3D printing porous supramolecular adsorbent

Abstract

The use of supramolecular receptors and photocurable porous polymers explores porous polymers listed with their high surface area, tunable pore size and adsorption capacity for cobalt recovery. A porous polymer structure includes a nanoporous polymer matrix having repeating units derived from an acceptor monomer and optionally a support monomer, where the nanoporous polymer matrix comprises a plurality of nanopores having an average pore size of 1 to 1000 nanometers. Methods for making the porous polymer structures and methods of binding target metal species are also described.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 531,908, filed August 10, 2023, the contents of which are incorporated herein by reference in their entirety.

[0003] US Federal Research Statement

[0004] This invention was made with government support from the U.S. National Science Foundation (grant number 2045336) and the U.S. Department of Energy's Office of Basic Energy Sciences (grant number DE-SC0024393). The government holds certain rights to this invention. Background Technology

[0005] Cobalt is a fundamental element required for a range of technologies, such as electric vehicles. It is also a critical material susceptible to instability in international supply chains. Adding to the availability problem, over 70% of cobalt production occurs in the Democratic Republic of Congo (DRC), where mining and refining practices are harmful to both human health and the environment. Recovering cobalt from end-of-life waste offers a potentially self-sufficient and sustainable solution to these problems. Conventional metallurgical recovery methods primarily rely on liquid-liquid extraction (LLE) using phosphorus-containing ligands such as dialkylphosphine (Cyanex 272). While effective, the formation of a third phase (i.e., emulsion), secondary waste generation, and extractant loss limit the widespread use of LLE in cobalt recovery. Therefore, alternative methods to LLE are needed that require fewer processing steps, minimize waste, and increase the reuse rate of the extractant. Summary of the Invention

[0006] A porous polymer structure comprising a nanoporous polymer matrix, the matrix including repeating units derived from acceptor monomers capable of binding to metals and optionally supporting monomers; wherein the nanoporous polymer matrix comprises a plurality of nanopores having an average pore size of 1 to 1000 nanometers.

[0007] A method for manufacturing the porous polymer structure includes: providing a resin mixture comprising: the acceptor monomer; optionally the supporting monomer; a photoinitiator; and a porogen; and irradiating the resin mixture with light to provide the porous polymer structure.

[0008] A method for incorporating a target metal class includes: contacting a fluid mixture containing the target metal class with the porous polymer structure.

[0009] A system for removing a target metal species from a fluid mixture, comprising: a feed vessel comprising a fluid mixture comprising the target metal species and having an inlet and an outlet; a pump in fluid communication with the outlet of the feed vessel, wherein the pump is capable of delivering the fluid mixture into a cartridge comprising the porous polymeric structure; wherein an outlet of the cartridge is in fluid connection with the inlet of the feed vessel.

[0010] The above described and other features are exemplified by the following figures and detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0011] The following drawings represent various example embodiments.

[0012] Figure 1 Schematic of a 3D printed structured supramolecular adsorbent that can selectively bind and release CoCl2.

[0013] Figure 2 Chemical structures of various example resin components are shown in accordance with an aspect of the present disclosure.

[0014] Figure 3 A depiction of thin film transmittance measurements and ternary diagrams showing resin formulations that did or did not undergo polymerization induced phase separation (PIPS) are shown. Selected resin formulations containing a 1 : 1 porogen to TPGDA are indicated. Images of films prepared with a range of cyclohexanol to 1-decanol ratios and a porogen-free control are also shown.

[0015] Figure 4 Representative images and analysis of a 0: 1 cyclohexanol to 1-decanol sample using SEM and ImageJ are shown. Bar graph of average pore diameter (nm) of resins prepared with a range of cyclohexanol to 1-decanol ratios from 1 : 0 to 0: 1. Pore diameter is the average of three trials, error bars represent one standard deviation from the mean.

[0016] Figure 5 A schematic of a DLP 3D printing is shown, which includes a light-emitting diode (LED), a digital mirror device (DMD), a vat of liquid resin, and a build platform.

[0017] Figure 6Representative images of printed and critical point dried (CPD) Kelvin Lattices, gyroid, and cubes (10 mm x 10 mm x 10 mm) prepared from resins containing a 0:1 ratio of cyclohexanol to 1-decanol are shown. Average compressive test modulus of elasticity of cubes (5 mm x 5 mm x 5 mm) prepared with different porogen ratios is shown. Modulus values are the average of three trials with one standard deviation from the average provided. Scanning electron microscope (SEM) images of Kelvin Lattices (10 mm x 10 mm x 10 mm) prepared with a 0:1 ratio of cyclohexanol to 1-decanol are also shown.

[0018] Figure 7 A graphical representation of the process for determining ion binding via conductivity measurements is shown.

[0019] Figure 8 Binding isotherms of CoCl2and LiCl in various solvents are shown, with uptake provided in millimoles of ions per grams of bulk adsorbent. Dashed lines represent a non-linear Freundlich model fit. Each symbol represents the average of three trials, with error bars representing one standard deviation from the average.

[0020] Figure 9 Digital camera images of Kelvin Lattices containing 5 mol% BDCA before and after CoCl2binding in 25 mM EtOH solution are shown (top). SEM-EDX mapping images of Co and Cl on the adsorbent surface (bottom).

[0021] Figure 10 Representative kinetic absorption isotherms measured using UV-visible absorption spectroscopy are shown. For clarity, provided symbols are indexed, and dashed lines represent a non-linear pseudo-first order fit. Rate constants (k1) were determined from the average of three trials, with error representing one standard deviation from the average.

[0022] Figure 11 Equilibrium uptake as a function of acceptor loading and pore size for Kelvin Lattices is shown.

[0023] Figure 12 Equilibrium uptake as a function of 3D microstructure is shown. Data provided is the average of three trials, with error bars representing one standard deviation from the average. SA:V is the surface area to volume ratio.

[0024] Figure 13 Graphical representation and experimental data of a cycle capture and release experiment are shown. Percent release is related to the amount of CoCl2bound in the same cycle.

[0025] Figure 14 Co 2+Li + Selective illustrations and experimental data. All data are the average of three independent experiments, error bars represent one standard deviation from the mean.

[0026] Figure 15 A schematic representation of the flow setup for the purification and in situ monitoring of the percolate from NdFeB magnets containing Nd, Dy, and Co is shown. DETAILED DESCRIPTION

[0027] Immobilized receptors combine facile reusability with tunable selectivity and affinity, making them an attractive platform for critical material recovery. Furthermore, the non-covalent (e.g., ionic) interactions of supramolecular receptors are highly dependent on environmental factors, such as solvent polarity, which enables on-demand binding and release. Recently, this approach has been investigated for the selective recovery of lithium from LiCl and LiPF6, using acetonitrile to methanol solvent switching to facilitate uptake and release. In these strategies, receptor-loaded organogels and polystyrene beads were synthesized via direct copolymerization and post-functionalization, respectively. However, these fabrication methods have geometric design constraints, and the resulting materials either have weak mechanical properties or have low surface-to-volume ratios, and thus poor ion capacity densities. As an alternative, nanoporous inclusions in particulate separation systems (i.e., beads) have been used to maximize surface-to-volume ratios for the capture of a wide range of analytes, such as Li, Na, Ca, Co, Ni, Mo, V, and Eu. However, their operation is energy-intensive due to the high pressure required for sufficient fluid flow (i.e., flux). In contrast, nanoporous planar membrane structures can facilitate high flux, but at the cost of often unfavorable surface-to-volume ratios. Thus, there is a trade-off between ion binding capacity per unit volume and fluid flux. Overcoming this dilemma is an almost unmet challenge.

[0028] To date, strategies to overcome the capacity flux paradigm have relied on ingenious geometric designs across a continuum from the nanoscale to the macroscale. This includes microstructuring (e.g., corrugation), combining multiple flat membranes into a single module (box), and coiled hollow fiber membranes. The apparent importance of multi-scale geometric control for high-performance ion separation has made the much-anticipated 3D printing an attractive manufacturing tool for this application. Furthermore, recent studies have shown that 3D-printed scaffolds have been used for gas separation, nuclear wastewater treatment, Au, Pd, Pt, and Co electronic waste recycling, petroleum extraction from contaminated water, and perchlorate remediation. Despite these impressive advances, the combination of supramolecular acceptors, nanoporous materials, and high-resolution 3D printing for separation has not yet been considered in the context of metal ion recognition. Therefore, whether such a method can be used to produce adsorbents for the capture of critical metal cations remains an open question. As described below, the inventors have now discovered that digital light processing (DLP) 3D printing can serve as a high-resolution, scalable, and low-waste tool for fabricating layered adsorbents for cobalt recovery. Figure 1 ).

[0029] This method relies on polymerization-induced phase separation (PIPS) from a photocurable resin used to mount nanopores during the DLP printing process. To achieve cobalt capture, a methacrylate-functionalized tetradentate dicyclohexylacetamide (BDCA) ligand was synthesized and directly incorporated into the 3D print. Based on previous studies of solvent polarity-dependent lithium binding using hydroxyacetamide-based acceptors such as BDCA, it was hypothesized that cobalt would also bind to BDCA due to the similar coordination preferences between the two ions. Indeed, the binding and release of cobalt chloride were demonstrated using ethanol and water as “green” solvents for polarity switching. Furthermore, we systematically investigated the effects of nanopore size and microlattice geometry on binding capacity and adsorption rate, demonstrating the practicality of structured adsorbents in the recovery of critical materials. Therefore, this disclosure provides a significant improvement to 3D-printed supramolecular adsorbents.

[0030] Therefore, one aspect of this disclosure is a porous polymer structure. The porous polymer structure comprises a nanoporous polymer matrix including repeating units derived from acceptor monomers and optionally supporting monomers.

[0031] The supporting monomer may or may not be present. When present, the supporting monomer contains at least one polymerizable group. The polymerizable group is capable of reacting with the reactive substance generated by the photoinitiator activation to provide a polymer. Therefore, the suitable monomer type will depend on the characteristics of the photoinitiator and the polymerization mechanism that the photoinitiator can achieve. Thus, the monomer composition may include radical polymerizable monomers (e.g., when using a radical generating initiator), cationic polymerizable monomers (e.g., monomers prepared when a photoacid generator is used as an initiator), anionic polymerizable monomers (e.g., when a photobase generator is used as an initiator), or combinations thereof (e.g., when using a combination of photoinitiators capable of promoting different polymerization mechanisms such as radicals and cations).

[0032] In one aspect, the polymerizable group comprises a radical polymerizable monomer having an olefinic degree of unsaturation. Exemplary radical polymerizable groups may include, but are not limited to, acrylates, methacrylates, acrylamides, methacrylamides, alkenyl aromatics (e.g., styrene and its derivatives), vinyl groups (e.g., vinyl acetate), or combinations thereof. In a particular aspect, the polymerizable group comprises acrylates or methacrylates. For example, the supporting monomer may have the following structure:

[0033] or ,

[0034] Wherein, R is an alkyl group or an alkylene glycol group. For example, in one aspect, R can be C 1-12 Alkyl groups or C 1-6 Alkyl group. In one aspect, R can be an ethylene glycol monomethyl ether group, a triethylene glycol monomethyl ether group, or a tetraethylene glycol monomethyl ether group. Other R groups are considered in this disclosure and can be selected based on the desired polarity of the R group guided by this disclosure.

[0035] In one aspect, the supporting monomer may include a crosslinking monomer. That is, the supporting monomer may contain at least two polymerizable groups, preferably at least two free radical polymerizable groups containing olefinic unsaturation. In some aspects, the supporting monomer may include a mixture of a monofunctional monomer and a crosslinking agent. In some aspects, the supporting monomer may only include monomers having at least two polymerizable groups. Exemplary free radical polymerizable groups may include, but are not limited to, acrylates, methacrylates, acrylamides, methacrylamides, alkenyl aromatics (e.g., styrene and its derivatives), vinyl groups (e.g., vinyl acetate), or combinations thereof. In a particular aspect, the polymerizable group includes acrylates or methacrylates. For example, the supporting monomer having at least two polymerizable groups may have the following structure:

[0036] or ,

[0037] Wherein, R' is an alkylene group or an alkylene diol group. For example, in one aspect, R' can be C 1-12 alkylene groups, or C 2-6 Alkylene group. In one aspect, R' can be an alkylene glycol group, such as a diethylene glycol group, a triethylene glycol group, a tetraethylene glycol group, a dipropylene glycol group, a tripropylene glycol group, and a tetrapropylene glycol group. In a particular aspect, the supporting monomer may comprise an alkylene glycol diacrylate, such as a tripropylene glycol diacrylate. Other monomers (e.g., crosslinking agents) having at least two polymerizable groups as considered in this disclosure include, but are not limited to, vinyl crosslinking agents, isocyanate crosslinking agents, epoxide crosslinking agents, thiol crosslinking agents, alkynyl crosslinking agents, acrylates of polyols, methacrylates of polyols, and allyl ethers of polyols, each monomer having its hydroxyl group substituted with at least two substituents. Examples of the aforementioned polyols include ethylene glycol, propylene glycol, polyoxyethylene glycol, polypropylene glycol, glycerol, polyglycerol, trimethylolpropane, pentaerythritol, sucrose, sorbitol, etc. Other examples of crosslinking agents may include divinylbenzene, N,N'-methylenebis(acrylamide), N,N'-ethylenebis(acrylamide), N,N'-propylenebis(acrylamide), N,N'-butylmethylenebis(acrylamide), N,N'-diallylacrylamide, N,N'-hexamethylenebisacrylamide, triallyl isocyanurate, 1,4-diaroylpiperazine-1,1,1-trimethylolpropane diallyl ether, triethylene glycol divinyl ether, diallyl maleate 3-(acryloylamino)methane, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 3-(acryloyloxy)-2-hydroxypropyl methacrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, diallyl phthalate, triallyl phosphate, allyl methacrylate, tetraallyloxyethane, triallyl cyanurate, divinyl adipate, vinyl crotonate, 1,5-hexadiene, allyl glycidyl ether, and pentaerythritol tetraallyl ether.

[0038] In some aspects, the monomer composition may include monomers having epoxy functional groups, isocyanate functional groups, isothiocyanate groups, carbonate groups, ester groups, vinyl sulfone groups, hydroxyl groups, thiol groups, alkynyl groups, or combinations thereof.

[0039] In one aspect, particularly when the photoinitiator comprises a photoacid generator, the monomer composition may contain cationic polymerizable groups such as cyclic ethers (e.g., epoxy groups, oxetyl groups, etc.), vinyl ethers, oxetanes, spirocyclic orthocarbonates, spirocyclic orthoesters, or combinations thereof. In a particular aspect, the cationic polymerizable groups may include cycloalkyl ether cationic polymerizable groups, preferably epoxy resins.

[0040] In one aspect, particularly when the photoinitiator comprises a photobase generator, the monomer composition may comprise a first monomer comprising at least two hydroxyl groups, at least two thiol groups, or combinations thereof. Non-limiting examples of a first monomer comprising at least two thiol groups may include trimethylolpropane tris(3-mercaptopropionate); trimethylolpropane tris(2-mercaptoacetate); pentaerythritol tetras(2-mercaptoacetate); pentaerythritol tetras(3-mercaptopropionate); ethoxylated trimethylolpropane tris(3-mercaptopropionate); 2,2'-(ethylenedioxy)diethanethiol; 3,6-dioxa-1,8-octanedithiol; 1,3-propanedithiol; 1,2-ethylenedithiol; 1,4-butanedithiol; 1,5-pentanedithiol; 1,6-hexanediol; Thiols; 1,9-nonanedithiol; xylenedithiol; thiobis(benzenethiol); 1,4-butanediol bis(mercaptoacetate); 1,4-bis(3-mercaptobutoxy)butane; tris[2-(3-mercaptopropoxy)ethyl]isocyanurate; 3,4-ethylenedioxythiophene; 1,10-decanedithiol; tricyclo[5.2.1.02,6]decanedithiol; benzene-1,2-dithiol; trithiocyanuric acid; 1-butanethiol; 1-hexanethiol; 1-heptanethiol; 1-octanethiol; 1-nonanethiol; 1-decanethiol; and 1-octadecanethiol. The monomer composition may further comprise a second monomer comprising at least two (meth)acrylate groups, at least two (meth)acrylamide groups, at least two vinyl sulfone groups, at least two isothiocyanate groups, at least two isocyanate groups, at least two epoxy groups, at least two carbonate groups, at least two ester groups, at least two alkynyl groups, or combinations thereof. Diisocyanates are particularly mentioned. Non-limiting examples of suitable aliphatic isocyanates include ethylene diisocyanate, trimethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), tetramethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, 1,6,11-undecanetriisocyanate, 1,3,6-hexamethylene triisocyanate, bis(ethyl isocyanate)-carbonate, and bis(ethyl isocyanate) ether. Other non-limiting examples of suitable aliphatic isocyanates include branched isocyanates such as trimethylhexane diisocyanate, trimethylhexamethylene diisocyanate (TMDI), 2,2'-dimethylpentane diisocyanate, 2,2,4-trimethylhexane diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,8-diisocyanate-4-(isocyanatomethyl)octane, 2,5,7-trimethyl-1,8-diisocyanate-5-(isocyanatomethyl)octane, 2-propyl isocyanate 2,6-diisocyanate hexanoate, lysine diisocyanate methyl ester, and lysine triisocyanate methyl ester. Non-limiting examples of suitable alicyclic isocyanates include binuclear compounds bridged by an isopropylidene group or an alkylene group of 1 to 3 carbon atoms.Non-limiting examples of suitable alicyclic isocyanates include 1,1'-methylenebis-(4-isocyanatocyclohexane), 4,4'-methylenebis-(cyclohexyl isocyanate) or 4,4'-dicyclohexylmethane diisocyanate, 4,4'-isopropylidenebis-(cyclohexyl isocyanate), 1,4-cyclohexyl diisocyanate (CHDI), and methyl 3-isocyanate-3,5,5-trimethylcyclohexyl isocyanate (a branched isocyanate, also known as isophorone diisocyanate or IPDI). In one aspect, the second monomer may include hexamethylene diisocyanate; isophorone diisocyanate; diisocyanate butane; diisocyanate octane; 1,3,5-tris(6-hexyl isocyanate)-1,3,5-triazine-2,4,6-trione; phenylene diisocyanate; xylene diisocyanate; toluene diisocyanate; cyclohexene diisocyanate; toluene diisocyanate; methylene bis(phenyl isocyanate); propyl isocyanate; 1-pentyl isocyanate; hexyl isocyanate; octyl isocyanate; nonyl isocyanate; sec-butyl isocyanate; 2-ethylhexyl isocyanate; cyclopentyl isocyanate; and 1-isocyanate-3-methylbutane. The use of poly(ethylene glycol) or poly(propylene glycol) diisocyanate-terminated polymers (e.g., toluene-2,4-diisocyanate-terminated polypropylene glycol with a number average molecular weight of 1000 to 5000 g / mol) is also mentioned. The first and second monomers may be selected to provide (polyester sulfides) (e.g., containing -O(C=O)-LS- bonds, where L is a linking group, such as C). 1-6 Alkylene linking groups), poly(amide sulfides), poly(sulfone sulfides), poly(urethane esters) (e.g., containing -NH(C=O)O- bonds), poly(thiourethane esters) (e.g., containing -NH(C=O)S- bonds), poly(dithiourethane esters) (e.g., containing -NH(C=S)S- bonds), poly(carbonate sulfides) (e.g., containing -O(C=O)OLS- bonds, where L is a linking group, such as C 1-6 (alkylene linkage group) or poly(ether sulfide).

[0041] The repeating units derived from the supporting monomer can be present in an amount of 0 to 99 weight percent based on the total weight of the polymer network. In one aspect, the polymer structure does not contain repeating units derived from the supporting monomer (i.e., repeating units derived from the supporting monomer are present in an amount of 0 weight percent). In one aspect, when present, the repeating units derived from the supporting monomer can be present in amounts of 1 to 99 weight percent, or 10 to 99 weight percent, or 10 to 90 weight percent, or 20 to 99 weight percent, or 30 to 99 weight percent, or 40 to 99 weight percent, or 50 to 99 weight percent, or 10 to 95 weight percent, or 25 to 95 weight percent, or 50 to 95 weight percent, or 10 to 90 weight percent, or 25 to 90 weight percent, or 50 to 90 weight percent, each amount based on the total weight of the polymer network.

[0042] In addition to the supporting monomer (when present), the nanoporous polymer matrix also includes repeating units derived from the acceptor monomer. In some aspects, the nanoporous polymer matrix consists of repeating units derived from the acceptor monomer. As used herein, the term "acceptor monomer" refers to a compound having a polymerizable group and a group capable of binding to a metal. Preferably, the polymerizable group of the acceptor monomer is a radical polymerizable group containing an olefinically unsaturated radical, such as acrylate, methacrylate, acrylamide, methacrylamide, alkenyl aromatics, vinyl groups, or combinations thereof. In one aspect, the polymerizable group of the acceptor monomer is a (meth)acrylate group. The acceptor monomer further includes at least one acceptor group capable of binding to a metal. Exemplary metals may include, for example, cobalt, nickel, lithium, manganese, lanthanides (e.g., trivalent lanthanides, preferably neodymium or dysprosium), group 13 elements (e.g., trivalent group 13 elements, preferably gallium or indium), or arsenic. A suitable acceptor group may be selected based on the characteristics of the metal to be bound. Suitable acceptor groups may include, but are not limited to, amide groups, calix[4]pyrrole groups, hydroxyacetamide, chelolactone, dipyridinecarboxylic acid or hydroxypyridinone iron(III).

[0043] In one aspect, the acceptor group includes an amide group, such as a dicyclohexylamide acceptor group. In another aspect, the acceptor group capable of binding to a metal may include a dicyclohexylamide group, for example, wherein the acceptor monomer has the following structure:

[0044] ,

[0045] Wherein, L is a linking group, and PG is a polymerizable group. The polymerizable group PG may include (meth)acrylates, (meth)acrylamides, alkenyl aromatics (e.g., styrene), vinyl groups, etc. 1-12 Alkylene groups, alkylene glycol groups, etc.

[0046] In one particular aspect, the receptor monomer may have the following structure:

[0047] .

[0048] In one aspect, the acceptor group capable of binding to a metal may include a tricyclohexylamide group, for example, wherein the acceptor monomer has the following structure:

[0049] ,

[0050] Wherein, L is a linking group, and PG is a polymerizable group. The polymerizable group PG may include (meth)acrylates, (meth)acrylamides, alkenyl aromatics (e.g., styrene), vinyl groups, etc. The linking group may be a single bond, C... 1-12 Alkylene groups, alkylene glycol groups, etc.

[0051] In one particular aspect, the receptor monomer may have the following structure:

[0052] .

[0053] In the presence of a cyclohexylamide acceptor group, other variations of the monomer structure described above may also be considered. For example, other linking groups or polymerizable portions (e.g., acrylates, (meth)acrylamide), styrene, vinyl groups, etc., are also possible. In one aspect, acceptor groups capable of binding to metals include dicyclohexylamide acceptor groups, and said metals include cobalt, nickel, or manganese.

[0054] In one respect, acceptor groups capable of binding to metals include hemispherical or crown ether-strap cup [4]pyrroles. For example, acceptor monomers may have the following structures:

[0055] ,

[0056] Wherein, L is a linking group, and PG is a polymerizable group. The polymerizable group PG may include (meth)acrylates, (meth)acrylamides, alkenyl aromatics (e.g., styrene), vinyl groups, etc. The linking group may be a single bond, C... 1-12 Alkylene, alkylene glycol groups, etc. In one particular aspect, the acceptor monomer may include hemispherical or crown ether-bound cup [4]pyrrole, and the metal may include lithium.

[0057] In one aspect, the acceptor group capable of binding to a metal may include alcoholamide, chelidonic acid, or dipyridylcarboxylic acid. For example, the acceptor monomer may have the following structure:

[0058] ,

[0059] In the above structure, PG is a polymerizable group (e.g., (meth)acrylate), (meth)acrylamide, alkenyl aromatic hydrocarbon (e.g., styrene), vinyl group, etc.), and L is a linking group (e.g., single bond, C). 1-12 The metal may be an alkylene group, an alkylene glycol group, etc., and X may be cyclohexyl, phenyl, or an alkyl group such as isopropyl. In one particular aspect, the acceptor monomer may include ethanolamide, chelidonic acid, or dipyridylcarboxylic acid, and the metal may include neodymium or dysprosium.

[0060] In one aspect, the acceptor group capable of binding to a metal may include a hydroxypyridinone Fe(III). For example, the acceptor monomer may have the following structure:

[0061] ,

[0062] In the above structure, PG is a polymerizable group (e.g., (meth)acrylate), (meth)acrylamide, alkenyl aromatic hydrocarbon (e.g., styrene), vinyl group, etc.), and L is a linking group (e.g., single bond, C). 1-12 (alkylene groups, alkylene glycol groups, etc.). In one particular aspect, the acceptor monomer may include hydroxypyridinone Fe(III), and the metal may include arsenic.

[0063] Repeating units derived from the supporting monomer and the acceptor monomer can typically be present in any proportion. In one aspect, the polymer matrix contains 1 to 100 weight percent of repeating units derived from the acceptor monomer. In another aspect, the polymer matrix contains 100 weight percent of repeating units derived from the acceptor monomer (i.e., the polymer matrix consists of repeating units derived from the acceptor monomer). In some aspects, the polymer matrix contains 1 to 99 weight percent, or 1 to 90 weight percent, or 1 to 75 weight percent, or 1 to 50 weight percent, or 1 to 20 weight percent, or 1 to 10 weight percent, or 10 to 99 weight percent, or 10 to 95 weight percent, or 10 to 75 weight percent, or 10 to 50 weight percent of repeating units derived from the acceptor monomer, each weight percent based on the total weight of the polymer network.

[0064] The nanoporous polymer matrix derived from the polymerization of supporting and acceptor monomers comprises a plurality of nanopores having an average pore size of 1 to 1000 nanometers. In one aspect, the plurality of nanopores may have an average pore size of 50 to 500 nanometers, or 80 to 280 nanometers.

[0065] In one aspect, the polymer matrix may have a three-dimensional lattice structure. The lattice structure may contain multiple interconnected channels. The average diameter of the channels is larger than the average diameter of the nanopores. For example, the channels may have an average diameter of 1 micrometer to 10 millimeters. In another aspect, the lattice structure may be a Kelvin lattice structure or a helical lattice structure.

[0066] Porous polymer structures can be advantageously fabricated using additive manufacturing processes, such as digital light processing (DLP) methods. In 3D printers used in DLP methods, a photocurable composition in liquid form can be provided in a container or laid on a sheet. A predetermined area of ​​the photocurable composition can be exposed to light of a selected wavelength (e.g., ultraviolet or visible light with a selected wavelength to activate a photoinitiator). The light irradiation can be controlled using a digital micromirror device or a rotating mirror. In DLP, additional layers are repeatedly or continuously laid and each layer is cured until the desired 3D article is obtained.

[0067] Therefore, another aspect of the present invention is a method for manufacturing a porous polymer structure. The method includes irradiating a resin mixture with light to provide a porous polymer structure. The resin mixture includes an acceptor monomer, a photoinitiator, a porogen, and optionally a supporting monomer. The supporting monomer and the acceptor monomer may be as described above.

[0068] The photoinitiator, when irradiated with light, particularly visible or ultraviolet light, can initiate a polymerization reaction. In one aspect, the photoinitiator can be a type I photoinitiator. A type I photoinitiator is a compound that undergoes unimolecular photolysis upon exposure to light. Type I photoinitiators may include photoacid generators, photobase generators, and initiators that form free radicals upon exposure to light. The reactive portion generated by homolytic cleavage of the photoinitiator will depend on the characteristics of the photoinitiator.

[0069] Exemplary free radical photoinitiators may include, but are not limited to, bisacylphosphine oxides (e.g., phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide), or dialkylgermanium (e.g., bis(4-methoxybenzoyl)diethylgermanium), photoinitiators containing titanium oxide derivatives, traded under the name IRGACURE, available from Ciba Specialty Chemicals, isopropylthioxanthone, benzophenone, 2,2-azobisisobutyronitrile (AIBN), camphorquinone, diphenyltrimethylbenzylphosphine oxide (TPO), (1-hydroxycyclohexylphenyl ketone) (HCP), bis(2,6-difluoro-3-(1-hydropyrrole-1-yl)phenyl)titanium oxide, etc. Compounds having the following structures are also considered:

[0070] ,

[0071] In the above formula, X 1 It is boron (B) or gallium (Ga); X 2 Each time it appears, it is independently hydrogen, chlorine (Cl), bromine (Br), or iodine (I); Z is carbon or nitrogen; R 1 Each occurrence is independently either substituted or unsubstituted C. 1-6 Alkyl groups, optionally substituted with one or more intra-chain or side-chain heteroatoms selected from the group consisting of oxygen and sulfur, optionally wherein R 1 Each occurrence of (i.e., in a single X) 1 (Partially) can combine to form cycloalkyl groups; R 2 Is it substituted or unsubstituted C? 1-6 Alkyl groups or substituted or unsubstituted C 6-20 Aromatic group; R 3 Each time it appears, it is independently hydrogen, substituted or unsubstituted C. 1-6 Alkyl groups or substituted or unsubstituted C 6-20 Aromatic group; R 4 Each time it appears, it is independently hydrogen, substituted or unsubstituted C. 1-6 Alkyl groups or substituted or unsubstituted C 6-20 An aromatic group; and Ar is a fused aromatic group, optionally substituted or unsubstituted, substituted by one or more intrachain or side-chain heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur. Such compounds are further described in international application PCT / US2004 / 033196, the entire contents of which are incorporated herein by reference.

[0072] In one particular aspect, the photoinitiator includes bis(2,4,6-trimethylbenzoyl)phosphine oxide (e.g., phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide).

[0073] In one aspect, the photoinitiator may be a photoacid generator. As used herein, "photoacid generator" refers to a polymerization initiator that can generate cationic substances when induced by light (e.g., infrared light, visible light, ultraviolet light, far-ultraviolet light, X-rays, or charged particle beams such as electron beams). Therefore, a photoacid generator can generate cationic substances in a light-induced chemical reaction and initiate cationic polymerization. In one aspect, the photoacid generator can generate Brønsted acids or Lewis acids under light irradiation. In one aspect, the photoacid generator may be a triarylsulfonium salt, an aryldiazo salt, a diaryliodonium salt, a dialkylbenzoylsulfonium salt, or a sulfonate compound. Exemplary photoacid generating agents may include, but are not limited to, bis[4-(diphenylsulfonium)phenyl]sulfide bis(hexafluoroantimonate / ester), triphenylsulfonium hexafluoroantimonate, tri(4-methoxyphenyl)sulfonium hexafluorophosphate, diphenyl-4-thiophenoxyphenylsulfonium hexafluoroantimonate / ester, diphenyl-4-thiophenoxyphenylsulfonium hexafluorophosphate, 4,4'-bis(diphenylsulfonium)phenyl sulfide-bis(hexafluoroantimonate / ester), 4,4'-bis(diphenylsulfonium)phenyl sulfide-bis(hexafluoroantimonate / ester), 4,4'-bis [Di(β-hydroxyethoxy)phenylsulfonium]phenyl sulfide-bis(hexafluoroantimonate) / ester, 4,4'-bis[di(β-hydroxyethoxy)phenylsulfonium]phenyl sulfide-bis(hexafluorophosphate) / ester, 4-[4'-(benzoyl)phenylthio]phenyl-di-(4-fluorophenyl)sulfonium hexafluoroantimonate / ester and 4-[4'-(benzoyl)phenylthio]phenyl-di-(4-fluorophenyl)sulfonium hexafluorophosphate / ester. Combinations of photoacid generating agents may also be used.

[0074] In one aspect, the photoinitiator can be a photobase generator. As used herein, "photobase generator" refers to a polymerization initiator that generates anionic compounds (e.g., organic bases) when induced by light (e.g., infrared, visible, ultraviolet, far-ultraviolet, X-rays, or charged particle beams such as electron beams). Therefore, a photobase generator can produce anionic compounds in a light-induced chemical reaction and initiate anionic polymerization. In one aspect, a photobase generator capable of generating amines upon exposure to light can be used, and includes, for example, o-nitrobenzylcarbamate compounds, α,α-dimethyl-3,5-dimethoxybenzylcarbamate compounds, acyloxyimino compounds, etc.

[0075] Specific examples of o-nitrobenzyl carbamate compounds include N-(2-nitrobenzyloxy)carbonyl-N-methylamine, N-(2-nitrophenoxy)carbonyl-N-n-propylamine, N-(-2-nitrobenzyloxy)carbonyl-N-n-hexylamine, N-(2-nitrobenzyloxy)carbonyl-N-cyclohexylamine, N-(2-nitrophenoxy)carbonylaniline, N-(2-nitrobenzyloxycarbonyl)carbonylpiperidine, and N,N'-bis(nitrobenzyloxycarbonyl)carbonylpiperidine. [(2-nitrobenzyloxy)carbonyl]-1,6-hexanediamine, N,N'-bis[(2-nitrobenzyloxy)carbonyl]-1,4-phenylenediamine, N,N'-bis[(2-nitrobenzyloxy)carbonyl]-2,4-toluenediamine, N,N'-bis[(2-nitrobenzyloxy)carbonyl]-4,4'-diaminodiphenylmethane, N,N'-bis[(2-nitrobenzyloxy)carbonyl]piperazine, N-(2, 6-Dinitrobenzyloxy)carbonyl-N-methylamine, N-(2,6-dinitrobenzyloxy)carbonyl-N-n-propylamine, N-(2,6-dinitrobenzyloxy)carbonyl-N-n-hexylamine, N-(2,6-dinitrobenzyloxy)carbonyl-N-cyclohexylamine, N-(2,6-dinitrobenzyloxy)carbonylaniline, N-(2,6-dinitrobenzyloxy)carbonylpiperidine, N,N'-bis[(2,6-dinitrobenzyloxy)carbonylpiperidine [(2,6-dinitrobenzyloxy)carbonyl]-1,6-hexanediamine, N,N'-bis[(2,6-dinitrobenzyloxy)carbonyl]-1,4-phenylenediamine, N,N'-bis[(2,6-dinitrobenzyloxy)carbonyl]-2,4-toluenediamine, N,N'-bis[(2,6-dinitrobenzyloxy)carbonyl]-4,4-diaminodiphenylmethane, N,N'-bis[(2,6-dinitrobenzyloxy)carbonyl]piperazine, etc.

[0076] Specific examples of the α,α-dimethyl-3,5-dimethoxybenzyl carbamate compounds include N-(α,α-dimethyl-3,5-dimethoxybenzyloxy)carbonyl-N-methylamine, N-(α,α-dimethyl-3,5-dimethoxybenzyloxy)carbonyl-N-n-propylamine, N-(α,α-dimethyl-3,5-dimethoxybenzyloxy)carbonyl-N-n-hexylamine, N-(α,α-dimethyl-3,5-dimethoxybenzyloxy)carbonyl-N-cyclohexylamine, N-(α,α-dimethyl-3,5-dimethoxybenzyloxy)carbonylaniline, and N-(α,α-dimethyl-3,5-dimethoxybenzyloxy)carbonylaniline. (Oxygenated) carbonyl piperidine, N,N'-bis[(α,α-dimethyl-3,5-dimethoxybenzyloxy)carbonyl]-1,6-hexanediamine, N,N'-bis[(α,α-dimethyl-3,5-dimethoxybenzyloxy)carbonyl]-1,4-phenylenediamine, N,N'-bis[(α,α-dimethoxy-3,5-dimethoxybenzyloxy)carbonyl]-2,4-toluenediamine, N,N'-bis[(α,α-dimethyl-3,5-dimethoxybenzyloxy)carbonyl]-4,4'-diaminodiphenylmethane, N,N'-bis[(α,α-dimethyl-3,5-dimethoxybenzyloxy)carbonyl]piperazine, etc.

[0077] Specific examples of the acyloxyimino compounds include acetophenone-O-propionyl oxime, benzophenone-O-propionyl oxime, acetone-O-propionyl oxime, acetophenone-O-butyryl oxime, benzophenone-O-butyryl oxime, acetone-O-butyryl oxime, bis(acetophenone)-O,O'-hexane-1,6-diacyl oxime, bis(benzophenone)-O,O'-hexane-1,6-diacyl oxime, bis(acetone)-O,O'-hexane-1,6-diacyl oxime, acetophenone-O-acrylyl oxime, benzophenone-O-acrylyl oxime, acetone-O-acrylyl oxime, etc.

[0078] In one aspect, the photoalkali may be an onium salt, such as that described in co-pending U.S. Patent Application 63 / 563072, filed March 8, 2024, the entire contents of which are incorporated herein by reference.

[0079] The concentration of the photoinitiator can be expressed as a molar concentration (i.e., the number of moles per liter (M) of the photocurable composition, or the number of millimoles (mM) per liter of the photocurable composition). The photoinitiator can typically be present in any suitable amount or concentration. The photoinitiator can be present in the photocurable composition at a concentration of 0.01 to 500 millimoles per liter of photocurable composition. Within this range, the concentration of the photoinitiator in the photocurable composition can be at least 0.05 mmol / L, or at least 0.1 mmol / L, or at least 0.5 mmol / L, or at least 1 mmol / L, or at least 2 mmol / L, or at least 5 mmol / L. Within this range, the photoinitiator may be present in the photocurable composition at a concentration of up to 400 mmol / L, or up to 300 mmol / L, or up to 200 mmol / L, or up to 100 mmol / L, or up to 50 mmol / L, or up to 40 mmol / L, or up to 30 mmol / L, or according to a concentration of up to 25 mmol / L, or up to 20 mmol / L, or up to 15 mmol / L, or up to 10 mmol / L. For example, in one aspect, the concentration of the photoinitiator may be present at 1 to 10 mmol / L, or 4 to 8 mmol / L, or 5 to 15 mmol / L. While the above concentrations may be preferred, other concentrations are also considered in this disclosure. For example, the photoinitiator may be present at a concentration of at least 0.01 mmol / L, at least 0.05 mmol / L, or at least 0.1 mmol / L, or at least 0.5 mmol / L to, or at least 1 mmol / L to, or at least 10 mmol / L to, or at least 100 mmol / L to at least 500 mmol / L, or at least 1 mol / L, or at least 5 mol / L. In one aspect, the photoinitiator may be present at a concentration not exceeding 10 mol / L, or not exceeding 5 mol / L, or not exceeding 1 mol / L, or not exceeding 500 mmol / L, or not exceeding 100 mmol / L, or not exceeding 50 mmol / L, or not exceeding 10 mmol / L, or not exceeding 1 mmol / L, or not exceeding 0.5 mmol / L, or not exceeding 0.1 mmol / L.

[0080] In addition to the supporting monomer (when present), acceptor monomer, and photoinitiator, the resin mixture also contains a porogen. A porogen is a compound that can be removed from the polymer matrix (e.g., during or after the manufacturing process). Removing the porogen leaves pores in the polymer structure and can be removed by, for example, diffusion, dissolution, degradation, volatilization, or a combination thereof. The porogen is preferably a liquid (e.g., at room temperature (25°C)), such as an organic solvent. Preferably, the acceptor monomer has a higher solubility in the porogen than in the supporting monomer to increase the surface exposure of the acceptor portion. A suitable porogen will initially be miscible with the resin mixture, but phase separation occurs during polymerization (e.g., the porogen will separate from the polymer). In other words, the porogen is a relatively poor solvent for the polymer, leading to phase separation and thus pore formation. Therefore, the polymer derived from the acceptor monomer and optionally the supporting monomer has a lower solubility in the porogen than in the supporting monomer (when present) and the acceptor monomer. In one aspect, the porogen can be a high-boiling-point liquid. Therefore, as those skilled in the art will recognize under the guidance of this disclosure, a suitable porogen will be selected based on the characteristics of the acceptor and supporting monomers. The porogen can generally be any solvent or liquid capable of providing the necessary phase separation during polymerization to provide the desired porous structure. It should be understood that not all porogens described below are equally effective in providing pores in the polymer structure of all compositions. Rather, those skilled in the art can readily select the optimal porogen for a particular polymer under the guidance of this disclosure.

[0081] Exemplary porogens may include, but are not limited to, alkanolic acid porogens, such as monools (e.g., compounds having a single hydroxyl group). An exemplary monool may be C... 1-12Alkyl monools. Suitable monools may include, but are not limited to, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, cyclohexanol, 1-decanol, etc., or combinations thereof. In some aspects, alkyl acetates (e.g., dodecyl acetate) may be used. Other porogens may include polar organic solvents such as dimethyl sulfoxide, dimethylformamide, dimethylacetamide, tetrahydrofuran, acetone, N-methylpyrrolidone, and acetonitrile. In one aspect, the porogen may include alkylene glycols or polymers thereof, such as polyethylene glycol or polypropylene glycol, preferably having hydroxyl terminal groups. The weight-average molecular weight of polyethylene glycol and polypropylene glycol can be 10,000 g / mol or less, or 8,000 g / mol or less, or 6,000 g / mol or less, or 4,000 g / mol or less, or 1,000 g / mol or less, or 800 g / mol or less, or 600 g / mol or less, or 400 g / mol or less. Other suitable porogens may include aliphatic water-soluble compounds having at least three hydroxyl groups. Typical porogens may include monosaccharides, disaccharides, and polysaccharides, such as glucose, ribose, sucrose, maltose, lactose, maltotriose, and dextran, such as monosaccharides like gluconic acid, mannitol, glucuronic acid, and glucosamine. Derivatives and polyols, such as glycerol, trimethylolpropane, and pentaerythritol, may also be used. Aromatic solvents such as benzene, toluene, and their substituted derivatives are also considered as porogens. Aliphatic hydrocarbons, such as C 6-20 Alkanes (e.g., hexane, cyclohexane, cyclooctane, decane, dodecane, etc.).

[0082] In one particular aspect, the porogen may include cyclohexanol, 1-decanol, or a combination thereof. In another aspect, the porogen may comprise cyclohexanol and 1-decanol, wherein the weight ratio of cyclohexanol to 1-decanol is 100:0 to 0:100, or 90:10 to 10:90, or 80:20 to 20:80, or 70:30 to 30:70, or 60:40 to 40:60.

[0083] The porogen may be present in an amount from 1 to 90 weight percent based on the total weight of the resin mixture. Within this range, the porogen may be present in an amount of at least 5 weight percent, or at least 10 weight percent, or at least 15 weight percent, or at least 20 weight percent, or at least 25 weight percent, or at least 30 weight percent, or at least 35 weight percent, or at least 40 weight percent, or at least 45 weight percent, each based on the total weight of the resin mixture. Still within this range, the porogen may be present in an amount of at most 85 weight percent, or at most 80 weight percent, or at most 75 weight percent, or at most 70 weight percent, or at most 65 weight percent, or at most 60 weight percent, or at most 55 weight percent, or at most 50 weight percent, or at most 45 weight percent, or at most 40 weight percent, or at most 35 weight percent, or at most 30 weight percent, or at most 25 weight percent, or at most 20 weight percent, or at most 15 weight percent, or at most 10 weight percent. As shown in the working example, the amount of the porogen can affect the pore size of the final porous polymer structure.

[0084] The resin mixture is liquid at room temperature (e.g., 25°C). In one aspect, one or both of the supporting monomer and the acceptor monomer are liquid at room temperature and capable of dissolving other components of the resin mixture. In one aspect, the resin mixture may optionally further contain a suitable solvent. When present, the solvent is selected to adequately dissolve or disperse the components of the resin mixture. A suitable solvent may be selected based on the selected components and under the guidance of this disclosure. Exemplary solvents may include, but are not limited to, tetrahydrofuran, dimethylformamide, N-methylformamide, formamide, acetonitrile, dimethylacetamide, dimethylethylacetamide, propylene carbonate, ethylene carbonate, N-methylpyrrolidone, dimethyl sulfoxide, and combinations thereof. In one aspect, the resin mixture does not contain a solvent.

[0085] In one aspect, the resin mixture may optionally further comprise additives, provided that the presence of the additives does not significantly and adversely affect one or more desired properties of the resin mixture, the light-based curing method, or the final cured composition. When present, the additives may be mixed with the resin mixture at any suitable time when mixing the components used to form the composition. In one aspect, the resin mixture may comprise fillers (e.g., glass, carbon, mineral, or metal) or reinforcing agents. The additives may be used in amounts generally known to be effective. In one aspect, the resin mixture may optionally comprise a viscosity modifier selected to adjust the viscosity of the mixture to a desired range. In one aspect, the resin mixture may comprise an oxygen scavenger. When present, the oxygen scavenger may comprise phosphine, thiols, olefins, or combinations thereof. Exemplary oxygen scavengers may include, but are not limited to, hydrogen donors (e.g., thiols, amines, hydrogen phosphites, silanes, stananes, benzaldehyde); n-vinylamides; reducing agents (e.g., phosphine, phosphite / salts, sulfite / salts, borane-amine complexes); singlet oxygen scavengers (e.g., diphenylfuran, anthracene); and combinations thereof. When included in a resin mixture, the oxygen scavenger may be present in an amount ranging from 1 to 100 mmol per liter of the resin mixture. Other concentrations are also considered in this disclosure. For example, the oxygen scavenger may be present at a concentration of at least 0.1 mmol / L, or at least 0.5 mmol / L, or at least 1 mmol / L, or at least 10 mmol / L, or at least 100 mmol / L, or at least 500 mmol / L, or at least 1 mmol / L, or at least 5 mmol / L. In one aspect, the oxygen scavenger may be present at a concentration not exceeding 10 mmol / L, or not exceeding 5 mmol / L, or not exceeding 1 mmol / L, or not exceeding 500 mmol / L, or not exceeding 10 mmol / L, or not exceeding 1 mmol / L, or not exceeding 0.5 mmol / L, or not exceeding 0.1 mmol / L. In some aspects, an additional oxygen scavenger is omitted or excluded from the resin mixture.

[0086] The method includes irradiating the resin mixture with light. In one aspect, the resin mixture can be irradiated with light having a wavelength of 400 to 1000 nanometers, for example 400 to 800 nanometers, or 450 to 750 nanometers. Any suitable light intensity can be used. In one aspect, the light may have a wavelength of less than 10 mW / cm². 2 The intensity. In one respect, the light intensity can be from 0.1 to less than 10 mW / cm². 2 or 0.5 to less than 10 mW / cm 2 or 1 to less than 10 mW / cm 2 or 2 to 8 mW / cm 2 Or 3 to 7 mW / cm 2 or 4 to 6 mW / cm 2or 1 to 8 mW / cm 2 or 1 to 7 mW / cm 2 1 to 6 mW / cm 2 Or 1 to 5 mW / cm 2 or 0.5 to 8 mW / cm 2 or 0.5 to 7 mW / cm 2 or 0.5 to 6 mW / cm 2 or 0.5 to 5 mW / cm 2 The light source may be 0.1 to 8 mW / cm², or 0.1 to 7 mW / cm², 0.1 to 6 mW / cm², or 0.1 to 5 mW / cm². In some respects, any combination of the above is also possible. In one respect, the light source may be a light-emitting diode (LED).

[0087] The reaction temperature is not particularly limited, as long as the reaction proceeds. For example, the method can be carried out at temperatures ranging from 0 to 100°C, such as 10 to 60°C or 20 to 40°C. The gelation time of the photocurable composition can be 60 seconds or less, or 1 to 30 seconds, or 1 to 15 seconds. Such timescales (e.g., 15 seconds or less) are particularly useful for applying the disclosed method to photolithography or 3D printing (additive manufacturing). Thus, in some aspects, the method can be a three-dimensional printing method, preferably a light-based additive manufacturing method, more preferably digital light processing, stereolithography, or computational axial lithography.

[0088] In one aspect, the method can be a light-based additive manufacturing method (e.g., a digital light processing method), wherein the method includes irradiating a first portion of a resin mixture with light to induce polymerization and form a first layer on a substrate. The light may be provided by a light source including a light-emitting diode. The light source may be an incoherent light source. The method further includes forming an additional layer by irradiating a second portion of the resin mixture to induce polymerization, thereby forming at least one additional layer on the first layer. The method steps of irradiating and forming the layers can be repeated until the desired number of layers are formed to provide a three-dimensional structure. In one aspect, each layer may comprise a cross-linked polymer matrix derived from carrier and acceptor monomers. In one aspect, adjacent layers may be chemically bonded at the interface between the layers. In one aspect, the method may have a printing rate of 60 seconds / layer or less, or 30 seconds / layer or less, 15 seconds / layer or less, or 10 seconds / layer or less. In one aspect, the method may have a printing rate of 1 millisecond / layer or higher, such as 50 milliseconds / layer or higher, 1 second / layer or higher, 5 seconds / layer or higher, 10 seconds / layer or higher, 15 seconds / layer or higher, 20 seconds / layer or higher, or 25 seconds / layer or higher. The printing rate may range from any of the aforementioned minimum values ​​to any of the aforementioned maximum values. For example, the method may have a printing rate from 1 millisecond / layer to 30 seconds / layer, or from 1 millisecond / layer to 25 seconds / layer, from 1 millisecond / second / layer to 20 seconds / layer, from 1 millisecond / layer to 15 seconds / layer, from 1 millisecond / layer to 10 seconds / layer, or from 1 millisecond / layer to 5 seconds / layer.

[0089] The method may also include removing porogens from the polymer structure. In one aspect, removing porogens may include, for example, volatilizing the porogens under reduced pressure and optionally under heating. In another aspect, porogens may be removed by critical point drying, which is believed to mitigate pore collapse. Critical point drying is a technique that avoids the effects of surface tension on the liquid / gas interface by essentially preventing the development of the liquid / gas interface. Critical point or supercritical drying does not cross any phase boundary but rather crosses the supercritical region, where the distinction between gas and liquid no longer applies. As a result, materials dehydrated using critical point drying are not exposed to surface tensions that could damage the pore structure. When the critical point of a liquid is reached, it may transition from liquid to gas without a sudden change in state.

[0090] The porous polymer structures according to this disclosure can be particularly used to capture (and release) target metals. Therefore, methods for incorporating target metals represent another aspect of this disclosure. The method includes contacting a fluid mixture with the porous polymer structure of this disclosure, wherein the fluid mixture contains the target metal. The target metal may include, for example, cobalt, nickel, lithium, manganese, neodymium, dysprosium, gallium, indium, or arsenic.

[0091] The contact is preferably carried out in the presence of a solvent. In other words, the fluid mixture may contain the target metal in the solvent. Choosing the solvent during contact (i.e., the solvent of the fluid mixture) improves the binding efficiency of the target metal to the porous polymer structure acceptor. In one aspect, the contact may be carried out in the presence of an alcohol solvent, such as ethanol or isopropanol.

[0092] The method may further include releasing the bound (or captured) target metal by contacting a porous polymer structure containing the captured target metal with a solvent that reduces the binding efficiency of the target metal to the receptor. Preferably, the solvent used to release the target metal has a higher polarity than the solvent used to capture the target metal. In one aspect, the solvent used to release the target metal may include water.

[0093] In one aspect, the fluid mixture containing the target metal class may be a stream derived from electronic waste. In one aspect, the fluid mixture may be a leachate from a magnet (e.g., an NdFeB magnet). In one aspect, the fluid mixture may be a leachate from a battery (e.g., containing Li, Co, Ni, Mn, or combinations thereof). In one aspect, the fluid mixture may contain more than one target metal class (e.g., Li and Co or Nd, Dy, and Co), and thus may be contacted with porous polymer structures containing more than one acceptor group or with multiple porous polymer structures, each containing acceptor groups specific to a particular target metal class. Contact with multiple porous polymer structures may be in series, and each porous polymer structure may provide a cartridge within a cartridge. In some aspects, particularly when other metal classes (e.g., Fe) may be present, the fluid mixture may first undergo other purification measures such as precipitation to remove the metal or other components that may interfere with the adsorption of the target metal class. Once the concentration of metal ions in the fluid mixture is sufficiently low (determinable by in-situ monitoring), the solvent polarity (and / or pH) may be switched to induce the release of the captured metal. Subsequent filtration, precipitation, and separation provide the desired recycled metals with high purity (e.g., greater than 99%), suitable for reuse in the manufacture of new devices (e.g., batteries, magnets, etc.).

[0094] A system for removing target metals from a fluid mixture represents another aspect of this disclosure. The system may include a feed container comprising a fluid mixture containing the target metals. As described above, the fluid mixture may be a leachate obtained from electronic or magnetic waste. The feed container is in fluid communication with a high-pressure pump capable of delivering the fluid mixture to a cartridge containing a porous polymer structure of this disclosure, wherein the porous polymer structure is capable of binding the target metals. Optionally, more than one cartridge may be fluidly connected in series, wherein each cartridge includes a porous polymer structure capable of binding different target metals. The cartridge outlet is in fluid communication with the feed container, such that the mixture can be circulated in a closed loop until the desired concentration of metals is obtained in the fluid mixture. The system may optionally include an in-situ monitoring system for analyzing the concentration of metals in the fluid mixture over time. Figure 15 An exemplary system is shown, schematically illustrating a system and process for purifying a fluid mixture derived from NdFeB magnet leachate.

[0095] This disclosure is further illustrated by the following embodiments, which are non-limiting.

[0096] Example

[0097] receptor synthesis

[0098] The porous adsorbent described in this article is prepared from a resin mixture containing a supporting monomer, an acceptor comonomer, and a porogen. Figure 2 The copolymerization method was chosen for one-step acceptor assembly, ensuring precise control of inclusion via feed-to-content ratios while minimizing the presence of unreacted functional groups that might arise with a post-polymerization strategy. Given the precedent of the BDCA acceptor's highly selective binding and release of LiPF6 in acetonitrile, and the affinity of ethanolamide for transition metals, the BDCA acceptor was chosen for Co... 2+The process was cyclical. First, a polymerizable methacrylate handle was attached to the BDCA acceptor for copolymerization with commercially available acrylate monomers commonly used as 3D printing resins. This was achieved by reacting tert-butoxycarbonyl (BOC)-protected 2-aminopropane-1,3-diol with 2-bromo-N,N-dicyclohexylacetamide in the presence of sodium hydride to generate the corresponding BOC-protected BDCA. The BOC was subsequently deprotected with trifluoroacetic acid, followed immediately by amide formation with methacryloyloxyethyl succinate (MA-OSu) to provide the desired BDCA methacrylate (BDCA-MA) monomer. Copolymerization between BDCA-MA and carbitol acrylate (the model monomer) initiated by phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO) provided the desired good acceptor incorporation upon exposure to 405 nm light. This proved correct, although NMR spectroscopy analysis showed that the reaction rate of BDCA-MA was slightly faster than that of carbitol acrylate.

[0099] Polymerization-induced phase separation (PIPS)

[0100] Using tripropylene glycol diacrylate (TPGDA) as a support material, 1-decyl alcohol (dec) and cyclohexanol (cyc) as porogens, and BAPO as a photoinitiator, a series of monomer-to-porogen ratios and 1-decyl alcohol-to-cyclohexanol ratios were evaluated for PIPS. Exemplary resin formulations are shown in Table 1.

[0101] Table 1

[0102]

[0103] To correlate composition with phase separation, thin films were cast between glass slides with 75 µm spacers and used with a 405 nm LED (5.0 mW / cm²). 2 Irradiated for 120 seconds, washed with acetone to remove porogen and residual monomer, and dried overnight in a vacuum oven. The transmittance of each membrane was then measured, and the transmittance was used to construct a ternary phase separation map using poly(TPGDA) prepared with porogen-free as a baseline. Figure 3 The decrease in transmittance is considered an indicator of phase separation caused by Rayleigh scattering due to nanoscale features. Therefore, a transmittance below one (~unity) is considered evidence of effective PIPS. Based on this, it is concluded that resins containing 50 wt.% TPGDA relative to the porogen cause phase separation, while higher TPGDA contents (lower porogen concentration) do not cause phase separation. Figure 3Qualitatively speaking, changing the ratio of cyclohexanol to 1-decanol while maintaining a constant TPGDA content of 50 wt.% provides good control over the extent of PIPS, as shown by the decrease in transmittance (increased opacity) when the ratio is reduced (i.e., more 1-decanol). Figure 3 (Image). Therefore, a porogen at 50 wt.% relative to TPGDA was subsequently used. The same samples were prepared using critical point drying (CPD) instead of vacuum oven drying to mitigate pore collapse. Scanning electron microscopy (SEM) was performed to determine the pore size according to a previously reported image analysis protocol. This analysis showed that the pore sizes were 100 ± 10, 122 ± 2, 115 ± 1, 168 ± 2, and 270 ± 30 nanometers (nm) for cyclohexanol to 1-decanol ratios of 1:0, 4:1, 1:1, 1:4, and 0:1, respectively. Figure 4 These results were used to confirm qualitative observations of opacity, which found that increasing the amount of 1-decyl alcohol relative to cyclohexanol resulted in larger phase-separated domains and larger pores after removal of the porogen.

[0104] Next, elemental analysis and attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy confirmed the incorporation of BDCA-MA into the polymer network using this method. By increasing the acceptor feed relative to TPGDA from 0 to 5 mol%, the resulting polymers were found to contain nitrogen contents ranging from 0.113 ± 0.006% to 0.57 ± 0.02%, as shown in Table 2.

[0105] Table 2

[0106]

[0107] These findings correlate closely with the theoretical loading levels (nitrogen contents of 0.13% and 0.60%, respectively), and are therefore considered evidence that acceptor loading has been successfully achieved. The ATR-FTIR spectra of the polymers further confirm the incorporation of BDCA-MA, as indicated by the concentrations at 3270 cm⁻¹. -1 (NH stretching) and 1639 cm -1 The presence of secondary amines and amides at the (C=O stretching) site is inferred. Based on this, it is concluded that light-driven PIPS made from resins containing BDCA-MA constitutes a feasible strategy for preparing materials with tunable pore size and acceptor content.

[0108] Digital Light Processing (DLP) 3D Printing

[0109] The polymer objects were fabricated using digital light processing (DLP) 3D printing, a layer-by-layer stereolithography technique that offers an attractive combination of build speed, feature resolution, and isotropic mechanical properties. All objects were produced using the following printing settings: bottom-up LED exposure at a center wavelength of 405 nm and an intensity of 8.6 mW / cm². 2 And irradiation for 1 second for every 25μm layer ( Figure 5 The printed objects were immersed in ethanol to remove residual resin components. These structures could be used directly for ion adsorption experiments (i.e., without drying); however, CPD was used to characterize the structures and enable gravimetric analysis for quantifying ion capacity (see below). The accessible surface area of ​​dried samples prepared as printed cylinders (3 mm × 22 mm) was estimated using the Brunauer-Emmett-Teller (BET) method with N2 as the probe gas. These studies show that for samples prepared from resins containing cyclohexanol and 1-decyl alcohol in ratios of 0:1 and 4:1, the surface area increased from 20.3 ± 0.3 m² to 45.4 ± 0.3 m² as the pore size decreased from 270 ± 30 nm to 122 ± 2 nm. 2 The overall trend is shown in Table 3, which summarizes the surface area, density, and porosity of different porogen compositions based on the nitrogen adsorption isotherm.

[0110] Table 3

[0111]

[0112] Notably, the sample with the smallest pore size (~100 nm, measured on the film using SEM) had a lower measured surface area compared to the sample with the second smallest pore size (~120 nm). This finding is attributed to the presence of phase-mixing regions or isolated pores. Finally, density measurements of the 3D-printed cubes showed that the porosity increased from 24 ± 2% to 50.6 ± 0.9% as the pore size increased from ~100 nm to 300 nm (Table 3). To test whether current additive manufacturing methods allow for the production of complex microarchitectures, three structures with external dimensions of 10 mm × 10 mm × 10 mm were produced: a cube, a Kelvin lattice, and a spiral. Figure 6 Such geometric control makes it possible to produce adsorbents with robust mechanical properties, longer service life, and reusability, while maximizing capacity and flux. These structures are produced with high feature fidelity, as evidenced by ~500µm pore sizes in Kelvin lattices and ~375µm wall thicknesses in helices. Therefore, this printing process provides hierarchical structures spanning nanometer to millimeter length scales, as determined by SEM imaging showing nanoporous voids, micrometer steps resembling those in corrugated films, and millimeter lattices. Figure 6The effect of pore size on mechanical integrity was also examined through uniaxial compression tests on 5 mm × 5 mm × 5 mm nanoporous cubes. These studies showed that the elastic modulus (E) of 100% cyclohexanol (~100 nm pores) to 100% 1-decanol (~300 nm pores) ranged from 410 ± 60 to 72 ± 8 MPa. Figure 6 Therefore, it can be concluded that the stiffness of these printed structures can be tuned by controlling the porosity. In turn, this capability provides a mechanism for designing adsorbents suitable for meeting the requirements of specific separation processes, such as specific fluid pressures.

[0113] Cobalt(II) chloride

[0114] Diffraction-grade BDCA-NiCl2 crystals were obtained via vapor diffusion from diethyl ether to an ethyl acetate solution containing BDCA-NiCl2, and used as a proxy. The resulting cluster structure revealed the presence of octahedral complexes, chloride-bridged bimetallic complexes, and tetrachlorometalates. In solution, these coordination complexes can exist in equilibrium with a variety of substances. This complexity makes it impossible to obtain a reliable binding constant for the free acceptor. However, for the case of an unactivated acceptor, the relative affinity can be inferred from the Freundlich constant and exponent.

[0115] The Co content of the 3D printing adsorbent was measured in so-called "green" solvents, namely ethanol (EtOH), isopropanol (IPA), and water (H2O). 2+ Combined curves were used to determine the most selective analyte binding and release environment. A Kelvin lattice (10 mm × 10 mm × 10 mm) containing 5 mol% BDCA acceptor and approximately 120 nm pores (from a 1:1 cyclohexanol:1-decanol) was placed in a container with a specified concentration (approximately mM) of cobalt chloride (CoCl2) or lithium chloride (LiCl). Figure 7 After standing for 12 hours to reach equilibrium, the 3D-printed structures were removed, the initial solvent was replaced with water, and conductivity values ​​were measured to determine ion concentration by comparison with calibration curves. The experimental binding curves were fitted to nonlinear Freundlich isotherms, R0 2 The value exceeds 0.95. In these models, the correction factor (n) provides an observation of ion-binding interactions. Specifically, when n -1 When the number is less than 1, binding is favorable, while n... -1 A value greater than 1 indicates unfavorable binding. For CoCl2, strong binding was observed in IPA and EtOH, with n values ​​of 2.80 and 2.27, respectively. Figure 8Conversely, weak binding of CoCl2 in H2O was observed, with an n value of 0.99. This difference allows for the use of EtOH or IPA as solvents for effective CoCl2 binding, while treatment with H2O can be used for Co... 2+ The release of [the solvent]. Ultimately, it is believed that this solvent polarity reversal, combined with appropriate 3D-printed acceptor-containing materials, can be used for cobalt recovery.

[0116] BDCA ligands also exhibit an affinity for lithium salts. Given this tendency, and the presence of Li in acid leaching solutions from lithium-ion batteries... + (and Co) 2+ The presence of ) was also examined, as well as the Li content of currently used BDCA-MA-based 3D printing adsorbents. + Binding capacity. A further motivation for these studies is the recognition of the ability to selectively separate these two ions (Co... 2+ For Li + The adsorption isotherms of LiCl in IPA and EtOH provide n values ​​of 1.74 and 1.13, respectively, both lower than the n value of CoCl2. Figure 8 ).

[0117] Given the increasing presence of manganese and nickel salts in lithium-ion battery cathodes, the affinity of BDCA ligands for them was also investigated. Freundlich isotherms showed that in EtOH, BDCA had a slightly higher affinity for CoCl2 than NiCl2 (n = 2.27 vs. 2.07), while a much lower affinity for MnCl2 was observed in EtOH (n = 1.14). These results lead us to believe that, in alcohol solvents, 3D-printed adsorbents can provide affinity for CoCl2. 2+ More than Li + and Mn 2+ Selectivity. Based on the relatively large differences in binding affinity in EtOH and its reduced toxicity compared to IPA, further experiments were performed using EtOH as a solvent.

[0118] Next, the fundamental binding kinetics and capacity of the structured adsorbents as a function of nanoporosity and microstructure were investigated using Kelvin lattice. The blue appearance of the tetrahedral cobalt complex provides a unique visual framework for adsorption and a colorimetric sensor for qualitatively assessing the extent of BDCA-CCl2 complex formation. Figure 9 The colored adsorbent was characterized using SEM and energy-dispersive X-ray (EDX) spectroscopy to determine its elemental composition. Plots of cobalt and chlorine showed a similarly uniform spatial distribution and provided a Co:Cl ratio of approximately 1:2. This elemental ratio was considered evidence that the bound cobalt was in a 2+ oxidation state.

[0119] The effect of nanopore size on cobalt uptake rate was also determined. It was hypothesized that increasing pore size would lead to an increase in diffusion transport rate, thereby increasing uptake. To verify this hypothesis, Kelvin lattices with pore sizes ranging from approximately 100 nm (cyclohexanol only) to approximately 300 nm (decanol only) were prepared using 5 mol% BDCA and a non-porous control (Table 1). The uptake rate was tracked by monitoring the change in absorption at 659 nm (tetrahedral cobalt complex) of the ethanol solution containing the printed object over time. Changes in CoCl2 concentration were determined based on calibration curves. Based on this, it was confirmed that, as predicted, the uptake rate increases with increasing pore size. Figure 10 Specifically, the sample with the largest pore size (approximately 300 nm) exhibited 8 ± 1 × 10⁻⁶. -2 min -1 The pseudo-first-order rate constant (k1) is given. Conversely, the sample containing the smallest pore size (approximately 100 nm) shows a k1 of 4 ± 2 × 10⁻⁶. -2 min -1 This finding supports the claim that the uptake of CoCl2 in these samples is diffusion-limited.

[0120] Then, the effect of receptor loading on the equilibrium capacity of CoCl2 was investigated for Kelvin lattices containing medium-sized nanopores (approximately 120 nm, from a 1:1 mixture of cyclohexanol and 1-decanol). For these studies, samples were immersed in a 25 mM CoCl2 solution (ethanol), aliquoted after 48 hours, and total uptake was determined spectroscopically. Increasing the BDCA receptor loading from 0 to 5 mol% resulted in a corresponding increase in uptake, as indicated by an increase in blue vision. Figure 11 Specifically, for 0, 1, 2.5, and 5 mol% BDCA-MA, the values ​​recorded were -0.7 ± 0.9, 3.5 ± 0.8, 9.5 ± 0.4, and 12 ± 2 mg·g, respectively. -1 The uptake values ​​were 80±20%, 89±5%, and 60±8% of the theoretical maximum binding capacity, respectively. Similar studies involving samples with minimal nanopores (approximately 100 nm) and 2.5 mol% BDCA-MA yielded 5±1 mg·g⁻¹. -1 The uptake value is equivalent to 50 ± 10% of the binding capacity ( Figure 11 As expected, increasing the nanopore size to approximately 300 nm while maintaining 2.5 mol% BDCA resulted in near 100% binding. Figure 11 ).

[0121] Finally, the effect of microstructure on CoCl2 capacity and uptake rate was examined. Figure 12Following the same immersion and UV-Vis absorption spectroscopy protocol used above, samples with cubic, Kelvin lattice, and helical geometries, exhibiting medium-sized nanopores (approximately 120 nm, from a 1:1 mixture of cyclohexanol and 1-decanol), as well as a non-porous cubic control, were tested. Geometries with larger surface area to volume ratios (helical > Kelvin lattice > cubic > non-porous Kelvin lattice > non-porous cubic) were found to result in higher capacity and faster uptake rates. Figure 12 Specifically, the absorption values ​​for helical, Kelvin lattice, cubic, and non-porous cubic structures are 94±7%, 91±4%, 75±3%, 32±8%, and 5±1% of the theoretical maximum capacity, respectively. These results indicate that the surface area to volume ratio affects the bonding performance. Therefore, the performance is directly related to both nanoscale and microscale geometries, which can be easily controlled using current 3D printing methods.

[0122] Extending existing platforms to the real world requires a combination of the ability to "capture" and release desired ions, and this needs to be repeatable across numerous cycles. This capability was tested via a "green" solvent cycle between EtOH and H₂O, containing a Kelvin lattice of 5 mol% BDCA with approximately 120 nm of pores (prepared from a 1:1 mixture of cyclohexanol and 1-decyl alcohol as pore-forming agents). Figure 13 The sample was placed in a stock solution of CoCl2 in EtOH (18.76 mM) and allowed to bind for 12 hours, then removed. The conductivity of the stock solution was measured to determine the amount of bound CoCl2 relative to the calibration curve. This indicated a binding capacity of 78 ± 2%, comparable to the binding capacity (60 ± 8%) obtained on a similar sample (5 mol% BDCA, 120 nm pore size, Kelvin lattice) after soaking for 48 hours to reach equilibrium using UV-Vis absorption spectroscopy. Subsequently, the Co-loaded adsorbent was placed in pure H2O for 12 hours, and the conductivity was measured to assess the amount of released CoCl2 based on the calibration curve. Notably, 90 ± 1% of the bound CoCl2 was released after the first cycle, which was further supported by the visual loss of the adsorbent color (i.e., from blue to white). Figure 13 The release of CoCl2 was attributed to an increase in the strength of the ion-solvent interaction, following a spectrochemical series of increasing polarity from ethanol to water. Repeating the process with the regenerated adsorbent for five cycles showed no statistically significant changes in binding or release capacity. Furthermore, no changes in the morphology or elastic modulus of representative samples were observed after cycling. Based on these findings, it can be concluded that this system provides good reproducibility when subjected to repeated use.

[0123] LiCoO2 is currently the most common cathode material in portable batteries. The recycling of these batteries involves an early acid leaching step (such as HCl). This produces Co... 2+ and Li + Separating individual ions from a mixture of these compounds is notoriously difficult. Therefore, determining the effect of this adsorbent on Co... 2+ The selectivity is higher than that of Li + With this goal in mind, a simulated percolation solution containing LiCl and CoCl2 in EtOH (2 mL) was prepared, and three different 3D-printed Kelvin lattices (230 mg sample, approximately 120 nm pore size) containing 5 mol% BDCA were placed in the mixed ionic solution. Figure 14 Inductively coupled plasma mass spectrometry (ICP-MS) analysis showed that Li + and Co 2+ The initial concentrations were 27.0 mM and 21.1 mM, respectively. After soaking the adsorbent in the solution for 12 hours, the sample that appeared blue was taken, rinsed with EtOH, and then placed in pure H2O (2 mL) for 12 hours to release the bound ions. At the end of this process, Li was found in the initial ethanol phase. + With Co 2+ The proportion is quite high, Li + and Co 2+ The concentrations were recorded as 20.7 ± 0.4 mM and 7.9 ± 0.9 mM, respectively. Figure 14 Conversely, the final aqueous phase was found to contain 2.6 ± 0.2 mM Li. + and 11.2 ± 0.1 mM Co 2 + This corresponds to Li. + With Co 2+ The proportion decreased from 1.28 to 0.23, a reduction of 5.6 times. The 3D printing carrier's effect on Co... 2+ Compared to Li + The selectivity corresponds to the previously determined binding isotherm in ethanol and is considered as a 3D-printed Kelvin lattice containing BDCA compared to Li. + A stronger bond with Co 2+ Evidence. More broadly, these findings demonstrate that 3D-printed nanoporous polymer adsorbents, as described in this article, can enable efficient lithium-ion battery recycling while generating minimal secondary waste.

[0124] Therefore, digital light processing allows for 3D printing of objects with defined microstructures. Current results demonstrate the platform's potential for recovering cobalt from spent lithium-ion batteries. Given its modularity, low cost, and minimal waste generation, the current strategy can be extended to the beneficiation and recycling of critical materials. Thus, this disclosure provides significant improvements.

[0125] The details of each experiment are as follows.

[0126] Materials: Unless otherwise specified, all reagents were used as is. 97% cobalt(II) chloride (anhydrous), 99% cyclohexanol, and 97% phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO) were purchased from Sigma-Aldrich. Tripropylene glycol diacrylate >90.0% (TPGDA) and ethyl 2-[2-(2-methoxyethoxy)ethoxy]acrylate >95% (both stabilized with hydroquinone monomethyl ether (MEHQ)) were purchased from TCI. Note that the monomers and crosslinking agents were not purified prior to use, and therefore any inhibitors from commercial sources (e.g., phenols) may remain. 99% 1-decyl alcohol was purchased from Acros Organics. Ethanol (ACS reagent grade, anhydrous) used for synthesis was purchased from RICCA Chemicals. Ethanol 200 standard was purchased from Decon Laboratories. CDCl3 (D 99.8%) and C6D6 (D 99.5%) were purchased from Cambridge Isotope Laboratory. Trifluoroacetic acid (>99%) was purchased from BeanTown Chemical. Triethylamine (>99%) was purchased from Fischer Scientific. N-hydroxysuccinimide (98%) was purchased from Oakwood Chemical. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) (>99%) was purchased from AK Scientific. BDCA was synthesized according to a literature procedure.

[0127] Resin Preparation: Mixtures of five porogens were prepared in cyclohexanol and 1-decyl alcohol ratios of 100:0, 80:20, 50:50, 20:80, and 0:100 wt.%. Non-porous resin mixtures without porogens were also prepared. Resins were prepared in the dark by wrapping 20 mL scintillation vials in aluminum foil. For formulations containing BDCA-MA, BDCA-MA was added to the vials, followed by the porogens. The vials were then vortexed until the monomers were completely dissolved in the porogens. Finally, a stock solution of TPGDA containing 2 wt.% BAPO relative to the monomers was added. The mixture was then briefly vortexed before printing to ensure resin homogeneity.

[0128] Synthesis of 2,5-dioxopyrrolidone-1-yl-1-{2-[(2-methylprop-2-enoyl)oxy]ethyl}succinate (MA-OSu). N-hydroxysuccinimide (590 mg, 5.17 mmol) and mono-2-(methacryloyloxy)ethyl succinate (1 mL, 5.17 mmol) were added to a two-necked round-bottom flask equipped with a magnetic stir bar, inlet adapter, and diaphragm, dissolved in CH2Cl2 (25 mL). Then, N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) (1 g, 5.17 mmol) dissolved in CH2Cl2 (10 mL) was added. The solution was stirred at room temperature under nitrogen for 6 hours, and then precipitated in a separatory funnel with 10% NH4Cl. （aq（水溶液）） and saturated NaHCO3 3（aq） Wash. The organic layer was then dried with anhydrous MgSO4, filtered, and concentrated under reduced pressure. The residue was purified by rapid chromatography using silica gel as the stationary phase and 40% ethyl acetate / 60% hexane as the eluent. The desired band was concentrated under reduced pressure to give a colorless liquid MA-OSu (1.44 g, 85%). 1 H NMR (400MHz, CDCl3): δ=6.11 (s, 1H), 5.58 (s, 1H), 4.40-4.29 (m, 4H), 2.82 (s, 4H), 2.80-2.73 (m, 2H), 1.93 (s, 3H). 13 C NMR (100 MHz, CDCl3): δ = 170.88, 169.01, 167.73, 167.19, 135.97, 126.23, 62.86, 62.34, 28.71, 26.33, 25.66, 18.37. ESI-HRMS: m / z = 345.1292([M+NH4] + ), (calculated value 345.1292).

[0129] Synthesis of tert-butyl (1,3-bis(2-(dicyclohexylamino)-2-oxoethoxy)propyl-2-yl)carbamate (BDCA-Boc). BDCA-Boc was prepared according to a previously reported procedure and using... 1 Characterized by H and ESI-HRMS. 1HNMR (400 MHz, CDCl3): d=5.68 (br, 1H), 4.12-4.02 (m, 4H), 3.85 (br, 1H), 3.74-3.51 (m, 4H), 3.31 (br, 2 H), 2.91 (br, 2H), 2.44 (br, 4H), 1.89-1.56 (m, 17H), 1.52-1.40 (m, 16H), 1.36-0.98 (m, 13H). ESI-HRS:m / z=656.4600 ([M+Na] + (Calculated value 656.4609).

[0130] Synthesis of 2-[(2-methylprop-2-enoyl)oxy]ethyl 3-({1,3-bis[(dicyclohexylcarbamoyl)methoxy]propyl-2-yl}carbamoyl)propionate (BDCA-MA). BDCA-Boc was prepared according to a previously reported procedure. Briefly, BDCA-Boc (200 mg, 0.316 mmol) was added to a double-necked round-bottom flask equipped with a magnetic stir bar, inlet adapter, and diaphragm, and dissolved in CH2Cl2 (10 mL). Trifluoroacetic acid (10 mL) was then slowly added to the solution. After stirring under nitrogen at room temperature for 2 hours, volatiles were removed under reduced pressure. The residue was dissolved in CH2Cl2 (10 mL), neutralized with 1N NaOH (aq), and then extracted with CH2Cl2 (3 × 10 mL). The combined organic extracts were dried over anhydrous MgSO4, filtered, and concentrated under reduced pressure. The residue was redissolved in CH₂Cl₂ (10 mL) and mixed with a CH₂Cl₂ (10 mL) solution containing MA-OSu (103 mg, 0.316 mmol). The mixture was reacted at room temperature for 6 hours. The solution was then distilled using saturated NaHCO₃ in a separatory funnel. 3（aq） After washing, the organic layer was dried with anhydrous MgSO4, filtered, and concentrated under reduced pressure. The residue was purified by rapid chromatography using silica gel as the mobile phase and 80% ethyl acetate / 20% hexane as the eluent. The desired band was concentrated under reduced pressure to give a colorless liquid BDCA-MA (189 mg, 80%). 1H NMR (400 MHz, CDCl3): δ=8.04 (br, 1H), 6.12 (s, 1H), 5.58 (s, 1H), 4.43 (s, 4H), 4.16-4.07 (m, 5H), 3.80-3.70 (m, 2H), 3.63-3.51 (m, 2H), 3.23 (br, 2H), 2.92 (br, 2H), 2.75-2.65 (m, 2H), 2.61-2.52 (m, 2H), 2.43 (br,4H), 1.94 (s, 3H), 1.85-1.74 (m, 9H), 1.72-1.63 (m, 3H), 1.54-1.42 (m, 8H), 1.35-1.04 (m, 13H). 13 C NMR (100 MHz, CDCl3): δ=172.23, 171.04, 167.86, 166.65, 135.52, 125.69, 70.36, 69.33, 62.05, 61 .73, 56.35, 55.70, 49.23, 30.81, 30.42, 29.54, 29.09, 26.21, 25.52, 25.01, 24.83, 17.90. ESI-HRS:m / z=746.4947 ([M+H] + (Calculated value 746.4950).

[0131] Instrumentation and Characterization

[0132] Nuclear magnetic resonance (NMR) spectroscopy: NMR spectra were recorded on an Agilent MR 400 MHz spectrometer using CDCl3 or C6D6 as solvents. 1 The H NMR spectra were referenced to the signals of residual proton impurities (observed at 7.26 ppm and 7.36 ppm, respectively). 13 C10 NMR spectra were recorded in decoupled mode, with reference to the chemical shifts of CDCl3 or C6D6 as appropriate (77.16 ppm and 128.37 ppm, respectively). Data are reported using the following multiplexing abbreviations: s = singlet, d = doublet, t = triplet, q = quadruplet, m = multipeak.

[0133] High-resolution mass spectrometry (HRMS): HRMS was performed on an Agilent Technologies 6530 Precision Mass Q-TOF LC / MS using APCI or ESI. The data were then analyzed using Agilent MassHunter qualitative analysis software.

[0134] Digital Light Processing (DLP) 3D Printer: 8.6 mW / cm² 2To achieve the desired intensity, samples were printed using a 1-second irradiation time per 25μm layer. After printing, all samples were washed with EtOH, post-cured at 370nm (part number ANYCUBIC-WASH-CURE) for 6 minutes while remaining in an ethanol solution, and then dried.

[0135] Critical Point Dryer (CPD): Samples are dried using a Quorum Technologies critical point dryer. The solvent is exchanged with liquid carbon dioxide over 40–60 minutes before being placed in a sealed chamber, and the temperature is raised to 37°C to reach the supercritical point. This drying method maintains the integrity of the sample and prevents artifacts that can occur during air drying, such as pore collapse.

[0136] Scanning electron microscopy (SEM): SEM studies were performed on a FEI Quanta 650 SEM / ESEM instrument at 5–10 kEv. SEM was used to examine the cross-sections and surface features of 3D printed objects. To improve imaging, samples were sputtered with Au / Pd (60:40) using an Electron Microscopy Science (EMS) sputtering coater. Sputtering was performed at 40 mA for 1.5 minutes. Energy-dispersive X-ray spectroscopy (EDX) was performed on an Apreo 2 C LoVac SEM equipped with a Bruker EDX system.

[0137] UV-Vis absorption and transmission spectroscopy: UV-Vis absorption spectroscopy was performed using a fiber-coupled spectrometer (QE PRO-ABS, Ocean Optics). Spectra were collected with a 5-boxcar width and the average of 5 scans. The spectrometer allows for measurements in the 200–950 nm spectral range with an optical resolution of 1.7 nm using a thin-backed, TE-cooled, 1024 × 58 element CCD array. The system was tailored for absorption measurements using a balanced deuterium-tungsten halogen light source (DH-2000-BAL) via a subminiature version a (SMA) 905 connector, with typical outputs of 194 μW (deuterium lamp) and 615 μW (tungsten lamp), covering a range of 230 nm–2.5 μm. The light source was connected to the sample holder via a multimode fiber optic cable (QP600-025-SR) with SMA connectors at both ends and a 600 μm core diameter. For solution measurements, a test tube rack (QNW QPOD 2eTM) with magnetic stirring and Peltier-driven temperature control was used, with a temperature control range of -30°C to 105°C. For thin film absorption measurements, an Ocean Insight (STAGE-RTL-T) reflectance-transmission sample stage was used. The sample rack was coupled to a spectrometer (QE PRO-ABS) via multimode fiber, which had a 5 μm (INTSMA-005 interchangeable slit) entrance slit. Transmittance measurements were performed directly on the polymer film using Ocean Optics software. Measurements were taken at three locations on the film and averaged. For kinetic experiments, a quartz cuvette with a stirring hole (1MS macro cuvette with magnetic stirrer groove, fireflesci) was used, modified with a diaphragm screw cap.

[0138] Compression tests were performed using a Shimadzu Autograph AGS-X universal testing machine equipped with a 10kN load cell. Samples were measured at three points using calipers, and the average value was taken to determine the height and contact area used for analysis. Compression was applied at a rate of 0.5 mm / min (approximately 10% / min) until failure.

[0139] Pore ​​size analysis: ImageJ software was used to determine the pore area and structure from SEM images. Images were converted to binary images, inverted, and all images were thresholded to 175 / 255. The area within the pores was calculated using ImageJ particle analysis software, with measurements taken against the image scale. For each component, three images were analyzed at approximately 25,000x magnification and used to generate the average and calculate the standard deviation of the nanopore diameter. The diameter was calculated based on the measured area from the ImageJ analysis, assuming the pores were geometrically circular on average.

[0140] Nitrogen adsorption and Brunauer-Emmett-Teller (BET) analysis: All samples were activated under reduced pressure at 70˚C for 15 h prior to the gas adsorption experiments. All isotherms were recorded on a Quantachrome Autosorb iQ apparatus at 77 K. N2 (99.995+%) was purchased from Praxair. Samples for gas adsorption were printed, using dried cylinders with a geometry of 22 mm × 3 mm (height × diameter). Surface area was determined using the BET equation, with three runs performed on the same sample to determine the mean and standard deviation.

[0141] Polymer density: The density of the non-porous polymer (TPGDA) ρ was measured under ambient conditions using an Archimedes density kit and calculated as follows:

[0142]

[0143] in, It is the mass of the dried polymer immersed in the auxiliary solvent, and This refers to the density of the auxiliary solvent under environmental conditions. Heptane, a hydrophobic and nonpolar solvent, is chosen. = 0.684 g / cm³, which was used as a reference solvent because solvent uptake by this medium should be negligible during the associated measurements. These measurements were performed with three separate samples to obtain an average. The density of the porous polymer was measured by 3D printing three 5mm × 5mm × 5mm solid cubes and drying them with a CPD. The samples were measured with calipers to determine the volume and with an analytical balance to determine the mass. The densities of the three samples were averaged to provide the standard deviation.

[0144] Conductivity: An Oakton CON 550 replacement conductivity cell K=1 probe was used for conductivity measurements. Conductivity standards of 84 μS / cm, 1413 μS / cm, and 12.89 84 mS / cm purchased from Oakton were used to calibrate the probe. Deionized water with a conductivity <1.0 μS / cm was used.

[0145] Attenuated total reflectance infrared (ATR-IR) spectra: ATR-FTIR spectra were recorded on Infinity Gold FTIR with ZnSe crystals at the Texas Materials Institute at the University of Texas at Austin (UT Austin).

[0146] Thermogravimetric analysis (TGA): Perform TGA on a TA Instruments TGA Q500 with a heating rate of 5.00℃ / min to 30℃, isothermal for 15 minutes, and a heating rate of 5.00℃ / min to 800℃.

[0147] Differential Scanning Calorimetry (DSC): DSC was performed using a TA Instruments DSC2500, employing a modulated heating-only method, increasing at a rate of 3.00 °C / min, ranging from -90 °C to 200 °C.

[0148] Inductively Coupled Plasma Mass Spectrometry: ICP-MS analysis was performed using an Agilent 7500ce inductively coupled plasma spectrometer and the quadrupole ICP-MS laboratory at the Jackson Institute of Earth Sciences (University of Texas at Austin).

[0149] Elemental analysis: Combustion elemental analysis was performed at the Atlantic Microlab in Norcross, Georgia, using a Carlo Erba 1108 elemental analyzer.

[0150] X-ray analysis: X-ray analysis of the single crystal was performed on a Rigaku Oxford Synergy-S instrument with a HyPix6000E detector, using a Cu Kα radiation source (λ = 1.5418 Å) and a collimating mirror monochromator.

[0151] This disclosure also includes the following aspects.

[0152] Aspect 1:

[0153] A porous polymer structure includes: a nanoporous polymer matrix comprising repeating units derived from a supporting monomer and an acceptor monomer capable of binding to a metal; wherein the nanoporous polymer matrix comprises a plurality of nanopores having an average pore size of 1 to 1000 nanometers.

[0154] Aspect 2:

[0155] The porous polymer structure as described in aspect 1, wherein the supporting monomer comprises a crosslinking agent, the crosslinking agent comprising at least two polymerizable groups, preferably at least two olefinically unsaturated polymerizable groups, more preferably (meth)acrylate groups.

[0156] Aspect 3:

[0157] The porous polymer structure as described in aspect 1 or 2, wherein the supporting monomer comprises alkylene glycol diacrylate, preferably tripropylene glycol diacrylate.

[0158] Aspect 4:

[0159] The porous polymer structure as described in any one of aspects 1 to 3, wherein the acceptor monomer comprises: an olefinic unsaturated polymerizable group, preferably a (meth)acrylate group; and at least one acceptor group capable of binding to the metal.

[0160] Aspect 5:

[0161] The porous polymer structure as described in any one of claims 1 to 4, wherein the metal comprises cobalt, nickel, lithium, manganese, arsenic, trivalent lanthanide elements, preferably neodymium or dysprosium, or trivalent group 13 metals, preferably gallium or indium.

[0162] Aspect 6:

[0163] The porous polymer structure as described in aspect 4 or 5, wherein the at least one acceptor group capable of binding with the metal includes a dicyclohexylamide acceptor group.

[0164] Aspect 7:

[0165] The porous polymer structure as described in any one of aspects 1 to 6, wherein the acceptor group capable of binding with the metal comprises a dicyclohexylamide group, preferably wherein the acceptor monomer has the following structure:

[0166] .

[0167] Aspect 8:

[0168] The porous polymer structure of any of aspects 1 to 6, wherein the acceptor group capable of binding with the metal comprises a tricyclohexylamide group, preferably wherein the acceptor monomer has the following structure:

[0169] .

[0170] Aspect 9:

[0171] The porous polymer structure described in any one of aspects 1 to 6, wherein the acceptor group capable of binding with the metal comprises hemispherical or crown ether-bound cup[4]pyrrole.

[0172] Aspect 10:

[0173] The porous polymer structure as described in any one of aspects 1 to 6, wherein the acceptor group capable of binding with the metal includes ethanolamide, chelidonic acid, or dipyridylcarboxylic acid.

[0174] Aspect 11:

[0175] The porous polymer structure as described in any one of aspects 1 to 6, wherein the acceptor group capable of binding with the metal includes hydroxypyridinone Fe(III).

[0176] Aspect 12:

[0177] The porous polymer structure as described in any one of aspects 1 to 11, wherein the nanoporous polymer matrix has a three-dimensional lattice structure comprising a plurality of channels having an average channel diameter of 1 micrometer to 10 millimeters.

[0178] Aspect 13:

[0179] The porous polymer structure as described in any one of aspects 1 to 12, wherein the nanoporous polymer matrix has a Kelvin lattice structure or a helical lattice structure.

[0180] Aspect 14:

[0181] The porous polymer structure as described in any one of aspects 1 to 13, wherein the plurality of nanopores have an average pore size of 50 to 500 nanometers or 80 to 280 nanometers.

[0182] Aspect 15:

[0183] The porous polymer structure as described in any one of aspects 1 to 14, wherein repeating units derived from the acceptor monomer are present in the polymer network in an amount of 1 to 50 weight percent, or 1 to 20 weight percent, or 1 to 10 weight percent, each amount based on the total weight of the polymer network.

[0184] Aspect 16:

[0185] The porous polymer structure as described in any one of aspects 1 to 15, wherein the porous polymer structure is prepared by an additive manufacturing process, preferably by digital light processing.

[0186] Aspect 17:

[0187] A method for manufacturing a porous polymer structure according to any one of aspects 1 to 16, the method comprising: providing a resin mixture comprising the supporting monomer, the acceptor monomer, a photoinitiator, and a porogen; and irradiating the resin mixture with light to provide the porous polymer structure.

[0188] Aspect 18:

[0189] The method of aspect 17, wherein the pore-forming agent is present in an amount of 1 to 90 weight percent based on the total weight of the resin mixture.

[0190] Aspect 19:

[0191] The method as described in aspect 17 or 18, wherein the photoinitiator is capable of initiating polymerization when irradiated with visible or ultraviolet light.

[0192] Aspect 20:

[0193] The method of any of aspects 17 to 19 further includes removing the pore-forming agent.

[0194] Aspect 21:

[0195] The method of any one of aspects 17 to 20, wherein the pore-forming agent comprises cyclohexanol, 1-decanol, or a combination thereof.

[0196] Aspect 22:

[0197] A method for incorporating a target metal, the method comprising: contacting a fluid mixture containing the target metal with a porous polymer structure as described in any one of aspects 1 to 16 above, or the porous polymer structure prepared by any one of aspects 17 to 21.

[0198] Aspect 23:

[0199] The method as described in aspect 22, wherein the contact is carried out in the presence of a solvent that improves the binding efficiency of the target metal to the receptor, preferably an alcohol solvent, more preferably ethanol or isopropanol.

[0200] Aspect 24:

[0201] The method, as described in any of aspects 22 to 23, further includes releasing the captured target metal class by contacting the porous polymer network containing the captured target metal class with a solvent (preferably water) that reduces the binding efficiency of the target metal class to the receptor.

[0202] Aspect 25:

[0203] The method described in any of aspects 22 to 24, wherein the target metal is cobalt, nickel, lithium, manganese, arsenic, a trivalent lanthanide element, preferably neodymium or dysprosium, or a trivalent group 13 metal, preferably gallium or indium.

[0204] Aspect 26:

[0205] A system for removing a target metal from a fluid mixture, the system comprising: a feed container including a fluid mixture containing the target metal and having an inlet and an outlet; a pump in fluid communication with the outlet of the feed container, wherein the pump is capable of delivering the fluid mixture into a cartridge comprising a porous polymer structure according to any one of aspects 1 to 16; wherein the outlet of the cartridge is in fluid communication with the inlet of the feed container.

[0206] Aspect 27:

[0207] The system as described in aspect 26 further includes an in-situ monitoring loop for analyzing the concentration of the metals in the fluid mixture.

[0208] Aspect 28:

[0209] The system described in aspect 26 or 27 includes one or more fluidly connected boxes in series, wherein each box includes a porous polymer structure capable of incorporating different target metal classes.

[0210] The compositions, methods, and articles may alternatively include, consist of, or substantially consist of any suitable materials, steps, or components disclosed herein. The compositions, methods, and articles may also be formulated to be free of or substantially free of any materials (or classes of substances), steps, or components that are not necessary to achieve the function or objective of the compositions, methods, or articles.

[0211] All scopes disclosed herein include endpoints, which can be independently combined with each other. "Combination" includes blends, mixtures, alloys, reaction products, etc. The terms "first," "second," etc., do not indicate any order, quantity, or importance, but are used to distinguish one element from another. The terms "a," "an," and "described" do not indicate a limitation of quantity and should be interpreted to cover both singular and plural unless otherwise stated herein or explicitly contradicted by the context. Unless explicitly stated otherwise, "or" means "and / or." Throughout the specification, the reference to "an aspect" means that a particular element described in connection with that aspect is included in at least one aspect described herein and may be present or absent in other aspects. The term "combination thereof" as used herein includes one or more listed elements and is open to the presence of one or more unnamed similar elements. Furthermore, it should be understood that the described elements can be combined in any suitable manner in each aspect.

[0212] Unless otherwise specified herein, all test standards are the most recent standards in effect as of the date of filing of this application, or, if priority is claimed, the most recent standards as of the date of filing of the earliest priority application in which the test standards appeared.

[0213] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if any terminology in this application contradicts or conflicts with a terminology in an incorporated reference, the terminology from this application shall take precedence over the conflicting terminology from the incorporated reference.

[0214] Compounds are described using standard nomenclature. For example, any position not substituted by any specified group is understood to be filled with the indicated bond or hydrogen atom at its valence. A dash ("-") not between two letters or symbols is used to indicate the attachment point of a substituent. For example, -CHO is attached to the carbonyl group.

[0215] Unless otherwise specified, each of the above groups may be unsubstituted or substituted, provided that the substitution does not have a significant adverse effect on the synthesis, stability, or use of the compound. "Substituted" means that the compound, group, or atom is substituted by at least one (e.g., 1, 2, 3, or 4) substituents other than hydrogen, wherein each substituent is independently nitro (-NO2), cyano (-CN), hydroxyl (-OH), halogen, mercapto (-SH), thiocyanate (-SCN), C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 1-6 Haloalkyl, C 1-9 Alkoxy, C 1-6 Halogenated alkoxy, C3-12 cycloalkyl, C 5-18 Cycloalkenyl, C 6-12 Aryl, C 7-13 Arylalkylene (e.g., benzyl), C 7-12 Alkyl arylide (e.g., tolyl), C 4-12 Heterocyclic alkyl, C 3-12 heteroaryl, C 1-6 alkylsulfonyl (-S(=O)2-alkyl), C 6-12 The substitution is an arylsulfonyl group (-S (=O, 2-aryl) or toluenesulfonyl group (CH3C6H4SO2-), provided that the valence does not exceed the normal valence of the substituted atom and that the substitution does not have a significant adverse effect on the preparation, stability, or desired properties of the compound. When a compound is substituted, the number of carbon atoms shown is the total number of carbon atoms in the compound or group (including carbon atoms of any substituent).

[0216] While specific embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that may not be currently foreseeable by the applicant or others skilled in the art are likely to occur. Therefore, the appended claims and their possible modifications are intended to cover all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims

1. A porous polymer structure comprising: Nanoporous polymer matrix comprising repeating units derived from the following substances: Receptor monomers capable of binding to metals, and Optional supporting monomer; The nanoporous polymer matrix comprises multiple nanopores having an average pore size of 1 to 1000 nanometers.

2. The porous polymer structure as described in claim 1, wherein, The supporting monomer is present and includes a crosslinking agent, which contains at least two polymerizable groups, preferably at least two olefinically unsaturated polymerizable groups, more preferably (meth)acrylate groups.

3. The porous polymer structure as described in claim 1, wherein, The acceptor monomer includes an olefinic unsaturated polymerizable group, preferably a (meth)acrylate group, and at least one acceptor group capable of binding to the metal.

4. The porous polymer structure as described in claim 1, wherein, The metals include cobalt, nickel, lithium, manganese, arsenic, trivalent lanthanides, preferably neodymium or dysprosium, or trivalent group 13 metals, preferably gallium or indium.

5. The porous polymer structure as described in claim 3, wherein, The at least one acceptor group capable of binding to the metal includes a dicyclohexylamide acceptor group.

6. The porous polymer structure as described in claim 1, wherein, The acceptor groups capable of binding to the metal include The dicyclohexylamide group, preferably wherein the acceptor monomer has the following structure: ;or The tricyclohexylamino group, preferably wherein the receptor monomer has the following structure: 。 7. The porous polymer structure as described in claim 1, wherein, The acceptor group capable of binding to the metal includes Spherical or crown ether-bound cup [4] pyrrole; or Ethanolamide, chelidonic acid, or dipyridylcarboxylic acid; or Hydroxypyridone iron (III).

8. The porous polymer structure as described in claim 1, wherein, The nanoporous polymer matrix has a three-dimensional lattice structure containing multiple channels with an average channel diameter of 1 micrometer to 10 millimeters.

9. The porous polymer structure as described in claim 1, wherein, The nanoporous polymer matrix has a Kelvin lattice structure or a helical lattice structure.

10. The porous polymer structure of claim 1, wherein, The plurality of nanopores have an average pore size of 50 to 500 nanometers or 80 to 280 nanometers.

11. The porous polymer structure of claim 1, wherein, Repeating units derived from the receptor monomer are present in the polymer network in amounts of 1 to 100 weight percent, or 1 to 99 weight percent, or 1 to 90 weight percent, or 1 to 50 weight percent, each amount being based on the total weight of the polymer network.

12. The porous polymer structure of claim 1, wherein, The porous polymer structure is prepared by additive manufacturing, preferably by digital light processing.

13. A method for manufacturing the porous polymer structure of claim 1, the method comprising: A resin mixture is provided, the resin mixture comprising: The receptor monomer; The optional support unit; Photoinitiators that can initiate polymerization when irradiated with visible or ultraviolet light; and Pore-forming agents; and The resin mixture is irradiated with light to provide the porous polymer structure.

14. The method of claim 13, wherein, The porogen is present in an amount of 1 to 90% by weight based on the total weight of the resin mixture.

15. The method of claim 13, further comprising removing the porogen.

16. A method for combining a target metallic object, the method comprising: The fluid mixture containing the target metal is brought into contact with the porous polymer structure of claim 1.

17. The method of claim 16, wherein, The contact is carried out in the presence of a solvent that enhances the binding efficiency of the target metal to the receptor, preferably an alcohol solvent, more preferably ethanol or isopropanol.

18. The method of claim 16, further comprising releasing the captured target metal class by contacting the porous polymer network containing the captured target metal class with a solvent that reduces the binding efficiency of the target metal class and the receptor, the solvent preferably being water.

19. A system for removing target metallic objects from a fluid mixture, the system comprising: A feed container containing a fluid mixture of a target metal type, and having an inlet and an outlet; A pump in fluid communication with the outlet of the feed container, wherein the pump is capable of delivering the fluid mixture into a cartridge comprising the porous polymer structure of claim 1; The outlet of the filter cartridge is fluidly connected to the inlet of the feed container; and The system may optionally include an in-situ monitoring loop for analyzing the concentration of metals in the fluid mixture.

20. The system of claim 19, comprising one or more series-fluid-connected housings, wherein, Each box contains a porous polymer structure capable of binding different target metals.

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