CLAIM OF PRIORITY

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/308,293, filed February 9, 2022, which is incorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] The invention relates to impermeable 2D polymers.

BACKGROUND

[0003] Polymers that extend covalently in two dimensions have been conceptualized for more than 85 years but their synthesis has remained elusive.

SUMMARY

[0004] In one aspect, a film can include a layer including a two dimensional polymer, the film having a low permeability. For example, the film can have an oxygen permeability of less than 6xl0' ⁵ barrer or less than 0.13xl0' ⁵ barrer.

[0005] In another aspect, a method of making a film can include coating a substrate with a two dimensional polymer to form a film, the film having a low permeability.

[0006] In another aspect, a method of altering permeability of a film can include coating a substrate with a two dimensional polymer to form a film, the film having a low permeability; and exposing the film to a solvent during or after forming the film.

[0007] In certain circumstances, the two dimensional polymer can be a polyaramide.

[0008] In certain circumstances, the layer can include a polyacrylate, a polymethacrylate, a polyvinylalcohol, a polyolefin, a polyethylene, a polypropylene, or a polyacrylonitrile.

[0009] In certain circumstances, the two dimensional polymer can have a controlled porosity.

[0010] In certain circumstances, the film can include a controlled porosity.

[0011] In certain circumstances, the controlled porosity can be created by exposure to a solventx. [0012] In certain circumstances, exposure to a solvent can include exposure to a solvent vapor, immersing in a solvent, or coating with a solvent.

[0013] In certain circumstances, the solvent can include a hydrocarbon or an alcohol.

[0014] In certain circumstances, the method can include depositing a polymer film on the substrate prior to coating the substrate with the two dimensional polymer.

[0015] In certain circumstances, the film can have an oxygen permeability at least 20 times, at least 30 times, at least 40 times, or at least 45 times less than a film including only a one dimensional polymer.

[0016] Other embodiments are described below and are within the claims.

DETAILED DESCRIPTION

[0017] Solution phase synthesis can be used to produce two dimensional polymers as ultra- light weight, high strength materials. Two-dimensional polymers are described, for example, in U.S. Patent Application No. 16/919,051 and Zeng, et al., Nature, 2022, Vol. 608, p. 91, each of which is incorporated by reference in its entirety.

[0018] Irreversible 2D polymerization without any 2D confinement is extremely untrivial because organic single bonds inside of the structure free rotate in 3D space, leading to enormous amount of twisty conformations. Although the in-plane 2D growth is entirely unfavored, it can still be realized using a number of strategies. The first one is to significantly reduce the energy barrier of in-planar growth by autocatalysis. Specifically, once negligible amount of 2D seeds are formed out of the very first random growth period, they serve as templates and guide monomers react on their 2D surfaces. This templating pathway can allow a rapid self-replication of 2D structures and therefore outcompete the random growth pathway. Another strategy is to diminish the entropy cost by rigidifying the whole reaction system, including aiming smaller nanopores with planar linkages, reducing degrees of freedom within the nanopore structure, and introducing hyperconjugations to help each segment keeps parallel with its neighbors. Hydrogen bonding can also have an impact on the synthesis of the final product.

[0019] Permeability of a two dimensional polymer can be altered by changing the pore size of the two dimensional structure. Pore size can be created by templated growth, introduction of mixed solvents to alter reaction kinetics, or including mixed monomer types in a reaction mixture. For example, alcohols such as isopropanol or ethanol can be added to the reaction mixture to change the intrinsic pore size and thus impact the overall permeability of the material.

[0020] Varying the monomers used to make the two dimensional polymer can alter the pore size of films of the two dimensional polymer. Moreover, combining different monomers to form a blended two dimensional polymer can alter the permeability of a film of the polymer.

[0021] In another aspect, a composition can include a two dimensional polymer derived from at least or

[0022] wherein Ri is a leaving group and R2 is H or C1-C6 alkyl, n is 2, 3, 4 or 5, m is 3, 4 or 5, and at least one of the A ring and the B ring is, independently, a planar symmetric ring. The symmetric ring can be a C3 or C4 symmetric ring. A C3 symmetric ring has a three-fold rotational axis perpendicular to the plane of the ring. A C4 symmetric ring has a four-fold rotational axis perpendicular to the plane of the ring.

[0023] In another aspect, a method of making a polymer can include contacting and wherein R ₁ is a leaving group and R ₂ is H or C1-C6 alkyl, n is 2, 3, 4 or 5, m is 3, 4 or 5, and each of the A ring and the B ring is, independently, an aromatic ring, [0024] In certain embodiments, the two dimensional polymer is derived from structures including ring A and ring B. The Lewis base sites on the aromatic ring in either monomer A or B can assist with overcoming solubility problems for the material.

[0025] A two dimensional material can be formed, for example, when n cis 3 and m is 3, n is 2 and m is 3, n is 3 and m is 2, n is 4 and m is 2 or n is 2 and m is 4. [0026] In certain circumstances, n can be 3, m can be 3, and the two dimensional material can include a structure wherein each Z is an amide, urea, or carbamate linkage.

[0027] In certain circumstances, R ₂ can be H. [0028] In certain circumstances, before reaction, the A ring can be

, wherein R is H, halo, C1-C6 alkoxy or C1-C6 alkyl and X is a leaving group.

[0029] In certain circumstances, before reaction, the A ring can be , wherein R is H, halo, C1-C6 alkoxy or C1-C6 alkyl and X is a leaving group.

[0030] In certain circumstances, before reaction, the B ring can be

, wherein each Y is, independently, N or CR ₃ , wherein R ₃ is H, halo, C1-

C6 alkoxy or C1-C6 alkyl.

[0031] In certain circumstances, X can be halo, hydroxyl, methoxy, or acetoxy.

[0032] In certain circumstances, the two-dimensional polymer can include a structure

[0033] Each ring can be an organic ring structure. Examples of 2D ring structures that could be modified to form the polymers described here can be found, for example, in Huang, et al., Nature Reviews Materials, Volume 1, Oct. 2016, pages 1-19, which is incorporated by reference in its entirety.

[0034] In certain circumstances, the A ring can include a carbocyclic aromatic.

[0035] In certain circumstances, the carbocyclic aromatic can be phenyl, naphthyl, antrhracenyl, phenanthrenyl, chrysenyl, pyrenyl, corannulenyl, triphenyl benzene, or coronenyl.

[0036] In certain circumstances, the B ring can include a heterocyclic aromatic. [0037] In certain circumstances, the heterocyclic aromatic can be pyridinyl, pyrimidinyl, triazinyl, pteridinyl, or a porphyrin.

[0038] In certain circumstances, before reaction, the A ring can be

, wherein R is H, halo, C1-C6 alkoxy or C1-C6 alkyl and X is a leaving group.

[0039] In certain circumstances, before reaction, the A ring can be , wherein R is H, halo, C1-C6 alkoxy or C1-C6 alkyl and X is a leaving group.

[0040] In certain circumstances, before reaction, the B ring can be

, wherein each Y is, independently, N or CR ₃ , wherein R ₃ is H, halo, C1-C6 alkoxy or C1-C6 alkyl. [0041] In certain circumstances, X can be halo, hydroxyl, methoxy, or acetoxy.

[0042] In another aspect, a composition can include a two dimensional polymer derived from a planar building block. The two dimensional polymer can include one or more of the following building blocks:

[0043] In these building blocks, each R, independently can be H, C1-C6 acyl or C1-C6 alkyl.

[0044] In the building blocks, each X can be an amino group, hydroxyl group, carboxyl group, anhydride group, or isocyanate group. [0045] The two dimensional polymer can form through reaction of X groups, anhydride groups or carbonyl groups of the building blocks with a polyamine building block.

[0046] In certain circumstances, the polyamine building block can include a planar amine including at least three amine groups each of which forms an amide bond with one of the planar building blocks to form the two dimensional polymer. For example, the planar amine can include a tri-amino aryl group.

[0047] In certain circumstances, the aryl can be a carbocyclic aromatic or a heterocyclic aromatic. For example, the carbocyclic aromatic can be phenyl, naphthyl, antrhracenyl, phenanthrenyl, chrysenyl, pyrenyl, corannulenyl, triphenyl benzene, or coronenyl. In another example, the heterocyclic aromatic is pyridinyl, pyrimidinyl, triazinyl, pteridinyl, or a porphyrin.

[0048] In certain circumstances, a planar building block can include where each X is an amino group, hydroxyl group, carboxyl group, anhydride group, or isocyanate group. Preferably, each X is the same. [0049] In certain circumstances, the planar building block can include

[0050] In certain circumstances, the planar building block can include where each X is an amino group, hydroxyl group, carboxyl group, anhydride group, or isocyanate group. Preferably, each X is the same. Each R, independently is H, C1-C6 acyl or C1-C6 alkyl. Preferably, each R is the same.

[0051] In certain circumstances, the planar building block can include where each X is an amino group, hydroxyl group, carboxyl group, anhydride group, or isocyanate group. Preferably, each X is the same.

[0052] In certain circumstances, the planar building block can include

[0053] In certain circumstances, the planar building block can include

[0054] In certain circumstances, the planar building block can include where each R, independently is H, C1-C6 acyl or C1-C6 alkyl. Preferably, each R is the same.

[0055] In certain circumstances, the planar building block can include [0056] In certain circumstances, the planar building block can include carboxyl group, anhydride group, or isocyanate group. Preferably, each X is the same.

[0057] In certain circumstances, the planar building block can include

[0058] In certain circumstances, the planar building block can include where each X is an amino group, hydroxyl group, carboxyl group, anhydride group, or isocyanate group. Preferably, each X is the same. [0059] In certain circumstances, the planar building block can include where each X is an amino group, hydroxyl group, carboxyl group, anhydride group, or isocyanate group. Preferably, each X is the same.

[0060] In certain circumstances, the planar building block can include where each X is an amino group, hydroxyl group, carboxyl group, anhydride group, or isocyanate group. Preferably, each X is the same.

[0061] In certain circumstances, the planar building block can include

where each X is an amino group, hydroxyl group, carboxyl group, anhydride group, or isocyanate group. Preferably, each X is the same.

[0062] In certain circumstances, the material includes a plurality of the structure. In other words, the material includes a two-dimensional network including repeating units of the structure. [0063] In certain circumstances, the material can have an in-plane structure. In certain circumstances, the material can have an out-of-plane structure. The in-plane structure is a structure in which the angle of the amide or other polar bonds are relatively small, for example, may be less than 30 degree. The out-of-plane structure is a structure having the amide or other polar bonds out of the plane of the ring structures. The out-of-plane structure can create high density of interlayer hydrogen bonds in the structure and thus have different pore sizes.

[0064] In another aspect, a method of manufacturing a composition described herein can include combining a planar building block with a polyamine building block to form the two dimensional polymer.

[0065] In certain circumstances, the combining takes place in a solvent selected from trifluoroacetic acid (TFA), trifluoroethanol (TFE), N-methyl-2-pyrrolidone (NMP), 1,3-dimethyl- 2-imidazolidinone (DMI), N,N'-dimethylpropyleneurea (DMPU), or hexamethylphosphoramide (HMPA) and salt solutions thereof. The salt can be a Lewis Acid, such as calcium chloride or lithium chloride.

[0066] The reaction conditions are important in determining whether the in-plane or out-of- plane structure is created. This is the case, in part, because the reaction is kinetically controlled. This selectivity can be important because in order to get strong interlayer hydrogen bonding, the amide bonds need to orient out of the molecular plane, and the out-of-plane structure is actually energetically unfavored compared to the in-plane structure. The energy difference is large (~70 Kcal/nanopore), making the achievement of the out-of-plane structure surprising. A common feature of those solvents is they are strong Lewis bases thus can serve as great hydrogen bond acceptors. Additives can also enhance the synthesis. The salts such as CaCh, LiCl and others are Lewis acids here, can help to dissolve the 2D molecules and also facilitate this reaction. Solubility is important because once the 2D polymer molecule leave the reaction system, it stops growing. According to simulation, the strength of bulk material has a strong correlation with the molecular size.

[0067] In another aspect, a method of forming a coating of a two-dimensional material can include depositing a material described herein on a surface. The coating can be formed by spin coating, dip coating or drop coating the material on the surface, for example, in a solution. The solvent can be polar and protic, for example, an acid such as trifluoroacetic acid (TFA).

[0068] The two dimensional polymer can be deposited to form a film. The film can have a thickness of 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, or 60 nm. The thickness can be less than 10 microns, less than 5 microns, less than 1 micron, less than 100 nm, less than 90 nm, less than 80 nm or less than 70 nm. The film can be substantially uniform in thickness.

[0069] The two dimensional polymer can be deposited on a layer of a second polymer. The second polymer can be a film-forming polymer, such as, for example, a polyacrylate, polymethacrylate, a polyvinylalcohol, a polyolefin, a polyethylene, a polypropylene, a polystyrene, a polysulfone, or a polyacrylonitrile. [0070] In one aspect, a film can include a layer including a two dimensional polymer, the film having a low permeability. For example, the film can have an oxygen permeability of less than 6xl0' ⁵ barrer or less than 0.13xl0' ⁵ barrer.

[0071] In another aspect, a method of making a film can include coating a substrate with a two dimensional polymer to form a film, the film having a low permeability.

[0072] In another aspect, a method of altering permeability of a film can include coating a substrate with a two dimensional polymer to form a film, the film having a low permeability; and exposing the film to a solvent during or after forming the film.

[0073] In certain circumstances, the two dimensional polymer can include a polyaramide. In certain circumstances, the two dimensional polymer can include a blend of at least two different polyaramides. For example, the different polyaramides can have the same composition and polymerized in different conditions. In another example, the different polyaramides can be derived from at least one different monomer.

[0074] In certain circumstances, the layer can include a polyacrylate, a polymethacrylate, a polyvinylalcohol, a polyolefin, a polyethylene, a polypropylene, or a polyacrylonitrile. The layer can be a monolayer blend of polymers. In another circumstance, the layer can be a bilayer, a trilayer, a tetralayer, or a multilayer of different polymers.

[0075] In certain circumstances, the two dimensional polymer can have a controlled porosity.

[0076] In certain circumstances, the film can include a controlled porosity.

[0077] In certain circumstances, the controlled porosity can be created by exposure to a solvent, immersing in a solvent, or coating with a solvent.

[0078] In certain circumstances, the solvent can include a hydrocarbon or an alcohol.

[0079] In certain circumstances, the method can include depositing a polymer film on the substrate prior to coating the substrate with the two dimensional polymer.

[0080] In certain circumstances, the film can have an oxygen permeability at least 20 times, at least 30 times, at least 40 times, or at least 45 times less than a film including only a one dimensional polymer.

[0081] To create the films for permeability measurements, a solution of 5-10mg/mL of 2D polyaramide (2DPA-1) in trifluoroacetic acid and a 10wt% polymethyl methacrylate (PMMA) in anisole are required. First, the PMMA solution is spin-coated onto a silicon wafer at 2000rpm for 1 minute, then heated at 110°C for five minutes. The 2DPA-1 solution is spin-coated on top of the PMMA layer at 2000rpm for 1 minute and subsequently heated at 50°C for five minutes. Next, using water, the spin-coated layers are removed from the silicon wafer. The layers are then transferred to a silicon substrate with etched wells such that the 2DPA-1 layer contacts the silicon substrate. The remaining water is removed from between the 2DPA-1 layer and the silicon substrate by drying for 2 hours at 45°C. Afterwards, the silicon substrate and spin-coated layers are suspended slightly above a layer of chloroform in a vial. Hexane is slowly added to the vial such that the silicon substrate system is fully submerged in hexane. Once the hexane has evaporated away, the 2DPA-1 layer is ready for permeability measurements.

[0082] The permeability of a 2DPA-1 film was calculated using the equations and methods outlined in Zeng et al. Air trapped in the etched wells in the silicon substrate cause the 2DPA-1 film to protrude, and this protrusion changed height in accordance with the 2DPA-1 film’s permeability. This height change was measured with atomic force microscopy (AFM). Results suggest an O ₂ permeability as low as 0.13*10 ^-5 barrer, which is 46 times less than one of the most impermeable 1D polymers, EVOH (6*10 ^-5 barrer), a material commonly used in food packaging as an O ₂ barrier. See, Leterrier, Y. Progress in Materials Science 48, 1-55 (2003), which is incorporated by reference in its entirety.

[0083] Details of one or more embodiments are set forth in the accompanying drawings and description. Other features, objects, and advantages will be apparent from the description, drawings, and claims. Although a number of embodiments of the invention have been described, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. It should also be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features and basic principles of the invention.