Porous substrates comprising PTFE compositions

Abstract

A porous substrate including a composition disposed thereon and a method of disposing a composition on a porous substrate. The composition includes a matrix. The matrix includes a plurality of polytetrafluoroethylene fibrils and a plurality of active particles.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 429,959, filed on December 2, 2022, the entire content of which is incorporated herein by reference. Background Art

[0003] Catalysts and sorbents (adsorbents and absorbers) can be used to remove unwanted chemicals from fluids (such as gases or liquids). For example, catalysts can be used to destroy chemicals such as ozone or to synthesize desired substances from reactant feedstocks. Sorbents can be used to separate or remove acidic molecules, basic molecules, ozone, or various other organic or inorganic compounds from fluids. When catalysts and sorbents are in powder or granular form, they can be difficult to handle. Thus, catalysts and sorbents are typically immobilized on carriers. Immobilizing a catalyst or sorbent on a carrier can make the catalyst or sorbent easier to handle; however, immobilizing a catalyst or sorbent on a carrier may reduce the surface area available for the catalyst or sorbent to remove unwanted chemicals from the fluid. Additionally, the physical and chemical properties of the carrier can affect the function of the catalyst (such as catalytic efficiency) or adsorbent. Moreover, the physical and chemical properties of the carrier can affect the final structure of products (such as filters) that include the catalyst or sorbent functionalized carrier. Ideally, a catalyst or sorbent functionalized carrier has one or more of the following characteristics: easy to shape; the catalyst or sorbent is immobilized in a structure that presents a large surface area for the catalyst or sorbent; and resistant to mechanical and chemical degradation. Summary of the Invention

[0004] The present disclosure provides a porous substrate having a composition disposed thereon. The composition includes a matrix that includes a plurality of PTFE fibrils and a plurality of active particles. In some embodiments, the plurality of PTFE fibrils includes short - strand PTFE fibrils and long - strand PTFE fibrils. In some embodiments, the composition further includes free active particles, free PTFE fibrils, or both. In some embodiments, the plurality of active particles, free active particles (if present), or both include a catalyst, an adsorbent, a growth seed, a metal - organic framework (MOF), or a combination thereof.

[0005] In some embodiments, the porous substrate includes a main surface and a plurality of macropores connected to the main surface. In some such embodiments, a first portion of the composition is disposed on at least a portion of the main surface, and at least a portion of the plurality of macropores is impregnated with a second portion of the composition. In some embodiments, the porous substrate further includes a third portion of the composition embedded within the porous substrate.

[0006] A method of disposing the composition on the porous substrate to produce the porous substrate of any of the foregoing embodiments is disclosed.

[0007] The terms "short - strand PTFE fibril" and "long - strand PTFE fibril" are used relatively. As measured by the Dimensional Analysis Test Method, the short - strand PTFE fibril has a length shorter than that of the long - strand PTFE fibril. As measured by the Dimensional Analysis Test Method, the average length of a plurality of short - strand PTFE fibrils is shorter than the average length of a plurality of long - strand PTFE fibrils. The length of the fibril is the maximum dimension of the fibril. The short - strand PTFE fibril and the long - strand PTFE fibril are formed from PTFE starting materials having different average PTFE resin sizes.

[0008] The term "active particle" as used herein refers to a particle comprising at least one component capable of participating in a chemical reaction (e.g., as a catalyst) and / or capable of acting as an adsorbent and / or absorbent.

[0009] Here, the terms "comprising" and its variants, when they appear in the specification and claims, do not have a limiting meaning. These terms should be understood to imply the inclusion of the stated steps or elements, or groups of steps or elements, but not the exclusion of any other steps or elements, or groups of steps or elements. The phrase "consisting of" means including and limited to whatever follows the phrase "consisting of". Thus, the phrase "consisting of" indicates that the listed elements are necessary or mandatory and that no other elements may be present. The phrase "consisting essentially of" means including any elements listed after the phrase and limited to other elements that do not interfere with or contribute to the activity or function specified in the disclosure of the listed elements. Thus, the phrase "consisting essentially of" indicates that the listed elements are necessary or mandatory, but other elements are optional and may or may not be present depending on whether they materially affect the activity or function of the listed elements. Any element or combination of elements recited in this specification in open - ended language (e.g., comprising and its derivatives) is considered to be additionally recited in closed - ended language (e.g., consisting of and its derivatives) and partially closed - ended language (e.g., consisting essentially of and its derivatives).

[0010] The words "preferred" and "preferably" refer to embodiments of the present disclosure that may provide certain benefits in certain circumstances. However, in the same or other circumstances, other embodiments may also be preferred. Moreover, reciting one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the present disclosure.

[0011] In this application, terms such as "a", "an", and "the" are not intended to refer to only a single entity, but rather include the general class that can be illustrated by a particular instance. The terms "a", "an", and "the" can be used interchangeably with the term "at least one". The phrases "at least one of..." and "comprising at least one of..." when used in conjunction with a list refer to any item in the list and any combination of two or more items in the list.

[0012] As used herein, the term "or" is generally used in its ordinary sense, including "and / or", unless the context clearly dictates otherwise.

[0013] The term "and / or" means one or all of the listed elements or any combination of two or more of the listed elements.

[0014] In addition, all numbers herein are assumed to be modified by the term "about", and in certain embodiments, preferably by the term "exactly". The term "about" as used herein in reference to a measured quantity refers to variations in that measured quantity that a person of ordinary skill in the art would expect to occur when making the measurement and exercising a degree of care commensurate with the purpose of the measurement and the precision of the measuring equipment used. At a minimum, and not to attempt to limit the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of significant digits reported and by applying ordinary rounding techniques.

[0015] Although the broad numerical ranges and parameters setting forth the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. However, all numerical values inherently contain a range necessarily resulting from the standard deviation found in their respective testing measurements.

[0016] As used herein, "up to" a number (e.g., up to 50) includes that number (e.g., 50). As used herein, "at least" a number (e.g., at least 50) includes that number (e.g., 50). As used herein, "not exceeding" a number (e.g., not exceeding 50) includes that number (e.g., 50).

[0017] In addition, numerical ranges expressed by endpoints herein include all numbers and endpoints falling within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0018] The term "room temperature" or "ambient temperature" as used herein refers to a temperature of 20°C to 25°C.

[0019] The term "in a range" or "within a range" (and similar expressions) includes the endpoints of the stated range.

[0020] References in this specification to "an aspect", "one aspect", "aspect", "an embodiment", "one embodiment", "certain embodiments", "some embodiments", or "one or more embodiments", etc., mean that a particular feature, structure, composition, or characteristic described in connection with that embodiment or aspect is included in at least one embodiment or aspect of the present disclosure. Thus, such phrases appearing throughout this specification are not necessarily referring to the same embodiment or aspect of the present disclosure. Additionally, the particular features, structures, compositions, or characteristics may be combined in any suitable manner in one or more embodiments or aspects.

[0021] When the term "on" is used to describe the situation where a composition or a hydrated solid is disposed on a surface or substrate, it includes that the composition or hydrated solid is placed (e.g., applied) directly or indirectly (e.g., on top of a primer coat) on the surface or substrate. Thus, for example, a composition or hydrated solid disposed on a primer coat or a pretreatment layer covering a substrate constitutes a composition or hydrated solid disposed on the substrate.

[0022] The foregoing summary of the present disclosure is not intended to describe every disclosed embodiment or every implementation of the present disclosure. The following description more particularly illustrates illustrative embodiments. Throughout the present disclosure, guidance is provided by way of examples, which may be used in various combinations. In each case, the listings are only used as representative groups and should not be construed as exclusive or exhaustive listings. Accordingly, the scope of the present disclosure should not be limited to the specific illustrative configurations described herein, but extends at least to the configurations described in the claim language and equivalents of those configurations. Any elements explicitly stated as alternatives in this specification may be explicitly included in or excluded from the claims in any desired combination. Although various theories and possible mechanisms may be discussed herein, in any event, these discussions should not limit the subject matter that may be claimed.

[0023] The entire disclosures of all patents, patent applications, and publications, and electronically available materials cited herein are hereby incorporated by reference in their entirety. If there is any inconsistency between the present disclosure and the disclosure of any document incorporated by reference herein, the present disclosure shall control. The foregoing detailed description and examples are provided for clarity of understanding only. No unnecessary limitations should be read therefrom. The invention is not limited to the exact details shown and described, as variations obvious to one of ordinary skill in the art will be included within the invention as defined by the claims.

[0024] All headings are for the convenience of the reader and, unless otherwise indicated, should not be used to limit the meaning of the text following the heading. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 are schematic diagrams of illustrative substrates at two magnification levels.

[0026] Figure 2A is a schematic diagram of short-strand PTFE fibrils.

[0027] Figure 2B is a schematic diagram of long-strand PTFE fibrils.

[0028] Figure 3A is Figure 1 a schematic diagram of a chain structure of multiple active particles around the fibrils of the substrate in

[0029] Figure 3B is including Figure 1 a schematic diagram of an agglomerated structure of a part of multiple active particles and a part of multiple fibrils of the substrate.

[0030] Figure 4 is a schematic diagram of a porous substrate having a composition disposed on and impregnated within the porous substrate and / or one or more components of the composition.

[0031] Figure 5 is a schematic diagram of particles embedded within the solid portion of a porous substrate.

[0032] Figure 6 is a flow chart outlining a first method of manufacturing a composition and / or a method of coating a substrate with the composition, the method being consistent with an embodiment of the present disclosure.

[0033] Figure 7 is a flow chart outlining a second method of manufacturing a composition and / or a method of coating a substrate with the composition, the method being consistent with an embodiment of the present disclosure.

[0034] Figure 8 is a flow chart outlining a method for drying a hydrated composition to form a substrate, the method being consistent with an embodiment of the present disclosure.

[0035] Figure 9 is a first scanning electron micrograph of a substrate consistent with the present disclosure. The substrate includes 40 wt-% K2CO3, 8.6 wt-% PTFE-12, and 51.4 wt-% PTFE-E. Image information: working distance (WD) = 4.0 mm; 5.0 kV LED; x11,000.

[0036] Figure 10It is the second scanning electron micrograph of a substrate consistent with the present disclosure. The substrate comprises 68.9 wt-% CARULITE, 15.5 wt-% PTFE-E, and 15.5 wt-% PTFE-12. Image information: WD = 4.9 mm; 5.0 kV LED; x370.

[0037] Figure 11 It is the third scanning electron micrograph of a substrate consistent with the present disclosure. The substrate comprises 68.9 wt-% CARULITE, 15.5 wt-% PTFE-E, and 15.5 wt-% PTFE-12. Image information: WD = 7.2 mm; 5.0 kV LED; x3,500.

[0038] Figure 12 It is the fourth scanning electron micrograph of a substrate consistent with the present disclosure. The substrate comprises 68.9 wt-% CARULITE, 15.5 wt-% PTFE-E, and 15.5 wt-% PTFE-12. Image information: WD = 7.5 mm; 5.0 kV LED; x1,100.

[0039] Figure 13A and 13B show the electron micrographs of the surface coating of a polyurethane substrate after precipitation under vacuum, the polyurethane substrate having a composition comprising K2CO3 particles, CSAC particles, long-strand PTFE fibrils, and short-strand PTFE fibrils. Image information for 13A: WD = 4.8 mm; 5.0 kV LED; x130. Image information for 13B: WD = 3.9 mm; 5.0 kV LED; x2300.

[0040] Figure 14A and 14B show Figure 13A and 13B cross-sectional SEM images of the polyurethane substrate. Image information for 14A: WD = 3.4 mm; 5.0 kV LED; x170. Image information for 14B: WD = 3.4 mm; 5.0 kV LED; x8000.

[0041] Figure 15 is a graph showing the H2S penetration performance through the substrates of FIGS. 16 and 17 at 25 °C, 100 - 300 cm 3 / min and 25 ppm.

[0042] Figure 16A and 16B show images of the main surface of the PU-15 substrate, the substrate being exposed to a method for setting a composition thereon, the method not including (16A) and including (16B) treatment with an ethanol bath.

[0043] Figure 17 shows electron micrographs comparing the surfaces of a PU-15 substrate having the composition disposed thereon, where the method of disposing the composition does not include (17A) and includes (17B) the use of ethanol as a wetting agent. Image information for 17A: WD = 4.2 mm; 5.0 kV LED; x4,300. Image information for 17B: WD = 6.4 mm; 5.0 kV LED; x19,000.

[0044] Figure 18 compares the surface integrity of polyurethane substrates having the composition disposed thereon, where the composition includes K2CO3 / CSAC only PTFE-E (18A - 18B) or both PTFE-E / PTFE-12 (18C - 18D). Image information for 18A: WD = 5.9 mm; 5.0 kV LED; x190. Image information for 18B: WD = 6.7 mm; 5.0 kV LED; x11,000. Image information for 18C: WD = 6.6 mm; 5.0 kV LED; x37. Image information for 18D: WD = 6.4 mm; 5.0 kV LED; x6,000. Detailed Description

[0045] The present disclosure provides a porous substrate having a composition disposed thereon and a method of disposing such a composition on such a substrate. The composition of the present disclosure includes a matrix that includes a plurality of PTFE fibrils and a plurality of active particles. In some embodiments, the composition may further include free active particles, free PTFE fibrils, or both.

[0046] Disposing the composition on the porous substrate includes disposing such a composition on the major surface of the substrate; impregnating the substrate with such a composition or one or more components of the composition (e.g., free active particles, free PTFE fibrils, the matrix, or any combination thereof); embedding such a composition or one or more components within the substrate; or any combination thereof. Thus, the porous substrate of the present disclosure may have the composition disposed on at least a portion of the major surface; may be impregnated with the composition and / or one or more components of the composition; may have the composition and / or one or more components embedded therein; or any combination thereof.

[0047] Composition

[0048] The composition of the present disclosure includes a matrix. The matrix of the present disclosure includes a plurality of PTFE fibrils and a plurality of active particles. In some embodiments, the composition may further include free active particles, free PTFE fibrils, or both.

[0049] A plurality of polytetrafluoroethylene (PTFE) fibrils

[0050] The compositions of the present disclosure include a matrix. The matrix of the present disclosure includes a plurality of PTFE fibrils. The fibrils may include single-strand PTFE or multi-strand PTFE. In some embodiments, the fibrils are arranged in a fibrous structure; that is, a plurality of ordered PTFE strands are generally arranged in the same direction.

[0051] The PTFE fibrils are formed from a PTFE resin. The PTFE resin may include PTFE polymers, oligomers, monomers, or any combination thereof. The PTFE resin may be solid or liquid. The PTFE resin may be an emulsion. The PTFE resin includes particles that include PTFE polymers, oligomers, monomers, or any combination thereof. Each particle of the PTFE resin has a resin particle size. The resin particle size is defined as the maximum distance across the resin particle.

[0052] In some embodiments, the plurality of PTFE fibrils are of a single type of PTFE fibril, such as short-strand PTFE fibrils or long-strand PTFE fibrils. In some embodiments, the matrix of the present disclosure includes short-strand PTFE fibrils (formed from short-strand PTFE resin) and long-strand PTFE fibrils (formed from long-strand PTFE resin).

[0053] Figure 2A A schematic diagram of a short-strand PTFE fibril 30 is shown. The short-strand PTFE fibril has a length 31 and a diameter 32. The length of a PTFE fibril (short-strand or long-strand) is the distance across the maximum dimension of the fibril. The diameter of a PTFE fibril (short-strand or long-strand) is the maximum distance across the minimum dimension of the fibril.

[0054] The short-strand PTFE fibrils are formed from a short-strand PTFE resin. The short-strand PTFE resin may be obtained or formed as an emulsion with a dispersant (e.g., water and / or an organic solvent) and / or a surfactant. As used herein, using a short-strand PTFE resin includes using the resin and / or using a short-strand PTFE emulsion with a dispersant and / or a surfactant. In some embodiments, as measured according to a size analysis test method, the short-strand PTFE resin, such as the PTFE resin for forming the short-strand PTFE fibrils of the matrix of the present disclosure, has an average resin particle size of 1 μm to 9 μm, preferably 3 μm to 5 μm. When the short-strand PTFE resin is incorporated into the matrix of the present disclosure (e.g., using the method of the present disclosure), the resin particles of the short-strand PTFE resin elongate (e.g., fibrilize) to form short-strand PTFE fibrils.

[0055] In some embodiments, the average length of the short-strand PTFE fibrils of the matrix, as measured by a size analysis test method, is 30 μm or less (down to 1 μm), preferably 20 μm or less (down to 1 μm), 10 μm or less (down to 1 μm) or 5 μm or less (down to 1 μm). In an embodiment, the average length of the short-strand PTFE fibrils of the matrix, as measured by a size analysis test method, is 30 μm or less (down to 1 μm), preferably 20 μm or less (down to 1 μm), 10 μm or less (down to 1 μm) or 5 μm or less (down to 1 μm). In some embodiments, the average diameter of the short-strand PTFE fibrils of the matrix, as measured by a size analysis test method, is 0.01 μm or greater, 0.05 μm or greater, 0.3 μm or greater or 0.5 μm or greater. In some embodiments, the average diameter of the short-strand PTFE fibrils of the matrix, as measured by a size analysis test method, is 1 μm or less, 0.5 μm or less or 0.3 μm or less.

[0056] The short-strand PTFE fibrils of the matrix are generally not arranged in an ordered manner (see, for example, Figure 8 and the discussion elsewhere in this document).

[0057] Figure 2BA schematic view of a long-strand PTFE fibril 20 is shown. The long-strand PTFE fibril 20 has a diameter 23 and a length 24. In some embodiments, the long-strand PTFE fibril 20 is composed of a plurality of component PTFE fibrils 22. The plurality of component PTFE fibrils 22 are generally arranged in the same direction, thereby forming a long-strand PTFE fibril structure. Thus, the long-strand PTFE fibril can be considered a fiber because it is composed of component fibrils that are generally arranged in a single direction. The plurality of component PTFE fibrils 22 are different from short-strand PTFE fibrils, at least because the component PTFE fibrils 22 have an average length that is longer than that of short-strand PTFE fibrils. In some embodiments, the average length of the long-strand PTFE fibril (and thus, the component PTFE fibrils) measured according to a size analysis test method is 40 μm or greater, 100 μm or greater, 150 μm or greater, 250 μm or greater, 500 μm, 700 μm or greater, 1000 μm or greater. In some embodiments, the average length of the long-strand PTFE fibril measured according to a size analysis test method is 2000 μm or less, 1000 μm or less, 700 μm or less, 500 μm or less, 250 μm or less, 150 μm or less or 100 μm or less. The plurality of component PTFE fibrils 22 do not need to interact directly; that is, there can be a space separating two or more of the component PTFE fibrils. Each of the component PTFE fibrils in the plurality of component PTFE fibrils 22 has a diameter that is less than the diameter of the long-strand PTFE fibril 20. The diameter 23 of the long-strand PTFE fibril is the sum of the thickness of each component PTFE fibril and the space (if any) between the component PTFE fibrils. In some embodiments, the average diameter of the long-strand PTFE fibril is 0.5 μm or greater, 1 μm or greater, 10 μm or greater or 50 μm or greater. In some embodiments, the average diameter of the long-strand PTFE fibril measured according to a size analysis test method is 100 μm or less, 50 μm or less, 10 μm or less or 1 μm or less. In some embodiments, the average diameter of the long-strand PTFE fibril measured according to a size analysis test method is from 0.5 μm to 50 μm, preferably from 1 μm to 50 μm, and more preferably from 10 μm to 50 μm.

[0058] The long-strand PTFE fibril is formed from a long-strand PTFE resin. In some embodiments, the average resin particle size of the long-strand PTFE resin measured according to a size analysis test method is 10 μm or greater, 25 μm or greater, 50 μm or greater, 100 μm or greater, 200 μm or greater and up to 1000 μm. After incorporating the long-strand PTFE resin into the matrix of the present disclosure (e.g., using the methods of the present disclosure), the particles of the long-strand PTFE resin elongate (e.g., fibrillate) to form the long-strand PTFE fibril.Figure 9 An example of a portion of the long-strand PTFE fibrils in the matrix of the present disclosure is shown in frame 30. Without being bound by theory, it is believed that the long-strand PTFE fibrils can impart a certain degree of mechanical rigidity to the matrix, thereby producing a membranous matrix.

[0059] Without being bound by theory, it is believed that the particles of the short-strand PTFE resin and the particles of the long-strand PTFE resin do not fuse to form PTFE fibrils; that is, it is believed that the particles of the long-strand PTFE resin form long-strand PTFE fibrils, while the particles of the short-strand PTFE resin form short-strand PTFE fibrils. The short-strand PTFE fibrils may be located within the long-strand PTFE fibrils; however, they are considered to be independent entities.

[0060] The average diameter of the PTFE fibrils, the average length of the PTFE fibrils, and the average resin particle size can be determined using various methods, including microscopy methods such as scanning electron microscopy (SEM; see the dimensional analysis test method) or transmission electron microscopy (TEM).

[0061] In some embodiments, based on the total weight of the composition and calculated according to the Composition Analysis Test Method, the composition and / or matrix of the present disclosure includes 5 weight percent (wt-%) or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, 55 wt-% or more, 65 wt-% or more, or 80 wt-% or more of a plurality of PTFE fibrils. In some embodiments, based on the total weight of the composition and calculated according to the Composition Analysis Test Method, the composition includes 95 wt-% or less, 80 wt-% or less, 65 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, or 15 wt-% or less of a plurality of PTFE fibrils.

[0062] The ratio of the short-strand PTFE fibrils to the long-strand PTFE fibrils in the composition can vary depending on the desired end application of the composition. The ratio and weight percentage of the short-strand PTFE fibrils and the long-strand PTFE fibrils in the composition are defined based on the quality of the short-strand PTFE resin and the quality of the long-strand PTFE resin used to manufacture the matrix. In some embodiments, the weight ratio of the short-strand PTFE fibrils to the long-strand PTFE fibrils can be from 5 parts to 1 part of the short-strand PTFE fibrils per 0.1 part of the long-strand PTFE fibrils, preferably from 3 parts to 1 part of the short-strand PTFE fibrils per 0.1 part of the long-strand PTFE fibrils.

[0063] In other words, the total amount of PTFE in the matrix (i.e., the sum of the short-strand PTFE fibrils and the long-strand PTFE fibrils) can include different weight percentages of short-strand PTFE fibrils and long-strand PTFE fibrils. In some embodiments, based on the total weight of the composition and calculated according to the compositional analysis test method, the composition includes 0.1 wt-% or more, 1 wt-% or more, 5 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, 55 wt-% or more, 65 wt-% or more, or 80 wt-% or more of short-strand PTFE fibrils. In some embodiments, based on the total weight of the composition and calculated according to the compositional analysis test method, the composition includes 95 wt-% or less, 80 wt-% or less, 65 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, 15 wt-% or less, 5 wt-% or less, or 1 wt-% or less of short-strand PTFE fibrils. In some embodiments, based on the total weight of the composition and calculated according to the compositional analysis test method, the composition includes 0.01 wt-% or more, 1 wt-% or more, 5 wt-% or more, 10 wt-% or more, 15 wt-% or more, 20 wt-% or more, 30 wt-% or more, or 40 wt-% or more of long-strand PTFE fibrils. In some embodiments, based on the total weight of the composition and calculated according to the compositional analysis test method, the composition includes 50 wt-% or less, 40 wt-% or less, 30 wt-% or less, 20 wt-% or less, 15 wt-% or less, 10 wt-% or less, 5 wt-% or less, or 1 wt-% or less of long-strand PTFE fibrils.

[0064] The plurality of PTFE fibrils or the short-strand PTFE fibrils and the long-strand PTFE fibrils can include various forms of PTFE, such as C3-PTFE, C2-PTFE, C1-PTFE, or any combination thereof. C1-PTFE is a polytetrafluoroethylene polymer including the repeating group -(CF2-C(F)(CF3))-. C2-PTFE is a polytetrafluoroethylene polymer including the repeating group -(CF2-C(F)(CF2-CF3))-. C3-PTFE is a polytetrafluoroethylene polymer including the repeating group -(CF2-C(F)(CF2-CF2-CF3))-. In some cases, it may be desirable to reduce the amount of fluorine in the final composition and / or reduce the amount of fluorine-carbon bonds used to produce PTFE. In some embodiments, the PTFE resin used to form the PTFE fibrils, and thus the PTFE fibrils in the matrix, can include any combination of C1 short-strand PTFE, C2 short-strand PTFE, C3 short-strand PTFE, C1 long-strand PTFE, C2 long-strand PTFE, or C3 long-strand PTFE.

[0065] Multiple active particles

[0066] The matrix of the present disclosure includes multiple active particles. The physical and / or chemical functions of the particles that make up the multiple active particles may vary depending on the intended use of a given matrix or a composition that includes such a matrix. The multiple active particles may include catalysts, sorbents (e.g., adsorbents, absorbers, or both), growth seeds, electroactive materials, metal-organic frameworks, bioactive materials, or any combination thereof.

[0067] In some embodiments, the multiple active particles include a catalyst. A catalyst is a chemical substance that changes the rate of one or more reactions without being consumed. The matrix may include any suitable catalyst or any combination of catalysts to facilitate any desired reaction. In some embodiments, the desired reaction may include nitrobenzene reduction, reduction of nitrogen oxide (NO x ) compounds, hydrogenation, or any combination thereof. Catalysts that are capable of removing, preventing, and / or reducing harmful gas emissions into the atmosphere may be of particular interest. For example, the multiple active particles may include a catalyst capable of reducing and / or converting one or more nitrogen oxide (NO x ) compounds (e.g., nitric oxide, nitrogen dioxide, dinitrogen trioxide, and / or nitrates) to diatomic nitrogen. The catalyst can be grafted onto a support such as a sorbent (described elsewhere herein).

[0068] In some embodiments, the catalyst is capable of destroying ozone (O3); that is, the catalyst is capable of converting ozone (O3) to oxygen (O2) through bond rearrangement. Examples of catalysts capable of destroying ozone include silicates, such as iron silicate, iron manganese silicate, zinc iron silicate, or any combination thereof; transition metal oxides, such as zinc oxide, manganese oxide, copper oxide, cerium dioxide, or any combination thereof; metals, such as reduced metals (i.e., zero-valent metals), including titanium, lead, iron, copper, zinc, chromium, cobalt, nickel, manganese, gold, silver, platinum, palladium, rhodium, tungsten, molybdenum, vanadium, zirconium, silicon, ruthenium, and combinations thereof; carbonates, such as barium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, or any combination thereof; zeolites; and any combination thereof. A zeolite is an aluminosilicate compound composed of aluminum, oxygen, silicon, and one or more counterions.

[0069] In some embodiments, the catalyst is capable of performing hydrogenation and / or cross-coupling reactions. Such chemical transformations can be used for small molecule synthesis. Examples of catalysts capable of initiating such reactions include platinum, palladium, rhodium, iridium, PdCl2, iron, iron oxide, gold, silver, copper, copper oxide, compounds containing them, and any combination thereof.

[0070] In some embodiments, the plurality of active particles include a catalyst capable of destroying ozone, the catalyst including manganese oxide (e.g., amorphous manganese oxide), copper oxide, or both. Amorphous materials have little to no crystallinity, as opposed to polymorphic materials. Examples of ozone-destroying catalysts including amorphous manganese oxide are available from Carus LLC (La Salle, IL) under the trade name CARULITE 400. In some embodiments, the plurality of active particles include a catalyst capable of destroying ozone, the catalyst including cerium dioxide. In some embodiments, the plurality of active particles include a catalyst capable of destroying ozone, the catalyst including manganese oxide, copper oxide, cerium dioxide, or any combination thereof.

[0071] In some embodiments, the active particles include a sorbent. In some embodiments, the sorbent is an adsorbent, an absorbent, or both. Examples of absorbents include cellulose, fumed silica, cotton, natural or synthetic sponges, clay, sodium polyacrylate, sodium alginate, gelatin, and wool.

[0072] In some embodiments, the plurality of active particles include an adsorbent, such as a physical adsorbent, a chemical adsorbent, a physical adsorbent-chemical adsorbent hybrid, or any combination thereof. In some embodiments, the adsorbent is a chemical adsorbent-physical adsorbent hybrid. Chemical adsorbent-physical adsorbent hybrids include graft hybrids and impregnation hybrids. A graft hybrid is a chemical adsorbent grafted onto a physical adsorbent or a physical adsorbent grafted onto a chemical adsorbent. An impregnation hybrid is a physical adsorbent impregnated with a chemical adsorbent or a chemical adsorbent impregnated with a physical adsorbent. Graft hybrids are characterized by covalent bonding between the chemical adsorbent and the physical adsorbent. Impregnation hybrids are characterized by the chemical adsorbent being located within the pores of the physical adsorbent. In an impregnation hybrid, the chemical adsorbent is held within the pores by non-covalent interactions (e.g., van der Waals forces). In some embodiments, the graft hybrid or impregnation hybrid includes one or more of the following physical adsorbents: activated carbon, zeolite, silicate, metal-organic framework (MOF), or mesoporous transition metal oxide.

[0073] An adsorbent is a material capable of adsorbing a chemical substance; that is, the material is capable of separating a chemical substance on at least a portion of its surface area. A physical adsorbent is an adsorbent that separates a chemical substance by forming weak interactions (e.g., van der Waals forces and / or electrostatic forces) between the physical adsorbent and the adsorbed chemical substance. A chemical adsorbent is an adsorbent that separates a chemical substance by forming an ionic bond or a covalent bond between the chemical adsorbent and the adsorbed chemical substance.

[0074] The identification of the adsorbent depends at least in part on the intended use of the composition. Adsorbents can include those capable of adsorbing basic compounds, acidic compounds, organic compounds, inorganic compounds, or any combination thereof. Such adsorbents can be physical adsorbents, chemical adsorbents, or physical-chemical adsorbent hybrids. Acidic compounds, basic compounds, organic compounds, inorganic compounds, or any combination thereof can be in liquid, gaseous, and / or vaporous states (preferably), or any combination thereof.

[0075] In some embodiments, the adsorbent is capable of adsorbing organic compounds in liquid, gaseous, and / or vaporous states (preferably), or both. Organic compounds are compounds that include at least one carbon-hydrogen covalent bond. Examples of organic compounds that the adsorbent can adsorb include aromatic hydrocarbons such as toluene, benzene, xylene, and ethylbenzene; siloxanes; polycyclic aromatic hydrocarbons such as the 16 polycyclic aromatic hydrocarbons listed as priority pollutants by the United States Environmental Protection Agency in 2005 (i.e., naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, (chrysene), benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(ghi)perylene, and indeno(1,2,3-cd)pyrene); normal alkanes such as methane, ethane, n-propane, n-butane, n-pentane, and n-hexane; normal alkenes such as methylene, ethylene, and propylene; various alcohols; aldehydes such as formaldehyde; siloxanes; and any combination thereof. Examples of adsorbents capable of adsorbing organic compounds include activated carbon, zeolites (e.g., zeolite X, zeolite A, zeolite Y, zeolite β, and zeolite ZSM-5), silicates, metal-organic frameworks (MOF), mesoporous transition metal oxides, and any combination thereof.

[0076] In some embodiments, the adsorbent is capable of adsorbing inorganic compounds in liquid, gaseous, and / or vaporous states (preferably), or both. Inorganic compounds are compounds that do not have at least one carbon-hydrogen bond. Examples of inorganic compounds that the adsorbent can adsorb include carbon dioxide; carbon monoxide; hydrogen sulfide; nitrogen oxides; sulfur oxides; water; perfluorocarbons such as tetrafluoromethane and hexafluoroethane; sulfur hexafluoride; ozone; and any combination thereof. Examples of adsorbents capable of adsorbing one or more organic compounds include activated carbon, zeolites (e.g., zeolite X, zeolite A, zeolite Y, zeolite β, and zeolite ZsM-5), silicates, metal-organic frameworks (MOF), mesoporous transition metal oxides, and any combination thereof. A zeolite physical adsorbent is an example of an adsorbent capable of adsorbing ozone.

[0077] In some embodiments, the adsorbent is capable of adsorbing acidic compounds in liquid, gaseous, and / or vaporous (preferably) or both states. An acidic compound is a compound that acidifies water when mixed with water having a pH of 7 such that the pH of the resulting solution is less than 7. Acidic compounds can be inorganic or organic compounds. Examples of acidic compounds that can be adsorbed by the adsorbent include sulfur dioxide, nitrogen dioxide, hydrogen sulfide, sulfur trioxide, nitric oxide, and any combination thereof. Examples of adsorbents capable of adsorbing acidic compounds and / or acidic gases include chemisorbents containing: Group I metal (Li, Na, K, Rb, Cs, Fr) carbonates; metal oxides; Group I (Li, Na, K, Rb, Cs, Fr) metal hydroxides; Group II metal (Be, Mg, Ca, Sr, Ba, Ra) hydroxides; Group II metal (Be, Mg, Ca, Sr, Ba, Ra) oxides; N-containing compounds such as amines (e.g., tetraethylenepentamine, ethylenediamine, and 3-aminopropyltriethoxysilane), imines (e.g., polyethyleneimine), and ammonium salts (e.g., ammonium persulfate); or any combination thereof. In some embodiments, the selected chemisorbent can be grafted onto or impregnated in a physical adsorbent such as activated carbon, zeolite, silicate, or any combination thereof.

[0078] In some embodiments, the adsorbent is capable of adsorbing basic compounds in liquid, gaseous, and / or vaporous (preferably) or both states. A basic compound is a compound that alkalizes water when mixed with water having a pH of 7 such that the pH of the resulting solution is greater than 7. Basic compounds can be inorganic or organic compounds. Examples of basic compounds that can be adsorbed by the adsorbent include ammonia and nitrogen trifluoride. Examples of adsorbents capable of adsorbing basic compounds include physical adsorbents such as activated carbon, zeolite, silicate, and combinations thereof. Other examples of adsorbents capable of adsorbing basic compounds include chemisorbents having a carboxylic acid (COOH) functional group. Examples of chemisorbent compounds having a carboxylic acid functional group include citric acid, terephthalic acid, trimesic acid, tartaric acid, maleic acid, benzoic acid, oxalic acid, and combinations thereof. Chemisorbents capable of adsorbing basic compounds include inorganic acids such as boric acid, nitric acid, sulfuric acid, hydrochloric acid, hydrogen chloride, hydrogen fluoride, hydrogen bromide, phosphoric acid, perchloric acid, periodic acid, or any combination thereof. Such chemisorbents can be grafted onto or impregnated in a physical adsorbent such as activated carbon, zeolite, silicate, or any combination thereof.

[0079] In some embodiments, the plurality of active particles includes a metal-organic framework (MOF). As used herein, the term "metal-organic framework (MOF)" refers to a compound comprising clusters of metal ions coordinated to organic ligands, which metal ion clusters form a two-dimensional or three-dimensional structure. The MOF can be an adsorbent (e.g., a physical adsorbent, a chemisorbent, or both), a catalyst, or both. Examples of MOF adsorbents include copper benzene-1,3,5-tricarboxylate (C18 H6Cu3O 12 , also known as HKUST-1, Cu-BTC MOF or MOF-199; available from NOVOMOF, Zofingen, Aargau, Switzerland); zirconium 1,4-benzenedicarboxylate MOF (Zr6O4(OH)4(dicarboxylic acid)6, also known as UiO-66; available from NOVOMOF, Switzerland); zirconium 4,4'-biphenyldicarboxylate MOF (Zr6O4(OH)4(4,4'-biphenyldicarboxylic acid)6, also known as UiO-67; available from NOVOMOF, Switzerland); and combinations thereof.

[0080] In some embodiments, the plurality of active particles include a bioactive material. A bioactive material is a material derived from a biological system. A bioactive material can be used as an adsorbent and / or a catalyst. Examples of bioactive materials include proteins, nucleotides, nucleic acids, sugars and polysaccharides, lipids, and any combination thereof. In some embodiments, the bioactive material is a protein, such as an enzyme. Lactase is an example of an enzyme that can be used as a bioactive material.

[0081] In some embodiments, the plurality of active particles include growth seeds. Growth seeds can be used as nucleation points for the synthesis of metal-organic frameworks (MOFs). In some such embodiments, the growth seeds include copper nitrate as a growth seed for a copper-based MOF such as copper benzene-1,3,5-tricarboxylate. In some embodiments, the growth seeds include trimesic acid as a growth seed for a copper-based MOF such as copper benzene-1,3,5-tricarboxylate. The growth seeds can react with one or more additional reagents before, during, or after matrix formation to form an MOF.

[0082] Each particle of the plurality of active particles has a particle size. The particle size is defined as the maximum distance across the particle. The average particle size of the plurality of active particles can vary depending on the intended use of the composition and / or the chemical or physical properties of the active particles. The average particle size of the plurality of active particles measured according to a size analysis test method can be 0.001 μm or greater, 0.01 μm or greater, 0.1 μm or greater, 1 μm or greater, 5 μm or greater, 10 μm or greater, or 100 μm or greater. The average particle size of the plurality of active particles measured according to a size analysis test method can be 500 μm or less, 100 μm or less, 10 μm or less, or 1 μm or less.

[0083] Generally, for particles including a catalyst, a smaller particle size may be preferred because their surface area and the density of active sites available for catalytic reactions increase. Thus, in some embodiments in which a plurality of active particles include a catalyst, the average particle size of the plurality of active particles measured according to a size analysis test method is from 0.001 μm to 5 μm, from 0.001 μm to 1 μm, or from 0.001 μm to 0.1 μm. Generally, active particles including an adsorbent having a small particle size may be preferred because a smaller particle size can allow for a larger surface area and greater diffusion. In some embodiments in which a plurality of active particles include an adsorbent, the average particle size of the particles in the plurality of active particles measured according to a size analysis test method is from 0.001 μm to 100 μm, from 1 μm to 100 μm, or from 0.001 μm to 0.1 μm.

[0084] The compositions and / or matrices of the present disclosure can have various amounts of active particles. The wt-% of the active particles (or any individual component of the active particles) in the composition and / or matrix can be calculated according to a composition analysis test method.

[0085] The sum of the wt-% of each component in the active particles is regarded as the wt-% of the active particles including the active particle components. For example, if the active particles include activated carbon, the amount of activated carbon is the wt-% of the active particles including activated carbon. If the active particles include manganese oxide and copper oxide, the wt-% of the active particles including manganese oxide and copper oxide is the sum of the wt-% of manganese oxide and the wt-% of copper oxide.

[0086] The total amount of active particles is the sum of the wt-% of one or more components of the plurality of active particles that make up the composition and / or matrix. For example, in an embodiment in which the active particles include manganese oxide and copper oxide, the total wt-% of the active particles in the matrix is the sum of the wt-% of manganese oxide and the wt-% of copper oxide.

[0087] In some embodiments, according to the compositional analysis test method, the total active particles in the composition and / or matrix are 50 wt-% or more, 70 wt-% or more, 80 wt-% or more, or 90 wt-% or more by weight of the composition and / or matrix. In some embodiments, according to the compositional analysis test method, the total active particles in the composition and / or matrix are 95 wt-% or less, 90 wt-% or less, 80 wt-% or less, or 70 wt-% or less by weight of the composition and / or matrix. In other words, in some embodiments, according to the compositional analysis test method, the composition and / or matrix comprises 50 wt-% or more, 70 wt-% or more, 80 wt-% or more, or 90 wt-% or more of active particles by weight of the composition and / or matrix. In some embodiments, according to the compositional analysis test method, the composition and / or matrix comprises 95 wt-% or less, 90 wt-% or less, 80 wt-% or less, or 70 wt-% or less of active particles by weight of the composition and / or matrix.

[0088] For some uses or compositions and / or matrices, it may be beneficial to have a low content of active particles in the composition and / or matrix. In some embodiments, according to the compositional analysis test method, the total active particle wt-% in the composition and / or matrix is 0 wt-% or more, 0.001 wt-% or more, 0.01 wt-% or more, 0.1 wt-% or more, 1 wt-% or more, 2 wt-% or more, 3 wt-% or more, 4 wt-% or more, 5 wt-% or more, 10 wt-% or more or 15 wt-% or more by weight of the composition and / or matrix. In some embodiments, according to the compositional analysis test method, the total active particle wt-% in the composition and / matrix is 20 wt-% or less, 15 wt-% or less, 10 wt-% or less, 5 wt-% or less, 4 wt-% or less, 3 wt-% or less, 2 wt-% or less, 1 wt-% or less, 0.1 wt-% or less, 0.01 wt-% or less or 0.001 wt-% or less by weight of the composition and / or matrix. In other words, in some embodiments, according to the compositional analysis test method, the composition and / or matrix comprises 0 wt-% or more, 0.001 wt-% or more, 0.01 wt-% or more, 0.1 wt-% or more, 1 wt-% or more, 2 wt-% or more, 3 wt-% or more, 4 wt-% or more, 5 wt-% or more, 10 wt-% or more or 15 wt-% or more of active particles by weight of the composition and / or matrix. In some embodiments, according to the compositional analysis test method, the composition and / or matrix comprises 20 wt-% or less, 15 wt-% or less, 10 wt-% or less, 5 wt-% or less, 4 wt-% or less, 3 wt-% or less, 2 wt-% or less, 1 wt-% or less, 0.1 wt-% or less, 0.01 wt-% or less or 0.001 wt-% or less of active particles by weight of the composition and / or matrix.

[0089] matrix

[0090] The compositions of the present disclosure include a matrix. The matrix includes a plurality of PTFE fibrils and a plurality of active particles. In some embodiments, the plurality of PTFE fibrils includes short-strand PTFE fibrils and long-strand PTFE fibrils. The plurality of PTFE fibrils can have any chemical and / or physical properties described herein. The plurality of active particles can have any chemical and / or physical properties described herein.

[0091] Figure 1A schematic diagram of a substrate consistent with an embodiment of the present disclosure is shown. Substrate 10 includes long-strand PTFE fibrils 20, short-strand PTFE fibrils 30, and a plurality of active particles 40. As described elsewhere herein, the fibrils of the long-strand PTFE fibrils 30 are longer and wider than the fibrils of the short-strand PTFE fibrils 30. When imaging the compositions of the present disclosure at a relatively low magnification (e.g., x370; see Figure 10 ), the long-strand PTFE fibrils can be observed. For example, a portion of the long-strand PTFE fibrils (box 21) can be seen in the SEM image of the substrate consistent with the present disclosure in Figure 10 . The component fibrils that make up the long-strand PTFE fibrils are visible (box 21). In the same figure, disordered short-strand PTFE fibrils can be seen, which are different from the long-strand PTFE fibrils (boxes 31a, 31b, and 31c). As described elsewhere herein, one or more short-strand PTFE fibrils can be located within the long-strand PTFE fibrils 32; however, the short-strand PTFE fibrils and the long-strand PTFE fibrils are independent entities. Therefore, the short-strand PTFE fibrils located within the long-strand PTFE fibrils are different from the multiple component fibrils 22 ( Figure 2B ) that make up the long-strand PTFE fibrils. As described elsewhere herein, the component fibrils of the long-strand PTFE fibrils are longer than the short-strand PTFE fibrils.

[0092] When imaging at a relatively high magnification (e.g., x9,000; x7,000; x11,000; x20,000), as shown in box 50 of Figure 1 , the multiple small-strand PTFE fibrils have a largely disordered structure; that is, the fibrils extend in different directions (e.g., along the x, y, and z directions). This phenomenon can be clearly seen in the SEM image of the substrate consistent with the present disclosure in Figure 9 . Compositions that include only short-strand PTFE fibrils do not include two different populations of PTFE fibrils (i.e., short-strand PTFE fibrils and long-strand PTFE fibrils). As described, a microscope (e.g., a scanning electron microscope) can be used to distinguish between compositions having a single population of PTFE fibrils (e.g., short-strand PTFE fibrils) and compositions having two populations of PTFE fibrils (e.g., short-strand PTFE fibrils and long-strand PTFE fibrils).

[0093] The plurality of active particles are distributed in the substrate and contact and / or interact with the long-strand PTFE fibrils 20 (if present), the short-strand PTFE fibrils 30, or both ( Figure 1)。The active particles that interact with other active particles, long-strand PTFE fibrils 20 (if present), short-strand PTFE fibrils 30, or combinations thereof are physically and / or chemically fixed in the matrix. That is, the term "interact" refers to physical forces (e.g., frictional force, gravitational force, compressive force, tensile force, electric force, magnetic force, spring force, applied force, and normal force) or chemical forces (e.g., van der Waals force, Debye force, Keesom force, London dispersion force, dipole-dipole force, and hydrogen bond) or combinations thereof between two or more active particles, between an active particle and a short-strand PTFE fibril (or multiple short-strand PTFE fibrils), and between an active particle and a long-strand PTFE fibril (if present; or multiple long-strand PTFE fibrils).

[0094] The plurality of active particles can have one or more configurations in which they interact with short-strand PTFE fibrils, long-strand PTFE fibrils (if present), or both. In some embodiments, at least a portion of the plurality of active particles and at least a portion of the plurality of PTFE fibrils adopt a chain-like structure, an agglomerated structure, or both. In some embodiments, at least a portion of the plurality of active particles forms a chain-like structure around one or more short-strand PTFE fibrils, one or more long-strand PTFE fibrils (if present), or both; at least a portion of the plurality of active particles forms an agglomerated structure with one or more short-strand PTFE fibrils, one or more long-strand PTFE fibrils (if present), or any combination thereof.

[0095] The terms "chain-like structure" and "chain structure" can be used interchangeably and refer to a self-supporting network of active particles that coats at least a portion of one or more PTFE fibrils. Figure 3A is a schematic diagram of a chain-like structure 80. In the chain-like structure, a plurality of active particles 40 form a self-supporting network that coats at least a portion of one or more PTFE fibrils 20 / 30 (e.g., one or more long-strand PTFE fibrils, one or more short-strand PTFE fibrils, or both). Although the self-supporting network may contact and / or interact with one or more PTFE fibrils that it at least partially coats, the main interaction that holds the chain-like structure together is the physical interaction between adjacent particles. Without being bound by theory, it is believed that if the at least partially coated (or fully coated) PTFE fibrils can be removed, the self-supporting network of particles will remain undisturbed. The individual active particles involved in the chain-like structure may not be clearly defined because the active particles may fuse with each other to produce a self-supporting network.

[0096] The self - supporting network of the active particles can be in a chain - like structure covering a part of a single PTFE fibril, a part of multiple PTFE fibrils, the whole PTFE fibril, or all of multiple PTFE fibrils. The self - supporting network of the active particles can be in a chain - like structure covering at least a part of one or more short - strand PTFE fibrils, at least a part of one or more long - strand PTFE fibrils, or both. It is generally considered that the chain - like structure mainly includes covering at least a part of one or more short - strand PTFE fibrils.

[0097] Figure 11 and Figure 12 are SEM images of compositions consistent with embodiments of the present disclosure, which clearly show the chain - like structures highlighted in boxes 71, 72, and 73. In these images, the particles form a self - supporting network or a "bead - like" structure surrounding one or more PTFE fibrils (e.g., one or more PTFE fibrils are the wires and the self - supporting network of the particles is the bead). The extent of the chain - like structure in box 71 is such that one or more PTFE fibrils cannot be seen (e.g., one or more PTFE fibrils are completely covered by the chain - like structure). In contrast, in the chain - like structures shown in boxes 72 and 73, a part of one or more PTFE fibrils involved in the chain - like structure is covered in the self - supporting network of the active particles. For example, the chain - like structure may have gaps where individual PTFE fibrils can be observed (indicated by * in Figure 12 ).

[0098] Without being bound by theory, it is believed that the chain - like structure can reduce the likelihood of the particles detaching from the composition (e.g., before, during, and / or after being disposed on a porous substrate). In addition, it is believed that the particles with a chain - like structure can have a large exposed surface area due to their spacing and the number of exposed faces. This property can enhance their activity as catalysts, adsorbents, growth seeds, MOFs, or any combination thereof.

[0099] The terms "agglomerated structure" and "agglomeration structure" as used herein are used interchangeably and refer to active particles or aggregates of active particles that are at least partially held together by one or more PTFE fibrils (e.g., short-strand PTFE fibrils or long-strand PTFE fibrils). In contrast to chain-like structures, the particles of the agglomerated structure do not form a self-supporting network that is typically independent of the PTFE fibrils. In the agglomerated structure, the active particles or aggregates of active particles are held in place by interaction with one or more PTFE fibrils (e.g., short-strand PTFE fibrils) that extend through (e.g., across) the particles or aggregates. An aggregate of active particles is a cluster of two or more active particles, each active particle interacting with at least one other active particle in the cluster. In an agglomerated structure that includes aggregates, the aggregates are held together by the interaction between the active particles and the interaction between the active particles and the PTFE fibrils. In contrast to chain-like structures, the active particles of the agglomerated structure are typically well-defined.

[0100] Figure 3B is a schematic diagram of two agglomerated structures 70 and 71 that are consistent with an embodiment of the present disclosure. The agglomerated structure 70 is a PTFE fibril from a plurality of PTFE fibrils 20 / 30 (short-strand PTFE fibrils or long-strand PTFE fibrils) that passes through a single active particle (i.e., interacts therewith) from a plurality of active particles 40. The agglomerated structure 71 is a number of PTFE fibrils from a plurality of PTFE fibrils 20 / 30 that passes through an aggregate that includes a plurality of active particles 40 (i.e., interacts therewith).

[0101] Figure 9 is a SEM image of a composition that is consistent with an embodiment of the present disclosure, which shows various agglomerated structures highlighted in boxes 81, 82, 83, and 84. Box 81, Box 82, and Box 83 show agglomerated structures in which a plurality of short-strand PTFE fibrils pass through an aggregate of active particles. Box 84 shows an agglomerated structure in which a plurality of short-strand PTFE fibrils pass through a single active particle.

[0102] Without being bound by theory, it is believed that the agglomerated structure can impart a certain degree of mechanical stability to at least a portion of the plurality of active particles, at least a portion of the plurality of PTFE fibrils (e.g., long-strand PTFE fibrils, short-strand PTFE fibrils, or both), or both. For example, it is believed that the agglomerated structure can at least partially inhibit the contraction (i.e., length reduction) of one or more PTFE fibrils participating in the agglomerated structure. In addition, it is believed that the agglomerated structure can reduce the likelihood of particle detachment because of the strength imparted by the PTFE fibrils that interact with the particles of the agglomerated structure.

[0103] Free active particles and free PFTE fibrils

[0104] The compositions of the present disclosure include a matrix, such as the matrices described herein. In some embodiments, the composition may include one or more additional components. Exemplary additional components include free active particles and free PTFE fibrils. In a porous substrate having the composition disposed thereon, the various components of the composition may or may not be located at different positions of the porous substrate (e.g., on a major surface, impregnated within the substrate, or embedded within the substrate), as described elsewhere herein.

[0105] In some embodiments, the composition includes free active particles. Free active particles differ from the plurality of active particles in the matrix in that the free active particles do not interact with the plurality of PTFE fibrils (or the free PTFE fibrils discussed elsewhere herein). The free active particles are embedded or impregnated within the porous substrate. Thus, the term "free active particles" refers to active particles that are embedded or impregnated within the porous substrate and do not interact with one or more PTFE fibrils. The free active particles can have any of the chemical and / or physical properties disclosed herein. In some embodiments, the plurality of active particles and the free active particles are made of the same material (e.g., having the same chemical and / or physical properties). For example, in some embodiments, the plurality of active particles includes a catalyst and the free active particles include the same catalyst. In some embodiments, the plurality of active particles and the free active particles are made of different materials (e.g., having different chemical and / or physical properties). For example, in some embodiments, the plurality of active particles may include a catalyst while the free active particles may include an adsorbent. In some embodiments, the plurality of active particles may include a first adsorbent while the free active particles may include a second adsorbent different from the first adsorbent.

[0106] In some embodiments, the composition includes free PTFE fibrils. Free PTFE fibrils differ from the plurality of PTFE fibrils in the matrix in that the free PTFE fibrils are not part of the fibril-active particle matrix structure. The free PTFE fibrils do not interact with the matrix or the free active particles; however, two or more free PTFE fibrils can interact with each other. The free PTFE fibrils are embedded or impregnated within the porous substrate. Thus, the term "free PTFE fibrils" refers to PTFE fibrils that are embedded or impregnated within the porous substrate and do not interact with the matrix or the free active particles. The free PTFE fibrils can interact with each other. The free PTFE fibrils can be short-strand PTFE fibrils, long-strand PTFE fibrils, or both.

[0107] Microscopes such as scanning electron microscopes can be used to visualize the free active particles and the free PTFE fibrils. Figure 18D An example image of the free PTFE fibrils is shown. Figure 18Dis an image of a porous substrate on which a composition consistent with an embodiment of the present disclosure is provided. Free PTFE fibrils can be seen throughout the surface. These fibrils do not interact with the matrix or free active particles. Figure 14B Shows an example of free active particles embedded and / or impregnated within a porous substrate. Figure 14B is a cross-section of a porous substrate on which a composition consistent with an embodiment of the present disclosure is provided. Small particles (active particles) can be seen parallel to the substrate polymer grains. These particles do not interact with the matrix or free PTFE fibrils.

[0108] The porous substrate provided with the composition

[0109] The present disclosure provides a porous substrate on which a composition and / or component of the present disclosure is provided. Such a substrate can be further processed into various materials such as filter media, membranes, reticulated foams, or reaction surfaces for secondary material coordination. These materials can be further included in filters; can be used as catalytic media for various chemical syntheses in petrochemical or pharmaceutical applications; can be used as intake filters for engine air systems; or can act as a destructive catalyst for chemical protection of membrane materials.

[0110] The porous substrate having the composition thereon can have the composition disposed on at least a portion of the main surface; the composition impregnated within the substrate, the composition embedded within the substrate; or any combination thereof.

[0111] porous substrate

[0112] The substrate of the present disclosure is a porous substrate. The porous substrate is defined by one or more main surfaces. The main surface is the surface of the substrate that forms an interface with the surrounding environment. The pores can be connected to the main surface of the substrate. The pores connected to the main surface are the pores that can allow a fluid (i.e., liquid or gas) or solid to enter through the outer surface. The pores connected to the main surface are not considered part of the main surface because the volume of the pores extends into the interior of the substrate. For example, the main surfaces of a cubic porous substrate are the faces of the cube. The main surface can have a constant or varying topography in the x, y, and / or z directions. For example, each main surface of the porous substrate can be smooth or rough. The porous substrate can have a single continuous main surface, such as, for example, a spherical or ovoid substrate. The porous substrate can have multiple main surfaces, such as, for example, a polyhedron.

[0113] The porous substrate has a plurality of pores. The pores are defined as the void spaces within the substrate. The void space of the pores is delimited by pore surfaces. The total amount of the void space is the pore volume. The pores can be through-holes, open pores, or blind pores. A through-hole is a pore that is connected to a main surface (e.g., accessible from it) through two or more pore openings. An open pore is a pore that is connected to a single pore opening on one main surface (e.g., accessible from it). A blind pore is a pore that is not connected to a pore opening on a main surface. The pores can have various morphologies.

[0114] The porous substrate includes a plurality of macropores. Macropores are pores that exist between parts of the material constituting the porous substrate (e.g., between polymer networks). Generally, macropores have pore opening sizes of 1 mm or greater, some of which can be seen with the naked eye. The composition can impregnate a portion of the macropores of the porous substrate (as described elsewhere herein). The macropores can be through-holes, blind pores, or open pores.

[0115] The porous substrate can include a plurality of micropores. Micropores are pores that exist between the solid parts of the material constituting the porous substrate. Micropores have pore opening sizes less than 1 mm. In some cases, micropores may be present within the pore walls of macropores. The composition can impregnate a portion of the micropores of the porous substrate (as described elsewhere herein). The micropores can be through-holes, blind pores, or open pores. The micropores can be collapsible pores as defined herein or not collapsible pores.

[0116] The term "macro / micro" should be understood as macropores and / or micropores (if micropores are present). It should be understood that the micropores associated with the term macro / micro are not collapsible pores.

[0117] In some embodiments, a porous substrate made of a wettable polymer material can include a plurality of collapsible pores. Collapsible pores are the interstitial spaces between polymer chains within the solid parts of the substrate, into which the composition can be embedded (as described elsewhere herein). The collapsible pores are in a collapsed state within the substrate framework, and fluids or solids cannot enter them before wetting the wettable material. Wetting the wettable material can expand the collapsible pores, thereby allowing fluids or solids to enter such pores. Drying the wettable material can cause the collapsible pores to collapse, thereby trapping some or no material within the pores in the interstitial spaces between the polymer chains upon collapse.

[0118] The porous substrate can be made of any suitable material. Some porous substrates are made of wettable materials. A wettable substrate is a substrate made of a material that can absorb a certain amount of liquid to expose collapsible pores. The wettable porous substrate can be a foam. The wettable porous substrate can be a reticulated foam. The term reticulated foam is generally used to refer to an open-cell foam that forms a net or grid shape (as opposed to a closed-cell foam that forms a bubble or cell shape). Most of the pores in the reticulated foam can be open pores and / or through-holes. Reticulated foams are generally very porous and have a low density. For example, the reticulated foam can have a porosity of 60% or greater, 90% or greater, or 95% or greater. The reticulated foam can be polymer-based; metal-based, metal oxide-based, or metal carbide-based; carbon-based; ceramic-based; or any combination thereof. Even if only one material is stated, the reticulated foam may be made of more than one material. Examples of polymer-based reticulated foams include reticulated polyester, reticulated polyether, reticulated polyurethane, unheated reticulated polyurethane, reticulated cellulose, and reticulated melamine. Examples of carbon-based reticulated foams include reticulated activated carbon, reticulated glassy carbon, and reticulated graphene. Examples of metal-based reticulated foams include reticulated foams made of reduced metals (i.e., zero-valent metals), such as titanium, lead, iron, copper, zinc, chromium, cobalt, nickel, manganese, gold, silver, platinum, palladium, rhodium, tungsten, molybdenum, vanadium, zirconium, silicon, ruthenium, or any combination thereof; reticulated alloys, such as reticulated steel; or any combination thereof. Examples of metal oxide-based reticulated foams include reticulated silica. Examples of metal carbide-based reticulated foams include reticulated silicon carbide.

[0119] The reticulated foam can have any suitable pores per inch (PPI). For example, the reticulated foam can be 3 PPI or greater, 10 PPI or greater, 20 PPI or greater, 30 PPI or greater, 40 PPI or greater, 50 PPI or greater, 60 PPI or greater, 70 PPI or greater, 80 PPI or greater, 90 PPI or greater, or 100 PPI or less, 90 PPI or less, 80 PPI or less, 70 PPI or less, 60 PPI or less, 50 PPI or less, 40 PPI or less, 30 PPI or less, 20 PPI or less, or 10 PPI or less.

[0120] Impregnated porous substrate

[0121] In some embodiments, the porous substrate having the composition disposed thereon is impregnated with the composition. In some such embodiments, at least a portion of the macropores / micropores of the porous substrate are impregnated with the composition of the present disclosure. The macropores / micropores can be impregnated with the composition or one or more components of the composition (e.g., the matrix, free active particles (if present), free PTFE particles (if present), or any combination thereof).

[0122] The term "impregnated" as used in the context of a porous substrate refers to a porous substrate that includes macropores / micropores having a macroporous / microporous surface that is at least partially coated with a composition; macropores / micropores having a macroporous / microporous region that is partially or completely filled with the composition; or both. For example, in some embodiments, the substrate can include a portion of the macropores / micropores having a macroporous / microporous surface that is partially or completely coated with the composition. In some embodiments, the substrate can include a portion of the macropores / micropores having a macroporous / microporous volume that is partially or completely filled with the composition. In some embodiments, the substrate can include a portion of the macropores / micropores having a macroporous volume that is partially or completely filled with at least one particle of free active particles.

[0123] In some embodiments where the composition includes free active particles, the substrate can include a first portion of the macropores / micropores impregnated with the composition, and a second portion of the macropores / micropores impregnated with at least one particle of free active particles. In some embodiments where the composition includes free active particles, the substrate can include a first portion of the macropores / micropores impregnated with the composition; a second portion of the macropores / micropores impregnated with at least one particle of free active particles; a third portion of the macropores / micropores impregnated with the composition and at least one particle of free active particles.

[0124] Embedded porous substrate

[0125] In some embodiments, the composition is embedded in the solid portion of the porous substrate. The composition and / or one or more components of the composition (e.g., matrix, free active particles (if present), free PTFE particles (if present), or any combination thereof) can be embedded within the porous substrate.

[0126] The terms "embedded" and "embedding" as related to a porous substrate refer to the insertion (e.g., sandwiching) of a composition into the collapsible pores of the substrate and remaining in the solid portion of the substrate located at or near the position of the collapsible pores after at least partial collapse of the collapsible pores. Collapsible pores are formed when a wettable substrate absorbs a wetting liquid and expands to expose interstitial spaces into which the composition can be inserted. After removing a sufficient amount of the wetting liquid, the substrate contracts and any components of the composition inserted into the collapsible pores are embedded in the solid portion of the substrate during contraction.

[0127] Without being bound by theory, it is believed that embedding the composition or components of the composition within the substrate can impart a certain degree of mechanical strength to the substrate. For example, it is believed that embedded free PTFE fibrils (long strands and / or short strands) increase the mechanical strength of the substrate, thereby increasing its stability against microcracks.

[0128] Figure 5 A schematic illustration of the formation of collapsible pores and the embedding of a composition into a porous substrate by insertion into such pores is shown. Figure 5FIG. 0 is a cross-sectional view of a solid portion of a wettable porous substrate 600A composed of a plurality of polymer chains 610. For clarity, a background 602 is included. Before adding the wetting liquid, the collapsible pores are in a collapsed state. After adding the wetting liquid, the substrate absorbs a portion of the wetting liquid and expands to form an expanded substrate 600B, which includes newly exposed collapsible pores 650. If there is a composition, the composition and / or individual components 660 of the composition (e.g., the matrix of the composition, free active particles, dissolved components of the free active particles that can precipitate to form free active particles, free PTFE fibrils, or any combination thereof) can migrate into the newly exposed collapsible pores 650 to form an inserted substrate 600C. Removing at least a portion of the wetting liquid causes the collapsible pores to collapse because the polymer chains re-associate, thereby embedding the inserted components within the solid portion of the substrate to form an embedded substrate 600D. In embodiments where the dissolved component constitutes at least a portion of the free active particles, removing at least a portion of the wetting liquid may cause the dissolved component to become supersaturated and precipitate, thereby producing free active particles embedded within the substrate. Without being bound by theory, it is believed that the degree of steric hindrance of the embedded free active particles may be lower than that of the plurality of active particles that are part of the matrix. Therefore, the embedded free active particles may be more suitable for use as catalysts and / or adsorbents.

[0129] FIG. 17D shows a scanning electron micrograph of a cross-section of the embedded substrate. The embedded PTFE fibrils can be seen extending along the surface of the cross-section.

[0130] A porous substrate having a composition disposed on at least a portion of a major surface, a composition embedded within the substrate, a composition impregnated within at least a portion of the macropores / micropores, or any combination thereof.

[0131] A porous substrate is disclosed that has a first portion of a composition disposed on at least a portion of a major surface and is impregnated with a second portion of the composition. In some such embodiments, at least a portion of the plurality of macropores / micropores of the substrate is impregnated with the composition. In some embodiments, the porous substrate has a first portion of the plurality of macropores / micropores impregnated with the composition and a second portion of the plurality of macropores / micropores impregnated with a component of the composition. In some such embodiments where the composition includes free active particles, the porous substrate has a first portion of the macropores / micropores impregnated with the matrix or the composition as a whole and a second portion of the macropores / micropores impregnated with at least one particle of the free active particles.

[0132] Figure 4Is a schematic diagram showing a porous substrate having: a main surface, at least a portion of which is coated with a first portion of the composition of the present disclosure; a first portion of macropores / micropores impregnated with a second portion of the composition; and a second portion of macropores / micropores impregnated with at least one free active particle. The porous substrate 100 includes six main surfaces, but only 3 main surfaces (110, 111, 112) are depicted. At least a portion of each main surface is coated with a first portion of the composition 10. The porous substrate includes a plurality of macropores / micropores 120 having at least one macropore / micropore opening connected to the main surface, and these macropores / micropores have different pore opening diameters and morphologies. At least a portion of the plurality of macropores / micropores 120 is impregnated with a second portion of the composition 10, at least one particle of the free active particles 130, or both. For example, a first portion 122 of the plurality of macropores / micropores 120 is impregnated with a second portion of the composition 10. In some embodiments, at least a portion of the inner surface of one or more macropores / micropores of the first portion 122 of the plurality of macropores / micropores may be coated with a second portion of the composition 10. In some embodiments, at least a portion of the macropore / micropore volume of one or more pores of the first portion 122 of the plurality of pores 120 may be filled with a second portion of the composition 10. In some embodiments, the entire macropore volume of one or more pores of the first portion 122 of the plurality of macropores / micropores may be filled with a second portion of the composition 10. A second portion 124 of the plurality of macropores / micropores 120 may be impregnated with one or more particles of the free active particles 130. A third portion 126 of the plurality of macropores / micropores 120 may be impregnated with both a composition (third portion) 10 and at least one particle of the free active particles 130 simultaneously.

[0133] A porous substrate is disclosed having a first portion of the composition of the present disclosure disposed on at least a portion of one or more main surfaces and a second portion of the composition embedded within the substrate. In some such embodiments, a plurality of components of the composition may be embedded within the substrate. For example, in some embodiments, one or more free PTFE fibrils, one or more free active particles, a matrix, or any combination thereof may be embedded within the substrate. In some embodiments, the porous substrate of the present disclosure has a composition disposed on at least a portion of one or more main surfaces and at least one free PTFE fibril (e.g., short strands of PTFE fibrils) embedded within the substrate.

[0134] A porous substrate is disclosed that has a first portion of the composition of the present disclosure disposed on at least a portion of one or more major surfaces; a second portion impregnated with the composition; and a third portion of the composition embedded therein. In some such embodiments, at least a portion of the macropores / micropores of the substrate is impregnated with the second portion of the composition. In some embodiments, the porous substrate has a first portion of macropores / micropores impregnated with a first component of the composition (e.g., a matrix) and a second portion of macropores / micropores impregnated with a second component of the composition (e.g., free active particles). In some such embodiments, multiple components of the third portion of the composition may be embedded within the substrate. In some embodiments, at least one free PTFE fibril (e.g., a strand of PTFE fibril) is embedded within the substrate. In some embodiments, at least one free active particle is embedded within the substrate.

[0135] In some embodiments, the amount of the composition impregnated or embedded within the porous substrate is greater than the amount of the composition disposed on at least a portion of the major surface of the substrate. In some such embodiments, the amount of the composition disposed on at least a portion of the major surface produces a thin layer of the composition on the major surface. Without being bound by theory, it is believed that from an adsorption perspective, it may be advantageous for the matrix and / or free active particles to be embedded within the solid portion of the substrate skeleton. For example, in embodiments where a thin film of the composition is disposed on at least a portion of the major surface, the pressure drop across the porous substrate may be less than the pressure drop across a porous substrate having a thicker film of the composition disposed on the major surface. Additionally, compared to a porous substrate having a thick film of the composition disposed on the major surface, a substrate having a thin film of the composition disposed on the major surface may result in the molecular diffusion rate being less affected by the thickness and porosity of the film.

[0136] The wt-% of each component of the porous substrate having the composition disposed thereon can be determined according to a compositional analysis test method.

[0137] In some embodiments, based on the total weight of the substrate-composition (the total weight of the substrate and the composition disposed thereon) and calculated according to the compositional analysis test method, the porous substrate having the composition disposed thereon comprises 0.001 wt-% or more, 0.01 wt-% or more, 0.1 wt-% or more, 5 wt-% or more, 10 wt-% or more, 20 wt-% or more, 30 wt-% or more, 40 wt-% or more, 50 wt-% or more, 60 wt-% or more, 70 wt-% or more, 80 wt-% or more, 90 wt-% or more, or 95 wt-% or more of the porous substrate. In some embodiments, based on the total weight of the substrate-composition and calculated according to the compositional analysis test method, the porous substrate having the composition disposed thereon comprises 99 wt-% or less, 95 wt-% or less, 90 wt-% or less, 80 wt-% or less, 70 wt-% or less, 60 wt-% or less, 50 wt-% or less, 40 wt-% or less, 30 wt-% or less, 20 wt-% or less, 10 wt-% or less, 5 wt-% or less, 1 wt-% or less, or 0.01 wt-% or less of the porous substrate.

[0138] In some embodiments, based on the total weight of the substrate-composition and calculated according to the compositional analysis test method, the porous substrate having the composition disposed thereon comprises 0.001 wt-% or more, 0.01 wt-% or more, 0.1 wt-% or more, 5 wt-% or more, 10 wt-% or more, 20 wt-% or more, 30 wt-% or more, 40 wt-% or more, 50 wt-% or more, 60 wt-% or more, 70 wt-% or more, 80 wt-% or more, 90 wt-% or more, or 95 wt-% or more of the composition. In some embodiments, based on the total weight of the substrate-composition and calculated according to the compositional analysis test method, the composition having the composition disposed thereon comprises 99 wt-% or less, 95 wt-% or less, 90 wt-% or less, 80 wt-% or less, 70 wt-% or less, 60 wt-% or less, 50 wt-% or less, 40 wt-% or less, 30 wt-% or less, 20 wt-% or less, 10 wt-% or less, 5 wt-% or less, 1 wt-% or less, or 0.01 wt-% or less of the composition.

[0139] In some embodiments, the porous substrate having the composition disposed thereon comprises 0 wt-% or more, 1 wt-% or more, 2 wt-% or more, 3 wt-% or more, 4 wt-% or more, 5 wt-% or more, 10 wt-% or more, or 15 wt-% or more, 20 wt-% or more, 30 wt-% or more, 40 wt-% or more, 50 wt-% or more, 70 wt-% or more, 80 wt-% or more, or 90 wt-% or more of active particles, based on the total weight of the substrate-composition and calculated according to the Composition Analysis Test Method. In some embodiments, the porous substrate having the composition disposed thereon comprises 95 wt-% or less, 90 wt-% or less, 80 wt-% or less, 70 wt-% or less, 50 wt-% or less, 40 wt-% or less, 30 wt-% or less, 20 wt-% or less, 15 wt-% or less, 10 wt-% or less, 5 wt-% or less, 4 wt-% or less, 3 wt-% or less, 2 wt-% or less, or 1 wt-% or less of active particles, based on the total weight of the substrate-composition and calculated according to the Composition Analysis Test Method.

[0140] In some embodiments, the porous substrate on which the composition is disposed comprises 1 wt-% or more, 5 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, 55 wt-% or more, 65 wt-% or more, or 80 wt-% or more PTFE fibrils (the sum of short-strand PTFE fibrils and long-strand PTFE fibrils), based on the total weight of the substrate-composition and calculated according to the Composition Analysis Test Method. In some embodiments, the composition comprises 95 wt-% or less, 80 wt-% or less, 65 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, 15 wt-% or less, or 5 wt-% or less PTFE fibrils, based on the total weight of the substrate-composition and calculated according to the Composition Analysis Test Method.

[0141] Method

[0142] Disclosed are methods of disposing the disclosed composition on a porous substrate to make the disclosed porous substrate.

[0143] Figure 6 , Figure 7 and Figure 8is a flow chart showing aspects of the illustrative methods disclosed herein. These steps can be performed in any order. In some embodiments, multiple steps can be performed simultaneously. The steps shown in dashed boxes are optional steps. Each optional step can be performed in a method that does not include any additional optional steps or includes one or more any additional optional steps (if multiple optional steps are included). For example, the first optional step can be performed in combination with one or more additional optional steps; or not in combination with additional optional steps. The flow chart also includes boxes regarding the components of the various compositions in the method (e.g., concentrated matrix premix, matrix premix, emulsion, aerated emulsion, aerated matrix premix, hydrated composition, etc.). Such boxes have element numbers designated by "c". It should be understood that the components included in a step are also included in any downstream steps, except for the drying step. For example, the dispersant included in the first step is subsequently included in the second step, the third step, and so on until the drying step is completed, in which case the dispersant can be at least partially eliminated during the drying step.

[0144] Figure 6 is a flow chart outlining a first exemplary method of disposing the compositions of the present disclosure on a porous substrate to produce the porous substrates of the present disclosure. The composition includes a matrix. The matrix includes a plurality of active particles and a plurality of PTFE fibrils formed from a PTFE resin. In some embodiments, the composition further includes free active particles, free PTFE fibrils, or both.

[0145] Method 200 optionally includes aerating the emulsion in optional step 210 to form an aerated emulsion. The aerated emulsion or mixture is characterized by the presence of bubbles and / or cavities. For example, the aerated emulsion can be characterized by having bubbles on the surface. Aeration can be achieved using a variety of techniques, such as mechanical shaking, gas injection, bottom-up foaming, or combinations thereof.

[0146] The emulsion (210c) includes a PTFE resin, a dispersant, and a surfactant. The surfactant can be any surfactant described elsewhere herein. The dispersant can be any dispersant described elsewhere herein. The aerated emulsion (201c) includes a PTFE resin, a dispersant, and a surfactant.

[0147] In some embodiments, method 200 optionally includes forming an emulsion by diluting a concentrated mixture ( Figure 6(not depicted in ) to form an emulsion. The concentrated mixture may include an emulsion of PTFE resin and a dispersant. In some embodiments, the concentrated mixture includes at least a portion of a surfactant. In some embodiments, based on the total weight of the concentrated mixture, the concentrated mixture includes 60 wt-% PTFE resin (e.g., 60 wt-% short strand PTFE resin). In some embodiments, the concentrated mixture is diluted with a dispersant. In some embodiments, the concentrated mixture is diluted with a solution including a dispersant and a surfactant. The surfactant may be the same surfactant or a different surfactant as in the emulsion.

[0148] Method 200 optionally includes, in optional step 230, aerating the matrix premix to form an aerated matrix premix. The aerating can be done by any means discussed elsewhere herein. The aerated matrix premix (230c) includes PTFE resin, a dispersant, a surfactant, and a solid particle composition.

[0149] A first illustrative method 200 optionally includes, in optional step 220, adding a solid particle composition to the aerated emulsion to form a matrix premix. The matrix premix (220c) includes PTFE resin, a surfactant, a solid particle composition, and a dispersant. The solid particle composition includes solid particles. In some embodiments, the solid particle composition includes 100 wt-% of solid particles (i.e., no other components are included in the solid particle composition). In other embodiments, the solid particle composition includes solid particles and a liquid carrier. The liquid carrier may include water, one or more organic solvents (e.g., ethyl acetate, ethanol, methanol, isopropanol, butanol, dichloromethane, toluene, acetonitrile, acetone, diethyl ether, pentanol, or tetrahydrofuran); or both. In some such embodiments, the solid particles in the solid particle composition are dissolved in the liquid carrier. In other embodiments, the solid particles of the solid particle composition are suspended in the liquid carrier. In yet other embodiments, a first portion of the solid particles is dissolved in the liquid carrier, and a second portion of the solid particles is suspended in the liquid carrier.

[0150] The plurality of active particles includes at least a portion of solid particles. In embodiments where the composition includes free active particles, the free active particles include at least a portion of solid particles. In some embodiments, the solid particles may already be in the form of the plurality of active particles and / or free active particles (if present). In some embodiments, the solid particles are not in the form of the plurality of active particles and / or free active particles (if present). In some such embodiments, at least a portion of the solid particles become the plurality of active particles and / or free active particles (if present) by aggregation and / or precipitation of the solid particles. For example, in some embodiments, at least a portion of the solid particles are dissolved in a liquid carrier, and throughout the process (e.g., during a drying step), the dissolved solid particles become supersaturated and precipitate to form the plurality of active particles and / or free active particles (if present).

[0151] The amount of solid particles (including in the solid particle composition) can vary depending on the characteristics of the solid particles and the desired end use of the porous substrate. In some embodiments, based on the total weight of the aerated matrix premix, the aerated matrix premix includes 0.5 wt-% or more, 10 wt-% or more, 30 wt-% or more, or 50 wt-% or more of solid particles. In some embodiments, based on the total weight of the aerated matrix premix, the aerated matrix premix includes 90 wt-% or less, 50 wt-% or less, 30 wt-% or less, or 10 wt-% or less of solid particles.

[0152] Method 200 includes contacting at least a portion of a porous substrate with a matrix premix or an aerated matrix premix in step 260. The porous substrate includes at least one major surface and a plurality of macropores / micropores (260c) connected to the major surface. In some embodiments, the porous substrate is a wettable porous substrate. The substrate contacts the matrix premix or the aerated matrix premix in a manner that exposes at least a portion of the major surface of the porous substrate and at least a portion of the plurality of macropores / micropores to the matrix premix or the aerated matrix premix. The contact can be in the form of: immersing at least a portion of the porous substrate in the matrix premix or the aerated matrix premix; pumping the matrix premix or the aerated matrix premix around at least a portion of the porous substrate; spraying an aerosolized matrix premix of the aerated matrix premix onto at least a portion of the porous substrate; or a combination thereof.

[0153] Method 200 also includes disposing the hydrated composition on a porous substrate. The hydrated composition includes a matrix, any other composition components (if included), at least a portion of a dispersant, at least a portion of a liquid carrier (if present), at least a portion of a wetting liquid (if present), and at least a portion of a surfactant. The plurality of active particles of the matrix includes at least a portion of solid particles. In some embodiments, the hydrated composition may include free active particles, free PTFE fibrils, or both. The hydrated composition may be disposed on at least a portion of at least one major surface of the substrate, impregnated into at least a portion of the plurality of macropores / micropores connected to at least one major surface, inserted into collapsible pores of the substrate, or any combination thereof. In some embodiments in which the porous substrate is a wettable porous substrate, the collapsible pores may be exposed by contacting the wettable porous substrate with a wettable liquid prior to contacting the wettable porous substrate with an aerated matrix premix. In some embodiments in which the porous substrate is a wettable porous substrate, the collapsible pores may be exposed by contacting the porous substrate with an aerated matrix premix (e.g., the aerated matrix premix includes a wetting liquid).

[0154] In some embodiments, disposing the hydrated composition on the porous substrate further includes mixing the matrix premix or the aerated matrix premix in step 240 while contacting at least a portion of the substrate such that at least a portion of the hydrated composition is disposed on the substrate.

[0155] Mixing can be achieved by a variety of techniques, including mechanical rotation (e.g., on a rotatable stage), mechanical stirring, immersion blending, vibrational stirring, ultrasonic stirring, or combinations thereof. In some embodiments, it may be desirable to use a mixing technique that does not include shear forces. Using a mixing technique that does not include shear forces can result in less fibrillation of the PTFE fibrils. Mixing can fibrillate (elongate) the PTFE resin into PTFE fibrils and emulsify the PTFE resin. Mixing can render the active particles uniform within the aerated matrix premix and form chain-like structures and / or agglomerated structures with the fibrillated and / or being fibrillated PTFE fibrils.

[0156] The mixing time can vary depending on the desired application of the porous substrate and / or the properties and / or amounts of the components (e.g., PTFE resin, surfactant, solid particles) in the aerated matrix premix. The mixing time can be 10 minutes or longer, 1 hour or longer, 3 hours or longer, or 24 hours or longer. The mixing time can be 48 hours or shorter, 24 hours or shorter, 3 hours or shorter, or 1 hour or shorter. In some embodiments, the mixing time is from 10 minutes to 3 hours, from 1 hour to 3 hours, from 1 hour to 24 hours, or from 3 hours to 24 hours.

[0157] In some embodiments, method 200 further includes contacting at least a portion of the substrate with a wetting liquid in optional step 265. In some embodiments, the wetting liquid does not include solid particles. The wetting liquid can be any liquid capable of wetting the substrate; i.e., causing the substrate to swell to expose collapsible pores in the solid portion of the substrate. In some embodiments, the wetting liquid is an organic solvent such as ethanol, methanol, acetone, or acetonitrile. In some embodiments, the wetting liquid is selected such that at least one component of the solid particles is insoluble therein. For example, in some embodiments where the solid particles include K2CO3, the wetting liquid can be ethanol. In other embodiments, the wetting liquid is selected such that at least one component of the solid particles is soluble in (and dissolved in) the wetting liquid. In some embodiments, the wetting liquid has the same properties as the liquid carrier of the solid particle composition (if a liquid carrier is used). In some embodiments, the wetting liquid is different from the liquid carrier of the solid particle composition (if a liquid carrier is used).

[0158] The amount of substrate-wetting liquid contact time can vary. In some embodiments, the substrate-wetting liquid contact time is 10 seconds or longer, 30 seconds or longer, 1 minute or longer, 5 minutes or longer, 1 hour or longer, 24 hours or longer. In some embodiments, the substrate-wetting liquid contact time is 48 hours or shorter, 24 hours or shorter, 1 hour or shorter, 5 minutes or shorter, 1 minute or shorter, or 30 seconds or shorter. Without being bound by theory, it is believed that contacting at least a portion of the substrate with the wetting liquid allows the porous substrate to swell, thereby exposing collapsible pores. The wetting liquid allows at least a portion of the composition or at least a portion of one or more components of the composition to migrate into the collapsible pores of the substrate. After drying, the collapsible pores at least partially collapse, and the composition or components of the composition in the collapsible pores are embedded within the solid portion of the substrate. In some embodiments, including the step of contacting at least a portion of the substrate with the wetting liquid can result in a greater amount of the composition and / or components of the composition impregnating the pores of the substrate and / or being embedded within the substrate compared to cases where this step is not included.

[0159] A first illustrative method 200 includes drying the hydrated composition in step 250 to form a composition disposed on a porous substrate. Drying the hydrated composition includes removing at least a portion of the dispersant, at least a portion of the liquid carrier (if present), and at least a portion of the surfactant from the hydrated composition. After step 200, the porous substrate includes a first portion of the composition disposed on at least a portion of the primary surface and at least a portion of a plurality of macropores / micropores impregnated with the second portion of the composition. In some embodiments, after step 200, the porous substrate further includes a third portion of the composition that is embedded (e.g., when the porous substrate is a wettable porous substrate and a wetting liquid is used).

[0160] Drying can be achieved to different extents (i.e., the amounts of dispersant, liquid carrier, and / or surfactant that may be present in the porous substrate after drying the hydrated composition), and includes various techniques such as those discussed herein (e.g., see the discussion regarding Figure 8 .

[0161] In some embodiments where the substrate is contacted with the wetting liquid (step 265) and at least a portion of the solid particles dissolve in the wetting liquid, drying the hydrated composition may further include causing at least a portion of the solid particles to precipitate to form free active particles. Some such free active particles may be embedded within the solid portion of the substrate.

[0162] In some embodiments of the first illustrative method 200, the plurality of PTFE fibrils of the matrix include short-strand PTFE fibrils formed from short strands of PTFE resin and long-strand PTFE fibrils formed from long strands of PTFE resin. In such embodiments, the PTFE resin of the matrix premix and / or the inflated matrix premix includes short-strand PTFE resin and long-strand PTFE resin. The PTFE resin of the inflated emulsion includes short-strand PTFE resin. The long-strand PTFE resin may be added at any step or multiple steps of method 200 such that the PTFE resin of one or more of the emulsion, inflated emulsion (210c), matrix premix (220c), or inflated matrix premix (230c) includes short-strand PTFE resin and long-strand PTFE resin. For example, in some embodiments, method 200 further includes adding long-strand PTFE resin to the emulsion such that the PTFE resin of the emulsion, the PTFE resin of the inflated emulsion (210c), the PTFE resin of the premix (220c), and the PTFE resin of the inflated premix (230c) include short-strand PTFE resin and long-strand PTFE resin. In some embodiments, method 200 further includes adding long-strand PTFE resin to the inflated emulsion such that the PTFE resin of the inflated emulsion (210c), the PTFE resin of the premix (220c), and the PTFE resin of the inflated premix (230c) include short-strand PTFE resin and long-strand PTFE resin. In some embodiments, method 200 further includes adding long-strand PTFE resin to the matrix premix such that the PTFE resin of the matrix premix (220c) and the PTFE resin of the inflated premix (230c) include short-strand PTFE resin and long-strand PTFE resin. In some embodiments, method 200 further includes adding long-strand PTFE resin to the inflated matrix premix such that the PTFE resin of the inflated matrix premix (230c) includes short-strand PTFE resin and long-strand PTFE resin.

[0163] In some embodiments of method 200, based on the total weight of the matrix premix or the aerated matrix premix, the matrix premix and / or the aerated matrix premix comprises 0.01 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, 55 wt-% or more, or 65 wt-% or more of PTFE resin. In some embodiments of method 200, based on the total weight of the matrix premix or the aerated matrix premix, the matrix premix and / or the aerated matrix premix comprises 80 wt-% or less, 65 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, or 15 wt-% or less of PTFE resin.

[0164] In some embodiments of method 200, based on the total weight of the matrix premix or the aerated matrix premix, the matrix premix and / or the aerated matrix premix comprises 0.01 wt-% or more, 1 wt-% or more, 5 wt-% or more, or 10 wt-% or more of long strand PTFE resin. In some embodiments of method 200, based on the total weight of the matrix premix or the aerated matrix premix, the matrix premix and / or the aerated matrix premix comprises 15 wt-% or less, 10 wt-% or less, 5 wt-% or less, or 1 wt-% or less of long strand PTFE resin.

[0165] In some embodiments of method 200, based on the total weight of the matrix premix or the aerated matrix premix, the matrix premix and / or the aerated matrix premix comprises 0.1 wt-% or more, 5 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, or 55 wt-% or more of short strand PTFE. In some embodiments of method 200, based on the total weight of the matrix premix or the aerated matrix premix, the matrix premix and / or the aerated matrix premix comprises 70 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, 15 wt-% or less, or 5 wt-% or less of short strand PTFE resin.

[0166] Figure 7 is a flow chart outlining a second illustrative method of disposing a composition of the present disclosure on a porous substrate to produce a porous substrate of the present disclosure. The composition comprises a matrix. The matrix comprises a plurality of active particles and a plurality of PTFE fibrils formed from a plurality of PTFE resins. In some embodiments, the composition further comprises free active particles, free PTFE fibrils, or both. The porous substrate comprises a major surface and a plurality of macropores / micropores connected to the major surface. In some embodiments, the porous substrate is a wettable porous substrate. In some such embodiments, a plurality of collapsible pores are exposed during one or more steps of method 400.

[0167] In some embodiments, method 400 optionally includes forming a matrix premix in optional step 460A. The matrix premix (460c(A)) includes a PTFE resin, a surfactant, and a dispersant. In some embodiments, the matrix premix is formed by diluting a concentrated matrix premix with a dispersant or a solution including a dispersant and a surfactant in step 460B. The concentrated matrix premix (460c(B)) includes a PTFE resin and a dispersant. In some embodiments, the concentrated matrix premix and the matrix premix include an emulsion containing a PTFE resin and a dispersant. In some embodiments, the concentrated matrix premix includes at least a portion of the surfactant. In some embodiments, based on the total weight of the concentrated matrix premix, the concentrated matrix premix includes an emulsion of 60 wt-% PTFE resin (e.g., 60 wt-% short strand PTFE resin).

[0168] In some embodiments, method 400 optionally includes aerating the matrix premix in optional step 450 to form an aerated matrix premix. The matrix premix (450c) includes a PTFE resin, a surfactant, and a dispersant. Aeration can be achieved using any of the techniques disclosed herein.

[0169] Method 400 includes contacting at least a portion of a substrate with the matrix premix or the aerated matrix premix in step 410. The aerated matrix premix is a matrix premix that has been aerated (e.g., such as in optional step 450). In some embodiments, it may be desirable to contact at least a portion of the substrate with the non-aerated matrix premix (i.e., the matrix premix). In other embodiments, it may be desirable to contact at least a portion of the substrate with the aerated matrix premix (i.e., the aerated matrix premix). The substrate contacts the aerated matrix premix or the matrix premix in a manner that exposes at least a portion of the major surface of the porous substrate and at least a portion of the plurality of macropores / micropores connected to the major surface to the aerated matrix premix or the matrix premix. The contacting can be achieved using any suitable technique described herein.

[0170] The contact time can vary. In some embodiments, the contact time is 10 seconds or longer, 30 seconds or longer, 1 minute or longer, 5 minutes or longer, 1 hour or longer, or 24 hours or longer. In some embodiments, the contact time is 48 hours or shorter, 24 hours or shorter, 1 hour or shorter, or 5 minutes or shorter, 1 minute or shorter, or 30 seconds or shorter.

[0171] Method 400 includes contacting at least a portion of a substrate with a solid particle composition. The solid particle composition includes solid particles. In some embodiments, the solid particle composition includes solid particles and a liquid carrier. In some embodiments where the porous substrate is a wettable porous substrate, the liquid carrier includes a wetting liquid. In such embodiments, the wetting liquid exposes a plurality of collapsible pores of the wettable porous substrate. The liquid carrier may include water; an organic solvent such as ethyl acetate, ethanol, methanol, isopropanol, butanol, dichloromethane, toluene, acetonitrile, acetone, diethyl ether, pentanol, tetrahydrofuran; or a combination thereof.

[0172] The solid particles may include one or more substances to form one or more different types of active particles (e.g., activated carbon and potassium carbonate). In some such embodiments, at least one component and / or at least a portion of the solid particles in the solid particle composition are dissolved in the liquid carrier (e.g., the wetting liquid). In other embodiments, the solid particles of the solid composition are suspended in the liquid carrier. In still other embodiments, a first portion of the solid particles is dissolved in the liquid carrier, and a second portion of the solid particles is suspended in the liquid carrier. For example, the solid particle composition may include a first chemical substance dissolved in the liquid carrier and a second chemical substance suspended in the liquid carrier.

[0173] At least a portion of the first plurality of active particles, at least a portion of the free active particles (if present), or both include at least a portion of the solid particles. In an embodiment, at least a portion of the substrate is contacted with a solid particle composition that does not include a liquid carrier; that is, the solid particle composition includes 100 wt-% solid particles. In some such embodiments, the contacting can be achieved by disposing the solid particles on at least a portion of the substrate. In other embodiments, the solid particle composition includes solid particles and a liquid carrier. In such embodiments, contacting at least a portion of the substrate with the solid particle composition can be achieved using any suitable technique described herein.

[0174] In embodiments where the solid particle composition includes a liquid carrier, based on the total weight of the solid particle composition, the solid particle composition includes 0.5 wt-% or more, 10 wt-% or more, or 30 wt-% or more, or 50 wt-% or more of solid particles. In embodiments where the solid particle composition includes a liquid carrier, based on the total weight of the solid particle composition, the solid particle composition includes 90 wt-% or less, 50 wt-% or less, 30 wt-% or less, or 10 wt-% or less of solid particles.

[0175] The amount of the substrate-solid particle composition contact time can vary. In some embodiments, the substrate-solid particle composition contact time is 10 seconds or longer, 30 seconds or longer, 1 minute or longer, 5 minutes or longer, 1 hour or longer, 24 hours or longer. In some embodiments, the substrate-solid particle composition contact time is 48 hours or shorter, 24 hours or shorter, 1 hour or shorter, 5 minutes or shorter, 1 minute or shorter, or 30 seconds or shorter.

[0176] In some embodiments, the step of contacting at least a portion of the substrate with a matrix premix or an aerated matrix premix is performed before the step of contacting at least a portion of the substrate with a solid particle composition (i.e., step 410 is performed before step 420). In some embodiments, the step of contacting at least a portion of the substrate with a solid particle composition is performed before the step of contacting at least a portion of the substrate with a matrix premix or an aerated matrix premix (i.e., step 420 is performed before step 410). Generally, when the substrate is subsequently contacted with a matrix premix, an aerated matrix premix, or solid particles, at least a portion of the substrate is saturated with the matrix premix, the aerated matrix premix, or the solid particle composition (e.g., still in contact therewith). For example, at least a portion of the substrate may be contacted with a large amount of a matrix premix, an aerated matrix premix, or a solid particle composition; then, the substrate is removed from the large amount of the matrix premix, the aerated matrix premix, or the solid particle composition. Due to the absorption / adsorption characteristics of some substrates, a portion of the large amount of the matrix premix, the aerated matrix premix, or the solid particle composition may have been adsorbed / absorbed onto the surface of the matrix and / or absorbed / adsorbed into the pores of the substrate (e.g., macropores / micropores and / or collapsible pores). Thus, during subsequent contact steps, at least a portion of the substrate is contacted with a matrix premix, an aerated matrix premix, or a solid particle composition. For example, in some embodiments, at least a portion of the substrate is immersed in a large amount of a matrix premix or an aerated matrix premix; removed from the large amount of the matrix premix or the aerated matrix premix; and then contacted with a large amount of a solid particle composition while at least a portion of the substrate is saturated with a portion of the large amount of the matrix premix or the aerated matrix premix. In some embodiments, at least a portion of the substrate is contacted with a large amount of a solid particle composition; removed from the large amount of the solid particle composition; and then contacted with a large amount of a matrix premix or an aerated matrix premix while at least a portion of the substrate is saturated with a portion of the large amount of the solid particle composition.

[0177] In some embodiments, the step of contacting at least a portion of the substrate with the matrix premix or the aerated matrix premix (step 410) is carried out simultaneously with the step of contacting at least a portion of the substrate with the solid particle composition (step 420). That is, while at least a portion of the substrate is in contact with a large amount of the solid particle composition, at least a portion of the substrate is in contact with a large amount of the matrix premix or the aerated matrix premix. For example, at least a portion of the substrate can first be immersed in a large amount of the matrix premix or the aerated matrix premix; then, while at least a portion of the substrate remains immersed in the large amount of the matrix premix or the aerated matrix premix, a large amount of the solid particle composition can be pumped upward, through, or around at least a portion of the substrate. In some embodiments, at least a portion of the substrate can first be immersed in a large amount of the solid particle composition; then, while at least a portion of the substrate remains immersed in the large amount of the solid particle composition, a large amount of the matrix premix or the aerated matrix premix can be pumped upward, through, or around at least a portion of the substrate.

[0178] Without being bound by theory, it is believed that contacting the substrate with the solid particle composition enables free active particles (if present) to be embedded within at least a portion of the plurality of collapsible pores of the substrate. It is also believed that contacting the substrate with the solid particle composition allows for an increase in the adhesion between the composition and the substrate. Additionally, it is believed that contacting the substrate with the solid particle composition permits a higher absorption capacity for acidic or basic gases, since the amount of chemically active adsorbent immobilized within the substrate is greater compared to what might be obtained by impregnating a carrier with a chemisorbent and then loading a hybrid material onto the substrate.

[0179] In some embodiments, the steps of contacting at least a portion of the substrate with the matrix premix or the aerated matrix premix (step 410) and contacting at least a portion of the substrate with the solid particle composition (step 420) can be repeated in sequence or repeated multiple times as separate steps (e.g., 2 times, 3 times, 4 times, etc.). For example, at least a portion of the substrate can be contacted with the matrix premix or the aerated matrix premix, contacted with the solid particle composition, and then contacted a second time with the matrix premix or the aerated matrix premix. In other embodiments, at least a portion of the substrate can be contacted with the matrix premix or the aerated matrix premix, contacted with a first solid particle composition, and then contacted a second time with the first solid particle composition, or contacted with a second solid particle composition, a third solid particle composition, etc. In some such embodiments, the composition of the first solid particle composition is different from the composition of the first solid particle composition. In some embodiments, the composition of the second solid particle composition is the same as the composition of the first solid particle composition.

[0180] In some embodiments, the matrix premix or the aerated matrix premix of method 400 further includes a second solid particle (i.e., the solid particles in the solid particle composition are the first solid particles). The amount of the second solid particle can vary depending on the characteristics of the second solid particle and the desired end application of the porous substrate. In some embodiments, based on the total weight of the matrix premix or the aerated matrix premix, the matrix premix or the aerated matrix premix includes 0.5 wt-% or more, 10 wt-% or more, or 30 wt-% or more of the second solid particle. In some embodiments, based on the total weight of the matrix premix or the aerated matrix premix, the matrix premix or the aerated matrix premix includes 50 wt-% or less, 30 wt-% or less, or 10 wt-% or less of the second solid particle. The plurality of active particles, free active particles, or both can include a portion of the second solid particle.

[0181] In some embodiments, the first solid particle and the second solid particle are made of the same material. In some embodiments, the first solid particle and the second solid particle are made of different materials.

[0182] In some embodiments, method 400 further includes contacting at least a portion of the substrate with a wetting liquid in optional step 425. The wetting liquid can be any liquid capable of wetting the substrate; that is, causing the substrate to swell to expose the collapsible pores in the solid portion of the substrate. In some embodiments, the wetting liquid is an organic solvent such as ethanol, methanol, acetone, or acetonitrile. In some embodiments, the wetting liquid is selected such that at least one component of the solid particle is insoluble therein. For example, in some embodiments where the solid particle includes K2CO3, the wetting liquid can be ethanol. In some embodiments, the wetting liquid has the same characteristics as the liquid carrier of the solid particle composition (if a liquid carrier is used). In some embodiments, the wetting liquid is different from the liquid carrier of the solid particle composition (if a liquid carrier is used).

[0183] In some embodiments, step 425 is performed after steps 410 and 420 (which can be performed in any order). In some such embodiments, the order of the steps is step 410, step 420, and then step 425. In other such embodiments, the order of the steps is step 420, step 310, and then step 425. In some embodiments, step 425 is performed after one of steps 410 or 420 but before the remaining uncompleted step. In some embodiments, at least a portion of the substrate can be contacted with the same wetting liquid or one or more different wetting liquids before and / or after the other steps of the method (e.g., steps 420 and step 410) are completed.

[0184] The amount of substrate-wetting liquid contact time can vary. In some embodiments, the substrate-wetting liquid contact time is 10 seconds or longer, 30 seconds or longer, 1 minute or longer, 5 minutes or longer, 1 hour or longer, 24 hours or longer. In some embodiments, the substrate-wetting liquid contact time is 48 hours or shorter, 24 hours or shorter, 1 hour or shorter, 5 minutes or shorter, 1 minute or shorter, or 30 seconds or shorter.

[0185] Without being bound by theory, it is believed that contacting at least a portion of the substrate with the wetting liquid allows the porous substrate to swell, thereby exposing collapsible pores. The wetting liquid allows at least a portion of the composition or at least a portion of one or more components of the composition to migrate into the collapsible pores of the substrate. After drying, the collapsible pores at least partially collapse, and the composition or components of the composition in the collapsible pores are embedded within the solid portion of the substrate. In some embodiments, including the step of contacting at least a portion of the substrate with the wetting liquid can result in a greater amount of the composition and / or components of the composition being impregnated into the pores of the substrate and / or embedded within the substrate compared to cases where this step is not included.

[0186] Method 400 includes disposing a hydrated composition on a porous substrate in step 430. The hydrated composition includes a matrix, free active particles (if present), free PTFE fibrils (if present), at least a portion of a dispersant, at least a portion of a liquid carrier (if present), at least a portion of a wetting liquid (if present), and at least a portion of a surfactant. The hydrated composition can be disposed on at least a portion of at least one major surface of the substrate, impregnating at least a portion of a plurality of macropores / micropores of the substrate, inserted into the collapsible pores of the substrate, or any combination thereof.

[0187] Method 400 includes drying the hydrated composition to form a composition disposed on the porous substrate. Drying the hydrated composition includes removing at least a portion of the dispersant, at least a portion of the liquid carrier (if present), and at least a portion of the surfactant from the hydrated composition. Drying can be achieved to different extents (i.e., the amount of dispersant, liquid carrier, and / or surfactant present in the porous substrate after drying), and includes various techniques such as those discussed herein (e.g., see the discussion regarding Figure 8 ).

[0188] In some embodiments, where the substrate solid particle composition includes a solid particle component and / or a portion of the solid particles dissolved in a liquid carrier and / or the substrate is in contact with a wetting liquid that includes a component capable of dissolving a portion of the solid particles, drying the hydrated composition can further include precipitating at least a portion of the solid particles to form free active particles. Some such free active particles can be embedded within the solid portion of the substrate.

[0189] In some embodiments of method 400, the plurality of PTFE fibrils of the matrix include short-strand PTFE fibrils formed from short-strand PTFE resin and long-strand PTFE fibrils formed from long-strand PTFE resin. In such embodiments, the PTFE resin of the aerated matrix premix (410c) or the matrix premix (410c) includes short-strand PTFE resin and long-strand PTFE resin. The PTFE resin of the concentrated matrix premix includes short-strand PTFE. The long-strand PTFE resin can be added at any step or multiple steps of method 400 such that the PTFE resin of one or more of the concentrated matrix premix (460c(B)), the matrix premix (460c(A)), and the aerated matrix premix (450c) includes short-strand PTFE resin and long-strand PTFE resin. For example, in some embodiments, method 400 further includes adding long-strand PTFE resin to the concentrated matrix premix such that the PTFE resin of the concentrated matrix premix, the PTFE resin of the matrix premix (450c), and the PTFE resin of the aerated matrix premix (450c) include short-strand PTFE resin and long-strand PTFE resin. In some embodiments, method 400 further includes adding long-strand PTFE resin to the matrix premix such that the PTFE resin of the premix (460c) and the PTFE resin of the aerated premix (450c) include short-strand PTFE resin and long-strand PTFE resin. In some embodiments, method 400 further includes adding long-strand PTFE resin to the aerated matrix premix such that the PTFE resin of the aerated matrix premix (450c) includes short-strand PTFE resin and long-strand PTFE resin.

[0190] In some embodiments of method 400, based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix or the matrix premix includes 0.01 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, 55 wt-% or more, or 65 wt-% or more of PTFE resin. In some embodiments of method 400, based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix or the matrix premix includes 80 wt-% or less, 65 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, or 15 wt-% or less of PTFE resin.

[0191] In some embodiments of method 400, based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix or the matrix premix comprises 0.01 wt-% or more, 1 wt-% or more, 5 wt-% or more, or 10 wt-% or more of long strand PTFE resin. In some embodiments of method 400, based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix or the matrix premix comprises 15 wt-% or less, 10 wt-% or less, 5 wt-% or less, or 1 wt-% or less of long strand PTFE resin.

[0192] In some embodiments of method 400, based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix or the matrix premix comprises 0.1 wt-% or more, 5 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, or 55 wt-% or more of short strand PTFE. In some embodiments of method 400, based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix or the matrix premix comprises 80 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, 15 wt-% or less, or 5 wt-% or less of short strand PTFE resin.

[0193] At any time during any of the methods of the present disclosure, a dispersant can be added to the components of the concentrated matrix premix, aerated emulsion, matrix premix, aerated matrix premix, or a combination thereof. In some embodiments, the dispersant can be added before or during the steps of any of the methods disclosed herein. For example, in embodiments where long strand PTFE resin is added to the concentrated matrix premix, emulsion, aerated emulsion, matrix premix, aerated matrix premix, the long strand PTFE resin can be added to a mixture comprising the dispersant. The dispersant can be added to dilute the components, suspend the components, facilitate the formation of a colloid comprising one or more components, facilitate the formation of an emulsion, facilitate aeration, or a combination thereof. For example, in some embodiments, the dispersant can be added to an aerated emulsion (e.g., 210c). In some embodiments, the dispersant can be added to a matrix premix (e.g., 220c and 460c). In some embodiments, the dispersant can be added to an aerated matrix premix (e.g., 230c and 450c). In some embodiments, the dispersant can be added to a mixture. In some embodiments, the dispersant can be added to an emulsion (e.g., 210c).

[0194] The method of the present disclosure includes drying a hydrated composition to form a composition disposed on a porous substrate. Drying the hydrated composition includes removing at least a portion of the dispersant and / or liquid carrier (if present) from the hydrated composition. Drying the hydrated composition also includes removing at least a portion of the surfactant from the hydrated composition. Based on the total weight of the porous substrate, the porous substrate formed after drying the hydrated composition includes 50 wt-% or less, 20 wt-% or less, 10 wt-% or less, 5 wt-% or less, or 1 wt-% or less of the dispersant and / or liquid carrier (if present). Based on the total weight of the porous substrate, the porous substrate formed after drying the hydrated composition includes 50 wt-% or less, 20 wt-% or less, 10 wt-% or less, 5 wt-% or less, or 1 wt-% or less of the surfactant. The degree of drying can vary depending on the desired application of the porous substrate and / or the next processing step.

[0195] The dispersant of any of the illustrative methods can be water, one or more organic solvents, or both. In some embodiments, the dispersant includes water. In some embodiments, the dispersant includes an organic solvent or a mixture of organic solvents. Examples of organic solvents that can be included in the dispersant include methanol, acetone, tetrahydrofuran, dimethylformamide, acetonitrile, isopropanol, ethanol, or combinations thereof.

[0196] Figure 8 is a flow chart outlining various drying techniques and / or steps of a drying method. In some embodiments, a hydrated composition is formed such that it is in contact with a solution of excess dispersant, liquid carrier (if present), and surfactant; i.e., the hydrated composition is disengaged from an aerated matrix premix, matrix premix, or solid particle composition. In such embodiments, drying the hydrated composition includes separating the hydrated composition from the remaining aerated matrix premix, matrix premix, or solid particle composition in step 500. This can be achieved by decanting the aerated matrix premix, matrix premix, or solid particle composition; or physically removing the hydrated composition from the aerated matrix premix, matrix premix, or solid particle composition.

[0197] In some embodiments, drying the hydrated composition comprises contacting at least a portion of the hydrated composition (e.g., the portion of the major surface of the porous substrate on which the hydrated composition is disposed), preferably the entire hydrated composition, with an absorbent material. The absorbent material can draw at least a portion of the dispersant, at least a portion of the surfactant, and at least a portion of the liquid carrier (if present) from the hydrated composition. Any suitable absorbent material can be used. Examples of absorbent materials include cotton; cellulose; sponges, including polyester, polyurethane, plant cellulose, melamine, or combinations thereof; anhydrous calcium chloride; anhydrous magnesium sulfate; sodium polyacrylate; and combinations thereof. The hydrated composition can be in contact with the absorbent material for a period of time. In some embodiments, the contact time is 1 second or longer, 1 minute or longer, or 1 hour or longer. In some embodiments, the contact time is 24 hours or shorter, 1 hour or shorter, or 1 minute or shorter. In such embodiments, the method further comprises removing at least a portion, preferably all, of the absorbent material from the hydrated composition in step 520.

[0198] In some embodiments, the hydrated composition is contacted with the absorbent material more than once. In other words, in some embodiments, the step of contacting at least a portion of the hydrated composition with the absorbent (step 510) and the step of removing at least a portion of the absorbent material from the hydrated composition (step 520) are repeated continuously multiple times (e.g., 2 to 10 times, 2 to 20 times, or 2 to 50 times), each time using fresh absorbent material that has not been in contact with the hydrated composition previously.

[0199] In some embodiments, drying the hydrated composition further comprises exposing the hydrated composition to an elevated temperature for a period of time in step 540. In some embodiments, the hydrated composition is exposed to a temperature of 100°C to 400°C, preferably 100°C to 300°C, for 0.1 hour to 24 hours, preferably 1 hour to 5 hours. Preferably, the hydrated composition is not subjected to calcination conditions. PTFE fibrils may shrink under calcination conditions (e.g., a temperature above 330°C), which may manifest as PTFE fibril breakage and a reduction in the mechanical stability of the matrix.

[0200] In some embodiments, drying the hydrated composition to form a matrix further comprises applying a vacuum to the hydrated composition. In some such embodiments, the hydrated composition is simultaneously exposed to an elevated temperature (e.g., 25°C to 150°C).

[0201] The surfactant of any illustrative method can be a nonionic non-fluorinated surfactant. A nonionic surfactant is a surfactant having an uncharged polar head group. Examples of nonionic non-fluorinated surfactants that can be used include ethoxylates, alkoxylates, and coconut amides. In some embodiments, the surfactant is polyethylene glycol trimethyl nonyl ether. In some embodiments, based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix and / or the matrix premix includes 0.5 wt-% or more, 5 wt-% or more, or 20 wt-% or more of the surfactant. In some embodiments, based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix and / or the matrix premix includes 40 wt-% or less, 20 wt-% or less, or 5 wt-% or less of the surfactant. Based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix or the matrix premix of any illustrative method can include 0.5 wt-% to 40 wt-%, preferably 5 wt-% to 20 wt-% of the surfactant.

[0202] The methods of the present disclosure can result in various loadings of multiple active particles. The loading of each solid particle (or any individual component of the solid particle) can be calculated according to a compositional analysis test method (i.e., the loading test method). The sum of the loadings of each component of the solid particle is regarded as the loading of the multiple active particles including the components of the solid particle. For example, if the solid particle includes activated carbon, the loading of the activated carbon is the loading of the multiple active particles including the activated carbon. If the solid particle includes manganese oxide and copper oxide, the loading of the multiple active particles including manganese oxide and copper oxide is the sum of the loading of manganese oxide and the loading of copper oxide.

[0203] The total active particle loading is the sum of the loadings of one or more components that make up the multiple active particles and the free active particles (if present). For example, in embodiments where the multiple active particles and the free active particles (if present) include manganese oxide and copper oxide, the total active particle loading is the sum of the loadings of manganese oxide and copper oxide. In some embodiments, the methods of the present disclosure result in a total active particle loading of 50 wt-% or more, 70 wt-% or more, 80 wt-% or more, or 90 wt-% or more. In some embodiments, the methods of the present disclosure result in a multiple active particle loading of 95 wt-% or less, 90 wt-% or less, 80 wt-% or less, or 70 wt-% or less.

[0204] Exemplary Embodiments

[0205] Throughout the exemplary embodiments, it should be understood that the term "macropore / micropore" refers to macropores or multiple macropores, micropores or multiple micropores (if present), or both.

[0206] Porous Substrate Embodiments

[0207] Embodiment 1C is a porous substrate comprising a composition disposed thereon, the composition comprising a matrix, the matrix comprising a plurality of PTFE fibrils and a plurality of active particles. In some embodiments, the plurality of PTFE fibrils comprise short-strand PTFE fibrils and long-strand PTFE fibrils.

[0208] Embodiment 2C is the porous substrate of Embodiment 1C, wherein the composition further comprises free active particles, free PTFE fibrils, or both. In some embodiments, the free PTFE fibrils comprise short-strand PTFE fibrils. In some embodiments, the plurality of active particles and the free active particles comprise the same material. In other embodiments, the plurality of active particles and the free active particles comprise different materials.

[0209] Embodiment 3C is the porous substrate of Embodiment 1C or 2C, wherein the porous substrate comprises a main surface and a plurality of macropores connected to the main surface; wherein a first portion of the composition is disposed on at least a portion of the main surface; and wherein at least a portion of the plurality of macropores is impregnated with a second portion of the composition.

[0210] Embodiment 4C is the porous substrate of Embodiment 3C, wherein a portion of the plurality of macropores / micropores comprises a first portion of the macropores / micropores; wherein the first portion of the macropores / micropores is impregnated with a first component of the composition; and wherein a second portion of the macropores / micropores is impregnated with a second component of the composition.

[0211] Embodiment 5C is the porous substrate of Embodiment 4C, wherein the first component and the second component are at least one particle of the matrix, free active particles, or at least one PTFE fibril of the free PTFE fibrils. In some embodiments, the first component is the matrix or the composition as a whole, and the second component is at least one particle of the free active particles.

[0212] Embodiment 6C is the porous substrate of any one of Embodiments 1C to 5C, wherein the porous substrate is a wettable porous substrate.

[0213] Embodiment 7C is the porous substrate of Embodiment 6C, wherein the porous substrate comprises a third portion of the composition embedded within the porous substrate (e.g., embedded within the solid portion of the porous substrate).

[0214] Embodiment 8C is the porous substrate of Embodiment 7C, wherein the porous substrate includes one or more components of the composition embedded therein. The one or more components can be part of the matrix, at least one particle of the free active particles, at least one PTFE fibril of the free PTFE fibrils, or any combination thereof. In some embodiments, the one or more components include free PTFE fibrils. In some such embodiments, the free PTFE fibrils include long-strand PTFE fibrils.

[0215] Embodiment 9C is the porous substrate of any one of Embodiments 1C to 8C, wherein the porous substrate is made of a material including reticulated foam. The reticulated foam can be polymer-based; metal-based, metal oxide-based or metal carbide-based; carbon-based; ceramic-based; or any combination thereof. The reticulated foam can include reticulated polyester; reticulated polyether; reticulated polyurethane; untreated reticulated polyurethane; reticulated cellulose; reticulated melamine; reticulated steel; reticulated activated carbon; reticulated glassy carbon; reticulated graphene; reticulated foam made of a metal such as a reduced metal (such as titanium, lead, iron, copper, zinc, chromium, cobalt, nickel, manganese, gold, silver, platinum, palladium, rhodium, tungsten, molybdenum, vanadium, zirconium, silicon, ruthenium or any combination thereof); reticulated silica; reticulated silicon carbide; or any combination thereof.

[0216] Embodiment 10C is the porous substrate of any one of Embodiments 1C to 9C, wherein at least a portion of the plurality of active particles and at least a portion of the plurality of PTFE fibrils adopt a chain-like structure, an agglomerated structure, or both.

[0217] Embodiment 11C is the porous substrate of any one of Embodiments 1C to 10C, wherein the short-strand PTFE fibrils, long-strand PTFE fibrils, free PTFE fibrils (if present), or any combination thereof include C3-PTFE, C2-PTFE, C1-PTFE, or a combination thereof.

[0218] Embodiment 12C is the porous substrate of any one of Embodiments 1C to 11C, wherein the plurality of active particles, free active particles (if present), or both include a catalyst, an adsorbent, a growth seed, a metal-organic framework (MOF), an electroactive material, a bioactive material, or any combination thereof.

[0219] Embodiment 13C is the porous substrate of Embodiment 12C, wherein the plurality of active particles include a catalyst; and wherein the catalyst is capable of destroying ozone.

[0220] Embodiment 14C is the porous substrate of Embodiment 11C or 12C, wherein the plurality of active particles, free active particles (if present), or both include a catalyst; and wherein the catalyst is capable of nitrobenzene reduction, hydrogenation, NOx reduction, or a combination thereof.

[0221] Embodiment 15C is the composition of Embodiment 13C, wherein a plurality of active particles include a catalyst; and wherein the catalyst includes ferrosilicate, ferromanganese silicate, zinc ferrosilicate, or any combination thereof; transition metal oxides, such as zinc oxide, manganese oxide, copper oxide, cerium dioxide, or any combination thereof; reduced metals (i.e., zero-valent metals), including titanium, lead, iron, copper, zinc, chromium, cobalt, nickel, manganese, gold, silver, platinum, palladium, rhodium, tungsten, molybdenum, vanadium, zirconium, silicon, ruthenium, or any combination thereof; carbonates, such as barium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, or any combination thereof; or any combination thereof.

[0222] Embodiment 16C is the porous substrate of Embodiment 12C, wherein a plurality of active particles, free active particles (if present), or both include an adsorbent; and wherein the adsorbent is a physical adsorbent, a chemical adsorbent, or a physical adsorbent-chemical adsorbent hybrid. In some embodiments, the physical adsorbent-chemical adsorbent hybrid is a graft hybrid or an impregnation hybrid.

[0223] Embodiment 17C is the porous substrate of Embodiment 16C, wherein a plurality of active particles, free active particles (if present), or both include an adsorbent; and wherein the adsorbent is capable of adsorbing basic compounds, acidic compounds, organic compounds, inorganic compounds, or any combination thereof. The acidic compounds, basic compounds, organic compounds, inorganic compounds, or any combination thereof may be liquid, gaseous, and / or vaporous (preferably), or both.

[0224] Embodiment 18C is the porous substrate of Embodiment 17C, wherein the adsorbent is capable of adsorbing basic compounds. The basic compounds may be liquid, gaseous, and / or vaporous (preferably), or both. In some such embodiments, the adsorbent includes an inorganic acid (e.g., boric acid, nitric acid, sulfuric acid, hydrochloric acid, hydrogen chloride, hydrogen fluoride, hydrogen bromide, phosphoric acid, perchloric acid, periodic acid, or any combination thereof) or a chemical adsorbent including a carboxylic acid functional group (e.g., citric acid, terephthalic acid, trimellitic acid, tartaric acid, maleic acid, benzoic acid, oxalic acid, or any combination thereof). In some embodiments, the basic compounds include ammonia.

[0225] Embodiment 19C is the porous substrate of Embodiment 17C, wherein the adsorbent is capable of adsorbing acidic compounds. The acidic compounds may be liquid, gaseous, and / or vaporous (preferably), or both. In some embodiments, the acidic compounds include sulfur dioxide, nitrogen dioxide, hydrogen sulfide, sulfur trioxide, nitric oxide, or any combination thereof.

[0226] Embodiment 20C is the porous substrate of Embodiment 17C, wherein the adsorbent is capable of adsorbing inorganic compounds. The inorganic compounds can be in liquid, gaseous, and / or vaporous (preferably) states, or both. In some such embodiments, the adsorbent includes activated carbon, zeolites (e.g., zeolite X, zeolite A, zeolite Y, zeolite β, and zeolite ZSM-5), silicates, metal-organic frameworks (MOFs), mesoporous transition metal oxides, or any combination thereof. In some embodiments, the inorganic compounds include carbon dioxide; carbon monoxide; water; perfluorocarbons (e.g., tetrafluoromethane and hexafluoroethane); sulfur hexafluoride; hydrogen sulfide; nitrogen oxides; sulfur oxides; ozone; or any combination thereof.

[0227] Embodiment 21C is the porous substrate of Embodiment 17C, wherein the adsorbent is capable of adsorbing organic compounds. The organic compounds can be in liquid, gaseous, and / or vaporous (preferably) states, or both. The organic compounds can include aromatic hydrocarbons (e.g., toluene, benzene, xylene, and ethylbenzene); siloxanes; polycyclic aromatic hydrocarbons (e.g., naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, , benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(ghi)perylene, and indeno(1,2,3-cd)pyrene)); n-alkanes (e.g., methane, ethane, propane, butane, pentane, and hexane); n-alkenes (e.g., methylene, ethylene, and propylene); aldehydes (e.g., formaldehyde); alcohols; siloxanes; or any combination thereof. In some such embodiments, the catalyst includes activated carbon, zeolites (e.g., zeolite X, zeolite A, zeolite Y, zeolite β, and zeolite ZSM-5), silicates, metal-organic frameworks (MOFs), mesoporous transition metal oxides, or any combination thereof.

[0228] Embodiment 22C is the porous substrate of any one of Embodiments 16C to 21C, wherein the adsorbent is a chemisorbent, a physisorbent, or a physisorbent-chemisorbent hybrid; and wherein the physisorbent includes activated carbon, zeolites, silicates, metal-organic frameworks (MOFs), mesoporous transition metal oxides, or a combination thereof.

[0229] Embodiment 23C is the porous substrate of Embodiment 19C, wherein the adsorbent includes a chemisorbent or a physisorbent-chemisorbent hybrid, and wherein the chemisorbent includes Group I metal carbonates; metal oxides; Group I metal hydroxides; Group II metal hydroxides; N-containing compounds such as amines, imines, ammonium salts, and combinations thereof; or a combination thereof. In some embodiments, the N-containing compounds include polyethyleneimine, tetraethylenepentamine, ethylenediamine, 3-aminopropyltriethoxysilane, ammonium persulfate, or a combination thereof.

[0230] Embodiment 24C is a porous substrate of Embodiment 12C, wherein the plurality of active particles, free active particles (if present), or both include growth seeds; and wherein the growth seeds are nucleation points for the growth of a metal-organic framework (MOF). In some embodiments, the growth seeds include copper nitrate, trimesic acid, or both.

[0231] Embodiment 25C is a porous substrate of Embodiment 12C, wherein the plurality of active particles, free active particles (if present), or both include a MOF; and wherein the MOF includes copper benzene-1,3,5-tricarboxylate.

[0232] Embodiment 26C is a porous substrate of Embodiment 12C, wherein the plurality of active particles include an electroactive material; and wherein the electroactive material is an anodic electroactive material, a cathodic electroactive material, or both.

[0233] Embodiment 27C is a composition of Embodiment 12C or 26C, wherein the electroactive material includes lithium or lithium and one or more metals.

[0234] Embodiment 28C is a porous substrate of Embodiment 12C, wherein the plurality of active particles include a bioactive material. The bioactive material can be a protein, lipid, nucleotide, nucleic acid, sugar, polysaccharide, or any combination thereof. The protein can be an enzyme. The enzyme can be lactase.

[0235] Embodiment 29C is a porous substrate of any one of Embodiments 1C to 28C, wherein the average particle size of the plurality of active particles, free active particles (if present), or both measured by a size analysis test method is 0.001 μm or greater, 0.01 μm or greater, 0.1 μm or greater, 1 μm or greater, 5 μm or greater, 10 μm or greater, or 100 μm or greater. The average particle size of the plurality of active particles, free active particles (if present), or both measured by a size analysis test method can be 500 μm or less, 100 μm or less, 10 μm or less, or 1 μm or less. In some embodiments in which the plurality of active particles, free active particles (if present) include a catalyst, the average particle size measured by a size analysis test method is 0.001 μm to 5 μm, 0.001 μm to 1 μm, or 0.001 μm to 0.1 μm. In some embodiments in which the plurality of active particles, free active particles (if present) include an adsorbent, the average particle size measured by a size analysis test method is 0.001 μm to 100 μm, 1 μm to 100 μm, or 0.001 μm to 0.1 μm.

[0236] Embodiment 30C is a porous substrate according to any one of Embodiments 1C to 29C, wherein the average length of the short PTFE fibrils measured according to the dimensional analysis test method can be 30 μm or less, 20 μm or less, 10 μm or less, or 5 μm or less. The average length of the short PTFE fibrils measured according to the dimensional analysis test method can be 1 μm or more, 5 μm or more, 10 μm or more, or 20 μm or more.

[0237] Embodiment 31C is a porous substrate according to any one of Embodiments 1C to 29C, wherein the average length of the long PTFE fibrils measured according to the dimensional analysis test method can be 40 μm or more, 100 μm or more, 150 μm or more, 250 μm or more, 500 μm or more, or 1000 μm or more. The average length of the long PTFE fibrils measured according to the dimensional analysis test method can be 2000 μm or less, 1000 μm or less, 700 μm or less, 500 μm or less, 250 μm or less, 150 μm or less, or 100 μm or less.

[0238] Embodiment 32C is a porous substrate according to any one of Embodiments 1C to 31C, wherein the average diameter of the short PTFE fibrils measured according to the dimensional analysis test method can be 0.01 μm or more, 0.05 μm or more, 0.3 μm or more, or 0.5 μm or more. The average diameter of the short PTFE fibrils measured according to the dimensional analysis test method can be 1 μm or less, 0.5 μm or less, or 0.3 μm or less.

[0239] Embodiment 33C is a porous substrate according to any one of Embodiments 1C to 32C, wherein the average diameter of the long PTFE fibrils measured according to the dimensional analysis test method can be 100 μm or less, 50 μm or less, 10 μm or less, or 1 μm or less. The average diameter of the long PTFE fibrils measured according to the dimensional analysis test method can be 0.5 μm or more, 1 μm or more, 10 μm or more, or 50 μm or more.

[0240] Embodiment 34C is a porous substrate of any one of Embodiments 1C to 33C, wherein, based on the total weight of the substrate-composition (the total weight of the substrate and the composition provided thereon) and calculated according to the compositional analysis test method, the substrate provided with the composition includes 0.001 wt-% or more, 0.01 wt-% or more, 0.1 wt-% or more, 5 wt-% or more, 10 wt-% or more, 20 wt-% or more, 30 wt-% or more, 40 wt-% or more, 50 wt-% or more, 60 wt-% or more, 70 wt-% or more, 80 wt-% or more, 90 wt-% or more, or 95 wt-% or more of the porous substrate. In some embodiments, based on the total weight of the substrate-composition and calculated according to the compositional analysis test method, the porous substrate provided with the composition includes 99 wt-% or less, 95 wt-% or less, 90 wt-% or less, 80 wt-% or less, 70 wt-% or less, 60 wt-% or less, 50 wt-% or less, 40 wt-% or less, 30 wt-% or less, 20 wt-% or less, 10 wt-% or less, 5 wt-% or less, 1 wt-% or less, or 0.01 wt-% or less of the porous substrate.

[0241] Embodiment 35C is a porous substrate of any one of Embodiments 1C to 34C, wherein, based on the total weight of the substrate-composition and calculated according to the compositional analysis test method, the substrate provided with the composition includes 0.001 wt-% or more, 0.01 wt-% or more, 0.1 wt-% or more, 5 wt-% or more, 10 wt-% or more, 20 wt-% or more, 30 wt-% or more, 40 wt-% or more, 50 wt-% or more, 60 wt-% or more, 70 wt-% or more, 80 wt-% or more, 90 wt-% or more, or 95 wt-% or more of the composition. In some embodiments, based on the total weight of the substrate-composition and calculated according to the compositional analysis test method, the composition provided with the composition includes 99 wt-% or less, 95 wt-% or less, 90 wt-% or less, 80 wt-% or less, 70 wt-% or less, 60 wt-% or less, 50 wt-% or less, 40 wt-% or less, 30 wt-% or less, 20 wt-% or less, 10 wt-% or less, 5 wt-% or less, 1 wt-% or less, or 0.01 wt-% or less of the composition.

[0242] Embodiment 36C is a porous substrate of any one of Embodiments 1C to 35C, wherein, based on the total weight of the composition and calculated according to the composition analysis test method, the composition includes 0.1 wt-% or more, 5 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, 55 wt-% or more, 65 wt-% or more, or 80 wt-% or more of a plurality of PTFE fibrils. Based on the total weight of the composition and calculated according to the composition analysis test method, the composition may include 95 wt-% or less, 80 wt-% or less, 65 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, 15 wt-% or less, or 5 wt-% or less of a plurality of PTFE fibrils.

[0243] Embodiment 37C is a porous substrate of any one of Embodiments 1C to 36C, wherein, based on the total weight of the substrate-composition and calculated according to the composition analysis test method, the substrate provided with the composition includes 1 wt-% or more, 5 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, 55 wt-% or more, 65 wt-% or more, or 80 wt-% or more of PTFE fibrils (the sum of short-strand PTFE fibrils and long-strand PTFE fibrils). In some embodiments, based on the total weight of the substrate-composition and calculated according to the composition analysis test method, the composition includes 95 wt-% or less, 80 wt-% or less, 65 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, 15 wt-% or less, or 5 wt-% or less of PTFE fibrils.

[0244] Embodiment 38C is a porous substrate of any one of Embodiments 1C to 37C, wherein, based on the total weight of the composition and calculated according to the composition analysis test method, the composition includes 0.1 wt-% or more, 1 wt-% or more, 5 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, 55 wt-% or more, 65 wt-% or more, or 80 wt-% or more of short-strand PTFE fibrils (if present). Based on the total weight of the composition and calculated according to the composition analysis test method, the composition includes 95 wt-% or less, 80 wt-% or less, 65 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, 15 wt-% or less, 5 wt-% or less, or 1 wt-% or less of short-strand PTFE fibrils (if present).

[0245] Embodiment 39C is a porous substrate of any one of Embodiments 1C to 38C, wherein, based on the total weight of the composition and calculated according to the compositional analysis test method, the composition comprises 0.01 wt-% or more, 1 wt-% or more, 5 wt-% or more, or 10 wt-% or more, 15 wt-% or more, 20 wt-% or more, 30 wt-% or more or 40 wt-% or more of long-strand PTFE fibrils (if present). Based on the total weight of the composition and calculated according to the compositional analysis test method, the composition comprises 50 wt-% or less, 40 wt-% or less, 30 wt-% or less, 20 wt-% or less, 15 wt-% or less, 10 wt-% or less, 5 wt-% or less or 1 wt-% or less of long-strand PTFE fibrils (if present).

[0246] Embodiment 40C is a porous substrate of any one of Embodiments 1C to 39C, wherein, according to the compositional analysis test method, the composition comprises 50 wt-% or more, 70 wt-% or more, 80 wt-% or more or 90 wt-% or more of active particles by weight of the composition and / or the matrix. In some embodiments, according to the compositional analysis test method, the total active particle wt-% in the composition and / or the matrix is 95 wt-% or less, 90 wt-% or less, 80 wt-% or less or 70 wt-% or less by weight of the composition and / or the matrix. In some embodiments, according to the compositional analysis test method, the total active particle wt-% in the composition and / or the matrix is 0 wt-% or more, 0.001 wt-% or more, 0.01 wt-% or more, 0.1 wt-% or more, 1 wt-% or more, 2 wt-% or more, 3 wt-% or more, 4 wt-% or more, 5 wt-% or more, 10 wt-% or more or 15 wt-% or more by weight of the composition and / or the matrix. In some embodiments, according to the compositional analysis test method, the total active particle wt-% in the composition and / or the matrix is 20 wt-% or less, 15 wt-% or less, 10 wt-% or less, 5 wt-% or less, 4 wt-% or less, 3 wt-% or less, 2 wt-% or less, 1 wt-% or less, 0.1 wt-% or less, 0.01 wt-% or less or 0.001 wt-% or less by weight of the composition and / or the matrix.

[0247] Embodiment 41C is a porous substrate of any one of Embodiments 1C to 40C, wherein, based on the total weight of the substrate-composition and calculated according to the compositional analysis test method, the substrate provided with the composition thereon comprises 0 wt-% or more, 1 wt-% or more, 2 wt-% or more, 3 wt-% or more, 4 wt-% or more, 5 wt-% or more, 10 wt-% or more, or 15 wt-% or more, 20 wt-% or more, 30 wt-% or more, 40 wt-% or more, 50 wt-% or more, 70 wt-% or more, 80 wt-% or more or 90 wt-% or more of active particles. In some embodiments, based on the total weight of the substrate-composition and calculated according to the compositional analysis test method, the porous substrate provided with the composition thereon comprises 95 wt-% or less, 90 wt-% or less, 80 wt-% or less, 70 wt-% or less, 50 wt-% or less, 40 wt-% or less, 30 wt-% or less, 20 wt-% or less, 15 wt-% or less, 10 wt-% or less, 5 wt-% or less, 4 wt-% or less, 3 wt-% or less, 2 wt-% or less or 1 wt-% or less of active particles.

[0248] Method Embodiment

[0249] Embodiment 1M is a method of disposing a composition on a porous substrate to produce a porous substrate of any one of Embodiments 1C to 30C,

[0250] the composition comprising a matrix, the matrix comprising a plurality of PTFE fibrils formed from a PTFE resin; and a plurality of active particles;

[0251] the method comprising:

[0252] i) optionally inflating the emulsion to form an inflated emulsion, the emulsion and the inflated emulsion comprising: a PTFE resin, a surfactant, and a dispersant;

[0253] ii) optionally adding a solid particle composition to the inflated emulsion to form a matrix premix, the solid particle composition comprising solid particles, the matrix premix comprising: a PTFE resin, a surfactant, a dispersant, and the solid particle composition;

[0254] iii) optionally inflating the matrix premix to form an inflated matrix premix; the inflated matrix premix comprising the matrix premix;

[0255] iv) contacting at least a portion of the porous substrate with the matrix premix or the inflated matrix premix;

[0256] v) Place the hydrated composition on a porous substrate, the hydrated composition comprising: a matrix, at least a portion of a dispersant, and at least a portion of a surfactant, and a plurality of active particles comprising at least a portion of solid particles; and

[0257] vi) Dry the hydrated composition to form a composition disposed on the porous substrate.

[0258] Embodiment 2M is a method of disposing a composition on a porous substrate to produce the porous substrate of any one of Embodiments 1C to 30C,

[0259] the composition comprising a matrix, the matrix comprising a plurality of PTFE fibrils formed from a PTFE resin; and a plurality of active particles;

[0260] The method comprises:

[0261] i) Optionally form a matrix premix, the matrix premix comprising a PTFE resin, a surfactant, and a dispersant;

[0262] ii) Optionally inflate the matrix premix to form an inflated matrix premix, the inflated matrix premix comprising the matrix premix;

[0263] iii) Contact at least a portion of the porous substrate with the matrix premix or the inflated matrix premix;

[0264] iv) Contact at least a portion of the substrate with a solid particle composition, the solid particle composition comprising solid particles;

[0265] v) Place the hydrated composition on at least a portion of the porous substrate; the hydrated composition comprising: a matrix, at least a portion of a dispersant, and at least a portion of a surfactant, and a plurality of active particles comprising at least a portion of solid particles; and

[0266] vi) Dry the hydrated composition to form a composition disposed on the porous substrate.

[0267] Embodiment 3M is the method of Embodiment 1M or 2M, wherein the composition further comprises free active particles, free PTFE particles, or both.

[0268] Embodiment 4Ma is the method of any one of Embodiments M1 to 3M, wherein the porous substrate comprises a main surface and a plurality of macropores / micropores connected to the main surface; wherein a first portion of the composition is disposed on at least a portion of the main surface, and wherein at least a portion of the macropores / micropores is impregnated with a second portion of the composition.

[0269] Embodiment 4M is the method of Embodiment 4Ma, wherein the composition further comprises free active particles; wherein at least a portion of the macropores / micropores comprises a first portion of the macropores / micropores; and wherein the first portion of the macropores / micropores is impregnated with a first component of the composition and the second portion of the macropores / micropores is impregnated with a second component of the composition. In some embodiments, the first component and the second component are at least one particle of a matrix and free active particles.

[0270] Embodiment 5M is the method of any one of Embodiments M1 to 4M (a and b), wherein the porous substrate is a wettable porous substrate comprising a plurality of collapsible pores and a third portion of the composition is embedded within the porous substrate.

[0271] Embodiment 6M is the method of Embodiment 5M (subordinate to Embodiment 3M), wherein one or more components of the composition are embedded within the porous substrate. In some embodiments, at least one particle of the free active particles, at least one PTFE fibril of the free PTFE fibrils, a portion of the matrix is embedded within the substrate, or any combination thereof.

[0272] Embodiment 7M is the method of any one of Embodiments 1M to 6M, wherein a plurality of PTFE fibrils of the matrix, free PTFE fibrils, or both comprise short-strand PTFE fibrils, long-strand PTFE fibrils, or both.

[0273] Embodiment 8M is the method of Embodiment 7M (subordinate to 3M), wherein the free PTFE fibrils comprise long-strand PTFE fibrils, short-strand PTFE fibrils, or both.

[0274] Embodiment 9M is the method of Embodiment 7M (subordinate to Embodiment 1M), wherein the PTFE resin of the inflated matrix premix comprises short-strand PTFE resin and long-strand PTFE resin.

[0275] Embodiment 10M is the method of Embodiment 9M, wherein the PTFE resin of the emulsion, the PTFE resin of the inflated emulsion, the PTFE resin of the concentrated matrix premix, and the PTFE resin of the matrix premix comprise short-strand PTFE resin.

[0276] Embodiment 11M is the method of Embodiment 10M, wherein the method further comprises adding long-strand PTFE resin to the emulsion such that the PTFE resin of the emulsion, the PTFE resin of the inflated emulsion, and the PTFE resin of the matrix premix also comprise long-strand PTFE resin.

[0277] Embodiment 12M is the method of Embodiment 10M, wherein the method further comprises adding long-strand PTFE resin to the matrix premix such that the PTFE resin of the matrix premix further comprises long-strand PTFE resin.

[0278] Embodiment 13M is the method of Embodiment 7M (subordinate to Embodiment 2M), wherein the PTFE resin of the matrix premix or the aerated matrix premix comprises short-strand PTFE resin and long-strand PTFE resin.

[0279] Embodiment 14M is the method of Embodiment 13M, wherein a plurality of PTFE resins of the matrix premix, a plurality of PTFE resins of the aerated matrix premix, or both comprise short-strand PTFE resin.

[0280] Embodiment 15M is the method of Embodiment 14M, wherein the method further comprises adding long-strand PTFE resin to the matrix premix or the aerated matrix premix such that the PTFE resin of the matrix premix and / or the aerated matrix premix further comprises short-strand PTFE.

[0281] Embodiment 16M is the method of any one of Embodiments 1M to 15M, wherein based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix and / or the matrix premix comprises 0.01 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more, or 55 wt-% or more or 65 wt-% or more of PTFE resin. Based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix and / or the matrix premix comprises 80 wt-% or less, 65 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, or 15 wt-% or less of PTFE resin.

[0282] Embodiment 17M is the method of any one of Embodiments 1M to 16M, wherein based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix and / or the matrix premix comprises 0.01 wt-% or more, 1 wt-% or more, 5 wt-% or more, or 10 wt-% or more of long-strand PTFE resin. Based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix and / or the matrix premix comprises 15 wt-% or less, 10 wt-% or less, 5 wt-% or less, or 1 wt-% or less of long-strand PTFE resin.

[0283] Embodiment 18M is the method of any one of Embodiments 1M to 17M, wherein, based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix and / or the matrix premix comprises 0.1 wt-% or more, 5 wt-% or more, 15 wt-% or more, 25 wt-% or more, 45 wt-% or more or 55 wt-% or more of short strand PTFE. Based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix and / or the matrix premix comprises 80 wt-% or less, 55 wt-% or less, 45 wt-% or less, 25 wt-% or less, 15 wt-% or less or 5 wt-% or less of short strand PTFE resin.

[0284] Embodiment 19M is the method of any one of Embodiments 1M to 18M, wherein the solid particle composition comprises 100 wt-% of solid particles.

[0285] Embodiment 20M is the method of any one of Embodiments 1M to 19M, wherein the solid particle composition further comprises a liquid carrier. In some embodiments where the porous substrate is a wettable porous substrate, the liquid carrier comprises a wetting liquid. In some embodiments, the liquid carrier comprises water, one or more organic solvents (e.g., ethyl acetate, ethanol, methanol, isopropanol, butanol, dichloromethane, toluene, acetonitrile, acetone, diethyl ether, pentanol and tetrahydrofuran) or both.

[0286] Embodiment 21M is the method of Embodiment 20M, wherein, based on the total weight of the solid particle composition, the solid particle composition comprises 0.5 wt-% or more, 10 wt-% or more, 30 wt-% or more or 50 wt-% or more of solid particles. Based on the total weight of the solid particle composition, the solid particle composition comprises 90 wt-% or less, 50 wt-% or less, 30 wt-% or less or 10 wt-% or less of solid particles.

[0287] Embodiment 22M is the method of any one of Embodiments 2M to 7M (subordinate to 2M) or 13M to 21M (subordinate to 2M), wherein the solid particle composition comprises first solid particles, and the matrix premix or the aerated matrix premix further comprises second solid particles. In such embodiments, the plurality of active particles, free active particles (if present) or both comprise at least a portion of the second solid particles.

[0288] Embodiment 23M is the method of Embodiment 22M, wherein, based on the total weight of the matrix premix or the aerated matrix premix, the matrix premix or the aerated matrix premix comprises 0.5 wt-% or more, 10 wt-% or more, or 30 wt-% or more of second solid particles. Based on the total weight of the matrix premix or the aerated matrix premix, the matrix premix or the aerated matrix premix comprises 50 wt-% or less, 30 wt-% or less, or 10 wt-% or less of second solid particles.

[0289] Embodiment 24M is the method of any one of Embodiments 2M to 7M (subordinate to 2M) or 13M to 23M (subordinate to 2M), wherein the solid particle composition comprises a first solid particle composition; and wherein the method further comprises contacting at least a portion of a substrate with a second solid particle composition. In some embodiments, the first solid particle composition and the second solid particle composition may be the same. In other embodiments, the first solid particle composition and the second solid particle composition may be different (e.g., different solid particles, different liquid carriers (if present), different wt-% of solid particles, or any combination thereof).

[0290] Embodiment 25M is the method of any one of Embodiments 1M to 12M (subordinate to Embodiment 1M) or 16M to 21 (subordinate to Embodiment 1M), wherein disposing the hydrating composition on the porous substrate further comprises mixing the matrix premix or the aerated matrix premix while contacting at least a portion of the substrate, such that the hydrating composition is disposed on at least a portion of the substrate.

[0291] Embodiment 26M is the method of any one of Embodiments 1M to 25M, wherein the method further comprises contacting at least a portion of the porous substrate with a wetting liquid that does not comprise solid particles. In some embodiments, the wetting liquid comprises one or more organic solvents (e.g., ethyl acetate, ethanol, methanol, isopropanol, butanol, dichloromethane, toluene, acetonitrile, acetone, diethyl ether, pentanol, and tetrahydrofuran).

[0292] Embodiment 27M is the method of Embodiment 26M (subordinate to Embodiment 2M), wherein after contacting at least a portion of the substrate with the matrix premix or the aerated matrix premix and after contacting at least a portion of the substrate with the solid particle composition, at least a portion of the porous substrate is contacted with the wetting liquid.

[0293] Embodiment 28M is the method of any one of Embodiments 1M to 27M, wherein drying the hydrating composition further comprises removing at least a portion of the dispersant, liquid carrier (if present), surfactant, or a combination thereof by contacting at least a portion of the hydrating composition with an absorbent material.

[0294] Embodiment 29M is the method of Embodiment 28M, wherein the hydrated composition is in contact with the absorbent material for 10 seconds or longer, 1 minute or longer, or 1 hour or longer. The hydrated composition is in contact with the absorbent material for 24 hours or shorter, 1 hour or shorter, or 1 minute or shorter.

[0295] Embodiment 30M is the method of Embodiment 28M or 29M, further comprising: removing at least a portion of the absorbent material that has been in contact with the hydrated composition; and repeating the steps of contacting the hydrated composition with the absorbent material and removing at least a portion of the absorbent material that has been in contact with the hydrated composition a number of times, each time using absorbent material that has not previously been in contact with the hydrated composition.

[0296] Embodiment 31M is the method of any one of Embodiments 28M to 30M, wherein the absorbent material comprises cotton; cellulose; sponge, including polyester, polyurethane, plant cellulose, melamine, or combinations thereof; anhydrous calcium chloride; anhydrous magnesium sulfate; sodium polyacrylate; or combinations thereof.

[0297] Embodiment 32M is the method of any one of Embodiments 1M to 31M, wherein drying the hydrated composition further comprises exposing the hydrated composition to an elevated temperature, applying a vacuum to the hydrated composition, or both.

[0298] Embodiment 33M is the method of Embodiment 32M, wherein drying the hydrated composition further comprises exposing the hydrated composition to a temperature of 100 °C to 400 °C, preferably 100 °C to 300 °C, for 0.1 hour to 24 hours, preferably 1 hour to 5 hours.

[0299] Embodiment 34M is the method of any one of Embodiments 1M to 33M, wherein, based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix and / or the matrix premix comprises 0.5 wt-% or more, 5 wt-% or more, or 20 wt-% or more of a surfactant. Based on the total weight of the aerated matrix premix or the matrix premix, the aerated matrix premix and / or the matrix premix comprises 40 wt-% or less, 20 wt-% or less, or 5 wt-% or less of a surfactant.

[0300] Embodiment 35M is the method of any one of Embodiments 1M to 34M, wherein the surfactant comprises a nonionic non-fluorinated surfactant.

[0301] Embodiment 36M is the method of Embodiment 35M, wherein the surfactant comprises polyethylene glycol trimethylnonyl ether.

[0302] Embodiment 37M is the method of any one of Embodiments 1M to 36M, wherein, based on the compositional test method (i.e., the loading test method), the total active particle loading produced by this method is 50 wt-% or more, 70 wt-% or more, 80 wt-% or more, or 90 wt-% or more. Based on the compositional test method (i.e., the loading test method), the total active particle loading produced by the method of the present disclosure is 95 wt-% or less, 90 wt-% or less, 80 wt-% or less, or 70 wt-% or less.

[0303] Examples

[0304] These examples are for illustrative purposes only and are not meant to unduly limit the scope of the appended claims. Although the broad numerical ranges and parameters that clarify the present disclosure are approximations, the numerical values listed in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors, which are necessarily caused by the standard deviations that occur in their respective test measurements. At the very least, rather than attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be interpreted at least in accordance with the number of significant digits reported and by applying ordinary rounding techniques.

[0305] Unless otherwise stated, all parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight, and all reagents used in the examples are obtained from or available from general chemical suppliers, such as, for example, Sigma-Aldrich, Saint Louis, MO; Carus, Peru, IL; Calgon Carbon, Moon Township, PA; Ultramet, Los Angeles, CA; or can be synthesized by conventional methods.

[0306] The following abbreviations may be used in the following examples and / or elsewhere in the present disclosure: Mn = number average molecular weight; ppm = parts per million; ppb = parts per billion; mL = milliliter; L = liter; LPM = liters per minute; m = meter, mm = millimeter, min = minute; s = second; cm = centimeter, μm = micrometer, kg = kilogram, g = gram, min = minute, s = second, h = hour, °C = degree Celsius, °F = degree Fahrenheit; wt% = weight percentage; M = mole; μM = micromole; mM = millimole; and DI water = deionized water.

[0307] Table 1 is a table of materials, which lists the components used in the examples and their related supplier sources, abbreviations, and Chemical Abstracts Service (CAS) numbers.

[0308] Table 1. Materials and related information.

[0309]

[0310] Testing method:

[0311] Size analysis

[0312] The various compositions and substrates in the examples were subjected to size analysis and morphological analysis by scanning electron microscopy (SEM) on a JSM-7100F microscope. Before imaging the samples, the samples were sputter-coated with gold / palladium for 120 seconds to prevent charging. Then, measurements were made using ImageJ software to calculate the average length of the long-strand PTFE fibrils, the average resin particle size of the long-strand PTFE resin; the average length of the short-strand PTFE fibrils; the average resin particle size of the short-strand PTFE resin; the average diameter of the short-strand PTFE fibrils; the average diameter of the long-strand PTFE fibrils; the average particle size of the plurality of active particles; the average particle size of the free active particles; and the average porosity. Ten repeated measurements were made of the length / width / diameter / particle size to generate the average values of the various elements.

[0313] Acid gas breakthrough

[0314] As a proof of concept, the coated polyurethane foam was subjected to H2S adsorption. The foam was laminated with 25% surface openings on the inlet side (left inlet) and 25% openings on the outlet side (right outlet) to create an S-shaped flow profile and maximize fluid residence time. The H2S breakthrough performance was evaluated at 25 ppm with an initial flow rate of 100 cm 3 / min and 300 cm 3 / min after 1200 min. The sample was saturated until it reached 32% (8 ppm) of the initial H2S concentration, which took approximately 6000 minutes.

[0315] Composition analysis

[0316] The amounts of the respective components in the matrix / composition and the composition-substrate composite were calculated according to the following composition analysis test method. The composition analysis test method can also be referred to as the loading test method.

[0317] The solid loading of the composition material was calculated based on the initial wetting formulation assuming that the solids were uniformly mixed and the water / surfactant mixture was completely removed. For example, the matrix and / or composition was formed from 13.3 g of CARULITE, 5 g of PTFE-E, and 3 g of PTFE-12 (total weight of 21.3 g). As stated by the manufacturer, the PTFE-E material is known to consist of 60 wt-% PTFE solids, and the weight of the PTFE solids thus obtained was calculated as the product of the weight fraction of the PTFE solids and the weight used (e.g., if 5 g of PTFE-E was used, then 60% PTFE固体 × 5 g乳液 = 3 g PTFE固体 )。 Then calculate the solid content of each component based on the dry components; that is, calculate without considering any contribution from the water or surfactant components, using the following formula:

[0318]

[0319] where X i is the weight percentage of a single component after drying, and M i is the single mass (g) of the solid component used in the matrix formulation without any solvent. For example, if formulating a composition comprising 10 g of CARULITE, 5 g of PTFE-E, and 3 g of PTFE-12, the solid fraction of CARULITE can be defined as:

[0320]

[0321] Thus, the composition or matrix comprises active particles (CARULITE) with a total wt-% of 62.5 wt-%. The composition or matrix also comprises 18.6 wt-% of short strand PTFE fibrils and 18.6 wt-% of long strand PTFE fibrils. In other words, the composition or matrix comprises 62.5 wt-% of active particles and 37.2 wt-% of PTFE fibrils.

[0322] For the substrate with the composition disposed thereon, the mass of the substrate and the mass of the matrix / composition disposed on the substrate can also be considered. For example, if 0.5 g of the above composition is disposed on a 0.5 g substrate (the difference in the mass of the substrate before and after disposing the composition is 0.5 g), then the amount of each composition component in the substrate-composition is 50% of the amount of the composition itself. For example, the substrate-composition will be 50 wt-% substrate; 31.25 wt-% active particles; 9.3 wt-% short strand PTFE fibrils; and 9.3 wt-% long strand PTFE fibrils.

[0323] Example 1: Disposing the composition on a porous substrate using the first method

[0324] The composition was set on PU-15 foam (a porous substrate) using the first method. The composition includes PTFE-E, PTFE-12, CSAC, and K2CO3. The method includes forming an aerated emulsion, which includes 5 g of PTFE-E resin and 3 g of PTFE-12 resin in 20 ml of DI water. Aeration was achieved by vigorously shaking by hand to cause foaming and suspend the PTFE-12 resin. Then, a solution of 13.3 g of CSAC and 20 g of K2CO3 dissolved in 20 mL of DI (a solid particle composition) was added to the aerated emulsion to form a matrix premix. The water / K2CO3 solution was added after CSAC to prevent PTFE surfactant instability. Then, a 3-inch (7.62 cm) by 3-inch (7.62 cm) PU-15 foam was immersed into the matrix premix, and then the liquid was absorbed onto the polymer structure. Then the sample was removed from the matrix premix and dried under vacuum for 24 h to force K2CO3 precipitation. Before setting the composition, the foam weighed 1.8051 g. After setting the composition, the foam weighed 16.2170 g. A nearly ten-fold loading was achieved by this method. Then the foam was characterized by SEM, as shown in Figures 13 and 14. The SEM images show that the composition includes a matrix and free active particles. The matrix is mainly distributed on the PU-15 surface( Figure 13A ), which can be seen from the fibrillation and interconnection of the particles around the polymer layer( Figure 13B ).

[0325] However, imaging of the PU-15 cross-section (Figure 14) shows that some of the active particles (i.e., free active particles) are absorbed into the polymer structure framework. In particular, Figure 14B shows that small particles are present parallel to the PU-15 polymer grains, which is an indication of precipitate growth within the polymer wall (free active particles are embedded within the solid portion of the porous polymer substrate). This phenomenon can be attributed to the fact that PU-15 is a wettable substrate. When the wetting liquid (in this case, a water / surfactant mixture) swells the substrate to create micropores, an indeterminate amount of dissolved K2CO3 may have migrated into the micropores of the structure with the wetting liquid.

[0326] The PU-15 substrate with the composition set thereon was evaluated for H2S adsorption to demonstrate the adsorption capacity of the material as a proof of concept. The acidic gas breakthrough test method was used. Briefly, the substrate was cut into 1-inch (2.54 cm) by 1-inch (2.54 cm) constructs and packaged in such a way as to create a z-shaped flow path throughout the structure to maximize the residence time as much as possible. More particularly, the PU-15 base layer was laminated in plastic such that 0.25 inches (0.635 cm) in the lower left corner and 0.25 inches (0.635 cm) in the upper right corner of the package were left empty, thus creating a z-shaped profile. As Figure 15As shown, the H2S breakthrough performance was evaluated at 25 ppm with an initial flow rate of 100 cm 3 / min, which was increased to 300 cm 3 / min after 1200 min. The adsorption amount of H2S on the substrate was found to be approximately 20 mg / g, which was comparable to the expected value relative to the amount of K2CO3 loaded. The pressure drop of the material was also small enough that it could not be detected by the test system, but this may be a secondary phenomenon due to the small sample size.

[0327] Example 2: Setting the composition on the porous substrate using the second method

[0328] The composition was set on the PU-15 porous substrate using the second method. The composition included PTFE-E, PTFE-12, CSAC, and K2CO3.

[0329] The solid particle composition was prepared as follows. First, CSAC was impregnated with different amounts of K2CO3 (1:1, 2.5:1, 5:1, 10:1 K2CO3:CSAC) in 30 mL of DI water. 5 g of the impregnated CSAC was added to 30 mL of ethanol to form the solid particle composition. Ethanol was selected as the liquid carrier for the solid particle composition because K2CO3 could not redissolve in the alcohol.

[0330] A concentrated emulsion (e.g., concentrated matrix premix) was prepared, which included PTFE-E (25 g) / PTFE-12 (7 g) in water. The concentrated emulsion was diluted with 20 mL of DI to form the matrix premix. No aeration was carried out.

[0331] PU-15 sheets (1 inch by 1 inch; 2.54 cm by 2.54 cm) were immersed in the matrix premix for 30 seconds on each side, then immersed in the solid particle composition bath, and then immersed in the ethanol bath. The sheets were then vacuum dried overnight at ambient temperature to extract any remaining water, ethanol, and surfactant, and to force any dissolved K2CO3 to precipitate from the residual water in the matrix premix. As shown in Figure 16, compared to the method described in Example 1 (16A), it was observed that coating PU-15 by this second method (16B) resulted in less blockage of the PU-15 pores.

[0332] Example 3: Setting the composition on the porous substrate using the third method and the fourth method

[0333] Example 3 compared the third and fourth methods of setting the composition on the PU-15 substrate. Both the third and fourth methods included exposing the substrate to a solid particle composition containing K2CO3 dissolved in water. The fourth method also included exposing the substrate to an ethanol bath (wetting the composition). In addition, this example compared the characteristics of a porous substrate provided with a composition including both PTFE-E and PTFE-12 and a porous substrate provided with a composition including only PTFE-E.

[0334] Table 2 shows the components of each composition set on each substrate, and whether the substrate was exposed to an ethanol bath (Method 4) or not (Method 3).

[0335] Table 2.

[0336]

[0337] Both Method 3 and Method 4 included inflating the PTFE-E emulsion and diluting it with 60 g of DI water to form an inflated emulsion. PTFE-12 (for Substrates 2 and 3) was added to the inflated emulsion and mixed until the PTFE-12 resin was no longer visible. Activated carbon was added to the inflated emulsion, and then mixed by stirring for 2 minutes to form a matrix premix. The polyurethane foam substrate was immersed in its respective matrix premix for 60 seconds. Then the substrate was transferred to a bath containing K2CO3 dissolved in water (e.g., a solid particle composition). This step initiated a phase change and produced a macroscopic condensation of PTFE / carbon / substrate. After soaking the sample in the K2CO3 solution for 60 seconds, Substrates 1 and 3 were transferred to a bath containing 200 mL of ethanol, at which time the condensed carbon / PTFE layer was immersed into the structural skeleton of the polyurethane sample.

[0338] All substrate samples were dried in vacuo (P = 0 bar) at 130 °C for 24 h to remove ethanol, water, and surfactant. Substrate 1 and Substrate 2 were compared using an electron microscope. Figure 17A The morphology of Substrate 2 was evaluated, indicating that the coating was mainly distributed on the surface and there was no obvious or distinct nucleation (e.g., embedding) of K2CO3 in the polyurethane skeleton. In contrast, the microscopic examination of Substrate 1 ( Figure 17B)It is demonstrated that immersing the substrate in ethanol after the K2CO3 / DI bath transfers K2CO3 ions into the polyurethane backbone. Subsequently, the vacuum drying step causes the ions to become supersaturated and eventually precipitate out into the polyurethane in the form of nucleated (e.g., embedded) K2CO3 particles (e.g., free active particles). It should be noted here that the importance of using ethanol as a wetting agent lies in i) the polyurethane can be wetted by the alcohol, and ii) K2CO3 is insoluble in ethanol. Therefore, its transfer from the initial coating to the ethanol bath is less favorable compared to the transfer from the solid phase to the polyurethane. Without being bound by theory, it is believed that the residual water in the surface coating acts as a carrier phase to migrate K2CO3 from the surface to the polyurethane, while the ethanol bath serves as a means to open the polyurethane chains and make them a wettable mixture (e.g., creating micropores).

[0339] Regarding the role of PTFE-E and PTFE-12, the morphologies of Substrate 1 and Substrate 3 were evaluated by electron microscopy as shown in Figure 18. Substrate 1 Figure 18A and 18B showed macroscopic cracks, which may be caused by swelling due to ethanol wetting. In addition, Substrate 3 was observed to be mechanically unstable because applying any pressure would turn the reticulated polymer into powder. In contrast, Figure 18C and 18D indicated that including PTFE-12 in Substrate 3 produced a surface without macroscopic cracks. Without being bound by theory, based on Figure 18D it is believed that multiple strands of PTFE-12 filled the macroscopic cracks caused by ethanol wetting, indicating that long strands of PTFE fibrils allow self-healing of the polyurethane backbone. In contrast, the PTFE introduced by PTFE-E may allow particle adhesion as shown in other embodiments.

Claims

1. A porous substrate, comprising: A composition disposed on the porous substrate; The composition includes a matrix, and the matrix includes: A plurality of PTFE fibrils; And A plurality of active particles.

2. The porous substrate according to claim 1, wherein The plurality of PTFE fibrils include short-strand PTFE fibrils and long-strand PTFE fibrils.

3. The porous substrate according to claim 1 or 2, wherein The composition further includes free active particles, free PTFE fibrils, or both.

4. The porous substrate according to any one of claims 1 to 3, wherein The porous substrate includes a main surface and a plurality of macropores connected to the main surface; wherein, a first portion of the composition is disposed on at least a portion of the main surface; and wherein, at least a portion of the plurality of macropores is impregnated with a second portion of the composition.

5. The porous substrate according to claim 4, which depends on claim 3, wherein, The portion of the plurality of macropores includes a first portion of the macropores; wherein, the first portion of the macropores is impregnated with a first component of the composition; and wherein, a second portion of the macropores is impregnated with a second component of the composition.

6. The porous substrate according to claim 5, wherein, The first component includes the matrix, and the second component includes at least one particle of the free active particles.

7. The porous substrate according to any one of claims 1 to 6, wherein, The porous substrate further includes a third portion of the composition embedded within the porous substrate.

8. The porous substrate according to claim 7, wherein, The porous substrate includes at least one free PTFE fibril of the free PTFE fibrils embedded within the porous substrate, at least one free active particle of the free active particles, at least a portion of the matrix, or any combination thereof.

9. The porous substrate according to any one of claims 1 to 8, wherein, The plurality of particles, the free active particles if present, or both include a catalyst, an adsorbent, a growth seed, a metal-organic framework (MOF), a bioactive material, an electroactive material, or any combination thereof.

10. The porous substrate according to any one of claims 1 to 8, wherein, The porous substrate is made of a material including: untreated reticulated polyurethane; reticulated silicon carbide, reticulated metal, reticulated alumina, reticulated cellulose; reticulated melamine; reticulated activated carbon; or any combination thereof.

11. The porous substrate according to any one of claims 2 to 10, which are dependent on claim 2, wherein, The free PTFE fibrils include long-strand PTFE fibrils.

12. A method for disposing a composition on a porous substrate, The composition includes a matrix, and the matrix includes a plurality of PTFE fibrils formed of a PTFE resin; And a plurality of active particles; The method includes: i) Optionally inflating the emulsion to form an inflated emulsion, and the emulsion and the inflated emulsion include: PTFE resin; Surfactant; and Dispersant; ii) Optionally adding a solid particle composition to the inflated emulsion to form a matrix premix, the solid particle composition including solid particles, and the matrix premix including: The PTFE resin: The surfactant; The dispersant; and The solid particle composition; iii) Optionally inflating the matrix premix to form an inflated matrix premix; the inflated matrix premix includes the matrix premix; iv) Contacting at least a portion of the porous substrate with the matrix premix or the inflated matrix premix; v) Disposing a hydrated composition on the substrate, the hydrated composition including: The matrix; At least a portion of the dispersant; and At least a portion of the surfactant; The plurality of active particles include at least a portion of the solid particles; and vi) Drying the hydrated composition to form the composition disposed on the porous substrate.

13. A method for disposing a composition on a porous substrate, The composition comprises a matrix, the matrix comprising a plurality of PTFE fibrils formed from a PTFE resin; and a plurality of active particles; The method comprises: i) Optionally forming a matrix premix, the matrix premix comprising: PTFE resin; and a surfactant; ii) Optionally aerating the matrix premix to form an aerated matrix premix, the aerated matrix premix comprising the matrix premix; iii) Contacting at least a portion of the porous substrate with the matrix premix or the aerated matrix premix; iv) Contacting at least a portion of the substrate with a solid particle composition, the solid particle composition comprising solid particles; v) Providing a hydrating composition on at least a portion of the porous substrate; the hydrating composition comprising: the matrix; at least a portion of the dispersant; and at least a portion of the surfactant; the plurality of active particles comprises at least a portion of the solid particles; and vi) Drying the hydrating composition to form the composition provided on the porous substrate.

14. The method according to claim 11 or 12, wherein Drying the hydrating composition produces the porous substrate according to any one of claims 1 to 11.

15. The method according to any one of claims 11 to 14, wherein The solid particle composition further comprises a liquid carrier.

16. The method according to any one of claims 12 to 15, dependent on claim 12, wherein, The solid particle composition comprises a first solid particle composition; and wherein the method further comprises contacting at least a portion of the substrate with a second solid particle composition.

17. The method according to any one of claims 12 to 16, which are dependent on claim 12, wherein, The solid particle composition comprises first solid particles; wherein the matrix premix or the aerated matrix premix further comprises second solid particles; and wherein at least a portion of the plurality of active particles, the free active particles if present, or both comprises at least a portion of the second solid particles.

18. The method according to claim 17, wherein, Based on the weight of the aerated matrix premix or the weight of the matrix premix, the aerated matrix premix or the matrix premix comprises 0.5 wt-% to 50 wt-% of the second solid particles.

19. The method according to any one of claims 11 to 18, wherein Drying the hydrating composition to form the composition provided on the porous substrate further comprises: removing at least a portion of the dispersant, at least a portion of the liquid carrier if present, at least a portion of the surfactant, or a combination thereof, by contacting at least a portion of the hydrating composition with an absorbent material.

20. The method according to any one of claims 11 to 18, wherein Drying the hydrating composition to form the composition provided on the porous substrate further comprises exposing the hydrating composition to an elevated temperature, applying a vacuum to the hydrating composition, or both.

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