Patent Application
20240326011
Solid, porous materials such as zeolites, porous carbons, metal organic frameworks (MOFs), and covalent organic frameworks (COFs) are promising materials for applications ranging from biomedicine to energy storage, catalysis, gas storage, and separations. COFs are of particular interest gas storage given their low densities, high surface areas, and excellent tunability. However, the wide-scale applicability of COF powders for storage applications has generally been limited by their poor packing densities, low thermal conductivities, and relatively weak interactions with gases like H2 that necessitate cryogenic storage temperatures to achieve appreciable capacities. Thus, there remains a need for improved framework compositions capable of reversibly storing H2 and other gases at conditions reasonable for large scale use.
An aspect of the present disclosure is a composition that includes a covalent organic framework (COF) having an internal volume and an outer surface and a first polymer covalently bonded to at least a portion of the outer surface, where the covalently bonded first polymer has a glass transition temperature (Tg) between about −130° C. and about +180° C., the composition is capable of reversibly adsorbing and desorbing H2 when the composition is at a temperature greater than or equal to the Tg, and the composition is capable of storing H2 within the internal volume when the composition is at a temperature less than Tg. In some embodiments of the present disclosure, the COF may include a chelated first row transition metal (Mt) that includes at least one of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and/or Zn.
In some embodiments of the present disclosure, the COF may include a first structure that includes at least one of
and where represents a covalent bond.
In some embodiments of the present disclosure, the COF may include a second structure that includes at least one of
In some embodiments of the present disclosure, the first polymer may include at least one of an alkyl chain, a siloxane, and/or an ethylene oxide group. In some embodiments of the present disclosure, the first polymer may include at least one of a poly(alkyl acrylate), a poly(alkyl methacrylate), a polydimethylsiloxane acrylate, a polydimethylsiloxane methacrylate, a polyethylene glycol acrylate, and/or a polyethylene glycol methacrylate.
In some embodiments of the present disclosure, the composition includes a third structure
where w is between 0 and 20, inclusively, m is between 1 and 500, inclusively, X includes a halogen, R1 includes a methyl group or H, and R2 includes at least one of an alkyl chain, a siloxane, and/or an ethylene oxide group. In some embodiments of the present disclosure, R2 may include at least one of
and n is between 1 and 500, inclusively. In some embodiments of the present disclosure, the composition may further include a fourth structure
where w is between 0 and 20, inclusively, X includes at least one of Cl, Br, or I, and R1 includes a methyl group or H.
In some embodiments of the present disclosure, the COF may have an average pore size between about 1 Å and about 40 Å. In some embodiments of the present disclosure, the COF may have an average surface area above about 400 m2/g. In some embodiments of the present disclosure, the COF may form a particle having an average diameter between about 10 nm and about 10 μm. In some embodiments of the present disclosure, the COF may have an H2 loading above about 0.01 g H2/g.
In some embodiments of the present disclosure, the composition may further include a second polymer that include at least one of a polydimethylsiloxane, a polyethyleneimine, a polyethylene glycol, a poly(alkyl acrylate), and/or a poly(alkyl methacrylate), where the COF is immersed in the second polymer, and the second polymer is characterized by a second Tg between about −130° C. and about +180° C.
An aspect of the present disclosure is a composition that includes a metal organic framework (MOF) having an internal volume and an outer surface and a first polymer covalently bonded to at least a portion of the outer surface, where the covalently bonded first polymer has a glass transition temperature (Tg) between about-130° C. and about +180° C., the composition is capable of reversibly adsorbing and desorbing H2 when the composition is at a temperature greater than or equal to the Tg, and the composition is capable of storing H2 within the internal volume when the composition is at a temperature less than Tg.
In some embodiments of the present disclosure, the MOF may include a first structure that includes at least one of
represents a covalent bond, and
represents a coordinate bond to Mt.
In some embodiments of the present disclosure, the MOF may include a second structure that includes at least one of
and represents a coordinate bond to Mt.
In some embodiments of the present disclosure, the composition includes a third structure
where w is between 0 and 20, inclusively, m is between 1 and 500, inclusively, X includes a halogen, R1 includes a methyl group or H, and R2 includes at least one of an alkyl chain, a siloxane, and/or an ethylene oxide group.
In some embodiments of the present disclosure, the composition may further include a fourth structure
where w is between 0 and 20, inclusively, X includes at least one of Cl, Br, and/or I, and R1 comprises a methyl group or H.
An aspect of the present disclosure is a method for making a composition, where the method includes synthesizing a framework material, synthesizing a first polymer, synthesizing a bifunctional linking polymer, attaching the bifunctional linking polymer to a surface of the framework material, and attaching a first polymer to the bifunctional linking polymer.
Some embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than limiting.
The embodiments described herein should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein. References in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, “some embodiments”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
Among other things, the present disclosure relates to a method for controlling and tuning the temperature at which a gas is released or captured from a framework-based material, e.g., a metal-organic framework (MOF) and/or a covalent organic framework (COF). In short, a polymer membrane is grown around a framework-based particle and the glass transition (Tg) temperature of that polymer membrane is used to influence the mass-transport of gases into and/or out of the framework. When the polymer chosen has the correct physiochemical properties and the temperature is above the polymer Tg, gas molecules readily diffuse through the rubbery polymer membrane. Below the polymer Tg, the polymer membrane becomes glassy and can be used to either trap gas inside the pores or exclude gas from entering. The polymer coating may also change the shape of the sorption isotherms, such that the quantity of “usable” gas may be increased multi-fold.
More specifically, as described herein, a surface-initiated atom transfer radical polymerization (SI-ATRP) procedure may be applied to covalently link a cross-linked membrane around the surface of 3D imine-linked COF colloids. In some embodiments of the present disclosure, a poly(dimethylsiloxane)-methacrylate (PDMS-MA) polymer was used to coat COF colloids that was sufficiently robust to survive temperatures up to and exceeding 200° C. This prevented the aggregation of COF colloids and allowed the activation of the first known Cu(I)-COF-based porous liquids (PLs) for ambient temperature H2 storage and transport. As used herein, a porous liquid refers to a COF that is immersed in a liquid, for example a liquid polymer. CO and H2 sorption in these materials were studied using diffuse reflectance infrared Fourier transform (DRIFTS) spectroscopy and temperature programmed desorption (TPD). Further, it is shown herein how the glass transition temperature of the polymer coating and a COF/polymer composition immersed in a second polymer can be employed to influence the kinetics of H2 diffusion through these nano encapsulated materials. Although the specific examples described herein focus on COFs, other frameworks such as metal organic frameworks (MOFs) may be treated in a similar fashion to generate MOF-based compositions capable of the reversible storage and release of H2.
Thus, the present disclosure relates generally to compositions based on organic framework materials (OFMs), of which COFs and MOFs are subsets, where the compositions are capable of reversibly adsorbing and desorbing H2. As shown herein, the mass transport for reversible adsorbing and desorbing can be influenced by a polymer that is covalently bonded to an outer surface of the OFM, by transitioning the polymer from a first state to a second state. When in the first state, the polymer is in a substantially glassy state, whereas when in the second state, the polymer is in a substantially liquid and/or rubbery state. The composition may be reversibly switched between the first state and the second state by changing the temperature of the composition, specifically by changing the composition's temperature from being above its glass transition temperature (Tg) to being below its Tg. When the composition is at a temperature greater than or equal to the Tg, the composition is in the liquid state and/or rubbery state and is capable of reversibly adsorbing and/or desorbing H2. Once H2 has been absorbed, the temperature may be dropped below the Tg, switching the polymer from the liquid state to the glassy state, essentially trapping the adsorbed H2 within the internal volume and/or surface area of the OFM. Subsequently, when there is a demand for H2, the H2 may be released by simply raising the temperature of the composition above the Tg.
In some embodiments of the present disclosure, the Tg of the polymer covalently bonded to an outer surface of an OFM may be between −130° C. and +180° C., or between −80° C. and +50° C., where the Tg of the polymer is determined with the polymer bonded to the OFM (e.g., not as a neat, pure, unbonded polymer). As described herein, examples of OFMs that may be bonded to a polymer, with the resultant composition capable of reversibly adsorbing and desorbing H2 include covalent organic frameworks (COFs) and/or metal organic frameworks (MOFs).
where represents a covalent bond to other structures of the COF, as described in more detail below. In some embodiments of the present disclosure, a first-row transition metal (Mt) may be Cu. In some embodiments of the present disclosure, at least a portion of the Cu of a First COF Structure may be in the Cu(I) valence state.
In some embodiments of the present disclosure, a COF may further include a Second COF Structure, where the Second COF Structure is either directly and/or indirectly bonded to the First COF Structure. Examples of Second COF Structures, which when combined with a First COF Structure, result in compositions capable of reversibly adsorbing and desorbing H2, include
where represents a covalent bond to other structures of the COF (e.g., the First COF Structure).
In some embodiments of the present disclosure, the polymer bonded to an outer surface of a COF may include at least one of an acrylate, methacrylate, and/or styrene. In some embodiments of the present disclosure, at least one of an acrylate and/or a methacrylate may include an alkyl chain between 1 and 20, or between 4 and 8 carbon atoms. Thus, in some embodiments of the present disclosure, a polymer bonded to an outer surface of a COF may include at least one of a poly(alkyl acrylate) and/or a poly(alkyl methacrylate). In some embodiments of the present disclosure, at least one of an acrylate and/or a methacrylate bonded to an outer surface of a COF may further include at least one of a siloxane and/or an ethylene oxide. Thus, in some embodiments of the present disclosure, a polymer bonded to an outer surface of a COF may include at least one of polydimethylsiloxane acrylate, polydimethylsiloxane methacrylate, polyethylene glycol acrylate and/or polyethylene glycol methacrylate.
In some embodiments of the present disclosure, a polymer bonded to the surface of a COF may form a structure, referred to herein as a Third COF Structure, which may include the following,
where w may be between 0 and 20, inclusively, or between 1 and 8, inclusively, and m may be between 1 and 500, inclusively, or between 5 and 50, inclusively. Bond 1 represents a bond between a Third COF Structure and a nitrogen atom of a Second COF Structure and bonds 2 and 3 each represent a bond between the Third COF Structure and another Third COF Structure or a Fourth COF Structure, which is defined below. Referring again to the Third COF Structure, in some embodiments of the present disclosure, X may include a halogen, for example at least one of Br, Cl, and/or I. In some embodiments of the present disclosure, R1 may include at least one of a methyl group and/or a hydrogen atom. In some embodiments of the present disclosure, R2 may include at least one of an alkyl chain, a siloxane, and/or an ethylene oxide. In some embodiments of the present disclosure, R2 may be an alkyl chain having between 1 and 20 carbon atoms, inclusively, or between 4 and 8 carbon atoms, inclusively. In some embodiments of the present disclosure, R2 may include at least one of
where n is between 1 and 500, inclusively, or between 5 and 50, inclusively.
In some embodiments of the present disclosure, a composition that includes a COF may include another structure, referred to herein as a the Fourth COF Structure, where the Fourth COF Structure may be defined by
where w, X, and R1 are as defined above for the Third COF Structure. Bond 1 represents a bond between a Fourth COF Structure and a nitrogen atom of a Second COF Structure and bonds 2 and 3 each represent a bond between the Fourth COF Structure and another Fourth COF Structure or a Third COF Structure, which is defined above.
In some embodiments of the present disclosure, a composition for adsorbing/desorbing H2 as described above may be further characterized by a number of physical properties and/or performance metrics. For example, in some embodiments of the present disclosure, a COF-containing composition may have an average pore size between about 1 Å and about 40 Å, inclusively, or between about 4 Å and about 25 Å, inclusively. In some embodiments of the present disclosure, a COF-containing composition may have an average surface area greater than or equal to about 400 m2/g, or between about 50 m2/g and about 3000 m2/g, inclusively. In some embodiments of the present disclosure, a COF-containing composition may form a substantially spherically shaped particle having an average diameter between about 10 nm and about 10 μm, or between about 50 and about 400 nm. In some embodiments of the present disclosure, a COF-containing composition, with the polymer covalently bonded to a surface of the COF, may have an H2 loading greater than or equal to about 0.01 g H2/g, or between about 0.001 g H2/g and about 0.04 g H2/g.
In some embodiments of the present disclosure, a composition as described above may further include a second polymer, such that a COF with a first polymer bonded to at least a portion of its outer surface is immersed in the second polymer. Examples of polymers that may be utilized as a “second polymer” include at least one of polydimethylsiloxane, polyethyleneimine, polyethylene glycol, poly(alkyl acrylate), and/or poly(alkyl methacrylate). A “second polymer”, like the “first polymer” described above that is covalently bonded to a surface of the COF may also be characterized by a Tg, as measured when the second polymer is neat (i.e., pure and not bonded to a substrate). In some embodiments of the present disclosure, the Tg of a second polymer may be between about −130° C. and about +180° C., or between about −80° C. and about +50° C. In some embodiments of the present disclosure, a second polymer may be a semi-crystalline polymer with a melting point between about −40° C. and about +180° C., or between about 0° C. and about +50° C. The presence of a second polymer provides additional tunability over the desorption temperature of H2. The second polymer may more efficiently trap H2 in the COF composition than a composition lacking the second polymer. Adjusting the ratio of the second polymer and the COF in the composition provides a means for optimizing the composition to store H2 for a given duration of time, which may be between 1 and 7 days, between 7 days and 365 days, or between 1 and 3 years. In some embodiments of the present disclosure, the Tg of a first polymer may be approximately equal to the Tg of a second polymer. In some embodiments of the present disclosure, the Tg of a first polymer may be different than the Tg of a second polymer.
In some embodiments of the present disclosure, an OFM may be a metal organic framework (MOF) that includes a first row transition metal (Mt), with examples including at least one of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and/or Zn. In some embodiments of the present disclosure, the first-row transition metal (Mt) may be chelated with an organic site contained within the MOF.
where represents a covalent bond to other structures of the MOF, as described in more detail below, and
represents coordinate or ionic bonds of at least one of a Mt—O bond, a Mt—N bond, and/or a Mt-halogen bond. In some embodiments of the present disclosure, a first-row transition metal (Mt) may include at least one of Ni and/or Co. In some embodiments of the present disclosure, a first-row transition metal (Mt) may include at least one of Ni(II) and/or Co(II). Bonds 1, 3, 4, and 5 represent coordinate bonds between the First MOF Structure and a Second MOF Structure, as described below. Bond 2 represents a coordinate bond to a Third MOF Structure or a Fourth MOF Structure, as described below. In the first example of the First MOF Structure, all Nitrogen atoms belong to the Second MOF Structure but are included here for clarity. In the third and fourth examples of the First MOF Structure, the First MOF Structure is the repeat unit; there is no Second MOF Structure.
In some embodiments of the present disclosure, a MOF may further include a Second MOF Structure, where the Second MOF Structure is either directly and/or indirectly bonded to the First MOF Structure. Examples of second structures, which when combined with a First MOF Structure result in compositions capable of reversibly adsorbing and desorbing H2, include
where bond 1 represents a coordinate Mt—N bond to a First MOF Structure.
In some embodiments of the present disclosure, the polymer bonded to an outer surface of a MOF may include at least one of an acrylate, methacrylate, siloxane, an ethylene oxide, or styrene. In some embodiments of the present disclosure, at least one of an acrylate and/or a methacrylate may include an alkyl chain between 1 and 20, or between 4 and 8 carbon atoms. Thus, in some embodiments of the present disclosure, a polymer bonded to an outer surface of a MOF may include at least one of a poly(alkyl acrylate) and/or a poly(alkyl methacrylate). In some embodiments of the present disclosure, at least one of an acrylate and/or a methacrylate bonded to an outer surface of a MOF may further include at least one of a siloxane and/or an ethylene oxide. Thus, in some embodiments of the present disclosure, a polymer bonded to an outer surface of a MOF may include at least one of polydimethylsiloxane acrylate, polydimethylsiloxane methacrylate, polyethylene glycol acrylate and/or polyethylene glycol methacrylate.
In some embodiments of the present disclosure, a polymer bonded to the surface of a MOF may form a structure, referred to herein as a Third MOF Structure, which may include the following,
where w may be between 0 and 20, inclusively, or between 1 and 8, inclusively, and m may be between 1 and 500, inclusively, or between 5 and 50, inclusively. Bond 5 represents a coordinate bond between the Third MOF Structure and a nitrogen atom of the Second MOF Structure and bonds 6 and 7 each represent a bond between the Third MOF Structure and another Third MOF Structure or a Fourth MOF Structure, which is defined below. Referring again to the Third MOF Structure, in some embodiments of the present disclosure, X may include a halogen, for example at least one of Br, Cl, and/or I. In some embodiments of the present disclosure, R1 may include at least one of a methyl group and/or a hydrogen atom. In some embodiments of the present disclosure, R2 may include at least one of an alkyl chain, a siloxane, and/or an ethylene oxide. In some embodiments of the present disclosure, an alkyl chain in R2 may have between 1 and 20 carbon atoms, inclusively, or between 4 and 8 carbon atoms, inclusively. In some embodiments of the present disclosure, R2 may include at least one of
where n is between 1 and 500, inclusively, or between 5 and 50, inclusively.
In some embodiments of the present disclosure, a composition that includes a MOF may include another structure, referred to herein as a the Fourth MOF Structure, where the Fourth MOF Structure may be defined by
where w, X, and R1 are as defined above for the Third MOF Structure. Bond 5 represents a coordinate bond between the Fourth MOF Structure and a nitrogen atom of the Second MOF Structure and bonds 6 and 7 each represent a bond between the Fourth MOF Structure and another Fourth MOF Structure or a Third MOF Structure, as described above.
In some embodiments of the present disclosure, a composition for adsorbing/desorbing H2 may be further characterized by a number of physical properties and/or performance metrics. For example, in some embodiments of the present disclosure, a MOF-containing composition may have an average pore size between about 1 Å and about 40 Å, inclusively, or between about 4 Å and about 25 Å, inclusively. In some embodiments of the present disclosure, a MOF-containing composition may have an average surface area greater than or equal to about 400 m2/g, or between about 50 m2/g and about 3000 m2/g, inclusively. In some embodiments of the present disclosure, a MOF-containing composition may form a particle having an average diameter between about 10 nm and about 10 μm, or between about 50 and about 400 nm. In some embodiments of the present disclosure, a MOF-containing composition, with the polymer covalently bonded to a surface of the MOF, may have an H2 loading greater than or equal to about 0.01 g H2/g, or between about 0.001 g H2/g and about 0.08 g H2/g.
In some embodiments of the present disclosure, a composition as described above may further include a second polymer, such that the MOF composition with a first polymer bonded to at least a portion of its outer surface is immersed in the second polymer. Examples of polymers that may be utilized as a “second polymer” include at least one of polydimethylsiloxane, polyethyleneimine, polyethylene glycol, poly(alkyl acrylate), and/or poly(alkyl methacrylate). A “second polymer”, like the “first polymer” described above that is covalently bonded to a surface of the MOF may also be characterized by a Tg, as measured when the second polymer is neat (i.e., pure and not bonded to a substrate). In some embodiments of the present disclosure, the Tg of a second polymer may be between about −130° C. and about +180° C., or between about −80° C. and about +50° C. In some embodiments of the present disclosure, the Tg of a first polymer may be approximately equal to the Tg of a second polymer. In some embodiments of the present disclosure, the Tg of a first polymer may be different than the Tg of a second polymer.
The present disclosure relates to the OFM compositions described above, as well as methods for making OFM compositions. In general, a method for making an OFM composition capable of reversibly storing H2 starts with the selection and/or synthesis of a suitable OFM (e.g., at least one of a COF and/or a MOF), which itself, even without the addition of a polymer to its surface, may be capable of reversibly adsorbing H2 and desorbing H2. Examples of OFMs include COFs and MOFs, of which each family is described above in detail. Next, a method of making an OFM-containing composition may include a step for bonding a polymer to an outer surface of the OFM. This polymer is referred to above as a “first polymer”. This addition of a first polymer to a surface of an OFM may involve multiple steps, depending upon the functional groups present on the surface of the OFM, as well as the structure and functional groups provided by the first polymer. A first polymer, once bonded to the OFM, should be capable of switching between a first glassy state and a second “softer” state upon transition through a temperature and/or temperature range. In some embodiments of the present disclosure, a method may continue by immersing the OFM composite material, with a first polymer bonded to at least a portion of its surface, in a second polymer. A second polymer may be characterized by being capable of reversibly switching between a first glassy state and a second “softer” state upon transition through a temperature and/or temperature range. This combination of an OFM, a first polymer, and a second polymer, as shown herein, can result in a final composition having a high adsorption capacity for H2, which can be released when needed. Among other things, a first polymer may act as a barrier to a second polymer, preventing the second polymer from infiltrating into the inner volume and/or surface area of OFM, leaving it available for H2 adsorption, whereas the second polymer may act as the primary barrier to H2 mass transfer in and out of the OFM, depending on its state, glassy or more liquid-like. These concepts are described in more detail in the following sections.
An exemplary method for synthesizing polymer/OFM compositions utilized a general surface-initiated atom transfer radical polymerization (SI-ATRP) procedure that chemically bonded a poly(dimethylsiloxane)-methacrylate (PDMS-MA) polymer (a “first polymer”) to the surface of 3D imine-linked COF colloids. A PDMS-MA polymer was chosen because, among other things, it can withstand temperatures up to about 200° C., thereby preventing aggregation of COF colloids and allowing the activation of copper to Cu(I), thereby enabling the synthesis of a Cu(I)-COF composition capable of ambient temperature H2 storage and transport. As shown herein, the CO and H2 sorption characteristics of these compositions were studied using diffuse reflectance infrared Fourier transform (DRIFTS) spectroscopy and temperature programmed desorption (TPD). These studies demonstrate how the glass transition temperature of the first polymer bonded to the COF, as well as a second polymer into which the COF/polymer composition can be immersed, affected the kinetics of H2 diffusion through these nano-encapsulated materials.
With the goal of synthesizing stable COF colloids containing Cu(I) contained in a First COF Structure of the COF such that the COF is capable of ambient temperature gas storage (e.g., H2) and transport in porous liquids (i.e., COFs immersed in a liquid), COF-301 was selected. Atomic Cu(I) can be positioned in phenol-imine docking sites (of a First COF Structure) of this particular 3D imine-based COF with a post-synthetic modification and activation procedure, after which stable complexes with H2, C2H4, and CO could be formed and detected near ambient temperature in bulk COF powder as described in J. Phys. Chem. C 2022, 126 (35), 14801-14812, which is incorporated herein by reference in its entirety. In addition, the particle size of the resultant COFs could be tuned using dilute nitrile-based solvents and optimized catalysts as described in J. Mat. Chem. A 2020, 8, 23455 23462, hereinafter referred to as the Mow reference, which is incorporated herein by reference in its entirety. This second method was used to synthesize the first reported colloids of COF-301.
Under the conditions outlined in the experimental section below, COF-301 formed spherical particles with a median diameter of 260 nm but having a diameter between 160 nm and 460 nm, as determined by TEM imaging and dynamic light scattering (see
After their synthesis, the colloids were purified by removing unreacted monomer and acid catalyst through centrifugation, decanting the supernatant, and immediate resuspension in fresh acetonitrile. As long as the COF-301 colloids remained in acetonitrile, they could stay suspended indefinitely (>1 year). However, if dried or placed in a different (co)solvent suspension, irreversible aggregation occurred rapidly, presumably due to the reaction of interparticle surface amines and aldehydes. The standard procedure for post synthetic loading of COF-301 with metal salts (e.g., stirring the COF in a Cu(II) formate solution) also induced near instant and irreversible aggregation of the colloids, presenting a challenge on how to add Cu binding sites in these materials while keeping them colloidal.
A surface functionalization technique for stabilizing COF colloids (see the Mow reference) was used that involved tethering a bulky imidazolium salt to unreacted amines on the colloid surface. The strategy proved effective at stabilizing COF colloids in a variety of organic solvents and ionic liquids and was successfully applied here to the COF-301 colloids, which were successfully loaded with Cu(II) formate, after which the suspension remained colloidal. The colloids turned from yellow-orange to red-brown upon loading with Cu. The surface functionalized colloids could now be thoroughly dried under vacuum and resuspended in common organic solvents. However, upon “activating” the COF and converting the Cu(II) formate to open Cu(I) sites in these materials by heating for several hours at 180° C., the colloids once again aggregated irreversibly. Although stable at 100° C., it appears the bonded imidazolium salt is not sufficiently robust at temperatures required to generate open Cu(I) sites with this technique. The imidazolium salt with an aldehyde functionality in it, was bonded to the surface of the COF in much the same way the polymer in the Third COF Structure was bonded to the COF. This resulted in the COF being miscible with ionic liquids where it otherwise wasn't. However, because it had only one anchoring point, whereas the polymer has many anchoring points, the latter appears stable to higher temperatures.
Due to these temperature instabilities, efforts then focused on implementing a more robust surface functionalization strategy for modifying the surface of a COF to enable the successful synthesis of Cu(I) loaded COF colloids suitable for porous liquid applications, for example reversible gas adsorption.
Using radical addition-fragmentation chain-transfer (RAFT) polymerization, a copolymer of 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM) and 4-vinyl benzaldehyde (VBA) was synthesized. The aldehyde groups in this random copolymer P(BIEM-r-VBA) (see
Controlling polymer membrane thickness: Essentially any vinyl monomer compatible with ATRP could be employed for the polymeric membrane, e.g., the “first polymer” as described above, for a COF-containing composition. PDMS-MA was chosen as the first polymer and PDMS as the second polymer into which the polymer/COF composition may be immersed, for a variety of reasons. PDMS is inexpensive and relatively non-toxic. The low vapor pressure and high thermal stability of this polymer ensures that the PDMS-MA-coated COFs can be activated at high temperatures without incurring decomposition of the coating. The fluidity of PDMS down to −40° C. also makes the solvent promising for low viscosity porous liquids applications (see
Synthesis of consistent, uniform PDMS-MA polymer coatings on the surfaces of colloids requires evaluation of the polymerization conditions. While linear PDMS cannot be grown via living polymerization techniques, so-called ‘bottlebrush’ PDMS-MA polymers can be grown via ATRP and are a good analogue with similar properties to PDMS. However, due to the nature of these materials (e.g., the densely grafted side chains), bottlebrush polymers can be challenging to synthesize in a controlled manner. As described herein, conditions were discovered that allowed the controlled synthesis of bottlebrush PDMS-MA that are simultaneously compatible with keeping COF-301 colloids well-dispersed.
An interesting feature of these materials is their tendency to depolymerize under certain conditions, which is caused by significant bond strain due to the bulkiness of these materials. Significant work has been implemented to understand the equilibrium between polymerization and depolymerization in the radical polymerization of these brush materials. Solvent selection, reaction temperature, and initial monomer concentration can all influence this equilibrium, yields, and molecular weights. High monomer concentrations drive polymerization, while good solvation of the polymer along with subsequent brush swelling and bond strain drive depolymerization. At some point during a reaction, the monomer concentration drops low enough to where polymerization and depolymerization are effectively in equilibrium, and chain growth halts.
A model ATRP reaction of PDMS-MA was conducted in acetonitrile, as this solvent may be optimal for keeping colloids dispersed when later conducting surface-initiated ATRP. However, while the polymerization proceeded, the poor solubility/immiscibility of the PDMS-MA brushes in acetonitrile led to poorly controlled chain growth with large batch to batch variability. In pure dioxane, the brushes were well solvated, but both the ATRP catalyst and the colloids were not, leading again to uncontrolled polymer growth. A 90:10 mixture of dioxane:acetonitrile was discovered to be the best compromise for catalyst solubility, brush solubility, and colloid dispersion. By employing CuCl/Me6TREN as the catalyst at room temperature, systematic chain growth between 20 and 35 Kg/mol was achieved using monomer:initiator ratios of 200:1 (see
Cu-loaded COF@xPDMS: With the propensity of COF colloids to flocculate, chemically bonding the colloids with a protective polymeric coating is a promising strategy to facilitate post-synthetic modifications and material activation. Here, the optimized bottlebrush PDMS-MA polymerization was applied to coat COF colloids with robust PDMS-MA coatings that enable Cu-loading and activation without irreversible aggregation. Although optimized for PDMS-MA polymerization, this general strategy can in principle be applied to tether any methacrylate-terminated polymer to the surface of imine-linked COFs.
A PDMS-MA coating was grown from the surface of COF-301 colloids using the best procedure described herein. Briefly, the P(BIEM-r-VBA) polymeric initiator (see
The uniformity of the coating can be observed with scanning transmission electron microscopy (STEM) images of individual particles. Furthermore, energy-dispersive x-ray spectroscopy (EDS) mapping was employed to clearly distinguish the outer coating from the inner COF core, as Si atoms were uniquely present in the coating and N atoms in the COF (see
A Brunauer-Emmet-Teller (BET) surface area analysis using an N2 isotherm was not useful once the coating was applied, as the coating effectively acts as a glassy encapsulant to exclude N2 adsorption at cryogenic temperatures (vide infra). However, at 0° C., where the coating is rubbery, CO2 adsorption into COF-301@‘thick’ PDMS-MA was estimated to be 80% of that of the uncoated material. When mass normalized to account for the sample coating, the adsorption of the active COF material remains essentially identical before and after the coating procedure (see
Compared to uncoated COF colloids that irreversibly aggregate, the COF-301@PDMS-MA particles readily resuspended in PDMS and other solvents after drying at 200° C. under ultra-high vacuum (see
The COF changed color from orange to red-brown upon addition of Cu. Features in the FT-IR spectra shifted upon Cu loading that were consistent with binding at the phenol-imine site (e.g., a shift in the imine stretch from 1610 to 1590 cm−1 was observed; see
Gas sorption in Cu(I)-based porous liquid: The availability of the Cu(I) site in Cu-COF-301@PDMS-MA was confirmed by dosing the system with carbon monoxide (CO) and studying its response using Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). A stretch associated with the CO—Cu(I) complex was observed at 2093 cm−1 in
A porous liquid (PL) was then made by suspending activated Cu(I)-COF-301@PDMS-MA in liquid PDMS (dried at 200° C.), and the Cu(I) site activity was confirmed by the appearance of the same CO—Cu(I) stretch at 2093 cm 1 in DRIFTS (see
Temperature programmed desorption (TPD). Here TPD was used to study general physisorption and associated kinetic phenomenon in these coated COF materials. For this work, H2 was primarily used, which typically requires cryogenic temperatures for appreciable gas loading in COF materials.
H2 desorbed from the crosslinked COF-301@x ‘thick’ PDMS-MA material near Tmax=−130° C., about 40° C. higher than the uncoated material (see
Quite interestingly, the addition of the crosslinking agent proved instrumental in creating a barrier for H2 diffusion. COF-301@PDMS-MA (with no added crosslinker) readily adsorbed H2 during a 10 minute dose at 77 K, similar to the uncoated material, with peak desorption occurring near −150° C. (see
The temperature of H2 desorption was further shifted in PLs made from 11 wt. % and 17 wt. % Cu(I)-COF@PDMS-MA suspended in liquid PDMS. H2 desorption was observed to peak near Tmax=−20° C. in these PL samples (see
Additional examples: In some embodiments of the present disclosure, a coating of a framework and/or some other porous sorbent materials such as carbon and silicon based, can also be utilized for gas purification and separation. In these cases, one or more gases of interest, e.g., a contaminate gas may be adsorbed inside the polymer coated sorbent material, while one or more other gases is excluded. For example, a water vapor/hydrogen gas mixture may be treated such that the hydrogen gas is preferentially adsorbed within a hydrophobic polymer coated sorbent, to the exclusion of the water. So, in some embodiments of the present disclosure, materials in a gaseous state that may be preferentially adsorbed in this manner include hydrogen, CO2, ammonia, and/or a noble gas (e.g., He, Ar, Ne, Xe). Examples of materials in a gaseous state that may be excluded from adsorption include water and volatile organics. In some embodiments of the present disclosure, a coating may be utilized to remove the requirement for the coated matrix to be stored under an inert atmosphere. In some embodiments of the present disclosure, a coating may be utilized to remove the requirement for the coated matrix to be stored under dry conditions. In some embodiments of the present disclosure, a polymer used for a coating could be of a hydrophilic or hydrophobic nature to achieve a desired separation.
General. Monomethacryloxypropyl terminated polydimethylsiloxane, 10 cSt (PDMS-MA) was purchased from Gelest. Tetrakis(4-aminophenyl) methane was purchased from Tokyo Chemical Industry and 2,5-dihydroxy terephthalaldehyde was purchased from A-Chem Block. Polydimethylsiloxane, trimethylsiloxy terminated (M.W. 6000) was purchased from Alfa Acsar. All other chemicals were purchased from Sigma Aldrich. 1H NMR (400 MHZ) spectra were recorded on a Bruker Avance III HD NanoBay NMR spectrometer. UV-Vis measurements were performed on a Varian 50 Conc UV-Visible Spectrophotometer.
Atom Transfer Radical Polymerization (ATRP) of Bottlebrush PDMS. The following procedure describes a generic PDMS brush polymerization using ATRP. A Schlenk flask was loaded with a stir bar, 2 mg (0.02 mmol) of CuCl2 g (2 mmol) of PDMS-methacrylate (PDMS-MA), 0.4 mL of dry acetonitrile, and 3.6 mL of dry 1,4-dioxane. After the heterogenous mixture was sparged with N2 for 20 minutes, 5.4 μL of N2 sparged tris[2-(dimethylamino)ethyl]amine (Me6TREN) (0.02 mmol) was injected and the mixture was sonicated for 20 minutes to ensure full dissolution of the Cu catalyst. A T0 aliquot was taken, after which 15 μL of a 10 v % stock solution of N2 sparged ethyl α-bromoisobutyrate initiator (EBriB, 0.01 mmol) in dioxane was injected. The polymerization was stirred at room temperature for 24 hours, with aliquots taken systematically to monitor polymer growth. Integration of the 1H NMR vinyl peaks over the course of the reaction indicated 70% conversion was achieved after 24 hours.
Colloidal COF Synthesis. Colloidal COF-301 was synthesized and purified. 80 mg (0.21 mmol) of tetrakis(4-aminophenyl) methane and 80 mg (0.48 mmol) of 2,5-dihydroxyterephthalaldehyde were added to a bomb flask and dissolved in 50 mL dry acetonitrile. The mixture was sparged with N2 for 10 minutes, and then 10 μL of trifluoroacetic acid was injected. After sparging the mixture another 5 minutes, the reaction was stirred at 120° C. for 72 hours. The COF colloid was purified with three cycles of centrifugation, decanting, and resuspension/stirring in acetonitrile.
Polymeric initiator synthesis. The polymeric initiator molecule was synthesized via a radical addition-fragmentation chain-transfer (RAFT) polymerization. A Schlenk flask was charged with 1.0 g (3.6 mmol) 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM), 63 mg (0.5 mmol) 4-vinyl benzaldehyde (VBA), 31 mg (0.09 mmol) 2-cyano-2-propyl dodecyltrithiocarbonate, 5 mg (0.03 mmol) azobisisobutyronitrile (AIBN), and 1 mL dimethylformamide. After three freeze-pump-thaw cycles, the reaction was heated at 60° C. for 40 hours. P(BIEM-r-VBA) was purified by thrice precipitating into 20 mL of cold methanol, collecting by centrifugation, and resuspending in 2 mL of tetrahydrofuan. Finally, it was dried on a Schlenk line vacuum overnight at 60° C. 1H NMR was used to estimate the ratio of initiating (Br) to anchoring (aldehyde) sites as 94:6.
COF-301@PDMS-MA Synthesis. P(BIEM-r-VBA) was first tethered to the COF-301 surface via a condensation reaction. 20 mg of P(BIEM-r-VBA) was added to 100 mg of colloidal COF suspended in 30 mL of acetonitrile. 10 μL of trifluoroacetic acid was injected and the reaction was stirred at 60° C. for 1 hour. The P(BIEM-r-VBA)-coated COF was purified of acid catalyst and excess unreacted polymeric initiator with three centrifugation, decanting, and resuspension cycles in acetonitrile. Surface-initiated ATRP (SI-ATRP) was then conducted to grow uniform PDMS-MA coatings around the COF colloids by adding 3 mg (0.03 mmol) CuCl, 3 g PDMS methacrylate (3 mmol), and 50 mg (0.25 mmol) ethylene glycol dimethacrylate to a Schlenk flask. 100 mg of COF-301@initiator suspended in 0.6 mL acetonitrile and 5.4 mL dioxane was added to the solution. The mixture was sparged with N2 for 30 minutes and sonicated for 10 minutes. 8 μL (0.03 mmol) of N2 spaged Me6TREN was injected, and the reaction was stirred at room temperature for up to 24 hours. The material was purified with five centrifuge, decanting, resuspension cycles in dichloromethane. The material was stored in dichloromethane but dried on a Schlenk line vacuum for 48 hours at 90° C. and further ‘activated’ for 2 hours at 200° C. under ultra-high vacuum prior to analysis with temperature programmed desorption. The success of the coating procedure was verified through TEM imaging and energy-dispersive spectroscopy (EDS) mapping of Si atoms unique to the polymeric coating (vide infra).
Cu loading into COF-301@PDMS-MA. 100 mg of purified COF-301@PDMS-MA was stirred with 140 mg Cu(II) formate in 50 mL of a 1:1 dichloromethane:methanol solution for 24 hours at 40° C. The Cu(II)-COF-301@PDMS-MA was purified with three centrifuge, decanting, resuspension cycles in methanol. Prior to activation, the Cu loaded COF colloids were collected by centrifugation and dried overnight at room temperature on a Schlenk line vacuum to yield a brown powder. Cu(II) formate in the COF could then be efficiently converted to open Cu(I) sites by activation at 200° C. under ultra-high vacuum for 2 hours, yielding a black powder. The presence and location of Cu in the COF was confirmed with TEM-EDS imaging (vide infra).
Porous Liquid Synthesis. Prior to synthesis of any porous liquids, both the Cu-COF-301@PDMS-MA and the PDMS (Mw ˜ 6000 g/mol) were dried and activated at 200° C. under ultra-high vacuum for 3 hours. The desired wt. % of Cu-COF@PDMS-MA was then added to the liquid PDMS in a He glovebox and stirred until suspended. The porous liquid was again dried for 1 hour at 200° C. under ultrahigh vacuum prior to further study.
Polymer molecular weight determination. Polymer samples were dissolved in HPLC grade tetrahydrofuran (THF) (˜1 mg/mL), filtered through alumina to remove Cu catalyst, and then filtered through a 0.45 μm PTFE filter. Size exclusion chromatography was then performed on a PL-Gel 300×7.5 mm (5 μm) mixed C column using an Agilent 1200 series autosampler, inline degasser, and diode array detector set to monitor absorbance at 254 nm. The column and detector temperatures were 35° C. HPLC grade THF was used as eluent (1 mL/min). Linear polystyrene standards were used for calibration.
Transmission Electron Microscopy (TEM). Scanning transmission electron microscopy (STEM) images and the corresponding energy dispersive x-ray spectroscopy (EDS) hypermaps were collected using an FEI Talos F200X operated at 200 kV. Samples were suspended in hexane and dropped onto a 300-mesh gold grid with lacey Formvar/carbon (Ted Pella, 060821). Elemental EDS maps were both collected (acquisition time 5 minutes) and processed by standard methods using Bruker ESPRIT software.
Temperature Programmed Desorption (TPD). TPD measurements were performed on a calibrated, custom-built system equipped with a Stanford Research Systems RGA 100, capable of measuring m/z=1-100 amu. M/z range of 1-50 amu was used for each experiment. Each sample contained 2-5 mg of active COF material and was activated at 200° C. prior to analysis. The samples were dosed with 1.3 bar H2 for 10 minutes at room temperature (porous liquids were stirred during dosing), followed by a liquid N2 quench and evacuation of the head space until the H2 signal reached a baseline pressure of 10−8 Torr. A type K thermocouple was employed to monitor the temperature, and the samples were heated at 15° C./min unless otherwise noted. Experimental parameters were controlled via a Lab View interface that is connected to the RGA, heating system, and pressure gauges. The output signal from the mass spectrometer was divided by the total sample mass to get a normalized signal.
Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). DRIFTS measurements were performed in a Thermo Scientific Nicolet iS50 FT-IR spectrometer equipped with a Harrick Scientific Praying Mantis reaction chamber. Unless otherwise noted, gas flow was set to 100 sccm. The samples were pre-treated at 200° C. under ultra-high vacuum for 3 hours. After cooling, the samples were sealed in an inert environment. The reaction chamber was purged with He at 100 sccm for ca. 10 minutes after loading the sample in an inert environment. A background spectrum was then collected. The Cu-COF@PDMS-MA, neat PDMS, and Cu-COF@PDMS-MA porous liquid were each exposed to 10% CO (CO/He) mixture for 30 minutes (Cu-COF@PDMS-MA, neat PDMS) or 1 hour (Cu-COF@PDMS-MA porous liquid) at room temperature The samples were then purged with He for 40-60 minutes to remove any free CO before collecting spectrum at a ramp rate of 5° C./min.
Physisorption Measurements. Isotherms were collected on a Micromeritics ASAP 2020. Each sample was degassed at 200° C. prior to analysis and transferred to the physisorption instrument without air exposure. CO2 isotherms were collected at 0° C. with a 30 second equilibration time. A DFT slit-pore model was used to extract pore size distributions.
X-Ray Diffraction (XRD). XRD measurements were performed on a PANalytical PW3040 X-Ray Diffractometer using Cu Kα (λ=1.54 Å) radiation. The scan rate was 2º/min, with a current of 40 mA and a voltage of 45 kV.
Differential Scanning calorimetry. The glass transition temperatures were obtained with a TA Instruments DSC 25 equipped with a Discovery liquid N2 pump allowing a minimum sampling temperature of −150° C. The system was calibrated at a given temperature ramp using an indium reference sample prior to sample measurements. The samples were heated at a 10° C./min ramp rate with a 50 mL/min N2 flow through the cell and 307 mL/min base purge.
As used herein the term “substantially” is used to indicate that exact values are not necessarily attainable. By way of example, one of ordinary skill in the art will understand that in some chemical reactions 100% conversion of a reactant is possible, yet unlikely. Most of a reactant may be converted to a product and conversion of the reactant may asymptotically approach 100% conversion. So, although from a practical perspective 100% of the reactant is converted, from a technical perspective, a small and sometimes difficult to define amount remains. For this example of a chemical reactant, that amount may be relatively easily defined by the detection limits of the instrument used to test for it. However, in many cases, this amount may not be easily defined, hence the use of the term “substantially”. In some embodiments of the present invention, the term “substantially” is defined as approaching a specific numeric value or target to within 20%, 15%, 10%, 5%, or within 1% of the value or target. In further embodiments of the present invention, the term “substantially” is defined as approaching a specific numeric value or target to within 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, or 0.1% of the value or target.
As used herein, the term “about” is used to indicate that exact values are not necessarily attainable. Therefore, the term “about” is used to indicate this uncertainty limit. In some embodiments of the present invention, the term “about” is used to indicate an uncertainty limit of less than or equal to ±20%, ±15%, ±10%, ±5%, or ±1% of a specific numeric value or target. In some embodiments of the present invention, the term “about” is used to indicate an uncertainty limit of less than or equal to ±1%, ±0.9%, ±0.8%, ±0.7%, ±0.6%, ±0.5%, ±0.4%, ±0.3%, ±0.2%, or ±0.1% of a specific numeric value or target.
Example 1. A composition comprising: an organic framework material having an internal volume and an outer surface; and a first polymer covalently bonded to at least a portion of the outer surface, wherein: the covalently bonded first polymer has a glass transition temperature (Tg) between about −130° C. and about +180° C., the composition is capable of reversibly adsorbing and desorbing H2 when the composition is at a temperature greater than or equal to the Tg, and the composition is capable of storing H2 within the internal volume when the composition is at a temperature less than Tg.
Example 2. The composition of Example 1, wherein Tg is between about −80° C. and about +50° C.
Example 3. The composition of either Example 1 or Example 2, wherein the organic framework material comprises at least one a covalent organic framework (COF) or a metal organic framework (MOF).
Example 4. The composition of any one of Examples 1-3, wherein the COF includes a chelated first row transition metal (Mt) comprising at least one of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, or Zn.
Example 5. The composition of any one of Examples 1-4, wherein: the COF comprises a first structure comprising at least one of
and represents a covalent bond.
Example 6. The composition of any one of Examples 1-5, wherein Mt is Cu. Cu(I).
Example 7. The composition of any one of Examples 1-6, wherein the Cu is
Example 8. The composition of any one of Examples 1-7, wherein the COF comprises a second structure comprising at least one of
Example 9. The composition of any one of Examples 1-8, wherein the first polymer comprises at least one of an alkyl chain, a siloxane, or an ethylene oxide group.
Example 10. The composition of any one of Examples 1-9, wherein the first polymer comprises at least one of an acrylate, methacrylate, or styrene.
Example 11. The composition of any one of Examples 1-10, wherein the acrylate or methacrylate further comprises an alkyl chain between 1 and 20, inclusively.
Example 12. The composition of any one of Examples 1-11, wherein the alkyl chain is between 4 and 8 carbon atoms, inclusively.
Example 13. The composition of any one of Examples 1-12, wherein the first polymer comprises at least one of a poly(alkyl acrylate), a poly(alkyl methacrylate), a polydimethylsiloxane acrylate, a polydimethylsiloxane methacrylate, a polyethylene glycol acrylate, or a polyethylene glycol methacrylate.
Example 14. The composition of any one of Examples 1-13, comprising a third structure
wherein: w is between 0 and 20, inclusively, m is between 1 and 500, inclusively, X comprises a halogen, R1 comprises a methyl group or H, and R2 comprises at least one of an alkyl chain, a siloxane, or an ethylene oxide group.
Example 15. The composition of any one of Examples 1-14, wherein w is between 1 and 8, inclusively.
Example 16. The composition of any one of Examples 1-15, wherein m is between 5 and 50, inclusively.
Example 17. The composition of any one of Examples 1-16, wherein the halogen comprises at least one of Br, Cl, or I.
Example 18. The composition of any one of Examples 1-17, wherein the alkyl chain in R2 is between 1 and 20 carbon atoms, inclusively.
Example 19. The composition of any one of Examples 1-18, wherein, R2 is between 4 and 8 carbon atoms, inclusively.
Example 20. The composition of any one of Examples 1-19, wherein: R2 comprises at least one of
and n is between 1 and 500, inclusively.
Example 21. The composition of any one of Examples 1-20, wherein, n is between 5 and 50, inclusively.
Example 22. The composition of any one of Examples 1-21, further comprising a fourth structure
wherein: w is between 0 and 20, inclusively, X comprises at least one of Cl, Br, or I, and R1 comprises a methyl group or H.
Example 23. The composition of any one of Examples 1-22, wherein w is between 1 and 8, inclusively.
Example 24. The composition of any one of Examples 1-23, wherein the COF has an average pore size between about 1 Å and about 40 Å.
Example 25. The composition of any one of Examples 1-24, wherein the average pore size is between about 4 Å and about 25 Å.
Example 26. The composition of any one of Examples 1-25, wherein the COF has an average surface area above about 400 m2/g.
Example 27. The composition of any one of Examples 1-26, wherein the average surface is between about 50 m2/g and about 3000 m2/g, inclusively.
Example 28. The composition of any one of Examples 1-27, wherein the COF forms a particle having an average diameter between about 10 nm and about 10 μm, or between about 50 and about 400 nm.
Example 29. The composition of any one of Examples 1-28, wherein the COF has an H2 loading above about 0.01 g H2/g.
Example 30. The composition of any one of Examples 1-29, wherein the H2 loading is between about 0.001 g H2/g and about 0.04 g H2/g.
Example 31. The composition of any one of Examples 1-30, further comprising: a second polymer comprising at least one of a polydimethylsiloxane, a polyethyleneimine, a polyethylene glycol, a poly(alkyl acrylate), or a poly(alkyl methacrylate), wherein: the COF is immersed in the second polymer, and the second polymer is characterized by a second Tg between about −130° C. and about +180° C.
Example 32. The composition of any one of Examples 1-31, wherein the second Tg is between about −80° C. and about +50° C.
Example 33. The composition of any one of Examples 1-32, wherein the MOF includes a chelated first row transition metal (Mt) comprising at least one of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, or Zn.
Example 34. The composition of Example 33, wherein: the MOF comprises a first structure comprising at least one of
represents a covalent bond, and
represents a coordinate bond to Mt.
Example 35. The composition of either Example 33 or Example 34, wherein Mt is at least one of Ni or Co.
Example 36. The composition of any one of Examples 33-35, wherein Mt is at least one of Ni(II) or Co(II).
Example 37. The composition of any one of Examples 33-36, wherein the MOF comprises a second structure comprising at least one of
and represents a coordinate bond to Mt.
Example 38. The composition of any one of Examples 33-37, wherein the first polymer comprises at least one of an alkyl chain, a siloxane, or an ethylene oxide group.
Example 39. The composition of any one of Examples 33-38, wherein the first polymer comprises at least one of an acrylate, methacrylate, or styrene.
Example 40. The composition of any one of Examples 33-39, wherein the acrylate or methacrylate further comprises an alkyl chain between 1 and 20, inclusively.
Example 41. The composition of any one of Examples 33-40, wherein the alkyl chain is between 4 and 8 carbon atoms, inclusively.
Example 42. The composition of any one of Examples 33-41, wherein the first polymer comprises at least one of a poly(alkyl acrylate), a poly(alkyl methacrylate), a polydimethylsiloxane acrylate, a polydimethylsiloxane methacrylate, a polyethylene glycol acrylate, or a polyethylene glycol methacrylate.
Example 43. The composition of any one of Examples 33-42, comprising a third structure
wherein: w is between 0 and 20, inclusively, m is between 1 and 500, inclusively, X comprises a halogen, R1 comprises a methyl group or H, and R2 comprises at least one of an alkyl chain, a siloxane, or an ethylene oxide.
Example 44. The composition of any one of Examples 33-43 wherein w is between 1 and 8, inclusively.
Example 45. The composition of any one of Examples 33-44, wherein m is between 5 and 50, inclusively.
Example 46. The composition of any one of Examples 33-45, wherein the halogen comprises at least one Br, Cl, or I.
Example 47. The composition of any one of Examples 33-46, wherein the alkyl chain in R2 is between 1 and 20, inclusively.
Example 48. The composition of any one of Examples 33-47, wherein R2 is between 4 and 8 carbon atoms, inclusively.
Example 49. The composition of any one of Examples 33-48, wherein the structure in R2 comprises
where n is between 1 and 500, inclusively.
Example 50. The composition of any one of Examples 33-49, wherein n is between 5 and 50, inclusively.
Example 51. The composition of any one of Examples 33-50, further comprising a fourth structure
wherein: w is between 0 and 20, inclusively, X comprises at least one of Cl, Br, or I, and R1 comprises a methyl group or H.
Example 52. The composition of any one of Examples 33-51, wherein w is between 1 and 8, inclusively.
Example 53. The composition of any one of Examples 33-52, wherein the MOF has an average pore size between about 1 Å and about 40 Å.
Example 54. The composition of any one of Examples 33-53, wherein the average pore size is between about 4 Å and about 25 Å.
Example 55. The composition of any one of Examples 33-54, wherein the MOF has an average surface area above about 400 m2/g.
Example 56. The composition of any one of Examples 33-55, wherein the average surface is between about 50 m2/g and about 3000 m2/g.
Example 57. The composition of any one of Examples 33-56, wherein the MOF forms a particle having an average diameter between about 10 nm and about 10 μm.
Example 58. The composition of any one of Examples 33-57, wherein the average diameter is between about 50 nm and about 400 nm.
Example 59. The composition of any one of Examples 33-58, wherein the MOF has an H2 loading above about 0.01 g H2/g.
Example 60. The composition of any one of Examples 33-59, wherein the H2 loading is between about 0.001 g H2/g and about 0.08 g H2/g.
Example 61. The composition of any one of Examples 33-60, further comprising: a second polymer comprising polydimethylsiloxane, polyethyleneimine, polyethylene glycol, poly(alkyl acrylate), poly(alkyl methacrylate), wherein: the MOF immersed in the second polymer, and the second polymer is characterized by a second Tg in a range between about −130° C. and about +180° C.
Example 62. The composition of any one of Examples 33-61, wherein the second Tg is between about −80° C. and about +50° C.
Example 63. A method for making a composition, the method comprising:
The foregoing discussion and examples have been presented for purposes of illustration and description. The foregoing is not intended to limit the aspects, embodiments, or configurations to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the aspects, embodiments, or configurations are grouped together in one or more embodiments, configurations, or aspects for the purpose of streamlining the disclosure. The features of the aspects, embodiments, or configurations, may be combined in alternate aspects, embodiments, or configurations other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the aspects, embodiments, or configurations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment, configuration, or aspect. While certain aspects of conventional technology have been discussed to facilitate disclosure of some embodiments of the present invention, the Applicants in no way disclaim these technical aspects, and it is contemplated that the claimed invention may encompass one or more of the conventional technical aspects discussed herein. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate aspect, embodiment, or configuration.
This application claims priority from U.S. Provisional Patent Application No. 63/488,061 filed on Mar. 2, 2023, the contents of which are incorporated herein by reference in the entirety.
This invention was made with government support under Contract No. DE-AC36-08GO28308 awarded by the Department of Energy. The government has certain rights in the invention.
| Number | Date | Country | |
|---|---|---|---|
| 63488061 | Mar 2023 | US |
