Systems and methods using photochemical oxygen storage and release - Patents.com

Abstract

Disclosed herein are methods for converting light energy into mechanical energy and / or for oxygen storage, purification, isolation, concentration, and / or removal. The methods can include exposing a mixture of a polycyclic aromatic compound and a photosensitizer to oxygen and light to form an endoperoxide, and decomposing the endoperoxide to reform the polycyclic aromatic compound and oxygen. The polycyclic aromatic compound can be a naphthalene compound or an anthracene compound and / or can have the formula (I): JPEG2022545700000020.jpg2735

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 892,758, filed August 28, 2019, which is incorporated herein by reference in its entirety.

[0002] Field This application relates to systems and methods for oxygen storage and release using photochemical reactions and the conversion of light into mechanical energy. [Background technology]

[0003] background Oxygen is usually purified using energy-intensive processes such as distillation of liquefied air, and efficient storage of oxygen usually requires compression for high pressure and / or liquefaction. Oxygen can also be produced from certain irreversible reactions, such as from alkaline perchlorates exposed to high temperatures, which can also release toxic chlorine gas. Few chemically reversible systems for oxygen storage have been reported, and those that do usually require high temperatures for oxygen release.

[0004] Furthermore, few methods have been reported for converting light energy, such as solar energy, into mechanical energy. Mechanical energy is generated using the splitting and recombination reaction of nitrosyl chloride (NOCl) gas under ultraviolet (UV) light to produce NO and Cl2. However, the maximum potential of this process is limited to a pressure / volume change of twice the initial number of moles of NOCl, and still requires UV light. Furthermore, nitrosyl chloride is highly toxic and irritating to the eyes, lungs and skin, is a strong oxidizing agent, and both reaction products, chlorine and NO gas, are also toxic. Summary of the Invention [Means for solving the problem]

[0005] overview Disclosed herein are embodiments of systems and methods for converting light energy into mechanical energy and / or oxygen storage, purification, isolation and / or concentration. Method embodiments can include exposing a first mixture containing a polycyclic aromatic compound and a photosensitizer to oxygen gas and light to form a second mixture containing endoperoxides, and changing the temperature of the second mixture and / or ceasing irradiation of the second mixture with light to regenerate at least a portion of the polycyclic aromatic compound and release at least a portion of the oxygen gas. In some embodiments, the method includes exposing a first mixture containing a polycyclic aromatic compound and a photosensitizer to a first portion of oxygen gas and light at a first temperature to form a second mixture containing endoperoxides, the first temperature being selected to substantially prevent the endoperoxides from decomposing. The method further includes increasing the temperature of the second mixture to a second temperature suitable for promoting decomposition of the endoperoxides to form regenerated polycyclic aromatic compounds and release oxygen. Typically, the second temperature is higher than the first temperature. The method also includes mixing the released oxygen with an air stream to form an oxygen-enriched air stream that can be provided as needed to a patient in need thereof. Exposing the first mixture to oxygen gas can include exposing the first mixture to ambient air, and / or the method can further include maintaining the second mixture at or below the first temperature for a selected period of time before raising the temperature of the second mixture to a second temperature. Optionally, the method can include exposing a second portion of the reformed polycyclic aromatic compound and photosensitizer to oxygen gas to reform at least a portion of the endoperoxides.

[0006] An alternative embodiment of the method includes the steps of: a) exposing a first mixture comprising a first polycyclic aromatic compound and a first photosensitizer to a first portion of oxygen gas and light from a first light source at a first temperature to form a second mixture comprising a first endoperoxide, wherein the first temperature is selected to substantially prevent decomposition of the first endoperoxide; b) raising the temperature of the second mixture to a second temperature greater than the first temperature and suitable for decomposing the first endoperoxide, thereby reforming at least a portion of the first polycyclic aromatic compound and forming a second portion of oxygen gas that is mixed with the first air stream to form a first oxygen-enriched air stream; c) exposing a third mixture comprising a second polycyclic aromatic compound and a second photosensitizer to a third portion of oxygen gas and light from a second light source at a third temperature to form a fourth mixture comprising a second endoperoxide, wherein the third temperature is selected to substantially prevent decomposition of the second endoperoxide; d) upon substantial decomposition of the first endoperoxide in the second mixture, raising the temperature of the third mixture to a fourth temperature greater than the third temperature and selected to decompose the second endoperoxide, thereby reforming at least a portion of the second polycyclic aromatic compound and forming a fourth portion of oxygen gas which mixes with the second air stream to form a second oxygen-enriched air stream; and e) exposing the first polycyclic aromatic compound and the first photosensitizer to a fifth portion of oxygen gas and light from the first light source to reform at least a portion of the first endoperoxide. Optionally, steps b and c may be performed simultaneously and / or steps d and e may be performed simultaneously.

[0007] An additional embodiment of the method includes exposing a first mixture including a polycyclic aromatic compound, a photosensitizer, and oxygen gas to light in an enclosed space having a first volume to form an endoperoxide by reaction between the polycyclic aromatic compound and the oxygen gas, thereby changing the volume of the enclosed space to a second volume smaller than the first volume. The method may further include removing the light to reform the polycyclic aromatic compound and release at least a portion of the oxygen gas into the enclosed space, thereby changing the volume of the enclosed space to a third volume, which may be greater than the second volume and substantially the same as the first volume. Changing the volume of the enclosed space may produce mechanical work, such as moving a piston.

[0008] A further embodiment of the method includes exposing a first mixture including a polycyclic aromatic compound, a photosensitizer, and oxygen gas to light in an enclosed space having a first pressure to form an endoperoxide by reaction between the polycyclic aromatic compound and the oxygen gas, thereby changing the pressure of the enclosed space to a second pressure less than the first pressure. The method may further include removing the light to reform the polycyclic aromatic compound and release at least a portion of the oxygen gas into the enclosed space, thereby changing the pressure of the enclosed space to a third pressure greater than the second pressure, which may be substantially the same as the first volume. Changing the pressure in the enclosed space may result in mechanical work.

[0009] Embodiments of the disclosed methods can further include exposing the reformed polycyclic aromatic compound to light to reform at least a portion of the endoperoxides, and then removing the light source to once again reform the polycyclic aromatic compound. The step of exposing the first mixture to light can be performed at a first temperature, and / or the step of removing the light can include raising the temperature to a second temperature that is higher than the first temperature.

[0010] In any embodiment, removing the light and / or ceasing or preventing irradiation with light can include physically removing the light source from the mixture, physically removing the mixture from the light source, or a combination thereof; shutting off the light source; turning off the light source; or any combination thereof.

[0011] In any of the disclosed embodiments, the polycyclic aromatic compound may be a naphthalene compound or an anthracene compound and / or may be represented by formula I [ka] may have the following structure:

[0012] With respect to formula I, R 1 , R 2 and R 3 is each independently H, OH, aliphatic, aryl, alkoxy, -O-acyl, -O-Si(alkyl), -O-amino acid, or -O-carbohydrate, n is 0-6, and "---" represents a bond, which may or may not be present. [ka] having a formula selected from:

[0013] In some embodiments, n=0, and / or R 1 and R 2 At least one of them is not H. 1 and R 2 can both be alkyl and / or can be the same or different from each other. In certain embodiments, R 1 and R 2 are the same and are not H. Also, in certain embodiments, the polycyclic aromatic compound is 1,4-dimethylnaphthalene.

[0014] Similarly, in any disclosed embodiment, the first temperature can be between −78° C. and 100° C., such as between 0° C. and 20° C. Additionally or alternatively, the second temperature can be between −40° C. and 100° C. or higher, such as between −40° C. and 50° C. or between 15° C. and 25° C.

[0015] The photosensitizer may be Rose Bengal, methylene blue, eosin B, Ru(bpy)3, methyl green, rubrene, fullerene, nanoparticles, or combinations thereof, and in certain disclosed embodiments, the photosensitizer is Rose Bengal. Additionally or alternatively, the light may be or include visible light and / or near infrared, and / or may have a wavelength between 380 nm and 1000 nm, such as between 380 nm and 740 nm or between 530 nm and 575 nm. In any embodiment, the light may be or include natural light, or the light may include light from an artificial light source, such as an LED light.

[0016] In any embodiment, the first mixture may be a solution or a solid. In an embodiment in which the first mixture is a solution, the solution may further comprise a solvent. The solvent may be any suitable solvent, such as acetonitrile, ethanol, methanol, dichloromethane, hexane, water, ether, dimethylformamide, carbon tetrachloride, chloroform, propylene carbonate, ethylene glycol, propylene glycol, tetrahydrofuran, or a combination thereof. In an alternative embodiment in which the first mixture is a solid, the solid may further comprise a solid support, such as a silica, such as zeolite, diatomaceous earth, a hydrogel, a polymer, a metal-organic framework motif, or a combination thereof. In certain embodiments, the polycyclic aromatic compound and / or the photosensitizer compound is associated, such as absorbed, adsorbed, or covalently bound, with a polymer that forms at least a portion of the solid support. The polymer may be a polyalkyl polymer, such as polyethylene or polypropylene; a polyalkyl glycol, such as polyethylene glycol or polypropylene glycol; a polypeptide; a conjugated polymer chain; a polyacrylic acid, or a combination thereof. In some embodiments, the polycyclic aromatic compound and / or the photosensitizer are covalently bonded to the polymer, and in certain embodiments, both the polycyclic aromatic compound and the photosensitizer are covalently bonded to the polymer. In some embodiments, the polymer has a molecular weight of 3 kDa or less to 1000 kDa or more, such as 5 kDa to 50 kDa. As used herein, the term "molecular weight" with respect to a polymer is the weight average molecular weight determined by proton NMR and size exclusion chromatography.

[0017] Also disclosed herein are embodiments of a system suitable for carrying out the disclosed method. The system can include a first chamber with a first mixture comprising a first polycyclic aromatic compound and a first photosensitizer, a first gas inlet, a first gas outlet, a first pump and a first light source, a second chamber with a second mixture of a first polycyclic aromatic compound and a second photosensitizer, a second gas inlet, a second gas outlet, a second pump and a second light source, and a controller configured to switch air streams between the first gas inlet and the second gas inlet. The system can also include a temperature controller, such as a heater, a cooler or a combination thereof.

[0018] An alternative embodiment of the system relates to an enclosed space, the volume and / or pressure of which may vary, containing a mixture including a polycyclic aromatic compound, a photosensitizer, and a gas including oxygen, and optionally a solvent. The system may further include a light source.

[0019] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings. The present invention provides, for example, the following items. (Item 1) exposing a first mixture comprising a polycyclic aromatic compound and a photosensitizer to a first portion of oxygen gas and light at a first temperature to form a second mixture comprising an endoperoxide, wherein the first temperature is selected to substantially prevent the endoperoxide from decomposing; raising the temperature of the second mixture to a second temperature higher than the first temperature and / or terminating irradiation to promote decomposition of the endoperoxides to form reformed polycyclic aromatic compounds and release oxygen; mixing the released oxygen with an air stream to form an oxygen-enriched air stream; A method comprising: (Item 2) 10. The method of claim 1, wherein exposing the first mixture to oxygen gas comprises exposing the first mixture to ambient air. (Item 3) 10. The method of claim 1, further comprising the step of supplying the oxygen-enriched air stream to a patient in need thereof. (Item 4) 10. The method of claim 1, further comprising maintaining the second mixture at or below the first temperature for a selected period of time before increasing the temperature of the second mixture to the second temperature. (Item 5) 10. The method of claim 1, further comprising exposing the reformed polycyclic aromatic compound and the photosensitizer to a second portion of oxygen gas to reform at least a portion of the endoperoxide. (Item 6) a) exposing a first mixture comprising a first polycyclic aromatic compound and a first photosensitizer to a first portion of oxygen gas and light from a first light source at a first temperature to form a second mixture comprising a first endoperoxide, wherein the first temperature is selected to substantially prevent decomposition of the first endoperoxide; b) increasing the temperature of the second mixture to a second temperature greater than the first temperature suitable for decomposing the first endoperoxide, thereby reforming at least a portion of the first polycyclic aromatic compound and forming a second portion of oxygen gas that is mixed with the first air stream to form a first oxygen-enriched air stream; c) exposing a third mixture comprising a second polycyclic aromatic compound and a second photosensitizer to a third portion of oxygen gas and light from a second light source at a third temperature to form a fourth mixture comprising a second endoperoxide, wherein the third temperature is selected to substantially prevent decomposition of the second endoperoxide; d) once the first endoperoxide has substantially decomposed, increasing the temperature of the third mixture to a fourth temperature greater than the third temperature and selected to decompose the second endoperoxide, thereby reforming at least a portion of the second polycyclic aromatic compound and forming a fourth portion of oxygen gas which mixes with a second air stream to form a second oxygen-enriched air stream; e) exposing the first polycyclic aromatic compound and the first photosensitizer to a fifth portion of oxygen gas and light from the first light source to reform at least a portion of the first endoperoxide. 2. The method of claim 1, comprising: (Item 7) The method of claim 6, wherein step b is performed simultaneously with step c. (Item 8) exposing a first mixture, including a polycyclic aromatic compound, a photosensitizer, and oxygen gas, to light in an enclosed space having a first volume to form an endoperoxide by a reaction between the polycyclic aromatic compound and the oxygen gas, thereby changing the volume of the enclosed space to a second volume smaller than the first volume; ceasing the irradiation with light to regenerate the polycyclic aromatic compound and release at least a portion of the oxygen gas into the enclosed space, thereby changing the volume of the enclosed space to a third volume that is substantially the same as the first volume. A method comprising: (Item 9) The method of claim 8 , wherein the change in volume of the enclosed space causes a piston to move. (Item 10) 9. The method of claim 8, further comprising exposing the reformed polycyclic aromatic compound to light to reform at least a portion of the endoperoxides, and then removing the light source to reform the polycyclic aromatic compound. (Item 11) 9. The method of claim 8, wherein exposing the first mixture to light occurs at a first temperature, and removing the light further comprises raising the temperature to a second temperature higher than the first temperature. (Item 12) exposing a first mixture, including a polycyclic aromatic compound, a photosensitizer, and oxygen gas, to light in an enclosed space having a first pressure to form an endoperoxide by reaction between the polycyclic aromatic compound and the oxygen gas, thereby changing the pressure of the enclosed space to a second pressure less than the first pressure; ceasing the irradiation with light to regenerate the polycyclic aromatic compounds and release at least a portion of the oxygen gas into the enclosed space, thereby changing the pressure in the enclosed space to a third pressure that is substantially the same as the first pressure. A method comprising: (Item 13) The method of claim 12 , wherein the change in pressure in the enclosed space produces work. (Item 14) 13. The method of claim 12, further comprising exposing the reformed polycyclic aromatic compound to light to reform at least a portion of the endoperoxides, and then removing the light source to reform the polycyclic aromatic compound. (Item 15) 13. The method of claim 12, wherein exposing the first mixture to light occurs at a first temperature, and removing the light further comprises raising the temperature to a second temperature higher than the first temperature. (Item 16) 16. The method according to claim 1, wherein the polycyclic aromatic compound is a naphthalene compound or an anthracene compound. (Item 17) The polycyclic aromatic compound has the formula I

change

change

[0020] [Figure 1] FIG. 1 is a graph of absorbance versus wavelength showing the absorbance profiles of various commercially available triplet photosensitizers.

[0021] [Diagram 2] FIG. 2 is a graph of the change in pressure (PSI) versus time showing the change in pressure over time due to consumption of O2 and subsequent release of oxygen under illumination with green light at 22° C. for a mixture of 1,4-dimethylnaphthalene and Rose Bengal.

[0022] [Diagram 3] FIG. 3 is a graph of change in pressure (PSI) versus time showing the change in pressure over time due to cycling the light on and off every 4 hours at 25° C. under atmospheric pressure conditions.

[0023] [Figure 4] FIG. 4 is a graph of change in pressure (PSI) versus time showing the change in pressure over time due to cycling the light on and off every 6 hours at 25° C. under atmospheric pressure conditions.

[0024] [Diagram 5] FIG. 5 is a graph of change in pressure (PSI) versus time showing the pressure change over time for 20%, 30% and 50% 1,4-dimethylnaphthalene (1,4-DMN) in an oxygen atmosphere illuminated with green light.

[0025] [Figure 6] FIG. 6 is a schematic diagram of an exemplary embodiment of a system for converting light energy into mechanical energy via pressure changes due to oxygen uptake and release.

[0026] [Figure 7] FIG. 7 is a schematic diagram of an exemplary embodiment of a continuous flow system for oxygen purification, concentration and / or isolation.

[0027] [Figure 8] FIG. 8 is a schematic diagram of an exemplary embodiment of an oxygen concentrator.

[0028] [Figure 9] FIG. 9 is a graph of the change in pressure (PSI) versus time showing the pressure change due to irradiation of 1,4-DMN and Rose Bengal for 90 minutes followed by 180 minutes of no irradiation at 25° C. under an oxygen headspace for three cycles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Detailed Description I. Definition The following explanations of terms and methods are presented to better explain the present disclosure and guide those skilled in the art in practicing the present disclosure. The singular forms "a", "an" and "the" refer to one or more than one, unless the context clearly dictates otherwise. The term "or" refers to a single element of the specified alternative elements or a combination of two or more elements, unless the context clearly dictates otherwise. As used herein, "comprises" means "includes". Thus, "including A or B" means "including A, B, or A and B," without excluding additional elements. All references, including patents and patent applications, cited herein are incorporated by reference.

[0030] Unless otherwise indicated, all numbers expressing amounts of components, molecular weights, percentages, temperatures, times, and the like used in the specification or claims are to be understood as being modified by the term "about". Thus, unless otherwise indicated, implicitly or explicitly, the numerical parameters described are approximations that may depend on the desired properties sought and / or detection limits under standard testing conditions / methods. When directly and explicitly distinguishing the embodiments from the prior art being discussed, the numerical values ​​of the embodiments are not approximations unless the word "about" is recited.

[0031] Unless otherwise explained, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs.Methods and materials similar to or equivalent to those described herein can be used to practice or test this disclosure, but suitable methods and materials are described below.The materials, methods and examples are merely illustrative and are not intended to be limiting.

[0032] "Substituted," when used to modify a named group or moiety, means that at least one, and possibly two or more, e.g., two, three, four or more, hydrogen atoms of the named group or moiety are independently replaced with the same or different substituents, as defined below and permitted by valence rules. In any particular embodiment, a group, moiety, or substituent may be substituted or unsubstituted, unless expressly defined as either "unsubstituted" or "substituted." Thus, any of the groups specified herein may be unsubstituted or substituted. In certain embodiments, a substituent may or may not be expressly defined as substituted, but is still intended to be substituted as appropriate. For example, an "alkyl" or "aryl" moiety may be unsubstituted or substituted, but an "unsubstituted alkyl" or an "unsubstituted aryl" is not substituted. Exemplary substituents include, but are not limited to, OH; halogen, such as F, Cl, Br, or I; alkyl, such as methyl, ethyl, propyl, isopropyl, butyl, iso-butyl, sec-butyl, or tert-butyl; alkoxy; acyl; benzyl; aryl, such as phenyl or naphthyl; or combinations thereof.

[0033] "Acyl" refers to the group -C(O)R, where R is H, aliphatic, or aromatic. Exemplary acyl moieties include, but are not limited to, -C(O)H, -C(O)alkyl, -C(O)C1-C6alkyl, -C(O)cycloalkyl, -C(O)alkenyl, -C(O)cycloalkenyl, -C(O)alkynyl, or -C(O)aryl. Specific examples include -C(O)H, -C(O)Me, -C(O)Et, or -C(O)phenyl.

[0034] "Aliphatic" refers to a substantially hydrocarbon-based group or moiety. An aliphatic group or moiety is acyclic (which includes alkyl, alkenyl, or alkynyl groups), It may be in its cyclic form (e.g., an alicyclic group or moiety including cycloalkyl, cycloalkenyl, or cycloalkynyl), and further include linear and branched chain arrangements, as well as all stereo and positional isomers. Unless expressly stated otherwise, an aliphatic group is a saturated acyclic aliphatic group or moiety having 1 to 25 carbon atoms (C 1~25 ); For example, 1 to 15 (C 1~15 ), 1~10 pieces (C 1~10 ), 1~6 pieces (C 1~6 ) or 1 to 4 carbon atoms (C 1~4 ), and in the case of unsaturated acyclic aliphatic groups or moieties, 2 to 25 carbon atoms (C 2~25 ); For example, 2 to 15 (C 2~15 ), 2~10 pieces (C 2~10 ), 2~6 pieces (C 2~6 ) or 2 to 4 carbon atoms (C 2~4 ), or in the case of an alicyclic group or moiety, 3 to 15 (C 3~15 ), 3~10 pieces (C 3~10 ), 3~6 pieces (C 3~6 ) or 3 to 4 (C 3~4 ) carbon atoms. An aliphatic group may be substituted or unsubstituted unless expressly referred to as "unsubstituted aliphatic" or "substituted aliphatic" or, for example, unsubstituted alkyl, alkenyl or alkynyl or cyclic versions thereof, or substituted alkyl, alkenyl or alkynyl or cyclic versions thereof. An aliphatic group may be substituted with one or more substituents (up to two substituents for each methylene carbon in the aliphatic chain, or up to one substituent for each carbon of the -C=C- double bond in the aliphatic chain, or up to one substituent for the carbon of the terminal methine group).

[0035] "Alkoxy" refers to the group -OR, where R is a substituted or unsubstituted alkyl group, or a substituted or unsubstituted cycloalkyl group. In certain instances, R is a substituted or unsubstituted cycloalkyl group. 1~6 Alkyl group or C 3~6is a cycloalkyl group. Methoxy (-OCH3) and ethoxy (-OCH2CH3) are exemplary alkoxy groups. In substituted alkoxy, R is a substituted alkyl or substituted cycloalkyl, examples of which include haloalkoxy groups such as -OCF2H or -OCF3.

[0036] "Alkyl" is 1 to 25(C 1~25 ) or more carbon atoms, more typically 1 to 10 (C 1~10 ) carbon atoms, for example, 1 to 6 (C 1~6 ) carbon atoms or 1 to 4 (C 1~4 (-CH(CH3)3) (-CH2CH3) (-CH2CH2CH3) (-CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-CH2CH2CH2CH3) (-C(CH3) ...

[0037] "Aromatic", unless otherwise specified, refers to a cyclic conjugated group or moiety of 5-15 ring atoms having a single ring (e.g., phenyl, pyridinyl, or pyrazolyl) or multiple fused rings, where at least one ring is aromatic (e.g., naphthyl, indolyl, or pyrazolopyridinyl), i.e., at least one ring and optionally the multiple fused rings have a contiguous delocalized pi-electron system. Typically, the number of out-of-plane pi-electrons corresponds to the Huckel rule (4n+2). The point of attachment to the parent structure is typically through the aromatic portion of the fused ring system. For example, [ka] However, in certain instances, the context or explicit disclosure may dictate that the point of attachment is through the non-aromatic portion of the fused ring system. For example, [ka] An aromatic group or moiety can contain only carbon atoms in the ring, such as in an aryl group or moiety, or can contain one or more ring carbon atoms and one or more ring heteroatoms (e.g., S, O, N, P, or Si) that contain lone pairs of electrons, such as in a heteroaryl group or moiety. Unless otherwise specified, an aromatic group can be substituted or unsubstituted.

[0038] "Aryl," unless otherwise specified, refers to an aromatic carbocyclic group of 6 to 15 carbon atoms having a single ring (e.g., phenyl) or multiple fused rings, where at least one ring is an aromatic fused polycyclic ring, where at least one ring is aromatic (e.g., 1,2,3,4-tetrahydroquinoline, benzodioxole, etc.), provided that the point of attachment is through the aromatic portion of the ring system. If any aromatic ring portion contains a heteroatom, the group is heteroaryl and not aryl. Aryl groups may be, for example, monocyclic, bicyclic, tricyclic, or tetracyclic. Unless otherwise specified, aryl groups may be substituted or unsubstituted. II. Overview

[0039] Certain polycyclic aromatic compounds, such as optionally substituted naphthalene or anthracene compounds, can react with singlet oxygen to reversibly form endoperoxides. As used herein, the terms naphthalene and anthracene compounds include the parent compounds, i.e., naphthalene or anthracene, respectively, unless expressly excluded or the context otherwise dictates. Scheme 1 illustrates an exemplary reversible reaction of 1,4-dimethylnaphthalene (1,4-DMN) to produce the corresponding 1,4-DMN endoperoxide. Singlet oxygen ( 1 O2) is triplet oxygen ( 3 O2), an excited state of oxygen that has unique reactivity compared to the reactivity of ground state oxygen. 1The unique reactivity of O2 finds utility in organic oxidation and cancer treatment. The stability of substituted naphthalene and anthracene endoperoxides can vary with different groups at the 1- and 4-positions of the naphthalene, or the 9- and 10-positions of the anthracene. Endoperoxides that are less stable at a particular temperature decompose more readily to give 1 It releases O2 and reforms the original naphthalene or anthracene compound, which is more stable than the endoperoxide. [ka]

[0040] The formation of endoperoxides, such as 1,4-DMN endoperoxide, results from reaction with singlet oxygen, which can be generated using triplet photosensitizers (PS), which transfer energy to ground state oxygen upon irradiation with suitable visible light (Scheme 1). Many triplet photosensitizers are commercially available, 1 The suitability of any particular photosensitizer is limited only by its solubility, unless it reacts with O2, polycyclic aromatic compounds, or the resulting endoperoxides. Thus, by selecting a particular photosensitizer or combination of photosensitizers, it is possible to use nearly all of the visible and NIR spectrum. 1 O2 and thus endoperoxides can be created (FIG. 1). Suitable photosensitizers include, but are not limited to, rose bengal, methylene blue, eosin B, Ru(bpy)3, methyl green, rubrene, fullerene (alkyl, aryl, alkoxy substituted or unsubstituted C 20~94 ), fluorenes (e.g., including 9,9-substituted or 2,7-substituted fluorenes), nanoparticles (e.g., CdTe, ZnSe, SiNPs, CNPs, AuNPs, BiNPs, or nanoparticles including encapsulated small molecule triplet photosensitizers that are bound or encapsulated by silica, proteins or polymers), or combinations thereof.

[0041] A typical solar energy conversion reaction converts solar energy into electricity, which must be stored until needed. In artificial photosynthesis, solar energy is converted into chemical potential in the form of solar fuel, which can be stored until needed. In contrast, disclosed herein are embodiments of systems and methods that exploit the reaction of polycyclic aromatic compounds with singlet oxygen for use in energy or oxygen storage and release applications. Certain embodiments allow for the direct conversion of solar energy into mechanical energy by producing pressure and / or volume changes in the system, which can drive mechanical devices such as pistons. Other embodiments allow for the reversible removal of oxygen from gas mixtures, leading to alternative applications such as oxygen storage, purification, concentration and / or removal.

[0042] Endoperoxides formed by the reaction of naphthalene or anthracene compounds and singlet oxygen release oxygen at a temperature-dependent rate. Thus, oxygen consumption can be controlled by controlling exposure to light, while oxygen release can be controlled using heat. Such systems and methods show promise for the generation of mechanical work in the form of pressure or volume change from light. To the inventors' knowledge, the direct conversion of visible light to mechanical energy has not been reported previously. Furthermore, due to the selective reaction with singlet oxygen, this approach can be used for the purification and / or removal of oxygen from gaseous mixtures such as atmospheric air. III.Compound

[0043] Suitable compounds for use in the disclosed technology include aromatic compounds that can form endoperoxides with singlet oxygen.In some embodiments, the compound is a polycyclic aromatic compound that comprises two or more rings, for example, two, three, four, five or more aromatic rings, and preferably two or three aromatic rings.Certain embodiments relate to compounds having formula I: [ka]

[0044] With respect to Formula I, the dashed lines (---) indicate an optional bond, i.e., the compound has the formula II [ka] or a naphthalene compound having formula III [ka] Anthracene having [ka] It is one of the compounds.

[0045] Similarly, with respect to Formulas I, II and III, R 1 and R 2 are each independently H; OH; aliphatic, such as alkyl (e.g., methyl, ethyl, isopropyl or n-propyl), alkenyl (e.g., ethenyl or propenyl), or alkynyl (e.g., ethynyl or propynyl) or cyclic versions thereof; aromatic, such as aryl (e.g., phenyl or naphthyl); -CHaryl, such as benzyl; alkoxy, such as -O-alkyl, preferably -O-CH, -O-Et or -O-iPr; -O-acyl, such as -OC(O)alkyl or -OC(O)aryl, preferably -OC(O)CH or -OC(O)phenyl; -O-Si(alkyl) such as -O-Si(Me) or -O-Si(iPr); halogen, such as F, Cl, Br or I; cyano; -O-amino acid, such as -O-Glu; [ka] or a polymer. n is 0 to 6, such as 0, 1, 2, 3, 4, 5, or 6. Also, R 3is, when present, OH; aliphatic, such as alkyl (e.g. methyl, ethyl, iso-propyl or n-propyl), alkenyl (e.g. ethenyl or propenyl) or alkynyl (e.g. ethynyl or propynyl) or cyclic versions thereof; aromatic, such as aryl (e.g. phenyl); alkoxy, such as -O-alkyl, preferably -O-CH3, -O-Et or -O-iPr; -O-acyl, such as -OC(O)alkyl or -OC(O)aryl, preferably -OC(O)CH3 or -OC(O)phenyl; -O-Si(alkyl)3, such as -O-Si(Me)3 or -O-Si(iPr)3; halogen, such as F, Cl, Br or I; cyano; -O-amino acid, such as -O-Glu; or [ka] or a polymer.

[0046] Each polymer, when present, may independently be a polyalkyl polymer, such as polyethylene or polypropylene; a polyalkyl glycol, such as polyethylene glycol or polypropylene glycol; a polypeptide; a polyacrylic acid polymer, or a conjugated polymer chain. In certain embodiments, the photosensitizer may also be conjugated to the polymer.

[0047] In some embodiments, R 1 and R 2 are the same, but in other embodiments, R 1 and R 2 In some embodiments, R 1 and R 2 is not H, and in certain embodiments, at least one of R 1 and R 2 Both are not H.

[0048] In one particular embodiment, n=0.

[0049] In some embodiments, n=0 and R1 and R 2 are both alkyl, such as methyl. In certain embodiments, the compound is 1,4-dimethylnaphthalene (1,4-DMN). IV. Oxygen Uptake and Release

[0050] Oxygen uptake is promoted by irradiation of a mixture of polycyclic aromatic compounds, such as naphthalene and / or anthracene, or their derivatives, and a photosensitizer with light. The mixture can be a solution of the polycyclic aromatic compounds and the photosensitizer in a suitable solvent. Suitable solvents for use in the disclosed technology include any solvent that dissolves the polycyclic aromatic compounds, such as naphthalene and / or anthracene compounds, and the photosensitizer, but does not chemically react with the polycyclic aromatic compounds, the photosensitizer, singlet oxygen, or the generated endoperoxide. Suitable solvents include, but are not limited to, acetonitrile; chlorinated solvents, such as dichloromethane, chloroform, dichloroethane, carbon tetrachloride, and chloroform; propylene carbonate; ethylene glycol; propylene glycol; tetrahydrofuran; hexane; ether; dimethylformamide; water; ethanol; methanol; or their deuterated analogs; or combinations thereof.

[0051] In alternative embodiments, the disclosed systems and methods can include a solid-state polycyclic aromatic compound / photosensitizer composition. Applying to a solid-state system can reduce or eliminate the need to aerate or mix with a gas such as air to facilitate oxygen dissolution. In such solid-state systems, the photosensitizer and polycyclic aromatic compound such as 1,4-DMN are loaded onto a suitable solid-state support by adsorption, absorption, etc., and / or are bound by covalent or ionic bonds. Suitable solid-state supports include, but are not limited to, porous and / or gas-permeable materials such as silica such as zeolites, diatomaceous earth, hydrogels, polymers, metal-organic framework motifs, or combinations thereof. The solid support can be selected to be transparent to the wavelength of light suitable for exciting the triplet photosensitizer, e.g., diatomaceous earth for wavelengths in the visible-NIR. And / or the path length of the solid support can be selected, e.g., to increase transparency with the polymer and / or to have a depth equivalent to the maximum depth of light penetration. Additionally or alternatively, the solid support can absorb light and act, for example, in conjunction with nanoparticles, as a singlet oxygen photosensitizer.

[0052] The light may be polychromatic or monochromatic visible and / or near infrared light and / or may have or include wavelengths of 380 nm or less to 1000 nm or longer, such as 380 nm to 740 nm, 380 nm to 700 nm. In certain embodiments, the light has or includes wavelengths of 500 nm to 600 nm, such as 530 nm to 575 nm. The wavelength of light may be selected based on the absorbance of the photosensitizer. Rose Bengal may be excited by green light of 500 to 570 nm, or methylene blue may be excited using red light of 580 to 640 nm. The light may be natural light, such as sunlight, and may be used unfiltered or filtered to only the desired wavelength range. Additionally or alternatively, the light may include artificial light, such as LED light, selected as needed to provide light having the desired wavelength.

[0053] In some embodiments of the disclosed systems and methods, oxygen uptake and oxygen release are typically performed in separate steps. Each step is performed at a temperature suitable to promote the respective reaction. For example, oxygen uptake can be performed at temperatures from -78°C or lower to 100°C or higher, such as -78°C to 50°C, -78°C to 20°C, -50°C to 20°C, -25°C to 20°C, 0°C to 20°C, or 10°C to 20°C. Also, oxygen release can proceed at temperatures from -40°C to 100°C or higher, such as -20°C to 50°C, -20°C to 30°C, -10°C to 30°C, 0°C to 30°C, 10°C to 30°C, 15°C to 25°C, or 20°C to 25°C.

[0054] In some embodiments, oxygen release is carried out at a temperature higher than the temperature at which oxygen uptake occurs. In other embodiments, the temperatures at which the two reactions are carried out may overlap or be substantially the same, but when the mixture of polycyclic aromatic compound and photosensitizer is irradiated, oxygen uptake dominates over oxygen release, resulting in an overall increase in the concentration of endoperoxides and a decrease in the concentration of oxygen gas. In such embodiments, once irradiation is stopped, oxygen release dominates, thus resulting in an increase in the concentration of oxygen gas.

[0055] In some embodiments, the endoperoxides are stored at a temperature below the oxygen release temperature, thus allowing the oxygen removed from the gas to be stored. The endoperoxides can be stored for a desired period of time, such as from greater than zero to 52 weeks, greater than zero to 30 weeks, greater than zero to 20 weeks, greater than zero to 10 weeks, greater than zero to 4 weeks, greater than zero to 1 week, greater than zero to 5 days, greater than zero to 3 days, greater than zero to 2 days, greater than zero to 24 hours, greater than zero to 18 hours, greater than zero to 12 hours, greater than zero to 6 hours, or greater than zero to 3 hours, such as from greater than zero to 1 year or longer. In some embodiments, the endoperoxides are used to store oxygen for emergency situations, such as for use in an aircraft's emergency oxygen system.

[0056] Regarding the preliminary study, the availability and high 1 Rose Bengal was used as a photosensitizer due to its O quantum yield (φ ≈ 0.76). In a closed system, 1,4-DMN (6.4 × 10 -2 M) Rose Bengal (1 x 10 -4 The photocatalytic oxidation of M) was monitored by the corresponding pressure drop from oxygen consumption. The stability of the corresponding endoperoxide varied with temperature. When the green light irradiation was switched off, 1 O2 was no longer produced and the endoperoxide of 1,4-DMN could be stored at temperatures at or below 20°C.

[0057] Increasing the temperature above 20°C resulted in the release of oxygen and the reformation of 1,4-DMN. The release of oxygen was monitored by the corresponding increase in pressure. As shown in Figure 2, 1 The initial generation of O2 led to the formation of endoperoxides, and the system pressure decreased due to oxygen consumption by 1,4-DMN. The results also showed that the endoperoxides were relatively stable between 16 °C and 20 °C, since no pressure increase was observed at these temperatures when the green light irradiation was turned off.

[0058] When the temperature was increased to 22 °C, a pressure increase was observed, likely due to destabilization of the endoperoxide and the resulting oxygen release and reformation of 1,4-DMN. Upon green light irradiation at 22 °C, the oxidation rate dominated oxygen release, leading to an overall consumption of oxygen and a pressure drop.

[0059] Because the photosensitizer does not chemically react or substantially decompose during consumption and release of oxygen, and the polycyclic aromatic compound is regenerated, the system can be cycled repeatedly without substantial loss of efficacy. This was demonstrated using 1,4-DMN over two cycles at 25°C by powering the green LED on and off at intervals of four hours (Figure 3).1 The production of O2 caused a pressure drop of approximately 0.5 PSI after 4 hours. After turning the light off for 4 hours, the pressure returned to near the starting pressure due to the release of stored oxygen. A similar pressure drop / pressure rise pattern was observed during the second 4 hour on / 4 hour off illumination cycle (Figure 3).

[0060] Scaling up the amount of 1,4 DMN to 0.32M produced similar results when cycled, but with a pressure change of nearly 1.5 PSI over a 12 hour interval (FIG. 4). The same percentage pressure change was observed at both 1,4-DMN concentrations, suggesting that oxygen was the limiting reagent. Increasing the amount of 1,4-DMN to 50% (3.2M) reduced the rate of oxygen consumption, and no oxygen consumption was observed at 90% (5.8M) 1,4-DMN. Results indicated that with higher concentrations of 1,4-DMN, the solubility of oxygen in the 1,4-DMN solution decreased, which may have reduced the effectiveness of the system. In some embodiments, the concentration of the polycyclic aromatic compound is greater than zero to 4M or higher, such as greater than zero to 3.5M, 0.01M to 3M, 0.02M to 2M, 0.05M to 1M, or 0.05M to 0.75M. In certain embodiments, for example, under 25° C. and atmospheric pressure conditions, the concentration range of 1,4-DMN is from 0.064 or less to 1 M or more, such as 0.064 M to 0.64 M.

[0061] One option to improve oxygen consumption at higher 1,4-DMN concentrations is to increase the concentration of oxygen, such as by using substantially pure oxygen gas. Nearly the same rates of oxygen consumption were observed for 20%, 30% and 50% (1.3M, 2.0M and 3.2M) solutions under oxygen headspace (16.9PSI, 1.13atm) (Figure 5). Although high oxygen consumption rates were observed, the nearly identical rates still indicated that 1,4-DMN did not limit the oxygen consumption rate at these concentrations. However, for oxygen purification applications under atmospheric pressure conditions, lower concentrations such as 0.064M or less to 1M, or 0.064M to 0.64M of 1,4-DMN were more suitable to dissolve oxygen in solution at 25°C in certain solvents such as acetonitrile.

[0062] The present system exhibits several major advantages over many light energy systems, including solar energy systems. The role of the triplet photosensitizer is simply to: 1 Since the photon absorbed only produces O2, a wide range of dyes can be used to absorb the entire visible spectrum, including NIR light. Similarly, the efficiency increases with lower energy irradiation, since each absorbed photon is available for the same purpose of producing endoperoxides. Furthermore, the reverse reaction does not require light to release oxygen, and therefore such a system can be used for oxygen release at night, which is a major challenge for most solar energy technologies. Although photothermal techniques have been used to convert solar energy to thermal energy, the disclosed system can also be cycled at a constant temperature by supplying and removing light. The disclosed exemplary system produces a quantum yield of endoperoxide formation of about 0.34, which results in a conversion efficiency to PV work of about 2% using 550 nm light. V.Applications

[0063] Embodiments of the disclosed systems and methods are useful for numerous applications, such as converting solar and / or artificial light into mechanical work, and / or oxygen purification, concentration, isolation, storage and / or removal. A. Production of mechanical work

[0064] In a closed system, the pressure change due to cycling on-off irradiation can result in a change in volume to drive a mechanical system. Under isothermal conditions, the work output (W) from the system can be calculated from Equation 1:

number

[0065] For Equation 1, n is the number of moles of O2, R is the ideal gas law constant, T is the temperature, V2 is the final volume, and V1 is the initial volume. As demonstrated in FIG. 6, the change in volume can be used to drive the piston. With reference to FIG. 6, a solution containing a triplet photosensitizer and a polycyclic aromatic compound such as 1,4-DMN, when exposed to a suitable light source, removes oxygen from the gas in the headspace, resulting in a drop in volume that can lower the piston. When the light is removed or turned off, the solution releases oxygen back into the headspace, restoring the initial volume and pushing the piston up. The overall result is the generation of mechanical work from cycling the exposure to light. This can be done at one of the temperatures where O2 uptake dominates over O2 release under illumination, or alternatively, the system can be shielded from illumination or otherwise prevented from being irradiated, as it is cooled during irradiation to reduce the O2 release rate and increase the O2 release rate.

[0066] Mechanical energy is generated using the splitting and recombination of nitrosyl chloride (NOCl) gas to produce NO and Cl2. However, the maximum potential of this process is limited to a pressure / volume change of twice the initial number of moles of NOCl, and it still requires UV light, as opposed to visible light, to operate. Furthermore, nitrosyl chloride is highly toxic and irritating to the eyes, lungs and skin, and is a strong oxidizer. Also, both chlorine and NO gas are toxic.

[0067] In contrast, the systems and methods disclosed herein have several advantages over previous attempts to generate mechanical work from light. First, the disclosed methods can use gases with high oxygen concentrations, such as ambient air, oxygen-enriched air, or substantially pure oxygen gas. Thus, potential environmental risks are significantly reduced. Also, the role of the triplet photosensitizer is not simply to 1 Since the photon absorbed is used to generate an endoperoxide, a wide range of dyes can be used to absorb the entire visible spectrum, including NIR light. Furthermore, since each absorbed photon is used to generate an endoperoxide, the efficiency increases with lower energy irradiation. Furthermore, the release reaction does not require light to release oxygen, so such a system can be used at night, which is a major challenge for most solar energy technologies. Although photothermal techniques have been used to convert solar energy into thermal energy, the disclosed method can be cycled at a constant temperature. B. Continuous Flow Reactor

[0068] Further disclosed herein are embodiments of continuous flow reactors suitable for oxygen purification, concentration, storage, isolation and / or removal, such as from the atmosphere or from an alternative mixture of gases. FIG. 7 presents a schematic diagram showing an exemplary embodiment of a continuous flow reactor. With reference to FIG. 7, reactor 2 comprises a first reaction tube 4 and a second reaction tube 6. Reactor 2 also comprises a first connecting tube 8 and a second connecting tube 10 fluidly connecting first reaction tube 4 and second reaction tube 6, such that fluids can flow in a loop as indicated by arrow 12 or in the opposite direction. The fluid can be a solution containing a polycyclic aromatic compound, such as a naphthalene and / or anthracene compound, and a photosensitizer, optionally in a suitable solvent as disclosed herein.

[0069] The reactor 2 also includes a gas inlet 14 that facilitates the introduction of a gas, such as air, into the first reaction tube 4. In some embodiments, the gas is bubbled through the fluid in the first reaction tube 4. In the first reaction tube 4, the fluid, such as a solution containing a polycyclic aromatic compound and a photosensitizer, is exposed to light 16 having a wavelength suitable for facilitating oxygen uptake from the gas into the polycyclic aromatic compound to form endoperoxides. The light 16 may be natural light and / or artificial light, such as from an LED light source. While FIG. 7 shows that the light source is present outside the first reaction tube 4, one skilled in the art will recognize that the light source can be located within the first reaction tube 4 and / or on the wall of the first reaction tube 4. In the case of an external light source, such as that shown in FIG. 7, the first reaction tube 4 can include a material that facilitates the passage of light from the light source to the fluid. In some embodiments, the first reaction tube 4 can be partially or substantially entirely formed from a material, while in other embodiments, the first reaction tube 4 includes one or more windows that facilitate the passage of light. Suitable materials include, but are not limited to, glass, acrylic, polyvinylidiene chloride, polycarbonate, silica, and combinations thereof.

[0070] Reactor 2 may also include a cooling device 18 to reduce and / or maintain the temperature of the fluid at a first temperature suitable for promoting oxygen uptake and / or endoperoxide formation. Although Figure 7 shows optional cooling device 18 located at the bottom of first reactor tube 4, one skilled in the art will recognize that cooling device 18 may be located at any location along first reactor tube 4 suitable for reducing and / or maintaining the fluid in first reactor tube 4 at the first temperature.

[0071] Additionally or alternatively, the reactor 2 can include an optional heater 20 that raises the temperature of the fluid to a second temperature suitable for promoting decomposition of the endoperoxide and / or release of the stored oxygen, which can then exit the reactor 2 through the oxygen outlet 22. As shown in FIG. 7, the heater 20 can be located at any suitable location along the second reactor tube 6, such as at the bottom of the second reactor tube 6. While FIG. 7 shows exemplary locations for the optional cooling device 18 and heater 20 in the flow path of the fluid in the reactor 2, one skilled in the art will recognize that the cooling device and / or heater can alternatively be located outside the respective reactor tube, thereby heating or cooling the fluid through the wall of the tube. Suitable heating and / or cooling devices include, but are not limited to, heat exchange devices. Heating devices such as resistors, filaments, or photothermal materials can be used to heat in direct or indirect contact with the chamber. Cooling can be achieved by the passage of air or liquid, by fans or pumps, or by thermoelectric cooling.

[0072] Additionally or alternatively, reactor 2 may include one or more agitators to facilitate mixing of the fluids, for example by stirring, in one or both of the first and second reaction tubes 4 and 6, respectively. Such agitation can facilitate singlet oxygen formation and the reaction between single oxygen and polycyclic aromatic compounds.

[0073] As oxygen is released, at least a portion of the polycyclic aromatic compounds are reformed in the fluid. The fluid containing the reformed polycyclic aromatic compounds returns to the first reaction tube 4 through the second connecting tube 10 to complete the cycle. In some embodiments, the fluid in the second reaction tube 6 is shielded from light, such as by having the walls of the second reaction tube 6 opaque, so that the fluid therein is maintained in the dark. This substantially prevents singlet oxygen formation from the released oxygen, as well as endoperoxide formation. C. Oxygen concentrator

[0074] Certain embodiments of the disclosed technology relate to oxygen concentrators. FIG. 8 presents an exemplary embodiment of an oxygen concentrator. With reference to FIG. 8, the concentrator comprises a chamber 100 with a gas inlet 102 through which a gas, such as air, enters the chamber 100 and is exposed to a medium 104. The medium 104 includes a polycyclic aromatic compound, such as a naphthalene and / or anthracene compound, and a photosensitizer. The medium 104 may be a liquid medium, such as a solution of the polycyclic aromatic compound and the photosensitizer, or the medium 104 may be a solid medium, and in some embodiments is a porous solid medium, such as a powder, a crystalline structure, a nanostructure, and / or a granule.

[0075] The chamber 100 may optionally include a pump 106 to facilitate gas uptake and / or compress gas within the chamber to further facilitate oxygen uptake by the medium 104. While FIG. 8 shows the pump 106 disposed within the chamber 100, one skilled in the art will appreciate that the pump 106 may be disposed outside the chamber 100 and fluidly coupled to the air inlet 102. In some embodiments, the pump 106 is disposed inside the chamber 100 and draws gas into the chamber through the gas inlet 102. In such embodiments, the gas inlet 102 may be a gas permeable membrane, a porous material, a valve, or an opening to a gas, such as ambient air.

[0076] The chamber 100 further comprises one or more light sources 108. As shown in FIG. 8, the light source 108 may be disposed within one or more walls of the chamber 100. Additionally or alternatively, the light source 108 may be disposed within the chamber 100 rather than in a wall of the chamber. Alternatively, the light source 108 may be a window in a wall of the chamber 100 or a window constituting a wall of the chamber 100 that facilitates light entering the chamber from an external source such as sunlight and / or external artificial light (not shown). The solid support, such as diatomaceous earth in the visible-NIR wavelengths, may be transparent to the wavelengths of light that excite the triplet photosensitizer. And / or the path length of the solid support may be minimized to increase transparency with a polymer or the like. Additionally or alternatively, the solid support may absorb light and act as a singlet oxygen photosensitizer with nanoparticles or the like.

[0077] The chamber 100 may also include a heating and / or cooling device. In some embodiments, the heating and / or cooling device is a single device, such as element 110 in FIG. 8. Alternatively, the chamber 100 may include separate heaters and coolers to heat and cool the chamber separately. Suitable heating and / or cooling devices include, but are not limited to, heat exchange devices. Heating devices such as resistors, filaments, or photothermal materials can be used to heat the chamber in direct or indirect contact. Cooling can be achieved by the passage of air or liquid, by a fan or pump, or by thermoelectric cooling.

[0078] During operation, a gas, such as air, enters the chamber 100 through the gas inlet 102 and is exposed to the medium. A light source 108 provides light of a suitable wavelength to promote oxygen uptake and endoperoxide formation by the medium. Residual gas may be exhausted from the chamber 100 through an outlet 112. In an alternative embodiment, residual gas is released from the gas inlet 102, which is configured to allow flow in both directions.

[0079] Once a desired amount of oxygen has been stored by the medium 104, the concentrator may be configured to release the oxygen. Typically, the light source 108 is turned off, removed, or shut off, and / or the heating / cooling device 110 is configured to heat the medium 104, thereby facilitating endoperoxide decomposition and oxygen release. In some embodiments, the gas inlet 102 continues to facilitate gas entering the chamber 100. The released oxygen mixes with a gas, e.g., air, to form an oxygen-rich gas mixture that exits the chamber 100 through the outlet 112. In some embodiments, the outlet 112 is connected to a breathing apparatus for supplying oxygen-rich air to a subject in need thereof.

[0080] In some embodiments, the oxygen concentrator comprises a single chamber 100, while other embodiments comprise two or more chambers, e.g., two, three, four, five or more chambers. In certain embodiments, the portable oxygen concentrator comprises two chambers; a first chamber is configured to store oxygen while a second chamber is configured to release oxygen. When the second chamber releases substantially all of its stored oxygen and / or is unable to provide an oxygen-rich gas having a desired oxygen content, the second chamber is reconfigured to store oxygen while the first chamber is reconfigured to store oxygen. In some embodiments with two or more chambers, the chambers may also comprise a pump in each chamber. However, in alternative embodiments, a system with two or more chambers may comprise less than one pump per chamber. For example, a system with two chambers may comprise a single pump configured to pump the first or second chamber individually, or to pump both chambers simultaneously.

[0081] The disclosed system overcomes many of the challenges currently faced by existing oxygen purification and / or storage solutions since oxygen consumption is primarily powered by sunlight or LEDs. Oxygen release can begin near room temperature or increase at temperatures slightly above 25° C. Storage of consumed oxygen is achieved at lower temperatures of about 16° C. and / or by keeping the solution in a sealed container.

[0082] The utility of the system described herein depends on its lifespan through repeated cycles of oxygen storage and release. After four cycles of irradiation under oxygen atmosphere, a clear change in the rate of oxidation was observed, indicated by a slowing rate of pressure drop from each cycle of irradiation (Figure 9). Despite this, the similar oxygen release rates indicate that 1,4-DMN is stable. If not, the release of oxygen may also be slowed if irreversible oxidation were to occur. Without being bound to a particular theory, the results suggest that photobleaching of Rose Bengal occurs, which may result in 1 This may suggest that less O2 was produced and therefore the oxidation rate was altered. However, this is not the case for methylene blue, eosin B, Ru(bpy)3, methyl green, rubrene, fullerene (alkyl, aryl, alkoxy substituted or unsubstituted C 20~94 ), fluorenes (including, for example, 9,9- or 2,7-substituted fluorenes), nanoparticles (e.g., CdTe, ZnSe, SiNPs, CNPs, AuNPs, BiNPs, or encapsulated small molecule triplet photosensitizers forming nanoparticles that are bound to and / or encapsulated by silica, proteins, or polymers), or combinations thereof. VI. ILLUSTRATIVE EMBODIMENTS

[0083] The following numbered paragraphs present exemplary embodiments of the disclosed technology.

[0084] Paragraph 1. exposing a first mixture comprising a polycyclic aromatic compound and a photosensitizer to a first portion of oxygen gas and light at a first temperature to form a second mixture comprising an endoperoxide, wherein the first temperature is selected to substantially prevent the endoperoxide from decomposing; raising the temperature of the second mixture to a second temperature higher than the first temperature and / or terminating irradiation to promote decomposition of the endoperoxides to form reformed polycyclic aromatic compounds and release oxygen; mixing the released oxygen with an air stream to form an oxygen-enriched air stream; The method includes:

[0085] Paragraph 2. The method of paragraph 1, wherein exposing the first mixture to oxygen gas includes exposing the first mixture to ambient air.

[0086] Paragraph 3. The method of paragraph 1 or paragraph 2, wherein the method further comprises the step of supplying the oxygen-enriched air stream to a patient in need thereof.

[0087] Paragraph 4. The method of any one of paragraphs 1-3, further comprising maintaining the second mixture at or below the first temperature for a selected period of time prior to raising the temperature of the second mixture to the second temperature.

[0088] Paragraph 5. The method of any one of paragraphs 1-4, further comprising exposing the reformed polycyclic aromatic compound and the photosensitizer to a second portion of oxygen gas to reform at least a portion of the endoperoxide.

[0089] Paragraph 6. a) exposing a first mixture comprising a first polycyclic aromatic compound and a first photosensitizer to a first portion of oxygen gas and light from a first light source at a first temperature to form a second mixture comprising a first endoperoxide, wherein the first temperature is selected to substantially prevent decomposition of the first endoperoxide; b) increasing the temperature of the second mixture to a second temperature greater than the first temperature suitable for decomposing the first endoperoxide, thereby reforming at least a portion of the first polycyclic aromatic compound and forming a second portion of oxygen gas that is mixed with the first air stream to form a first oxygen-enriched air stream; c) exposing a third mixture comprising a second polycyclic aromatic compound and a second photosensitizer to a third portion of oxygen gas and light from a second light source at a third temperature to form a fourth mixture comprising a second endoperoxide, wherein the third temperature is selected to substantially prevent decomposition of the second endoperoxide; d) once the first endoperoxide has substantially decomposed, increasing the temperature of the third mixture to a fourth temperature greater than the third temperature and selected to decompose the second endoperoxide, thereby reforming at least a portion of the second polycyclic aromatic compound and forming a fourth portion of oxygen gas which mixes with a second air stream to form a second oxygen-enriched air stream; e) exposing the first polycyclic aromatic compound and the first photosensitizer to a fifth portion of oxygen gas and light from the first light source to reform at least a portion of the first endoperoxide. The method includes:

[0090] Paragraph 7. The method of paragraph 6, wherein step b is performed simultaneously with step c.

[0091] Paragraph 8. exposing a first mixture, including a polycyclic aromatic compound, a photosensitizer, and oxygen gas, to light in an enclosed space having a first volume to form an endoperoxide by a reaction between the polycyclic aromatic compound and the oxygen gas, thereby changing the volume of the enclosed space to a second volume smaller than the first volume; removing the light to regenerate the polycyclic aromatic compounds and release at least a portion of the oxygen gas into the enclosed volume, thereby changing the volume of the enclosed volume to a third volume that is substantially the same as the first volume. The method includes:

[0092] Paragraph 9. The method of paragraph 8, wherein the change in the volume of the enclosed space causes a piston to move.

[0093] Paragraph 10. exposing a first mixture, including a polycyclic aromatic compound, a photosensitizer, and oxygen gas, to light in an enclosed space having a first pressure to form an endoperoxide by reaction between the polycyclic aromatic compound and the oxygen gas, thereby changing the pressure of the enclosed space to a second pressure less than the first pressure; removing the light to regenerate the polycyclic aromatic compounds and release at least a portion of the oxygen gas into the enclosed volume, thereby changing the pressure in the enclosed volume to a third pressure that is substantially the same as the first pressure. The method includes:

[0094] Paragraph 11. The method of paragraph 10, wherein the change in pressure in the enclosed space produces work.

[0095] Paragraph 12. The method of any one of Paragraphs 8-11, further comprising exposing the reformed polycyclic aromatic compound to light to reform at least a portion of the endoperoxides, and then removing the light source to reform the polycyclic aromatic compound.

[0096] Paragraph 13. The method of any one of paragraphs 8-12, wherein the step of exposing the first mixture to light is performed at a first temperature, and the step of removing the light further comprises the step of raising the temperature to a second temperature higher than the first temperature.

[0097] Paragraph 14. The method of any one of Paragraphs 1 to 13, wherein the polycyclic aromatic compound is a naphthalene compound or an anthracene compound.

[0098] Paragraph 15. The polycyclic aromatic compound is represented by formula I [ka] (In the formula, R 1 , R 2 and R 3 are each independently H, OH, aliphatic, aryl, alkoxy, -O-acyl, -O-Si(alkyl), -O-amino acid, or -O-carbohydrate; n is 0 to 6; "---" represents a bond that may or may not be present.) 15. The method of paragraph 14,

[0099] Paragraph 16. The compound [ka] 16. The method of paragraph 15, having a formula selected from:

[0100] Paragraph 17. The method of paragraph 15 or paragraph 16, where n=0.

[0101] Paragraph 18.R 1 and R 2 Any one of paragraphs 15 to 17, where at least one of is not H.

[0102] Paragraph 19.R 1 and R 2 and n is an integer from 1 to 18.

[0103] Paragraph 20.R 1 and R 2 is the same as H, but is not any one of paragraphs 15 to 19.

[0104] Paragraph 21. The method of any one of Paragraphs 15 to 19, wherein the polycyclic aromatic compound is 1,4-dimethylnaphthalene.

[0105] Paragraph 22. The method of any one of paragraphs 1 to 7 and 13 to 21, wherein the first temperature is between -78°C and 25°C.

[0106] Paragraph 23. The method of Paragraph 22, wherein the first temperature is from 0°C to 20°C.

[0107] Paragraph 24. The method of any one of paragraphs 1 to 7 and 13 to 23, wherein the second temperature is between -40°C and 100°C.

[0108] Paragraph 25. The method of Paragraph 24, wherein the second temperature is between 15°C and 25°C.

[0109] Paragraph 26. The method of any one of Paragraphs 1 to 25, wherein the photosensitizer is Rose Bengal, Methylene Blue, Eosin B, Ru(bpy)3, Methyl Green, Rubrene, fluorene, fullerene, a nanoparticle, or a combination thereof.

[0110] Paragraph 27. The fullerene optionally substituted with alkyl, aryl, alkoxy, or combinations thereof. 20~94 It is a fullerene, the fluorene is a 9,9-substituted fluorene or a 2,7-substituted fluorene; The nanoparticles are CdTe, ZnSe, SiNP, CNP, AuNP, or BiNP nanoparticles, or are silica, protein, or polymer nanoparticles containing triplet photosensitizers, or combinations thereof; The method in paragraph 26.

[0111] Paragraph 28. The method of Paragraph 26, wherein the photosensitizer is Rose Bengal.

[0112] Paragraph 29. The method of any one of Paragraphs 1 to 28, wherein the light comprises light having a wavelength between 380 nm and 1000 nm.

[0113] Paragraph 30. The method of Paragraph 29, wherein the light is visible light.

[0114] Paragraph 31. The method of Paragraph 30, wherein the visible light has a wavelength of 380 nm to 740 nm.

[0115] Paragraph 32. The method of Paragraph 31, wherein the visible light comprises light having a wavelength of 530 nm to 575 nm.

[0116] Paragraph 33. The method of any one of Paragraphs 1 to 21, wherein the light comprises natural light.

[0117] Paragraph 34. The method of Paragraph 33, wherein the light is sunlight.

[0118] Paragraph 35. The method of any one of Paragraphs 1 to 33, wherein the light comprises light from an LED light source.

[0119] Paragraph 36. The method of any one of Paragraphs 1 to 35, wherein the first mixture is a solution and further comprises a solvent.

[0120] Paragraph 37. The method of Paragraph 36, wherein the solvent is acetonitrile, ethanol, methanol, dichloromethane, hexane, water, ether, dimethylformamide, carbon tetrachloride, chloroform, propylene carbonate, ethylene glycol, propylene glycol, tetrahydrofuran, or a combination thereof.

[0121] Paragraph 38. The method of Paragraph 36, wherein the solvent is acetonitrile.

[0122] Paragraph 39. The method of any one of Paragraphs 1 to 38, wherein the first mixture is a solid.

[0123] Paragraph 40. The method of Paragraph 39, wherein said solid further comprises a zeolite, a diatomaceous earth, a hydrogel, a polymer, a metal-organic framework motif, or a combination thereof.

[0124] Paragraph 41. The method of Paragraph 40, wherein the polymer comprises polyethylene, polypropylene, polyethylene glycol, polypropylene glycol, a peptide, polyacrylic acid, or a combination thereof.

[0125] Paragraph 42. The method of Paragraph 41, wherein the polymer has a molecular weight of from 5 kDa to 500 kDa.

[0126] Paragraph 43. a first chamber including a first mixture including a first polycyclic aromatic compound and a first photosensitizer, a first gas inlet, a first gas outlet, a first pump, and a first light source; a second chamber including a second mixture of the first polycyclic aromatic compound and a second photosensitizer, a second gas inlet, a second gas outlet, a second pump, and a second light source; a controller configured to switch an air stream between the first gas inlet and the second gas inlet; and A system comprising:

[0127] Paragraph 44. The system of paragraph 43, further comprising a temperature control device.

[0128] Paragraph 45. The system of Paragraph 44, wherein the temperature control device is a heater, a cooler, or a combination thereof.

[0129] Paragraph 46. An enclosed space of variable volume containing a mixture containing a polycyclic aromatic compound, a photosensitizer, and a gas containing oxygen A system comprising:

[0130] Paragraph 47. Confined spaces where the pressure may fluctuate, containing mixtures containing polycyclic aromatic compounds, photosensitizers, and gases containing oxygen A system comprising:

[0131] Paragraph 48. A system according to paragraph 46 or paragraph 47, further comprising a light source.

[0132] In view of the many possible embodiments to which the principles of the present disclosure can be applied, it should be recognized that the illustrated embodiments are merely preferred examples of the present technology and should not be taken as limiting the scope of the present invention. Rather, the scope of the present invention is defined by the following claims. Accordingly, the inventors claim as their invention all that comes within the scope and spirit of these claims. The present invention provides, for example, the following items. (Item 1) exposing a first mixture comprising a polycyclic aromatic compound and a photosensitizer to oxygen gas and light to form a second mixture comprising an endoperoxide; changing a temperature of the second mixture and / or ceasing the irradiation of the second mixture with the light to regenerate at least a portion of the polycyclic aromatic compounds and release at least a portion of the oxygen gas. The method includes: (Item 2) exposing a first mixture comprising a polycyclic aromatic compound and a photosensitizer to a first portion of oxygen gas and light at a first temperature to form a second mixture comprising an endoperoxide, wherein the first temperature is selected to substantially prevent the endoperoxide from decomposing; raising the temperature of the second mixture to a second temperature higher than the first temperature and / or terminating irradiation to promote decomposition of the endoperoxides to form reformed polycyclic aromatic compounds and release oxygen; mixing the released oxygen with an air stream to form an oxygen-enriched air stream; The method according to item 1, comprising: (Item 3) 3. The method of claim 2, wherein exposing the first mixture to oxygen gas comprises exposing the first mixture to ambient air. (Item 4) 3. The method of claim 2, further comprising the step of supplying the oxygen-enriched air stream to a patient in need thereof. (Item 5) 3. The method of claim 2, further comprising maintaining the second mixture at or below the first temperature for a selected period of time before increasing the temperature of the second mixture to the second temperature. (Item 6) 3. The method of claim 2, further comprising exposing the reformed polycyclic aromatic compound and the photosensitizer to a second portion of oxygen gas to reform at least a portion of the endoperoxide. (Item 7) a) exposing a first mixture comprising a first polycyclic aromatic compound and a first photosensitizer to a first portion of oxygen gas and light from a first light source at a first temperature to form a second mixture comprising a first endoperoxide, wherein the first temperature is selected to substantially prevent decomposition of the first endoperoxide; b) increasing the temperature of the second mixture to a second temperature greater than the first temperature suitable for decomposing the first endoperoxide, thereby reforming at least a portion of the first polycyclic aromatic compound and forming a second portion of oxygen gas that is mixed with the first air stream to form a first oxygen-enriched air stream; c) exposing a third mixture comprising a second polycyclic aromatic compound and a second photosensitizer to a third portion of oxygen gas and light from a second light source at a third temperature to form a fourth mixture comprising a second endoperoxide, wherein the third temperature is selected to substantially prevent decomposition of the second endoperoxide; d) once the first endoperoxide has substantially decomposed, increasing the temperature of the third mixture to a fourth temperature greater than the third temperature and selected to decompose the second endoperoxide, thereby reforming at least a portion of the second polycyclic aromatic compound and forming a fourth portion of oxygen gas which mixes with a second air stream to form a second oxygen-enriched air stream; e) exposing the first polycyclic aromatic compound and the first photosensitizer to a fifth portion of oxygen gas and light from the first light source to reform at least a portion of the first endoperoxide. The method according to item 1, comprising: (Item 8) 8. The method according to item 7, wherein step b is carried out simultaneously with step c. (Item 9) exposing a first mixture, including a polycyclic aromatic compound, a photosensitizer, and oxygen gas, to light in an enclosed space having a first volume to form an endoperoxide by a reaction between the polycyclic aromatic compound and the oxygen gas, thereby changing the volume of the enclosed space to a second volume smaller than the first volume; ceasing the irradiation with light to regenerate the polycyclic aromatic compound and release at least a portion of the oxygen gas into the enclosed space, thereby changing the volume of the enclosed space to a third volume that is substantially the same as the first volume. The method according to item 1, comprising: (Item 10) 10. The method of claim 9, wherein the change in the volume of the enclosed space causes a piston to move. (Item 11) 10. The method of claim 9, further comprising exposing the reformed polycyclic aromatic compound to light to reform at least a portion of the endoperoxides, and then removing the light source to reform the polycyclic aromatic compound. (Item 12) 10. The method of claim 9, wherein exposing the first mixture to light is performed at a first temperature, and removing the light further comprises raising the temperature to a second temperature higher than the first temperature. (Item 13) exposing a first mixture, including a polycyclic aromatic compound, a photosensitizer, and oxygen gas, to light in an enclosed space having a first pressure to form an endoperoxide by reaction between the polycyclic aromatic compound and the oxygen gas, thereby changing the pressure of the enclosed space to a second pressure less than the first pressure; ceasing the irradiation with light to regenerate the polycyclic aromatic compounds and release at least a portion of the oxygen gas into the enclosed space, thereby changing the pressure in the enclosed space to a third pressure that is substantially the same as the first pressure. The method according to item 1, comprising: (Item 14) Item 14. The method of item 13, wherein the change in pressure in the enclosed space produces work. (Item 15) Item 14. The method of item 13, further comprising exposing the reformed polycyclic aromatic compound to light to reform at least a portion of the endoperoxides, and then removing the light source to reform the polycyclic aromatic compound. (Item 16) Item 14. The method of item 13, wherein exposing the first mixture to light is performed at a first temperature, and removing the light further comprises raising the temperature to a second temperature higher than the first temperature. (Item 17) 17. The method according to any one of items 1 to 16, wherein the polycyclic aromatic compound is a naphthalene compound or an anthracene compound. (Item 18) The polycyclic aromatic compound has the formula I [ka] (In the formula, R 1 , R2 and R 3 are each independently H, OH, aliphatic, aryl, alkoxy, -O-acyl, -O-Si(alkyl), -O-amino acid, or -O-carbohydrate; n is 0 to 6; "---" represents a bond that may or may not be present.) 18. The method according to item 17, comprising the steps of: (Item 19) The compound [ka] Item 19. The method of item 18, having a formula selected from: (Item 20) 19. The method according to item 18, wherein n=0. (Item 21) R 1 and R 2 Item 19. The method according to item 18, wherein at least one of is not H. (Item 22) R 1 and R 2 and are both alkyl. (Item 23) R 1 and R 2 22. The method according to item 21, wherein (Item 24) Item 18. The method of item 17, wherein the polycyclic aromatic compound is 1,4-dimethylnaphthalene. (Item 25) Item 18. The method according to item 17, wherein the first temperature is from -78°C to 25°C. (Item 26) Item 26. The method according to item 25, wherein the first temperature is 0°C to 20°C. (Item 27) Item 18. The method according to item 17, wherein the second temperature is from -40°C to 100°C. (Item 28) Item 28. The method according to item 27, wherein the second temperature is 15°C to 25°C. (Item 29) 17. The method according to any one of items 1 to 16, wherein the photosensitizer is Rose Bengal, Methylene Blue, Eosin B, Ru(bpy)3, Methyl Green, Rubrene, Fluorene, Fullerene, Nanoparticles or a combination thereof. (Item 30) The fullerene is optionally substituted with alkyl, aryl, alkoxy, or combinations thereof. 20~94 It is a fullerene, the fluorene is a 9,9-substituted fluorene or a 2,7-substituted fluorene; The nanoparticles are CdTe, ZnSe, SiNP, CNP, AuNP, or BiNP nanoparticles, or are silica, protein, or polymer nanoparticles containing triplet photosensitizers, or combinations thereof; Item 29. The method according to item 29. (Item 31) 30. The method of claim 29, wherein the photosensitizer is Rose Bengal. (Item 32) 17. The method according to any one of items 1 to 16, wherein the light comprises light having a wavelength of 380 nm to 1000 nm. (Item 33) 33. The method of claim 32, wherein the light is visible light. (Item 34) Item 34. The method according to item 33, wherein the visible light has a wavelength of 380 nm to 740 nm. (Item 35) Item 35. The method according to item 34, wherein the visible light comprises light having a wavelength of 530 nm to 575 nm. (Item 36) 17. The method according to any one of items 1 to 16, wherein the light comprises natural light. (Item 37) 37. The method of claim 36, wherein the light is sunlight. (Item 38) 17. The method of any one of items 1 to 16, wherein the light comprises light from an LED light source. (Item 39) 17. The method according to any one of items 1 to 16, wherein the first mixture is a solution and further comprises a solvent. (Item 40) 40. The method of claim 39, wherein the solvent is acetonitrile, ethanol, methanol, dichloromethane, hexane, water, ether, dimethylformamide, carbon tetrachloride, chloroform, propylene carbonate, ethylene glycol, propylene glycol, tetrahydrofuran, or a combination thereof. (Item 41) 40. The method of claim 39, wherein the solvent is acetonitrile. (Item 42) 17. The method according to any one of items 1 to 16, wherein the first mixture is a solid. (Item 43) 43. The method of claim 42, wherein the solid further comprises a zeolite, a diatomaceous earth, a hydrogel, a polymer, a metal-organic framework motif, or a combination thereof. (Item 44) 44. The method of claim 43, wherein the polymer comprises polyethylene, polypropylene, polyethylene glycol, polypropylene glycol, a peptide, polyacrylic acid, or a combination thereof. (Item 45) Item 45. The method of item 44, wherein the polymer has a molecular weight of 5 kDa to 500 kDa. (Item 46) a first chamber including a first mixture including a first polycyclic aromatic compound and a first photosensitizer, a first gas inlet, a first gas outlet, a first pump, and a first light source; a second chamber including a second mixture of the first polycyclic aromatic compound and a second photosensitizer, a second gas inlet, a second gas outlet, a second pump, and a second light source; a controller configured to switch an air stream between the first gas inlet and the second gas inlet; and A system comprising: (Item 47) Item 47. The system of item 46, further comprising a temperature control device. (Item 48) Item 48. The system of item 47, wherein the temperature control device is a heater, a cooler, or a combination thereof. (Item 49) A confined space of variable volume containing a mixture including a polycyclic aromatic compound, a photosensitizer, and a gas including oxygen. A system comprising: (Item 50) A confined space in which the pressure may fluctuate, containing a mixture containing a polycyclic aromatic compound, a photosensitizer, and a gas containing oxygen. A system comprising: (Item 51) 51. The system of claim 49 or 50, further comprising a light source.

Claims

1. exposing a first mixture comprising a polycyclic aromatic compound and a photosensitizer to a first portion of oxygen gas and light at a first temperature to form a second mixture comprising an endoperoxide, wherein the first temperature is selected to substantially prevent the endoperoxide from decomposing, and exposing the first mixture to the first portion of oxygen gas comprises exposing the first mixture to ambient air; raising the temperature of the second mixture to a second temperature higher than the first temperature and / or terminating irradiation to promote decomposition of the endoperoxides to form reformed polycyclic aromatic compounds and release oxygen; mixing the released oxygen with an air stream to form an oxygen-enriched air stream; The method of claim 1, wherein the polycyclic aromatic compound is represented by Formula II. 【Chemistry 16】 wherein R 1 , R 2 and R 3 are each independently H; OH; C 1-25 aliphatic; C 6-15 aryl; alkoxy of the formula -O-C 1-25 alkyl or -O-C 3-15 cycloalkyl; -O-acyl of the formula -O-C(O)H, -O-C(O)C 1-25 aliphatic or -O-C(O)-aromatic, where aromatic refers to a ring moiety having from 5 to 15 ring atoms; -O-Si(C 1-25 alkyl) 3 ; -O-amino acid; or -O-carbohydrate; n is 0 to 6) The method has the structure:

2. 10. The method of claim 1, further comprising maintaining the second mixture at or below the first temperature for a selected period of time before increasing the temperature of the second mixture to the second temperature.

3. 3. The method of claim 1 or claim 2, further comprising exposing the reformed polycyclic aromatic compound and the photosensitizer to a second portion of oxygen gas to form a second endoperoxide.

4. n=0, R １ and R ２ are both C 1-25 alkyl, or The method according to any one of claims 1 to 3, which is a combination thereof.

5. The method according to any one of claims 1 to 4, wherein the polycyclic aromatic compound is 1,4-dimethylnaphthalene.

6. The first temperature is between −78° C. and 25° C.; the second temperature is between −40° C. and 100° C.; or The method according to any one of claims 1 to 5, which is a combination thereof.

7. The method of any one of claims 1 to 6, wherein the photosensitizer is a triplet photosensitizer.

8. The triplet photosensitizer is Rose Bengal, Methylene Blue, Eosin B, Ru(bpy) ３ 8. The method of claim 7, wherein the fluorene is selected from the group consisting of methyl green, rubrene, fluorene, fullerene, nanoparticles, or combinations thereof.

9. The fullerene is optionally substituted with alkyl, aryl, alkoxy, or combinations thereof. ２０～９４ It is a fullerene, the fluorene is a 9,9-substituted fluorene or a 2,7-substituted fluorene; The nanoparticles are CdTe, ZnSe, SiNP, CNP, AuNP, or BiNP nanoparticles, or are silica, protein, or polymer nanoparticles containing triplet photosensitizers, or combinations thereof; The method according to claim 8.

10. The method of any one of claims 1 to 9, wherein the light comprises light having a wavelength of from 380 nm to 1000 nm.

11. The method of claim 10 , wherein the light comprises natural light or light from an LED light source.

12. The method of any one of claims 1 to 11, wherein the first mixture is a solution and further comprises a solvent.

13. 13. The method of claim 12, wherein the solvent is acetonitrile, ethanol, methanol, dichloromethane, hexane, water, ether, dimethylformamide, carbon tetrachloride, chloroform, propylene carbonate, ethylene glycol, propylene glycol, tetrahydrofuran, or a combination thereof.

14. 14. The method of any one of claims 1 to 13, wherein the first mixture is a solid and optionally further comprises a zeolite, a diatomaceous earth, a hydrogel, a polymer, a metal-organic framework motif, or a combination thereof.

15. 15. The method of claim 14, wherein the polymer comprises polyethylene, polypropylene, polyethylene glycol, polypropylene glycol, a peptide, polyacrylic acid, or a combination thereof.

16. A method for producing an oxygen-enriched air stream suitable for administration to a patient in need thereof, the method comprising: exposing a first mixture comprising a polycyclic aromatic compound and a photosensitizer to a first portion of oxygen gas and light at a first temperature to form a second mixture comprising an endoperoxide, wherein the first temperature is selected to substantially prevent the endoperoxide from decomposing, and exposing the first mixture to the first portion of oxygen gas comprises exposing the first mixture to ambient air; raising the temperature of the second mixture to a second temperature higher than the first temperature and / or terminating irradiation to promote decomposition of the endoperoxides to form reformed polycyclic aromatic compounds and release oxygen; mixing the released oxygen with an air stream to form the oxygen-enriched air stream; and the polycyclic aromatic compound is represented by formula II 【Chemistry 17】 wherein R 1 , R 2 and R 3 are each independently H; OH; C 1-25 aliphatic; C 6-15 aryl; alkoxy of the formula -O-C 1-25 alkyl or -O-C 3-15 cycloalkyl; -O-acyl of the formula -O-C(O)H, -O-C(O)C 1-25 aliphatic or -O-C(O)-aromatic, where aromatic refers to a ring moiety having from 5 to 15 ring atoms; -O-Si(C 1-25 alkyl) 3 ; -O-amino acid; or -O-carbohydrate; n is 0 to 6) The method has the structure:

Images