the slope of the graph of filtrate volume versus flow rate was gentler when the volume ratio of porous glass particles on the large pore size side was higher, indicating higher clogging resistance. The evaluation results showed that the filters of Examples 2, 4, and 5 were rated A, while the filter of Example 7 was rated D.

[0129] [Table 5]

[0130] [Table 6]

[0131] The above tests showed that a porous glass material with excellent processing ability and ability to exhibit properties was obtained.

[0132] <Examples 2-1 to 2-31> [Production of Porous Glass Material] Porous glass materials of Examples 2-1 to 2-31 were produced using the same procedures as those shown in Examples 1 to 13 above. Phase-separated glass particles were produced under the phase-separation conditions shown in Table 7, and the particles were micronized, classified, and mixed under the conditions shown in Table 8. Subsequently, the glass was pressure-molded and heat-treated at 640°C for 10 hours to obtain a sintered body. The glass was processed into a plate shape, immersed in 1N HCl for 17 hours, and then washed with 0.1N NaOH and water at 80°C to obtain various porous glass materials with different pore sizes and pore size peak numbers. In Table 8, "-" indicates that the result is not applicable.

[0133] [Table 7]

[0134] [Table 8]

[0135] [Measurement of characteristic values] The pore diameter and particle diameter were measured in the same manner as in Examples 1 to 13, and the above-mentioned A values ​​to F values ​​and peak intensity were determined. The peak intensity refers to the value on the vertical axis at the peak top in a graph of Log differential pore volume versus pore diameter, with pore diameter on the horizontal axis and Log differential pore volume on the vertical axis. Further, by mercury intrusion porosimetry under the same conditions as in Examples 1 to 13, the pore volume, pore surface area, and porosity were determined in the range of 0.003 to 200 μm. The measurement and calculation results are shown in Tables 9 and 10. In the tables, "-" indicates that the measurement was not performed or is not applicable.

[0136] [Characteristics evaluation] (Test Example 2-1: Filter material resistance per unit thickness) In the same manner as in Test Example 2, the filter resistance per unit thickness of the porous glass material was evaluated.

[0137] (Test Example 2-2: Recovery amount of extracellular vesicles) As an example of the individual properties of porous glass materials, we evaluated the recovery performance of extracellular vesicles dispersed in human serum when using a porous glass substrate as a filter. CD63, a protein characteristic of extracellular vesicles, was used as an indicator of the recovery amount.

[0138] -Recovery of CD63 using porous glass substrate 500 μL of human serum pretreated with a 0.2 μm cellulose acetate filter was placed in the tube and centrifuged at 6000 G for 10 minutes. Next, 100 μL of buffer solution was placed in the tube and centrifuged at 3000 G for 5 minutes. Then, 100 μL of surfactant-containing solution was placed in the tube and centrifuged at 300 G for 1 minute, held for 5 minutes, and then centrifuged at 6000 G for 5 minutes. This dissolved the lipid membrane of the extracellular vesicles captured on the porous glass substrate, and proteins contained in the extracellular vesicles, including CD63, were recovered in the filtrate.

[0139] Evaluation of CD63 recovery by ELISA (enzyme-linked immunosorbent assay) The Human CD63 ELISA Kit (ab275099) was used. 30 μL of the resulting filtrate was mixed with 0.1 μL of HAMA Blocker and 19.9 μL of the included sample diluent. The mixture was then added to an ELISA plate at 50 μL / well. Additionally, a standard sample, a standard blank, and a solution consisting of 15 μL of PBS, 15 μL of surfactant-containing solution, 0.1 μL of HAMA Blocker, and 19.9 μL of sample diluent were added to the ELISA plate at 50 μL / well. The procedure was then carried out according to the ELISA kit instructions. Finally, the absorbance at 450 nm was measured using an Agilent Technologies BioTek Cytation 5 Cell Imaging Multimode Reader. The CD63 concentration in the purified filtrate was calculated by converting the concentration from the calibration curve. This concentration was used as an indicator of CD63 recovery and used to compare the extracellular vesicle capture performance between samples.

[0140] The CD63 concentrations in the resulting filtrates are shown in Table 11. [Table 9]

[0141] [Table 10]

[0142] [Table 11]

[0143] (※6)This item is an estimated value.

[0144] Figure 9 shows a graph plotting the filter resistance per unit thickness and the CD63 concentration in the filtrate for each example in Table 11. The plots for Examples 2-1 to 2-12 are represented by circles, and the plots for Examples 2-28 to 2-31 are represented by triangles. As shown in the figure, a porous glass substrate with multiple pore size peaks was shown to be able to achieve both high water permeability and high capture performance.

[0145] Figure 10 shows the relationship between the pore surface area and the CD63 concentration in the filtrate for Examples 2-1 to 2-12. Figure 11 shows the relationship between the pore surface area and the filter resistance per unit thickness for Examples 2-1 to 2-27. As shown in the figure, a correlation was found between the pore surface area and the CD63 concentration, and between the pore surface area and the filter resistance, suggesting that the balance between water permeability and capture performance can be adjusted by adjusting the pore surface area.

[0146] The Young's modulus of the porous glass substrate was calculated based on the following formula (X) described in "On the effective young's modulus of elasticity for porous materials: microstructure modeling and comparison between calculated and experimental values," by A.R. Boccaccini, G. Ondracek, P. Mazilu, and D. Windelberg in "Journal of the Mechanical Behavior of Materials." The Young's modulus when the porosity was 0% was estimated from the value measured using the ultrasonic pulse method based on JIS R1602 (1995).

[0147]

number

[0148] E eff : Actual Young's modulus E M : Young's modulus when porosity is 0% C D :Porosity

[0149] The relationship between the porosity and the Young's modulus of the porous glass substrate is shown in Table 12 and Figure 12. It can be seen that particularly good strength can be obtained when the porosity is 70% or less.

[0150] [Table 12]

[0151] Example 3 [Composition analysis of porous glass materials] Porous glass filters for composition analysis were prepared according to the procedures described in Examples 1 to 13 above. After preparing the glass base material, phase-separation heat treatment was performed under two conditions: Condition A: 740°C, 4 hours and 30 minutes; and Condition B: 770°C, 7 hours and 15 minutes. Phase-separated glass blocks A and B were obtained, respectively. Each was crushed into cullets and then pulverized in a ball mill to obtain phase-separated glass particles A and B. Phase-separated glass particles A and B were mixed at mass ratios of 75% and 25%, respectively, and pressure-molded. The molded body was sintered by heat-treating at 640°C for 10 hours to obtain a phase-separated sintered glass block (a porous glass material precursor). The molded body was then processed to a size of 40 mm in diameter and 2.0 mm in thickness, immersed in 1N HCl at 90°C for 72 hours for leaching, and washed with 0.1N NaOH and water at 80°C to obtain a porous glass material. The porous glass material thus obtained was cut to a predetermined size and subjected to composition analysis using a wavelength dispersive X-ray fluorescence analyzer ("ZSX Primus II" manufactured by Rigaku Corporation). The porous glass composition obtained by analysis is shown in Table 13. The composition of the porous glass material can be adjusted by the original glass base material, phase separation heat treatment conditions, mixing conditions, etc., so it is not necessarily limited to the composition shown in Table 13, but is shown as one example.

[0152] [Table 13]

Claims

1. A porous glass material in which two or more types of porous glass particles having different pore sizes are bonded together, wherein two or more of the two or more types of porous glass particles contain pores having a structure derived from phase separation due to spinodal decomposition.

2. 2. The porous glass material according to claim 1, wherein two or more peaks are observed in a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, and at least two of the two or more peaks have a peak half-width X and a peak pore diameter Y that satisfy the relationship X / Y<2.

0.

3. The porous glass material according to claim 1, wherein the two or more types of porous glass particles are n types of porous glass particles, where n is an integer of 2 or more, and when the 1st to n / 2nd porous glass particles of the n types of porous glass particles are designated as porous glass particles L when n is an even number, or the 1st to (n+1) / 2nd porous glass particles of the n types of porous glass particles are designated as porous glass particles L when n is an odd number, counting in order of pore diameter, the minor axis of at least one type of the porous glass particles L is larger than the pore diameter.

4. the two or more types of porous glass particles are n types of porous glass particles, where n is an integer of 2 or greater, and among the n types of porous glass particles, the 1st to n / 2nd porous glass particles when n is an even number, or the 1st to (n+1) / 2nd porous glass particles when n is an odd number, counted in order of decreasing pore diameter, are referred to as porous glass particles L; and the 1st to n / 2nd porous glass particles when n is an even number, or the 1st to (n+1) / 2nd porous glass particles when n is an odd number, counted in order of decreasing pore diameter, are referred to as porous glass particles S; the minor axis of any of the porous glass particles S is 2 to 500 times the pore diameter of any of the porous glass particles L.

5. 2. The porous glass material according to claim 1, wherein 2 to 20 peaks are observed in a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry.

6. 2. The porous glass material according to claim 1, wherein two or more peaks are observed in a pore diameter range of 0.005 to 100 μm in a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry.

7. 2. The porous glass material according to claim 1, wherein two or more peaks are observed in a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, and in any two of the two or more peaks, the ratio of the peak pore diameter on the larger pore diameter side to the peak pore diameter on the smaller pore diameter side is 1.5 or more.

8. 2. The porous glass material according to claim 1, wherein the peak particle diameter of each of the two or more types of porous glass particles is 0.04 to 200 μm.

9. 2. The porous glass material according to claim 1, wherein the volume fraction of the porous glass particles having the smallest volume fraction among the two or more types of porous glass particles is 5% by volume or more with respect to the total volume fraction of the two or more types of porous glass particles.

10. 2. The porous glass material according to claim 1, wherein in a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, one or more peaks are observed in the pore diameter range of 0.01 to 0.5 μm and one or more peaks are observed in the pore diameter range of more than 0.5 μm to 20 μm.

11. The porous glass material is SiO ２ and Al ２ O ３ The porous glass material of claim 1 , comprising:

12. two or more types of phase-separated glass materials having different structural scales of phase separation due to spinodal decomposition are microparticulated to obtain two or more types of phase-separated glass particles; mixing the two or more types of phase-separated glass particles; the mixed phase-separated glass particles are heated to bond the particles together, thereby obtaining a molded body; A method for producing a porous glass material precursor.

13. two or more types of phase-separated glass materials having different structural scales of phase separation due to spinodal decomposition are microparticulated to obtain two or more types of phase-separated glass particles; mixing the two or more types of phase-separated glass particles; the mixed phase-separated glass particles are heated to bond the particles together to obtain a molded body; the molded body is brought into contact with at least one selected from the group consisting of water at 40°C or higher, an acidic solution, and an alkaline solution, thereby removing the eluted phase from the phase-separated glass particles, thereby obtaining a porous glass material. A method for producing porous glass materials.

14. The method according to claim 12 or 13, wherein after obtaining the two or more types of phase-separated glass particles, the two or more types of phase-separated glass particles are classified before being mixed.

15. The method according to claim 12 or 13, wherein after mixing the two or more types of phase-separated glass particles, the mixed phase-separated glass particles are pressure-molded before heating the phase-separated glass particles.

16. A substance-trapping filter comprising the porous glass material according to any one of claims 1 to 11.

17. The substance capture filter according to claim 16, which is used to capture extracellular vesicles.

18. 17. The substance capture filter according to claim 16, further comprising a coating layer containing a protein adhesion inhibitor.

19. 17. The substance capture filter according to claim 16, wherein the peak particle diameter of each of the two or more types of porous glass particles is 0.5 to 100 μm.

20. A method for capturing a substance, comprising contacting a solution or suspension containing a target substance with the substance-capturing filter according to claim 16.

21. In a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry, two or more peaks are observed within the pore diameter range of 0.005 to 100 μm, In at least two of the two or more peaks, the peak half width X and the peak pore diameter Y satisfy the relationship of X / Y<2.0; The porosity is 30 to 70%, SiO ２ and Al ２ O ３ A porous structure comprising at least one component selected from the group consisting of:

22. 22. The porous structure of claim 21, which is porous glass.

23. Furthermore, MgO, CaO, BaO, Na ２ O and K ２ 22. The porous structure of claim 21, comprising at least one component selected from the group consisting of:

24. 22. The porous structure according to claim 21, wherein in any two of the two or more peaks, the ratio of the peak pore diameter on the larger pore diameter side to the peak pore diameter on the smaller pore diameter side is 1.5 or more.

25. Pore ​​surface area is 0.01 to 100 m ２ / g.

26. The porous structure according to claim 21, wherein a peak is observed in a pore diameter range of 0.05 μm or more in a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry.

27. 22. The porous structure according to claim 21, wherein one or more peaks are observed in the pore diameter range of 0.01 to 0.5 μm and in the pore diameter range of more than 0.5 μm and not more than 20 μm in a graph of log differential pore volume versus pore diameter obtained by mercury intrusion porosimetry.

28. The porous structure according to claim 21, comprising pores having a structure resulting from phase separation due to spinodal decomposition.

29. 22. The porous structure according to claim 21, wherein two or more types of porous glass particles having different pore sizes are bonded together.

30. The porous structure according to claim 21, which is a plate-like structure having a thickness of 5 mm or less.

31. The porous structure according to any one of claims 21 to 30, which is used for a filter.

32. A substance-trapping filter comprising the porous structure according to any one of claims 21 to 30.

33. The substance capture filter according to claim 32, which is used to capture extracellular vesicles.

34. 33. The substance capture filter of claim 32, further comprising a coating layer containing a protein adhesion inhibitor.

35. A method for capturing a substance, comprising contacting a solution or suspension containing a target substance with the substance-capturing filter according to claim 32.

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