The present disclosure relates to a sorbent polymer composite article, methods of forming a sorbent polymer composite article, and methods of using a sorbent polymer composite article for the purpose of adsorption, including adsorption for direct air capture (DAC) of carbon dioxide.
Increasing carbon dioxide (CO2) levels associated with greenhouse gas emissions are shown to be harmful to the environment. As reported by the Climate.gov article “Climate Change: Atmospheric Carbon Dioxide,” the 2019 average carbon dioxide level in the atmosphere was 409.8 ppm, the highest level that has been noted in the past 800,000 years. The rate of increase of CO2 in the atmosphere is also much higher than the rates in previous decades.
In order to limit the impact of climate change, it is not only necessary to reduce CO2 emissions in the near future to zero but also to achieve negative CO2 emissions. Several possibilities exist in order to achieve negative emissions, e.g. combustion of biomaterials for the generation of electricity combined with CO2 capture from the combustion flue gas and subsequent CO2 sequestration (“BECCS”) or direct air capture of CO2 (“DAC”).
Gas separation by adsorption has many different applications in industry, for example removing a specific component from a gas stream, where the desired product can either be the component removed from the stream, the remaining depleted stream, or both. Thereby, both trace components as well as major components of the gas stream can be targeted by the adsorption process. One important gas separation application is in capturing CO2 from gas streams, e.g., from flue gases, exhaust gases, industrial waste gases, biogas or atmospheric air. Atmospheric air is considered a dilute feed stream of CO2.
Capturing CO2 directly from the atmosphere, referred to as DAC, is one of several means of mitigating anthropogenic greenhouse gas emissions and has attractive economic prospects as a non-fossil, location-independent CO2 source for the commodity market and for the production of synthetic fuels. The specific advantages of CO2 capture from the atmosphere include: a) DAC can address the emissions of distributed sources (e.g. vehicles . . . land, sea and air), which account for a large portion of the worldwide greenhouse gas emissions and can currently not be captured at the site of emission in an economically feasible way; b) DAC can address legacy emissions and can therefore create truly negative emissions, and c) DAC systems do not need to be attached to the source of emission but may be location independent and can be located at the site of further CO2 processing or usage.
There is increasing motivation to develop and improve upon these processes to make them more efficient, maximizing the amount of CO2 removed from the atmosphere while minimizing the energy required in the process.
There are established articles and techniques for DAC. An example is using an article including a substrate such as a monolith that supports or is coated with a sorbent material. Variations are established by changing the type of substrate and the sorbent that is used. However, these previously established articles and methods present limitations in the ability to efficiently cycle between adsorbing and desorbing states. They also have limitations with respect to the durability of the article. The articles may also degrade when exposed to high temperatures or high moisture level environments, or combinations thereof, which can result in a shorter lifetime.
A sorbent polymer composite article is disclosed for adsorption, including adsorption for DAC. The sorbent polymer composite article includes a composite layer comprising a porous polymer and a sorbent material. The sorbent polymer composite article also includes at least one hydrophobic layer on either side of the first composite layer.
According to one example (“Example A”), a sorbent polymer composite article includes a first composite region including a first porous polymer and a sorbent material, the first composite region having a first hydrophobicity, and a second region of a second porous polymer positioned adjacent to a first side of the first composite region, the second region having a second hydrophobicity that exceeds the first hydrophobicity.
According to a second example (“Example B”), a method of forming a sorbent polymer composite article includes the steps of forming a first composite region comprising a first porous polymer and a sorbent material, and forming a second hydrophobic region comprising a second porous polymer on a first side of the first composite region.
According to a third example (“Example C”), a method of using a sorbent polymer composite article for adsorption includes the steps of providing a sorbent polymer composite article includes a first composite region having a first porous polymer and a sorbent and having a first hydrophobicity, and a second region positioned adjacent to a first side of the first region and having a second hydrophobicity that exceeds the first hydrophobicity, directing a feed stream including carbon dioxide across the sorbent polymer composite article, and adsorbing the carbon dioxide into the sorbent polymer composite article.
According to a fourth example (“Example D”), a sorbent polymer composite article includes a first region having a sorbent material and a screen, a second region including a second polymer positioned adjacent the first region, and a third region including a third polymer positioned adjacent the first region.
According to a fifth example (“Example E”), a sorbent polymer composite article includes a first composite region having a first porous polymer and a sorbent material, the first composite region having a first hydrophobicity, a second region of a second porous polymer positioned adjacent to a first side of the first composite region, the second region having a second hydrophobicity that exceeds the first hydrophobicity, a third region of a third porous polymer positioned adjacent to a second side of the first composite region, the third region having a third hydrophobicity that exceeds the first hydrophobicity, and an end-sealing region disposed to encompass an end of the first composite region between the second and third regions.
This disclosure is not meant to be read in a restrictive manner. For example, the terminology used in the application should be read broadly in the context of the meaning those in the field would attribute such terminology.
With respect to terminology of inexactitude, the terms “about” and “approximately” may be used, interchangeably, to refer to a measurement that includes the stated measurement and that also includes any measurements that are reasonably close to the stated measurement. Measurements that are reasonably close to the stated measurement deviate from the stated measurement by a reasonably small amount as understood and readily ascertained by individuals having ordinary skill in the relevant arts. Such deviations may be attributable to measurement error, differences in measurement and/or manufacturing equipment calibration, human error in reading and/or setting measurements, minor adjustments made to optimize performance and/or structural parameters in view of differences in measurements associated with other components, particular implementation scenarios, imprecise adjustment and/or manipulation of objects by a person or machine, and/or the like, for example. In the event it is determined that individuals having ordinary skill in the relevant arts would not readily ascertain values for such reasonably small differences, the terms “about” and “approximately” can be understood to mean plus or minus 10% of the stated value.
The term “fibril” as used herein describes an elongated piece of material such as a polymer, where the length and width are substantially different from each other. For example, a fibril may resemble a piece of string or fiber, where the width (or thickness) is much shorter or smaller than the length.
The term “node” as used herein describes a connection point of at least two fibrils, where the connection may be defined as a location where the two fibrils come into contact with each other, permanently or temporarily. In some examples, a node may also be used to describe a larger volume of polymer than a fibril and where a fibril originates or terminates with no clear continuation of the same fibril through the node. In some examples, a node has a greater width but a smaller length than the fibril.
As used herein, “nodes” and “fibrils” may be used to describe objects that are usually, but not necessarily, connected or interconnected, and have a microscopic size, for example. A “microscopic” object may be defined as an object with at least one dimension (width, length, or height) that is substantially small such that the object or the detail of the object is not visible to the naked eye or difficult, if not impossible, to observe without the aid of a microscope (including but not limited to a scanning electron microscope or SEM, for example) or any suitable type of magnification device.
The present disclosure relates to a sorbent polymer composite article, methods of forming a sorbent polymer composite article, and methods of using a sorbent polymer composite article to adsorb and separate one or more desired substances from a source stream. While the sorbent polymer composite article is described below for use in the capture of CO2 from a dilute feed stream, such as air, it may also be used in other adsorbent methods and applications. These methods include, but are not limited to, adsorption of substances from various inputs, including other gas feed streams (e.g., combustion exhaust) and liquid feed streams (e.g., ocean water). The adsorbed substance is not limited to CO2. Other adsorbed substances may include, but are not limited to, other gas molecules (e.g., N2, CH4, and CO), liquid molecules, and solutes. In certain embodiments, the input may be dilute, containing on the order of parts per million (ppm) of the desired substance.
The first porous polymer 22 of the first composite region 28 may be one of expanded polytetrafluoroethylene (ePTFE), expanded polyethylene (ePE), polytetrafluoroethylene (PTFE), or another suitable porous polymer. It will be appreciated that non-woven materials such as nanospun, meltblown, spunbond and porous cast films could be among the various other suitable porous polymer forms. The first porous polymer 22 may be expanded by stretching the polymer at a controlled temperature and a controlled stretch rate, causing the polymer to fibrillate. Following expansion, the first porous polymer 22 may comprise a microstructure of a plurality of nodes 30 and a plurality of fibrils 34 that connect adjacent nodes 30. In these instances, the first porous polymer 22 includes pores 32 bordered by the fibrils 34 and the nodes 30. An exemplary node and fibril microstructure is described in U.S. Pat. No. 3,953,566 to Gore, incorporated herein by reference in its entirety. The pores 32 of the first porous polymer 22 may be considered micropores. Such micropores may have a single pore size or a distribution of pore sizes. The average pores size may range from 0.1 microns to 100 microns in certain embodiments.
The sorbent material 24, 24′ of the first composite region 28 is a substrate having a surface configured to hold the desired substance from the input on the surface via adsorption. The sorbent material 24, 24′ varies based on which substances are targeted for adsorption. In various embodiments, the sorbent material 24, 24′ is a carbon dioxide adsorbing material which may include, but is not limited to, an ion exchange resin (e.g., a strongly basic anion exchange resin such as Dowex™ Marathon™ A resin available from Dow Chemical Company), zeolite, activated carbon, alumina, metal-organic frameworks, polyethyleneimine (PEI), desiccant, carbon molecular sieve, carbon adsorbent, graphite, activated alumina, molecular sieve, aluminophosphate, silicoaluminophosphate, zeolite adsorbent, ion exchanged zeolite, hydrophilic zeolite, hydrophobic zeolite, modified zeolite, natural zeolites, faujasite, clinoptilolite, mordenite, metal-exchanged silico-aluminophosphate, uni-polar resin, bi-polar resin, aromatic cross-linked polystyrenic matrix, brominated aromatic matrix, methacrylic ester copolymer, graphitic adsorbent, carbon fiber, carbon nanotube, nano-materials, metal salt adsorbent, perchlorate, oxalate, alkaline earth metal particle, ETS, CTS, metal oxide, chemisorbent, amine, organo-metallic reactant, hydrotalcite, silicalite, zeolitic imadazolate framework and metal organic framework (MOF) adsorbent compounds, and combinations thereof.
The sorbent material 24, 24′ may be present in the first porous polymer 22 as a coating, a filling, entrained particles, and/or in another suitable form, as described further below. In the illustrated embodiment of
The optional carrier 26 of the first composite region 28 is a material that is configured to increase the surface area of the region it occupies which may allow for an increased surface area that is available for adsorption of the desired substance. The carrier 26 may include a mesoporous silica, polystyrene beads, porous polymeric bed or sphere, oxide supports, another suitable carrier material. The carrier 26 may further include a porous film comprising porous inorganic materials within it such as calcium sulfate, alumina, activated charcoal and fumed silica. As noted above, the carrier 26 may be present in the pores 32 of the first composite region 28 as high surface area particles that are coated or functionalized with the sorbent material 24′. The combination of the carrier 26 coated with the sorbent material 24′ increases the surface area available for adsorption. In these embodiments, the nodes 30 and fibrils 34 may or may not be coated with sorbent material 24. When the nodes 30 and fibrils 34 are not coated, the original hydrophobicity of the first porous polymer 22 may be retained.
The first composite region 28 of the sorbent polymer composite article 20 includes a first side 72 (e.g., an upper side in
The first composite region 28, the second region 36, and the third region 38 of the sorbent polymer composite article 20 may be formed using different processes. In certain embodiments, the first composite region 28, the second region 36, and/or the third region 38 may be formed as discrete layers and then coupled together. In this case, the first porous polymer 22 of the first composite region 28, the second porous polymer 40 of the second region 36, and/or the third porous polymer 48 of the third region 38 may be distinct structures. In other embodiments, the first composite region 28, the second region 36, and/or the third region 38 may be formed together and then subjected to different coating processes or surface treatments, as described further below, to differentiate certain regions. In this case, the first porous polymer 22 of the first composite region 28, the second porous polymer 40 of the second region 36, and/or the third porous polymer 48 of the third region 38 may be continuous or integrated structures.
The first composite region 28, the second region 36, and the third region 38 of the sorbent polymer composite article 20 may have differing degrees of hydrophobicity. The hydrophobicity may be altered through various methods, such as through applying coatings or surface treatments which can include, but are not limited to, plasma etching and applying micro-topographical features. The first composite region 28 has a first hydrophobicity, the second region 36 may have a second hydrophobicity, and the third region 38 may have a third hydrophobicity. The first hydrophobicity is less than that of each the second hydrophobicity and the third hydrophobicity. The second hydrophobicity may be less than, greater than, or equal to the third hydrophobicity. The greater hydrophobicity of the second region 36 and the third region 38 may reduce the permeation of liquid water through the respective regions 36, 38, thus form ing a barrier between any liquid water in the surroundings and the components of the first composite region 28. This reduces degradation of the sorbent material 24, 24′ within the first composite region 28 that liquid water could cause, increasing the lifetime and durability of the sorbent polymer composite article 20. The greater hydrophobicity of the second region 36 and the greater hydrophobicity of the third region 38 relative to the first hydrophobicity of the first composite region 28 may result from the lack of sorbent material 24, 24′ within the second and third regions 36, 38.
In some embodiments, the first composite region 28 is sealed with a coating (not shown). In certain instances, the coating is configured to be a carbon adsorbing material similar to the above-described sorbent materials 24, 24′.
The second porous polymer 40 of the second region 36 and the third porous polymer 48 of the third region 38 may be at least one of polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), expanded polyethylene (ePE), or other suitable porous polymers. The second porous polymer 40 of the second region 36 may be identical to or different from the third porous polymer 48 of the third region 38. Further, the first porous polymer 22 of the first composite region 28, the second porous polymer 40 of the second region 36, and the third porous polymer 48 of the third region 38 may be identical to or different from each other.
In various embodiments, the thickness of the second region 36 is less than that of the first composite region 28, and the thickness of the third region 38 is less than that of the first composite region 28. The overall thickness of the sorbent polymer composite article 20 may be about 0.1 mm to about 5.0 mm. In certain embodiments, the thickness of the first composite region 28 may account for a majority of the overall thickness, such as about 70%, about 80%, about 90%, or more of the overall thickness.
The pore characteristics of the porous polymers 22, 40, 48 of each of the respective first composite region 28, the second region 36, and the third region 38 are variable. In certain embodiments, the second and third regions 36, 38 may have fewer and/or smaller pores 44, 54, than the first composite region 28 to selectively limit permeation of undesired contaminants (e.g., water) into the first composite region 28 while permitting permeation of desired molecules (e.g., CO2) into the first composite region 28. By contrast, the first composite region 28 may have more and/or larger pores 32 than the second and third regions 36, 38 to encourage movement of CO2 through the first composite region 28 for adsorption and desorption.
Further, the pore characteristics can be varied among different embodiments. This variation of the pore characteristics can be dependent on the entire thickness of the sorbent polymer composite article 20, as well as of the individual thicknesses of the first composite region 28, second region 36 and third region 38.
Referring back to
Further, the ability to vary the hydrophobicity, thickness, pore characteristics, and other properties of the first composite region 28, the second region 36, and the third region 38 may increase durability and conformability of the sorbent polymer composite article 20. Further, the use of a relatively thin and flexible sorbent polymer composite article 20 may allow the sorbent polymer composite article 20 to conform to different configurations for adsorption and desorption of the CO2.
Referring still to
In the illustrated embodiment of
At block 104, the method includes coupling the second hydrophobic region 36 onto the first side 72 of the first composite region 28, wherein the coupling includes laminating, adhering, or otherwise attaching the second hydrophobic region 36 to the first side 72 of the first composite region 28. At block 106, the method includes coupling the third hydrophobic region 38 onto the second side 74 of the first composite region 28, wherein the coupling includes laminating, adhering, or otherwise attaching the third hydrophobic region 38 to the second side 74 of the first composite region 28. In some embodiments, the coupling of the third hydrophobic region 38 in block 106 may occur before or simultaneously with the coupling of the second hydrophobic region 36 in block 104.
The sorbent polymer composite article 20″ further comprises a second region 36 that has been integrally formed with the first side 72 of the first composite region 28. In this embodiment, the first porous polymer 22 of the first composite region 28 may be continuous with the second porous polymer 40 of the second region 36. In certain embodiments, the sorbent polymer composite article 20″ may further include a third region 38 having a third porous polymer 48 that is integrally formed with the second side 74 of the first composite region 28. In this embodiment, the first porous polymer 22 of the first composite region 28 may be continuous with the third porous polymer 48 of the third region 38.
In certain embodiments, the second region 36 and the third region 38 are regions of modified surfaces of the first composite region 28 of the sorbent polymer composite article 20″, the sorbent polymer composite article 20″ being monolithic. In these embodiments, the second region 36 and the third region 38 may be created by performing a surface treatment on the porous polymers 40, 48 that results in each region 36, 38 having a higher hydrophobicity than the hydrophobicity of the first porous polymer 22 of the first composite region 28. This surface treatment may include eroding the sorbent material 24, 24′ beyond the first side 72 of the first composite region 28 and beyond the second side 74 of the first composite region 28 such that the porous polymers 40, 48 of the second region 36 and the third region 38, respectively, does not contain the sorbent material 24, 24′. Rather than applying and then eroding the sorbent material 24, 24′ from the second region 36 and the third region 38, the surface treatment may involve masking the second region 36 and the third region 38 such that the sorbent material 24, 24′ is deposited only within the first composite region 28. The surface treatment may also involve applying a hydrophobic coating to the second region 36 and the third region 38. More information regarding these and other surface treatments is provided below.
In certain embodiments, the steps of adsorbing the CO2 molecules 16 to the sorbent polymer composite article 20 at block 406 and subsequently desorbing the CO2 16 from the sorbent polymer composite article 20 at block 408 may be repeated. Thus, the sorbent polymer composite article 20 may cycle between adsorbing and desorbing stages efficiently and with increased durability.
A sorbent polymer composite article was produced incorporating a sorbent filled tape. The sample was produced by obtaining an amorphous silica powder (Syloid C 803, available from Grace Industries, Columbia, MD.) and combining with a PTFE resin. The proportions of the blend were 60% by weight of silica and 40% by weight of PTFE. The components were blended using the process described in U.S. Pat. No. 4,985,296 to Mortimer, Jr. The process included mixing the blend of 60% by weight silica and 40% by weight of PTFE in an aqueous dispersion. Next, the process included coagulating the filler and the PTFE. The process then included lubricating the filled PTFE with an extrusion lubricant (Isopar K) and paste extruding to form a tape. The process then included expanding the tape by stretching it and forming the porous PTFE tape with the filler distributed within it, and lastly compressing it to the desired thickness. The resultant filled tape measured approximately 0.762 mm thick and 150 mm wide. This tape was cut into samples approximately 53 mm×85 mm.
A sorbent polymer composite article was produced incorporating a fiberglass screen between membranes of ePTFE. This sample was produced by first spraying two coats of polyurethane adhesive (Gorilla brand Spray Adhesive, Gorilla Glue Company, Cincinnati, OH), onto a fiberglass mesh/screen (Saint-Gobain, ADFORS, Fiberglass Vent Screen). The adhesive was allowed to dry until it was no longer tacky. An expanded ePTFE was obtained that was produced in accordance with the teachings of U.S. Pat. No. 5,814,405 to Branca et al. The ePTFE membrane was adhered to one side of the adhesive-coated screen using local heat from a soldering iron to reflow the polyurethane and cause adhesion. The same silica powder as mentioned in Example 1 was then applied to the construct and the screen apertures were filled with the silica. A straight-edge (ruler) was used to level the powder along the screen surface. Another layer of the same ePTFE membrane was used to cover the screen and powder. This construct was set into a t-shirt press set to 150 degrees C. The press was closed and applied pressure and heat to the construct for 30 seconds. The sample was removed, cooled and trimmed with scissors. The final samples measure approximately 53 mm×85 mm.
A sorbent polymer composite article was produced incorporating a sorbent filled tape. The sample was produced by obtaining an amorphous silica powder (Syloid C 803, available from Grace Industries, Columbia, MD.) and combining with a PTFE resin. The proportions of the blend were 60% by weight of silica and 40% by weight of PTFE. The mixture was then processed into a tape as described in Example 1. The resultant tape measured approximately 0.762 mm thick and 150 mm wide.
An expanded ePTFE membrane was obtained which was produced in accordance with the teachings of U.S. Pat. No. 5,814,405 to Branca et al. The ePTFE membrane was placed on both surfaces of the sample. The sample was then placed in a Carver hydraulic press and compressed between shims of aluminum. The pressure compressed the sample to approximately ⅓ its original thickness. The samples were removed and trimmed to approximately 53 mm×85 mm.
The sorbent polymer composite articles of Example 1, 2, and 3 were then analyzed for several characteristics. One tested characteristic was the hydrophobicity of the sorbent polymer composite article. The hydrophobicity tests revealed that the hydrophobicity of the sorbent polymer composite was not altered by the coating. While PEI is hydrophilic, the studies found that the hydrophobicity of the ePTFE layers was maintained in the sorbent polymer composite article after coating treatment. Results also showed that the critical size of the H2O droplets determined if they would run off of the sorbent polymer composite article or remain on the surface. However, shaking the sorbent polymer composite articles removed the H2O droplets that remained on the sorbent polymer composite article. This is a benefit of creating a conformable sorbent polymer composite article.
Further, the sorbent polymer composite articles of Example 1, 2, and 3 were subjected high temperatures to replicate temperature swing adsorption. The samples were able to endure 5 cycles of the temperature swing adsorption while maintaining proper function.
A sorbent polymer composite article was produced incorporating a filled tape containing Dowex particles. Dowex Marathon A in chloride form was obtained from Lenntech USA, South Miami, FL. The resin was then cryo-milled to an approximately 50 micron mean size. The Dowex resin powder was then mixed with PTFE resin at a ratio of 60% by weight Dowex and 40% by weight PTFE. The mixture was then processed into a tape as described in Example 1. The resultant tape measured approximately 0.762 mm thick and 150 mm wide. This tape was cut into samples approximately 53 mm×85 mm and labeled for testing.
Process 1 (Dry)
A sorbent polymer composite article was produced incorporating a fiberglass screen between membranes of ePTFE. This sample was produced by first spraying two coats of polyurethane adhesive (Gorilla brand Spray Adhesive, Gorilla Glue Company, Cincinnati, OH), onto a fiberglass mesh/screen (Saint-Gobain, ADFORS, Fiberglass Vent Screen). The adhesive was allowed to dry until it was no longer tacky. An expanded ePTFE was obtained that was produced in accordance with the teachings of U.S. Pat. No. 5,814,405 to Branca et al. The ePTFE membrane was adhered to one side of the adhesive-coated screen using local heat from a soldering iron to reflow the polyurethane and cause adhesion. The same Dowex resin mentioned in Example 4 was then applied to the construct and the screen apertures were filled with the resin. A straight-edge (ruler) was used to level the powder along the screen surface. Another layer of the same ePTFE membrane was used to cover the screen and resin. This construct was set into a t-shirt press set to 125 degrees C. The press was closed and applied pressure and heat to the construct for 30 seconds. The sample was removed, cooled and trimmed with scissors to approximately 53 mm×85 mm.
Process 2 (Wet)
A sorbent polymer composite article was produced incorporating a fiberglass screen between membranes of ePTFE. This sample was produced by first spraying two coats of polyurethane adhesive (Gorilla brand Spray Adhesive, Gorilla Glue Company, Cincinnati, OH), onto a fiberglass mesh/screen (Saint-Gobain, ADFORS, Fiberglass Vent Screen). The adhesive was allowed to dry until it was no longer tacky. An expanded ePTFE membrane was obtained which was produced in accordance with the teachings of U.S. Pat. No. 5,814,405 to Branca et al. The ePTFE membrane was adhered to one side of the adhesive-coated screen using local heat from a soldering iron to reflow the polyurethane and cause adhesion. The same Dowex resin as mentioned in Example 5a was then mixed with 70% IPA until it obtained a consistency of a thin slurry. It was then applied to the construct and the screen apertures were filled with the resin slurry. A straight-edge (ruler) was used to level the slurry along the screen surface. Another layer of the same ePTFE membrane was used to cover the screen and resin. This construct was allowed to dry for 30 minutes and then placed into a t-shirt press set to 125 degrees C. The press was closed and applied pressure and heat to the construct for 30 seconds. The sample was removed, cooled and trimmed with scissors to approximately 53 mm×85 mm.
Those of skill in the art will recognize that other porous materials may be readily substituted in the foregoing example. It will be appreciated that non-woven materials such as nanospun, meltblown, spunbond and porous cast films could be substituted for the fiberglass mesh/screen of Examples 5a and 5b.
A sorbent polymer composite article was produced incorporating a layer of SnowPure laminated with ePTFE sheets on either side. A polypropylene-base membrane containing a Dowex Marathon A resin, available from SnowPure, LLC, San Clemente, Calif. was obtained. An expanded ePTFE membrane was obtained which was produced in accordance with the teachings of U.S. Pat. No. 5,814,405 to Branca et al. The ePTFE membrane was placed on each surface of the SnowPure material and tacked in place using the localized heat of a soldering iron tip. The heat of the soldering iron partially melted the polypropylene substrate in the SnowPure membrane and caused adhesion to the ePTFE. The sample was then cut/trimmed to approximately 53 mm×85 mm.
The samples from Examples 5a, 5b, and 6 were analyzed for their performance when undergoing moisture swing adsorption in comparison with the competing article (SnowPure only) as the baseline.
The results with respect to the CO2 adsorption and the kinetics of the adsorption both suggest the benefits of using the Dowex and ePTFE sorbent polymer composite article composites formed according to Examples 5a and 5b.
Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present disclosure. For example, while the embodiments described above refer to particular features, the scope of this disclosure also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present disclosure is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.
This application is a national phase application of PCT Application No. PCT/US2022/019116, internationally filed on Mar. 7, 2022, which claims priority to U.S. Provisional Application No. 63/157,426, filed on Mar. 5, 2021, and U.S. Provisional Application No. 63/302,847, filed on Jan. 25, 2022, the disclosure of each application being hereby incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2022/019116 | 3/7/2022 | WO |
Number | Date | Country | |
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63302847 | Jan 2022 | US | |
63157426 | Mar 2021 | US |