Systems and methods for capturing fluids using cross-linked binders

Abstract

In some embodiments, the present disclosure relates to a system. The system includes a substrate and a fluid trapping material formed on one or more surfaces of the substrate. The fluid capture material includes a sorbent material incorporating one or more fluids including water, carbon dioxide, sulfur oxides, or a combination thereof. The fluid trapping material also includes one or more binder materials, wherein the binder materials are at least partially cross-linked.

Description

BACKGROUND OF THE INVENTION

[0001] The subject matter disclosed herein relates to techniques for capturing one or more target fluids. More specifically, the subject matter disclosed herein relates to using combinations or mixtures of binders and sorbents to form fluid capture materials or coatings.

[0002] Certain industrial systems can generate multiple fluids during operation of these industrial systems, such as water and carbon dioxide (CO 2 2). In some cases, the fluids can be emitted as exhaust gases or otherwise go unused. Certain components of industrial systems (e.g., substrates) can include coatings capable of capturing or extracting fluids.

[0003] Regarding Federally Sponsored Research and

[0004] Development Statements

[0005] [0002.2] This invention was made with government support under Contract No. HR001-21-C-0020 awarded by the Defense Advanced Research Projects Agency and DE-FE0031956 awarded by the Department of Energy. The government has certain rights in this invention. SUMMARY OF THE INVENTION

[0006] Certain embodiments equivalent to the scope of the originally filed claims are outlined below. These embodiments are not intended to limit the scope of the technology, but rather these embodiments are only intended to provide a brief overview of possible forms of the technology. In fact, the systems and methods of the present invention can include various forms that may be similar to or different from the embodiments set forth below.

[0007] In one embodiment, the present disclosure relates to a system. The system includes a substrate and a fluid capture material formed on one or more surfaces of the substrate. The fluid capture material includes a sorbent material that binds one or more fluids, the one or more fluids including water, carbon dioxide, sulfur oxides, or combinations thereof. The fluid capture material includes one or more binder materials and the binder materials are at least partially crosslinked.

[0008] In one embodiment, the present disclosure relates to a method. The method includes providing an adsorbent material that binds one or more fluids, the one or more fluids including water, carbon dioxide, sulfur oxides, or combinations thereof. The method further includes providing one or more binder materials, wherein the one or more binder materials include components capable of forming a crosslinked polymer. Additionally, the method includes providing a crosslinking agent. Further, the method includes generating an adsorbent-binder material based on the adsorbent material, the one or more binder materials, and the crosslinking agent. Additionally, the method includes applying the adsorbent-binder material to a substrate and forming a fluid capture material using the adsorbent-binder material applied to the substrate, wherein the fluid capture material includes a crosslinked polymer.

[0009] In one embodiment, the present disclosure relates to a system. The system includes a fluid capture material that binds one or more fluids. The fluid capture material includes an adsorbent material configured to bind one or more fluids, the one or more fluids including water, carbon dioxide, sulfur oxides, or combinations thereof. The fluid capture material further includes a binder material, wherein the binder material is at least partially crosslinked. Additionally, the fluid capture material includes an air contactor having one or more surfaces coated with the fluid capture material. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] These and other features, aspects, and advantages of the present invention will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like reference characters represent like parts throughout the drawings, wherein:

[0011] Figure 1 is a flow chart of an embodiment of a method for using a fluid capture system having one or more substrates to capture a target fluid according to the present disclosure;

[0012] Figure 2 is according to the present disclosure for use in Figure 1 a flow chart of an embodiment of a method for generating a fluid capture material using a binder and adsorbent combination to be used in a fluid capture system;

[0013] Figure 3 is a cross-sectional view of an embodiment of a substrate coated with Figure 2 a fluid capture material according to the present disclosure;

[0014] Figure 4 is a graph depicting the measurement results of the carbon dioxide (CO 2 ) concentration over time of a fluid flow directed to a substrate having a fluid capture material according to the present disclosure;

[0015] Figure 5is a visualization flowchart showing operational aspects of a fluid capture system having one or more substrates coated with a fluid capture material; and

[0016] Figure 6 is a graph depicting the weight gain over time of a substrate having a fluid capture material exposed to a fluid flow, according to the present disclosure. DETAILED DESCRIPTION

[0017] One or more specific embodiments of the present disclosure will now be described. To provide a concise description of these embodiments, not all features of an actual implementation may be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Additionally, it should be understood that such development efforts may be complex and time-consuming, but would still be a routine task of design, fabrication, and manufacture for those of ordinary skill in the art who would benefit from the present disclosure.

[0018] When introducing elements of various examples of the present disclosure, the articles "a," "an," "the," and "said" are intended to mean that there is one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. Further, it should be understood that references to "an example" or "examples" of the present disclosure are not intended to be construed as excluding the existence of other examples that also incorporate the recited features.

[0019] In the context of the present invention, the term "about" or "approximately" is intended to mean that the indicated value is not exact and that the actual value may not materially vary in a manner that would differently affect the relevant operation from the indicated value. For example, as used herein, the term "about" or "approximately" is intended to convey a suitable value within a particular manufacturing or operating tolerance (e.g., ±10%, ±5%, ±1%, ±0.5%), as would be understood by those skilled in the art.

[0020] As generally discussed herein, one or more fluids are produced (e.g., water and / or CO 2Some systems (e.g., gas turbines) may include one or more substrates having a surface coating that binds the one or more fluids, thereby extracting or capturing the one or more fluids from a source fluid (e.g., an exhaust gas stream, an ambient air stream, etc.). For example, these systems may include combustion systems that utilize a fuel source (e.g., fossil fuel). Thus, one or more substrates of these combustion systems may include a surface coating capable of extracting carbon dioxide. As another non-limiting example, these systems may include a water capture system that typically includes a surface coating capable of extracting water from ambient air. In certain embodiments, it may be desirable to capture at least a portion of these fluids, such as to address certain entity guidance (e.g., government regulation) and / or utilize the one or more fluids, rather than not capture these fluids, such as by discharging or otherwise releasing these fluids into the surrounding airspace or other adjacent environments.

[0021] This disclosure relates to techniques for improving the efficiency of capturing or extracting certain fluids from a fluid stream by forming a fluid capture material or fluid capture coating using an adsorbent material (e.g., an adsorbent component) and a binder material capable of crosslinking and crosslinking the binder material (e.g., using a crosslinking agent). As described in more detail herein, the adsorbent material generally includes a material capable of binding certain fluids, such as carbon dioxide (CO 2 )、 water (H 2 O), oxygen (O 2 ) or other gas molecules that may be formed due to a decomposition reaction (e.g., combustion). For example, the adsorbent material may include a metal-organic framework (MOF) and / or a covalent organic framework (COF). In some embodiments, the adsorbent material may include a polymeric resin, silica, zeolite, and other materials capable of capturing fluids as discussed herein. The binder material may include one or more materials that can prevent, reduce, or mitigate the decomposition or dissolution of the adsorbent material (i.e., improve stability). As described in more detail herein, it is currently recognized that forming a fluid capture material using an adsorbent material and a crosslinked binder material can provide improved fluid binding capacity (e.g., in a reversible or irreversible manner) compared to conventional fluid binding materials or coatings.

[0022] More specifically, the disclosed fluid capture materials or coatings can be formed by crosslinking a binder material capable of forming a crosslinked polymer. In at least some cases, the disclosed fluid capture materials can include a portion (e.g., mass percentage) that is a crosslinked polymer (e.g., a crosslinked binder material). For example, such a portion can be less than 20 mass% of the total mass of the fluid capture material, between 1 mass% and 15 mass%, between 5 mass% and 10 mass%, or less than 10 mass%. Generally, the crosslinked polymer can be formed using thermal techniques, radiation techniques (e.g., irradiation with ultraviolet (UV) light), and / or chemical techniques (e.g., using a crosslinking agent via free radical polymerization or condensation reactions). In embodiments using a crosslinking agent, the fluid capture material can also include the crosslinking agent. That is, the crosslinking agent can be present in the fluid capture material. It is currently recognized that compared to fluid capture materials formed using uncrosslinked and / or non-crosslinkable binders or polymers, fluid capture materials that include a crosslinked polymer (e.g., using a crosslinked polymer to form the fluid capture material) can result in a fluid capture material having a relatively large amount of adsorbent (e.g., a relatively small amount of binder material (e.g., less than 15 mass%, less than 12 mass%, less than 10 mass%, less than 8 mass%, less than 5 mass%)). Thus, increasing the amount of adsorbent material improves the fluid binding capacity of the fluid capture material by having a larger amount of adsorbent material in the fluid capture material. Additionally, by forming the fluid capture material with a crosslinked polymer, the disclosed fluid capture materials can have improved adhesion or binding to a substrate (e.g., a metal substrate, a polymer substrate (e.g., glass-filled nylon), a polymer composite substrate, etc.) and stability or resistance to dissolution.

[0023] With this in mind, Figure 1 is a flowchart of an embodiment of a method 10 for capturing or extracting a fluid from a fluid stream. As shown, a fluid capture system 12 receives a fluid from a fluid source 14. Generally, the fluid source 14 can include an exhaust fluid stream (e.g., an exhaust gas stream) and / or ambient air. As described herein, the fluid source 14 can include one or more target fluids (e.g., one or more target gases) that may be desired to be captured or otherwise extracted or separated from the exhaust fluid stream. For example, it may be desired to capture certain combustion products. That is, in some cases, it may be desired to capture CO 2 to reduce the amount of CO emitted into the environment (e.g., according to certain regulations). Additionally or alternatively, it may be desired to capture H 2 O to reduce the moisture content of the air stream. As another non-limiting example, capture certain sulfur oxides (SO 2 produced from the exhaust gas. x) can be advantageous. In any case, the fluid capture system 12 generally receives fluid from a fluid source 14, and one or more substrates 16 of the fluid capture system 12 extract one or more target fluids 18 from the fluid of the fluid source 14, thereby producing a purified gas stream 20.

[0024] In certain embodiments, the fluid capture system 12 can be provided as part of a gas turbine system, a chemical production system, or other systems that produce a fluid stream (e.g., a gas stream, an exhaust gas stream) having gas molecules that may be desirable to capture. As shown, the fluid capture system 12 can include one or more substrates 16. As described herein, the substrate 16 can include a coating formed of one or more semi-permeable materials (e.g., capable of allowing certain gases to permeate through the substrate) that are capable of binding certain fluids (i.e., the target fluid 18 or gas). For example, the coating can be a fluid capture material formed using an adsorbent material and a binder material capable of forming a cross-linked polymer.

[0025] As described herein, the fluid capture material can improve the amount of target fluid 18 extracted from the fluid source 14 and / or can have improved stability compared to certain coatings used to extract fluid from the fluid source 14. To illustrate this, Figure 2 is a flowchart of an embodiment of a method 30 for producing air contact with a fluid capture material.

[0026] To begin the method 30, at block 32, an adsorbent-binder material 38 is produced using an adsorbent material 34, a binder material 36, and a cross-linking agent 37. Generally, using the adsorbent material 34, the binder material 36, and the cross-linking agent can include forming a mixture, such as a solution or slurry including the adsorbent material 34 and the binder material 36 in a suitable solvent capable of dissolving at least a portion of the adsorbent material and / or the binder material. Examples of such solvents include, but are not limited to, toluene, ethyl acetate, ethanol, 2-(2-butoxyethoxy)ethyl acetate, water, isopropyl alcohol, methyl ethyl ketone, or any combination thereof (i.e., for miscible solvents). As discussed herein, the cross-linking agent 37 can include certain chemical cross-linking agents. Thus, the cross-linking agent 37 can also be added to the mixture of the adsorbent material 34 and the binder material 36. In some embodiments, the cross-linking agent 37 can be added after forming the mixture of the adsorbent material 34 and the binder material 36. For example, in embodiments where the binder material 36 is a polymeric material, the cross-linking agent 37 can be added after a period corresponding to a suitable degree of polymerization of the binder material 36 (e.g., after initiating the polymerization of the binder material 36). However, in certain embodiments, the cross-linking agent 37 can be added before initiating the polymerization of the binder material 36.

[0027] The adsorbent material 34 is generally capable of adsorbing fluids such as water and / or CO 2The material. In some embodiments, the adsorbent material 34 may include a metal-organic framework (MOF) and / or a covalent organic framework (COF). For example, the adsorbent material may include an MOF capable of adsorbing a fluid as described herein, such as an iron-based MOF, a zirconium-based MOF (e.g., MOF-808, such as MOF-808-Gly), an aluminum-based MOF (e.g., MOF-303, MIL-160), a zeolitic imidazolate framework (ZIF), an amine-containing MOF, other MOFs, an amine-containing COF, ZIF, silica, etc. In some embodiments, the adsorbent material 34 may include a polymeric resin, silica, zeolite, or a combination thereof.

[0028] The binder material 36 may include one or more oligomeric or polymeric materials, monomeric or oligomeric materials capable of polymerization, or a combination thereof. At least in some cases, the binder material 36 may improve the affinity of the adsorbent material 34 for binding a gas or certain gases and / or improve the stability (e.g., thermal stability) of the adsorbent material 34. In some embodiments, the binder material 36 may include a material that forms a polymer having a thermal stability of about 200 °C. In some embodiments, the binder material 36 may include a silicon-containing polymer or binder (e.g., siloxane or silane, such as aminopropyl sesquisiloxane, aminoethylaminopropyl sesquisiloxane, alkoxysilane), a vinyl polymer (e.g., polyvinyl ester, such as polyvinyl acetate; polyvinyl alcohol), and copolymers thereof such as polyvinyl butyral. In some embodiments, the binder material 36 may include a polysaccharide (e.g., ethyl cellulose, starch, and alkyl cellulose), a nitrogen-containing polymer (e.g., polyethyleneimine (PEI)). In some embodiments, the binder material 36 may include a combination of the aforementioned polymers (i.e., 2, 3, 4, or more than 4 of these polymers). For example, the binder material 36 may be a "hybrid binder mixture". As mentioned herein, a "hybrid binder mixture" may include a mixture or blend of different types of binder materials, such as a mixture of an organic polymer and a sesquisiloxane binder, or other combinations of binder materials described herein. At least in some cases, the binder material 36 may be selected to enhance the adsorption of the target fluid on the coating (e.g., fluid capture material) produced using the adsorbent material 34. For example, in an embodiment where PEI is used as the binder material, the PEI may include PEI-low (e.g., M W between approximately 20,000 g / mol and 25,000 g / mol, and Mn between approximately 8,000 g / mol and 12,000 g / mol) or PEI-high (e.g., M wbetween about 70,000 g / mol and 80,000 g / mol, and Mn is between about 55,000 g / mol and 65,000 g / mol).

[0029] As described herein, the binder material 36 can be a polymer material capable of crosslinking. That is, it is currently recognized that the formation of a fluid capture material in which at least a portion of the polymer portion of the adsorbent-binder material 38 is a crosslinked polymer can reduce the likelihood of decomposition and / or dissolution of the adsorbent material 34. In addition, the use of a crosslinked polymer can enable the fluid capture material to have a relatively large amount of adsorbent material bound to the target fluid 18 and thus can have a higher fluid binding capacity compared to a coating formed without the crosslinked polymer. In other words, conventional techniques for combining the adsorbent material 34 and the binder material 36 can produce a fluid-bonded material having a relatively low fluid binding capacity compared to the adsorbent material (e.g., due to a dilution effect or a knockdown effect). It is currently recognized that crosslinking the binder material 36 can produce a fluid capture coating or fluid capture material having a relatively high binding capacity compared to not crosslinking the binder material 36. In addition, the binding capacity of the disclosed fluid capture coating or material (i.e., including the crosslinked binder material) can have a binding capacity approximately equal to that of the adsorbent material 34 itself (e.g., the adsorbent material 34 in powder form).

[0030] In one embodiment, the binder material 36 includes a material capable of self-crosslinking. For example, the binder material 36 can include silanol (SiOH) functional groups and / or alkoxysilane (SiOR) functional groups. It should be noted that binder materials 36 containing such functional groups can undergo intermolecular condensation reactions that cause the binder material 36 to crosslink upon heating. For example, it is currently recognized that an amine-containing component (e.g., an amine-containing MOF) can cause certain binder materials 36 (e.g., epoxy resins) to crosslink. As another non-limiting example, an amine-containing component can crosslink certain Si-O polymeric structures, such as silsesquioxanes, to form a crosslinked Si-O polymeric structure (e.g., amine-impregnated silica).

[0031] In one embodiment, the binder material comprises a polyvinyl alcohol polymer. Suitable polyvinyl alcohol polymers include, but are not limited to, polyvinyl alcohol homopolymers and polyvinyl alcohol copolymers. In one embodiment, the binder polymer composition comprises a polyvinyl alcohol - polyvinylamine copolymer (PVA - PVAm), which comprises a first crosslinkable functional group and a second crosslinkable functional group. Although derivatives of polyvinyl alcohol are suitable for the practice of the present invention, other polymeric materials can also be used in the binder polymer composition, including but not limited to polyacrylates, polymethacrylates, poly(2 - hydroxyethyl methacrylate), functionalized polyarylenes containing amine, carboxylic acid, amide, hydroxyl moieties, etc. In one embodiment, the binder polymer composition for preparing the fluid capture material comprises at least one polymer having a number average molecular weight greater than about 2500 Daltons. In another embodiment, the binder polymer composition for preparing the fluid capture material comprises at least one polymer having a number average molecular weight in the range of greater than 2500 Daltons to about 500,000 Daltons. In another embodiment, the binder polymer composition for preparing the fluid capture material comprises at least one hydrophilic polymer having a number average molecular weight in the range of about 75,000 Daltons to about 250,000 Daltons. The number average molecular weight can be determined by a variety of techniques known to those of ordinary skill in the art, including 1 H - NMR spectroscopy and gel permeation chromatography (GPC).

[0032] As described above, the binder material 36 can include a mixture of polymer materials capable of crosslinking. For example, the binder material 36 can include a mixture of polyvinyl alcohol (PVA) and polyacrylic acid (PAA). For example, the mixture can include 10 wt% PVA and 90 wt% PAA, 30 wt% PVA and 70 wt% PAA, 50 wt% PVA and 50 wt% PAA, 70 wt% PVA and 30 wt% PAA, or 90 wt% PVA and 10 wt% PAA.

[0033] In some embodiments, the binder material 36 can be dissolved in a solvent to a specific viscosity. For example, in an embodiment where the binder material 36 comprises ethyl cellulose, the binder material 36 can comprise a 7 - 15 cP solution in a 6% ethanol solution of toluene. When dissolved in a 1:1 toluene 2-(2 - butoxyethoxy)ethyl acetate solvent, the resulting slurry can comprise 30% solids and 11% binder. As another non - limiting example, in an embodiment where the binder material 36 comprises ethyl cellulose, the binder material 36 can comprise an approximately 300 cP solution in a 5% ethanol solution of toluene.

[0034] Generally speaking, the amount of crosslinking agent 37 can be less than the amount of binder material 36. In some embodiments, the ratio of crosslinking agent 37 added to binder material 36 to form the adsorbent-binder composite 38 can be less than about 1 / 3, less than about 1 / 4, less than about 1 / 5, or less than about 1 / 6. For example, the adsorbent-binder composite 38 can be formed by blending a 10 wt% solution of binder material 36 and a 2 wt% solution of crosslinking agent 37 (i.e., the ratio of crosslinking agent 37 to binder material 36 is 1 / 5).

[0035] It should be noted that, at least in some cases, the crosslinking agent 37 can also be the binder material 36. That is, the crosslinking agent 37 can be a polymer capable of crosslinking. For example, PAA can be used as a crosslinking agent for PVA.

[0036] As described herein, the crosslinking agent 37 crosslinks the binder material 36. In some embodiments, the degree of crosslinking (i.e., the crosslink density, which refers to the density of the chains or chain segments connecting two parts of the polymer network, rather than the density of the crosslink junctions) can be greater than 10%, greater than 20%, greater than 30%, greater than 40%, greater than 50%, greater than 60%, greater than 70%, greater than 80%, or greater than 90%.

[0037] Regarding the adsorbent-binder material 38 (e.g., the adsorbent-binder composite), the amounts of binder material 36 and adsorbent material 34 can be such that the adsorbent-binder material 38 includes greater than 50% adsorbent material, greater than 60% adsorbent material, greater than 70% adsorbent material, greater than 80% adsorbent material 34, greater than 85% adsorbent material 34, or greater than 90% adsorbent material 34.

[0038] A wide variety of crosslinking agents can be used to react with the binder, and these crosslinking agents can be monomers, oligomers, polymers, or combinations of the foregoing. In some embodiments, crosslinking agent 37 can include chemical crosslinking agents such as epoxy resins, acid anhydrides, and the like. In some embodiments, crosslinking agent 37 can include one or more materials such as nanoparticles, micron-sized particles, or larger-sized particles, or molecular precursors that can form particles. For example, the crosslinking agent can include silica particles such as colloidal silica; or tetraalkoxysilanes that can form silica particles. In some embodiments, crosslinking agent 37 can include particles having different size distributions. That is, crosslinking agent 37 can include particles of a first size distribution and a second size distribution. For example, crosslinking agent 37 can have a micron-sized distribution. In some embodiments, crosslinking agent 37 can have a nano-sized distribution and a micron-sized distribution (i.e., a bimodal size distribution). At least in some cases, the bimodal size distribution can improve wear resistance. In embodiments where crosslinking agent 37 includes particles having different size distributions, the mixture of particles can vary. For example, the mixture can include 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, etc. of nano-sized particles and 90 wt%, 80 wt%, 70 wt%, 60 wt%, 50 wt%, 40 wt%, 30 wt%, etc. of micron-sized particles. In embodiments where crosslinking agent 37 includes particles (e.g., micron-sized particles, nanoparticles, or larger particles), the particles can have a distribution of shapes. For example, crosslinking agent 37 can include 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95% spherical micron-sized particles. At least in some cases, the combination of particle shape (e.g., spherical) and different size distributions can improve the properties of the resulting fluid capture material discussed herein.

[0039] In some embodiments, crosslinking agent 37 contains functional groups that are sensitive to the formation of free radicals caused by exposure to high-energy radiation (e.g., ultraviolet light or electron beam) and / or heat. Those of ordinary skill in the art will know that the structure of free radicals is understood to determine their reactivity, and the structure of the crosslinking agent can be selected to provide higher or lower levels of chemical reactivity of the free radicals generated by such crosslinkable functional groups upon irradiation or heat exposure. In one embodiment, the crosslinking agent contains functional groups capable of forming secondary or tertiary aliphatic or cycloaliphatic free radicals. In another alternative embodiment, the crosslinking agent contains functional groups capable of forming aromatic free radicals (e.g., benzyl free radicals). Other crosslinkable functional groups include methacrylates, acrylates, acrylamides, vinyl ketones, styrenics, vinyl ethers, vinyl groups, allyl groups, benzyl groups, and groups containing a tertiary carbon-hydrogen bond, such as isobutyl groups.

[0040] Suitable crosslinking agents 37 include, but are not limited to, methacrylate, acrylate, and vinyl ketone reagents. These reagents can covalently bond with the binder material or form crosslinked polymers themselves when exposed to high-energy irradiation or heat. For example, suitable crosslinking agents include, but are not limited to, the following reagents: acryloyl chloride, (2E)-2-butenoyl chloride, maleic anhydride, 2(5H)-furanone, methyl acrylate, 5,6-dihydro-2H-pyran-2-one, ethyl acrylate, methyl crotonate, allyl acrylate, vinyl crotonate, 2-isocyanatoethyl methacrylate, methacrylic acid, methacrylic anhydride, methacryloyl chloride, glycidyl methacrylate, 2-ethylacryloyl chloride, 3-methylenedihydro-2(3H)-furanone, 3-methyl-2(5H)-furanone, 2-methyl methyl acrylate, methyl trans-2-methoxyacrylate, citraconic anhydride, itaconic anhydride, (2E)-methyl 2-methyl-2-butenoate, 2-ethyl ethyl methacrylate, ethyl 2-cyanoacrylate, dimethyl maleic anhydride, 2-methylallyl methacrylate, (2E)-ethyl 2-methyl-2-butenoate, 2-ethyl ethyl acrylate, (2E)-methyl 2-methyl-2-pentenoate, 2-hydroxyethyl methacrylate, methyl 2-(1-hydroxyethyl)acrylate, 3-(methacryloyloxy)propyltrimethoxysilane, 3-(diethoxymethylsilyl)propyl methacrylate, 3-(trichlorosilyl)propyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate, 3-tris(trimethylsilanoxy)silylpropyl methacrylate, 6-dihydro-1H-cyclopenta(c)furan-1,3(4H)-dione, methyl 2-cyano-3-methylcrotonate, trans-2,3-dimethylacrylic acid, and N-(hydroxymethyl)acrylamide.

[0041] Suitable vinyl and allyl reagents that can be used as crosslinking agents include, but are not limited to, allyl bromide, allyl chloride, diketene, 5-methylenedihydro-2(3H)-furanone, 3-methylenedihydro-2(3H)-furanone, 2-chloroethyl vinyl ether, and 4-methoxy-2(5H)-furanone.

[0042] Suitable isocyanate reagents that can be used as crosslinking agents include, but are not limited to, vinyl isocyanate, allyl isocyanate, furfuryl isocyanate, 1-ethyl-4-isocyanatobenzene, 1-ethyl-3-isocyanatobenzene, 1-(isocyanatomethyl)-3-methylbenzene, 1-isocyanato-3,5-dimethylbenzene, 1-bromo-2-isocyanatoethane, (2-isocyanatoethyl)benzene, 1-(isocyanatomethyl)-4-methylbenzene, 1-(isocyanatomethyl)-3-methylbenzene, 1-(isocyanatomethyl)-2-methylbenzene, etc.

[0043] Suitable styrene reagents that can be used as crosslinking agents include, but are not limited to, 3-vinylbenzaldehyde, 4-vinylbenzaldehyde, 4-vinylbenzyl chloride, trans-cinnamoyl chloride, phenylmaleic anhydride, 4-hydroxy-3-phenyl-2(5H)-furanone, and the like.

[0044] Suitable epoxide reagents that can be used as crosslinking agent 37 include, but are not limited to, glycidyl methacrylate, glycidyl vinyl ether, 2-(3-butenyl)oxirane, 3-vinyl-7-oxabicyclo[4.1.0]heptane, limonene oxide, and the like.

[0045] In some embodiments, crosslinking agent 37 may include multiple (e.g., two, three, or more than three) different types of functional groups that can promote the formation of the fluid capture material 44. Generally speaking, crosslinking agent 37 may include a first functional group that reacts with the binder material 36 and a second functional group that can be crosslinked. For example, crosslinking agent 37 may include an anhydride functional group and an acrylate functional group, an epoxide functional group and an acrylate functional group, an isocyanate functional group and a methacrylate functional group, and the like. As a non-limiting example, the binder material 36 may include poly(vinyl alcohol) and crosslinking agent 37 may include 2-isocyanatoethyl methacrylate (2-IEM), which includes both an isocyanate functional group and a methacrylate functional group. As another non-limiting example, the binder material 36 may include poly(vinyl butyral) and crosslinking agent 37 may include 2-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane.

[0046] In some embodiments, one or more additives may be added to form the adsorbent-binder material 38. For example, the additives may include dispersants to facilitate the formation of a suspension, such as anionic dispersants, cationic dispersants, non-ionic dispersants, defoamers, wetting agents, thickeners, or any combination thereof. For example, suitable anionic dispersants may include polymeric alkoxylates or phosphates. For example, suitable non-ionic dispersants may include polyurethanes. For example, suitable cationic dispersants may include ammonium polyoxyethylene fatty sulfates. Generally, the amount of dispersant added may be less than the amount of binder material 36. For example, the adsorbent-binder material 38 may include 10 wt% of binder material 36 and 0.5 wt% of dispersant, 1 wt% of dispersant, or more than 1 wt% of dispersant. As another non-limiting example, the adsorbent-binder material 38 may include 15 wt% of binder material 36 and 1 wt% of dispersant, 3 wt% of dispersant, or more than 5 wt% of dispersant. As another non-limiting example, the adsorbent-binder material 38 may include 13 wt% of binder material 36 and 1 wt% of dispersant, 3 wt% of dispersant, or more than 5 wt% of dispersant. For example, in an exemplary adsorbent-binder material 38 where the binder material 36 is aminopropyl sesquisiloxane, the binder material 36 may be formed using a binder solution having 13% binder and 2% dispersant. The dispersant may include polyethyleneimine (PEI), such as PEI-low (e.g., M w between approximately 20,000 g / mol and 25,000 g / mol, and M n between approximately 8,000 to 12,000) or PEI-high (e.g., M w between approximately 70,000 g / mol and 80,000 g / mol, and M n between approximately 55,000 to 65,000).

[0047] In block 40, the adsorbent-binder material 38 is deposited, applied to, integrally formed with (e.g., during manufacturing), or otherwise coupled to the substrate 16, such as to one or more surfaces of the substrate 16, to form a fluid capture coated substrate 42. In some embodiments, the substrate can include certain metal substrates (e.g., aluminum, titanium) or 3-D printed metal substrates. For example, the substrate 16 can include a fluid contactor having a metal surface. In some embodiments, the substrate 16 includes a metal alloy (e.g., Inconel or stainless steel). As mentioned herein, a "fluid contactor" or "direct fluid contactor" refers to a structure configured to receive a fluid flow, and the structure can include porous and / or semi-porous materials such that a portion of the fluid flow can permeate through the fluid contactor. In some embodiments, the fluid flow can include an ambient air flow. In some embodiments, the fluid flow can include a flue gas flow or an exhaust gas flow from a power generation device (e.g., a gas turbine). Thus, the binder material 36 can be selected to have a relatively high adhesion to the metal surface.

[0048] In some embodiments, the substrate 16 can be a polymer or a polymer composite. Polyolefins (e.g., polyethylene, polypropylene, polymethylpentene, polystyrene, substituted polystyrenes, poly(vinyl chloride) (PVC), polyacrylonitrile), polyamides, polyesters, polysulfones, polyethers, acrylic and methacrylic polymers, polystyrene, polyurethanes, polycarbonates, polyesters (e.g., polyethylene terephthalate, polybutylene terephthalate), polyethersulfone, polypropylene, polyethylene, polyphenylene sulfone, cellulose polymers, polyphenylene ether, polyamides (e.g., nylon, polyphenylene terephthalamide), and combinations of two or more of the foregoing polymers can be used as the substrate. Fluoropolymers that can be used as the substrate include, but are not limited to, ePTFE, polyvinylidene fluoride (PVDF), poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP), poly(ethylene-altetrafluoroethylene) (ETFE), polychlorotrifluoroethylene (PCTFE), poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP), and polyvinyl fluoride (PVF).

[0049] Generally speaking, depositing the adsorbent-binder material 38 onto the substrate 16 may include curing the adsorbent-binder material 38 including the crosslinking agent 37 to form a fluid capture material 44 or a coating that is a polymer and adsorbent composite material. In other words, the fluid capture material 44 refers to the adsorbent-binder material 38, where the binder material 36 is crosslinked by one or more crosslinking agents 37. As described herein, crosslinking the adsorbent-binder material 38 can provide a material and / or coating (i.e., the fluid capture material 44) with relatively high structural integrity compared to not crosslinking the adsorbent-binder material 38. In addition, crosslinking the adsorbent-binder material 38 can provide a material and / or coating with a relatively high binding capacity for fluids.

[0050] It should be noted that, at least in some cases, the adsorbent-binder material 38 can be deposited on the substrate 16 multiple times. It is currently recognized that, at least in some cases, depositing a relatively thick layer (e.g., greater than 1 mm, greater than 2 mm, or greater than 5 mm) can cause the fluid capture material 44 (e.g., the fluid capture material or the fluid capture coating) to have one or more cracks. Therefore, in order to reduce, prevent, or mitigate cracking (e.g., mud cracking), it may be advantageous to deposit multiple layers to ultimately form a fluid capture material 44 with a desired thickness (e.g., between 0.1 mm and 0.9 mm, between 1.1 mm and 1.3 mm, between 0.1 mm and 2.0 mm, between 2.5 mm and 3.5 mm). For example, the fluid capture material 44 can include 3 layers and have a total thickness of 1.2 mm. As another non-limiting example, the fluid capture material can include 6 layers and have a total thickness of 3 mm. For example, to deposit multiple layers, the method 30 can include depositing a first amount of the adsorbent-binder material 38, curing the first amount of the adsorbent-binder material to form the first layer, and repeating the method one or more times to form one or more additional layers, thereby forming a fluid capture material with multiple layers (e.g., 2, 3, 4, 5, 6, 7). In some embodiments, the first layer of the fluid capture material 44 can be pre-wetted before adding the second layer. Generally speaking, pre-wetting includes providing a suitable solvent to the first layer, such as toluene, ethanol, water, or a combination thereof. After pre-wetting the first layer, the second layer can be formed on top of the pre-wetted first layer. Generally speaking, the second layer can be formed in a manner that is generally similar to that described for the first layer.

[0051] In some embodiments, the total thickness of the fluid capture material or coating can be less than 1 mm. For example, the total thickness can be between 0.1 mm and 0.9 mm, between 0.2 mm and 0.8 mm, between 0.2 mm and 0.7 mm, between 0.3 mm and 0.6 mm, or between 0.4 mm and 0.5 mm. In some embodiments, each layer of the fluid capture material 44 can have the same thickness such that the thickness formed for each layer (e.g., as described with respect to Figure 2 is the total thickness / n, where "n" is the number of layers formed. In some embodiments, one or more layers of the fluid capture material 44 can have different thicknesses. For example, each subsequently formed layer can have a thinner thickness than the previous layer. Alternatively, each subsequently formed layer can have a thicker thickness than the previous layer.

[0052] As described herein, the fluid capture material 44 can be deposited onto one or more surfaces of the substrate 16, such as an air contactor. To illustrate this, Figure 3 shows a cross-sectional view of a substrate 16 (i.e., a fluid capture coated substrate 42) including the fluid capture material 44. In the illustrated embodiment, the substrate 16 is a material formed using additive printing. Additionally, as shown, the fluid capture material 44 includes one or more channels 46 that generally penetrate through a portion of the fluid capture material 44. Typically, the adsorbent material 34 is capable of forming a porous material. Thus, one or more channels 46 can also be formed in the fluid capture material 44.

[0053] As shown, each channel 46 generally includes a wall 48 to which the fluid capture material 44 is bonded on its surface. Thus, a gas flow passing through the channels of the fluid capture coated substrate 42 can contact the fluid capture material 44 and, therefore, facilitate the binding of the target fluid (e.g., CO 2 ) to the fluid capture material 44.

[0054] As described herein, the disclosed fluid capture material 44 can have a relatively high fluid binding capacity (e.g., water capacity and / or CO 2 capacity). Table 1 shows the results of CO 2 capacity measurements for certain substrates coated with the fluid capture material 44. Generally, the fluid capture material 44 corresponding to Table 1 is knife-coated onto 2-inch by 2-inch Inconel 718 specimens and the CO 2 capture performance (e.g., CO 2Capacity). Sampling of the MOF-binder composite is evaluated in an aluminum weighing pan to determine film curing conditions, initial structural integrity of the film, and ambient adsorption measurements. An exemplary method of coating a specimen with a slurry (i.e., adsorbent-binder material 38) requires mixing MOF powder (i.e., adsorbent material 34) with a suitable binder material 36, wetting agent, additives, and solvent in a container. The mixture can be vortexed for 1 - 2 min and then sonicated in an ultrasonic bath at 72 kHz for 20 min. The slurry is then applied to the substrate 16 using a spatula with a suitable gap (10 - 50 mils, 254 - 1270 μm) and allowed to dry under ambient conditions. For coatings in an aluminum pan, the slurry can be added to the pan using a plastic pipette, the pan can be tilted to cover the bottom, and allowed to dry under ambient conditions. Once dry, the pan or specimen is cured and activated using appropriate conditions.

[0055] Table 1 - CO of Certain Fluid Capture Materials 2 Capacity

[0056]

[0057] Table 1 shows examples of fluid capture materials 44 that can be used to capture CO 2 . Generally speaking, Table 1 shows the CO 2 capacity of a control (e.g., Example 1) compared to samples of fluid capture materials 44 formed from an adsorbent material (i.e., MOF-808-Gly) and a binder material capable of crosslinking (e.g., Examples 2 and 3). More specifically, Example 1 includes the adsorbent material MOF-808-Gly in powder form that is not deposited on the specimen. Example 1 has a CO 2 capacity of 0.3 mmol / g at 400 ppm CO 2 in N 2 at 20 °C and 20% RH.

[0058] Examples 2 and 3 illustrate fluid capture materials 44 formed using an adsorbent material and a finally crosslinked binder material. More specifically, Example 2 is a fluid capture material 44 having an adsorbent material 34 (e.g., MOF-808-Gly) and a binder material 36 capable of crosslinking (e.g., aminopropyl sesquisiloxane). To prepare Example 2, a slurry is prepared by mixing 2.44 g of a 25% aqueous solution of aminopropyl sesquisiloxane, 17.6 g of deionized water, 0.12 g of Triton TM X-100, and 5.1 g of MOF-808-Gly. After mixing, the slurry is applied to a 2” × 2” Inconel specimen, dried, and cured overnight at 120 °C under vacuum. Obtained when exposed to N 2400 ppm CO in a gas stream 2 has an equilibrium CO uptake of 0.37 mmol / g 2 absorption rate (e.g., CO 2 capacity) of a high-quality coating.

[0059] Example 3 is a fluid capture material 44 having an adsorbent material 34 (e.g., MOF-808-Gly), a binder material 36 (e.g., PVA), and a crosslinker 37 (e.g., PAA). To prepare Example 3, a slurry was prepared by mixing 1.55 g of an aqueous solution of 15% PVA (e.g., 88% hydrolyzed) and 3% PAA, 5.2 g of deionized water, approximately 3 mg of Triton TM X-100 and 2.5 g of MOF-808-Gly. After mixing, the slurry was coated on a 2”×2” Inconel specimen, dried, and cured overnight at 125 °C under vacuum. A fluid capture material was obtained that was rated 3B in the ASTM D3359-17 adhesion test and had an equilibrium CO 2 400 ppm CO in a gas stream 2 uptake of 0.38 mmol / g when exposed to N 2 at 20 °C and 75% RH. Generally, Examples 2 and 3 illustrate two crosslinked aqueous binder formulations used with MOF-808-Gly to form a fluid capture material 44 that has an approximate CO 2 binding capacity equal to that of Example 1. In addition, Examples 2 and 3 of the fluid capture material have good adhesion to the substrate.

[0060] In some embodiments, the fluid capture material 44 can be formed using a non-aqueous solvent. For example, another example of the fluid capture material 44 (i.e., Example 4) generally includes an adsorbent material 34 (e.g., MOF-808-Gly) and a silicon-containing binder material 36 capable of crosslinking. First, 1.2 mL of a 0.2 g / mL solution of SPR100 in methyl ethyl ketone (MEK) was mixed with 94 mg of disilanol PDS-1615, 53 μL of alkoxysilane SIB1 140.0, and 69 mg of Hypermer TM-KD1 was mixed in a vial. Separately, 3.0 g of MOF-808-Gly was mixed with 5 mL of isopropanol (IPA). The solution containing SPR100 was added to the MOF-808-Gly / IPA suspension. The SPR100 vial was rinsed with 2 × 0.5 mL of MEK and added to the combined mixture. The slurry was further diluted with 2 mL of IPA to obtain a viscosity suitable for coating. Then, 38 μL of trihexylamine was added to the slurry and the mixture was coated on a 2” × 2” Inconel specimen, dried, and cured at 90 °C under vacuum for 1 hr. A high-quality coating was obtained that was rated 4A in the ASTM D3359-17 adhesion test.

[0061] As described above, in certain embodiments, the fluid capture material 44 is capable of binding water. Several embodiments of the fluid capture material 44 according to the present disclosure and the performance of such fluid capture material 44 are described below.

[0062] A first embodiment of the fluid capture material 44 that binds water may include an adsorbent material 34 (i.e., MOF-303), a binder material 36 (i.e., PVA), and a crosslinking agent (i.e., PAA) deposited on a metal substrate. More specifically, a first embodiment of the fluid capture material 44 that binds water may be prepared by forming a slurry by mixing an aqueous solution of 0.56 g of 15% poly(vinyl alcohol) [PVA, 88% hydrolyzed] and 3% poly(acrylic acid) [PAA], 2.0 g of deionized water, approximately 3 mg of AGITAN 351, 1.0 g of MOF-303, and 0.02 g of Tergitol 15-S-7. After mixing, the slurry was coated on a 2” × 2” Inconel specimen and cured overnight at 125 °C. A high-quality coating was obtained that had good adhesion and had an equilibrium water absorption rate of 26-28% when tested in a humidity chamber set at 20% RH and 25 °C.

[0063] A second embodiment of the fluid capture material 44 for bound water includes an adsorbent material 34 (e.g., MOF-303), a binder material 36 (e.g., PVA), and a crosslinking agent (e.g., PAA) deposited on a glass-filled nylon specimen (e.g., a glass-filled nylon substrate). More specifically, the second embodiment of the fluid capture material 44 for bound water can be prepared by forming a slurry similar to that described above for the first embodiment of the fluid capture material 44 for bound water and coating the slurry on a 2”×2” glass-filled polyamide (PA12) nylon specimen. The coated sample is dried at room temperature and then cured at 120 °C overnight. Once cooled to room temperature, the sample is immersed in water to release air bubbles and then patted dry. Then a second layer of slurry is coated as previously described. This process is repeated one more time. After final curing at 120 °C, the coating weighs 0.9216 g and adheres well to the substrate. The equilibrium water absorption at 20% RH / 25 °C is 28%.

[0064] A third embodiment of the fluid capture material 44 for bound water includes a variety of binder materials 36. For example, the third embodiment of the fluid capture material 44 for bound water can include binder materials 36 such as PVA, PAA, and poly(methyl / phenylsilsesquioxane). More specifically, the third embodiment of the fluid capture material 44 for bound water can be prepared by mixing 1.78 g of an aqueous solution of 7.5% PVA [80% hydrolyzed] and 1.5% PAA with 3.5 g of deionized water, 0.02 g of DISPERBYK 190, approximately 3 mg of AGITAN 351, and 2.0 g of MOF-303. A solution of 0.08 g of Wacker MP-50E silicone emulsion diluted with 0.5 g of deionized water is added to the mixture. After mixing, the slurry is coated on a 2”×2” glass-filled PA12 nylon specimen. After drying at room temperature, the sample is cured at 120 °C for 4 hours. After cooling, the sample is immersed in water to release air bubbles, patted dry, and then another layer of slurry is coated. Then the drying / curing process is repeated as previously described. Then more than two layers of slurry are coated on top of the first two layers using the same procedure. The weight of the dried / cured coating at the end of the process is 1.4946 g. The coating adheres well and has no cracks. The equilibrium water absorption at 20% RH / 25 °C is 31 - 32%.

[0065] A fourth embodiment of the fluid capture material 44 for bound water includes an adsorbent material 34, such as MIL-160. To prepare the fourth embodiment of the fluid capture material for bound water, 2.44 g of an aqueous solution of 13.5% PVA [88% hydrolyzed] and 4.5% PAA is mixed with 5.9 g of deionized water, 0.040 g of DISPERBYK 190, 0.030 g of AGITAN 351, 4.34 g of MIL-160, and 0.050 g of Tergitol 15-S-7. After mixing, the slurry is coated onto a 2”×2” Inconel specimen. The sample is dried at room temperature and then overnight at 120 °C. After cooling, the sample is immersed in water to release bubbles and then patted dry. A second layer of slurry is applied as previously described and cured. The second layer does not adhere to the first layer but instead flakes off subsequently.

[0066] A fifth embodiment of the fluid capture material 44 for bound water includes a plurality of binder materials 36, such as a silicone-containing binder material, PVA, and PAA. It is currently recognized that the use of a hybrid binder material 36 (i.e., two, three, four, or more than four different or distinct binder materials) can improve the adhesion characteristics of the fluid capture material 44 or the layer to the substrate and / or the adhesion characteristics of each layer of the multi-layer coating. To prepare the fifth embodiment of the fluid capture material for bound water, 8.0 g of an aqueous solution of 7.5% PVA [80% hydrolyzed] and 1.5% PAA is mixed with 9.0 g of deionized water, 0.10 g of DISPERBYK 2055, 0.015 g of AGITAN 351, and 8.0 g of MIL-160. A solution of 0.08 g of Wacker MP-50E silicone emulsion diluted with 2.0 g of deionized water is added thereto. After mixing, a small Inconel heat exchanger is coated with the slurry. After drying at room temperature, the sample is cured at 120 °C for 2 hours. After cooling, the sample is immersed in water to release bubbles, patted dry, and then coated with another layer of slurry. Then the drying / curing process is repeated as previously described. Finally, a third layer is applied as previously described. After final curing overnight at 120 °C, a 3.1 g well-adhered coating is obtained. The equilibrium water absorption at 20% RH / 25 °C is 30 - 32%.

[0067] It is further recognized that crosslinking of the composite coating can improve the structural integrity of the fluid capture material 44 or the coating. To illustrate the improved structural integrity based on the addition of the crosslinking agent 37, two compositions of the adsorbent material 34 and the binder material 36 are prepared. The first composition is according to the disclosed fluid capture material 44 and is thus formed by crosslinking of the binder material 36 (i.e., by addition of PAA). In the second composition, the binder material 36 is not crosslinked (i.e., no PAA is added). To prepare the first composition, a slurry is prepared by mixing 0.56 g of an aqueous solution of 13.5% poly(vinyl alcohol) [PVA, 88% hydrolyzed] and 4.5% poly(acrylic acid) [PAA], 1.4 g of deionized water, 0.02 g of DISPERBYK 190, and 1.0 g of MIL-160. After mixing, the slurry is coated on a 1”×1” Inconel specimen, dried at room temperature, and cured overnight in a vacuum oven at 125 °C. The specimen is cooled to room temperature in a vacuum desiccator and then quickly weighed. It is then immersed in 10 mL of deionized water and placed in an oven at 90 °C for 2 hours. At the end of this time, the specimen is removed and dried at 90 °C for 1 hour, followed by drying in a vacuum oven at 125 °C for 2 hours. Finally, the sample is cooled in a vacuum desiccator and reweighed as previously described. The weights are: (1) uncoated specimen: 5.0038 g; (2) coated specimen after curing: 5.3206 g (i.e., coating weight is 0.3168 g); (3) coated specimen after immersion / drying: 5.3087 g (i.e., coating is 0.3049 g); and (4) coating weight retained after immersion: 96.2%.

[0068] To prepare the second composition (i.e., prepared without using crosslinker 37), a slurry was prepared by mixing 0.67 g of an aqueous solution of 15% poly(vinyl alcohol) [PVA, 88% hydrolyzed], 1.3 g of deionized water, 0.02 g of DISPERBYK 190, and 1.0 g of MIL-160. After mixing, the slurry was coated on a 1”×1” Inconel specimen, dried at room temperature, and cured overnight in a vacuum oven at 125 °C. The specimen was cooled to room temperature in a vacuum desiccator and then quickly weighed. It was then immersed in 10 mL of deionized water and placed in an oven at 90 °C for 2 hours. Shortly after immersion in water, the coating began to crack and peel off the specimen. At the end of this time, the specimen was removed and dried at 90 °C for 1 hour, followed by drying in a vacuum oven at 125 °C for 2 hours. Finally, the sample was cooled in a vacuum desiccator and reweighed as previously described. Weights were: (1) uncoated specimen: 5.0320 g; (2) coated specimen after curing: 5.1974 g (i.e., coating weight was 0.1654 g); (3) coated specimen after immersion / drying: 5.0573 g (i.e., coating was 0.0253 g); and (4) coating weight retained after immersion: 15.3%. In particular, the first composition (i.e., an embodiment of the fluid capture material 44 including a crosslinked binder) contains PAA, and the cured film obtained in this case retained 96% of its mass after 2 hours in 90 °C water. In contrast, using the second composition (i.e., when using PVA without any crosslinker), only 15% of this mass was retained after testing in the same manner.

[0069] As described herein, the fluid capture material 44 can be formed using crosslinker 37, which has different types of functional groups that can promote the formation of the fluid capture material 44. To prepare an embodiment of such a composition, 0.30 g of poly(vinyl butyral) was dissolved in 6.0 g of isopropanol. Additionally, 0.065 g of 2-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane, 3.0 g of amine-treated silica adsorbent, and 0.07 g of BYK9076 were then admixed therein. The resulting slurry was applied to an aluminum specimen using a spatula. After drying at room temperature, the sample (e.g., the aluminum specimen coated with the slurry) was placed in an oven at 90 °C for 1 hour to cure. Using 400 ppm CO in nitrogen 2 The CO was measured under dry conditions at 25 °C 2 absorption rate. The average value was determined to be 0.734 mol CO 2 / kg coating (0.032 g / g).

[0070] Figure 4 is one having the same as CO 2A graph with the y-axis corresponding to the amount (ppm) and the x-axis corresponding to time (minutes (min)). In this example, the fluid capture material 44 is formed using a binder material 36 including PVA / PAA, as described for Example 3 in Table 1. Additionally, the fluid capture material 44 is subjected to a fluid flow of 50 standard cubic centimeters per minute (sccm) with 400 ppm CO 2 and 75% relative humidity (RH). As generally shown in the figure, CO is detected approximately 170 min after the fluid flow enters the fluid capture material or coating 2 .

[0071] As described herein, the fluid capture material 44 is capable of capturing a target fluid, such as H 2 O. In such embodiments, it is currently recognized that it may be advantageous to form a fluid capture material 44 that is capable of releasing the captured fluid. To illustrate this Figure 5 is a diagram illustrating a method 60 for capturing a target fluid (e.g., target fluid 18 as described with respect to Figure 1 ) and subsequently releasing the target fluid in a controlled manner (i.e., when it may be desirable to remove the target fluid 18). For example, in an embodiment where the target fluid 18 includes water, it may be desirable to extract water from a fluid source (such as air having a relatively high moisture content (e.g., greater than 500 ppm of water)) using the disclosed fluid capture material 44 and subsequently release the water, thereby producing pure water

[0072] Referring to method 60, at block 62, a gas flow 64 is provided to a substrate 16 coated with the fluid capture material 44. The water in the gas flow 64 binds to the capture coating, thereby producing a dry gas flow 66. At block 68, a heat exchanger 70 is heated (e.g., using hot air at a temperature greater than 80°C, greater than 85°C, greater than 90°C, or greater than 95°C). In any case, the water bound to the fluid capture material 44 can be released as steam 72. At block 74, a condenser 76 can receive the steam 72 and cool the steam 72, thereby producing water 78. At block 80, heat can be recovered. In this way, the fluid capture material 44 can be used to extract a fluid and, in certain embodiments, release the fluid

[0073] As described herein, the fluid capture material 44 can include a crosslinking agent 37 (i.e., a polymer used to crosslink to form the fluid capture material 44). In some embodiments, the crosslinking agent 37 can include colloidal silica Figure 6A graph is shown with an x-axis corresponding to time and a y-axis corresponding to weight gain (%). In this graph, the relationship between the weight gain and time of a gas capture coating formed by the following is shown: PVA as a binder and MOF as an adsorbent (i.e., "PVA + MOF"); PVA as a binder, silica as a crosslinking agent, and MOF as an adsorbent (i.e., "PVA + silica + MOF"); and silica and starch as crosslinking agents and MOF as an adsorbent (i.e., "PVA + silica + starch + MOF"). As shown, the fluid capture material with a crosslinking agent (i.e., thus having a crosslinked polymer composite matrix) has a relatively high weight gain, which corresponds to more of the target fluid 18 being adsorbed onto the fluid capture material 44.

[0074] Accordingly, the present disclosure relates to a fluid capture material or a fluid capture material that provides improved fluid binding capacity and stability. The fluid capture material or coating generally includes an adsorbent material and a binder material. As described herein, the resulting fluid capture material or coating may include a crosslinked polymer formed from one or more binder materials and certain crosslinking agents such as ultraviolet light, silica, polyacrylic acid, heat, or combinations thereof.

[0075] The technical effects of the present invention include, but are not limited to, improving the capacity and / or capture efficiency of a substrate by the fluid capture material. By providing the disclosed fluid capture material, the amount of certain gases retained in the exhaust gas stream can be reduced. In addition, by forming a fluid capture material that includes a crosslinked polymer, a relatively larger amount of adsorbent material can be used compared to the binder material, thereby improving the fluid binding capacity of the fluid capture material.

[0076] This written description uses examples to disclose the present invention, including the best mode, and also enables any person skilled in the art to practice the present invention, including making and using any device or system and performing any combined method. The patentable scope of the present invention is defined by the claims, and may include other examples that occur to those skilled in the art. If such other examples have structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not materially different from the literal language of the claims, then such other examples are intended to be within the scope of the claims.

Claims

1. A system, comprising: a substrate; and a fluid capture material formed on one or more surfaces of the substrate, wherein the fluid capture material comprises: an adsorbent material configured to bind one or more fluids, the one or more fluids including water, carbon dioxide, sulfur oxides, or a combination thereof; and one or more binder materials, wherein the binder materials are at least partially crosslinked.

2. The system according to claim 1, wherein the fluid capture material comprises less than 15 wt% of the one or more binder materials.

3. The system according to claim 1, wherein the adsorbent material comprises a metal-organic framework (MOF), a covalent organic framework (COF), a polymeric resin, silica, zeolite, or a combination thereof.

4. The system according to claim 1, the system comprising a crosslinking agent, wherein the binder material is at least partially crosslinked with the crosslinking agent, and wherein the crosslinking agent comprises one or more of a methacrylate reagent, an acrylate reagent, a vinyl ketone reagent, a vinyl reagent, or an allyl reagent.

5. The system according to claim 1, the system comprising a crosslinking agent, wherein the binder material is at least partially crosslinked with the crosslinking agent, and wherein the crosslinking agent comprises polyacrylic acid.

6. The system according to claim 1, wherein the one or more binder materials comprise a vinyl polymer, starch, an alkyl cellulose, or a combination thereof.

7. The system according to claim 1, the system comprising a crosslinking agent, wherein the binder material is at least partially crosslinked with the crosslinking agent, and wherein the ratio of the crosslinking agent to the binder material is less than 25%.

8. The system according to claim 1, wherein the thickness of the fluid capture material is between 0.1 mm and 3.5 mm.

9. The system according to claim 1, wherein the fluid capture material comprises greater than 90 wt% of the adsorbent material.

10. The system according to claim 1, wherein the at least partially crosslinked binder material has a crosslinking density greater than 10%.

11. A method, comprising: providing an adsorbent material configured to bind one or more fluids, the one or more fluids including water, carbon dioxide, sulfur oxides, or a combination thereof; providing one or more binder materials, wherein the one or more binder materials comprise components capable of forming a crosslinked polymer; providing a crosslinking agent; generating an adsorbent-binder material based on the adsorbent material, the one or more binder materials, and the crosslinking agent; applying the adsorbent-binder material to a substrate; and forming a fluid capture material using the adsorbent-binder material applied to the substrate, wherein the fluid capture material comprises a crosslinked composite material.

12. The method according to claim 11, wherein forming the fluid capture material comprises: forming a first layer of the fluid capture material using the adsorbent-binder material; pre-wetting the first layer; and forming a second layer on the pre-wetted first layer.

13. The method according to claim 12, wherein the one or more binder materials comprise a first binder material and a second binder material, and wherein the first binder material is different from the second binder material.

14. The method according to claim 11, wherein providing the one or more binder materials comprises providing a first amount of the one or more binder materials, wherein providing the crosslinking agent comprises providing a second amount of the crosslinking agent, and wherein the ratio of the second amount to the first amount is less than 1 / 3.

15. The method according to claim 11, wherein providing the one or more binder materials comprises providing a first amount of the one or more binder materials, wherein providing the crosslinking agent comprises providing a second amount of the crosslinking agent, and wherein the ratio of the second amount to the first amount is less than 1 / 4.

16. A system comprising: a fluid capture material configured to bind one or more fluids, wherein the fluid capture material comprises: an adsorbent material configured to bind one or more fluids, the one or more fluids including water, carbon dioxide, sulfur oxides, or combinations thereof; and one or more binder materials, wherein the one or more binder materials are at least partially crosslinked; and a fluid contactor having one or more surfaces coated with the fluid capture material.

17. The system according to claim 16, wherein the thickness of the fluid capture material on at least one of the one or more surfaces is between 0.1 mm and 2.0 mm.

18. The system according to claim 16, wherein the thickness of the fluid capture material on at least one of the one or more surfaces is between 0.5 mm and 1.5 mm.

19. The system according to claim 16, wherein the fluid capture material comprises greater than 90 wt% of the adsorbent material.

20. The system according to claim 16, wherein the at least partially crosslinked binder material has a crosslink density of greater than 50%.

Images