Patent Application
20170341054
The present disclosure relates generally to nanotechnological structures. Such structures as well as methods of making and using them are provided.
Functionalizing fibers with tailored chemistry has received interest in both academia and industry, and the results have increased fiber water repellency, fire resistance, fiber strength, and antimicrobial properties. The broad use of natural and synthetic fibers in the form of paper, fabrics, plastic, air filtration media, membranes, and other technologies have resulted in a variety of different methods used to impart chemical functionality to fibers.
Of these methods, particular effort has been placed on synthesizing metal particles by loading cellulose with metal nanoparticle precursors and reacting the precursors to produce a nanometal particle functionalized fabric. Additionally, functionalized cellulose fibers have been synthesized via a layer-by-layer approach where ultrathin organic multilayered films are assembled on a substrate. Still, other methods to modify cellulose have included: the use of carboxyl groups to impart functionality; utilization of sulfur groups to bind silver and other metals; and copper has been embedded for antimicrobial properties. A variety of different types of cellulose have been modified as well, including aerogels and cellulose derived from plant fibers.
Alloys in the form of quantum dots have also been added to both cellulose and nylon fibers. For example, quantum dots have been added to pre-electro spinning polymer solutions to prepare quantum dot fiber composites, and nylon quantum dot hybrid fibers have been prepared via in-situ polymerization. It has also been shown that, water-soluble ZnS quantum dots can be functionalized and utilized in an ink jet printer to impart nanotechnology to the surface of cotton or paper.
In addition to non-porous particles, porous metal organic framework (MOF) structures have been added to fibers using a variety of methods. Specifically, MOF crystals have been grown on cellulose fibers; added to polymer modified fibers; encapsulated in electrospun fibers; immobilized on fibers via solvothermal synthesis methods; developed in layer-by-layer process; and attached using microwave synthesis methods. Of particular interest is the use of atomic layer deposition to grow Cu-BTC MOF crystals on polymer fibers, and the application of MOF materials via ink jet printing onto paper.
However, of all the approaches and techniques used to combine nanostructures with fibers, a broadly applicable approach is absent. Unique synthetic conditions must be developed each time a nanostructure is to be added to a fiber and in some cases, such as atomic layer deposition, sophisticated laboratory equipment is required, which is not effective at an industrial scale. Furthermore, there are no such methods that are readily adaptable to industrial fiber production settings. Currently, there is a need for generic synthetic methods that utilize conditions commonly found in chemical production facilities, such as moderate temperature and pressure requirements, limited vacuum conditions, and methods amenable to roll-to-roll processing technology.
The problems described above are addressed in this disclosure by the provision of a fiber coated with a functional nanostructure comprising a reactive dye conjugating moiety; and by the provision of a method of attaching a functional nanostructure to a fiber substrate using a reactive dye conjugating moiety. Reactive dye conjugating moieties bind tenaciously to fibers, do not require highly stringent synthetic conditions, may employ inexpensive commercially available reagents, and are suitable for use in fabric manufacturing facilities.
A general embodiment of the method comprises the following steps in any order: (a) covalently binding the reactive dye conjugating moiety to the fiber substrate; (b) covalently binding a bonding agent to the reactive dye conjugating moiety; and (c) binding the functional nanostructure to the bonding agent.
A general embodiment of the coated fiber comprises: (a) the fiber substrate; (b) a reactive dye conjugating moiety covalently bound to the fiber; (c) a bonding agent covalently bound to the reactive dye conjugating moiety; and (d) the functional nanostructure bound to the bonding agent.
A second general embodiment of the coated fiber is a product of any of the methods above.
A manufactured article is provided, which comprises any of the coated fibers provided above.
The above is a simplified summary in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview. It is not intended to identify key or critical elements or to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as are commonly understood by one of ordinary skill in the art of this disclosure. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well known functions or constructions may not be described in detail for brevity or clarity.
With reference to the use of the word(s) “comprise” or “comprises” or “comprising” in the foregoing description and/or in the following claims, unless the context requires otherwise, those words are used on the basis and clear understanding that they are to be interpreted inclusively, rather than exclusively, and that each of those words is to be so interpreted in construing the foregoing description and/or the following claims.
The term “consisting essentially of” means that, in addition to the recited elements, what is claimed may also contain other elements (steps, structures, ingredients, components, etc.) that do not adversely affect the operability of what is claimed for its intended purpose as described in this disclosure. This transitional phrase does not encompass embodiments that contain other elements that adversely affect the operability of what is claimed for its intended purpose as described in this disclosure, even if such other elements would be beneficial or neutral with regard to the operability of what is claimed for a purpose other than the ones described in this disclosure.
It will be understood that when a feature or element is referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element, or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
The terms “about” or “approximately” mean within a range of reasonable error around a central value. Such reasonable error may for example stem from the precision of an instrument or method used to measure the value. The error could also stem from the precision of a method of making a component of a device. Specific examples of such limits of reasonable error are 20%, 10%, 5%, 2.5%, and 1%. Unless specified otherwise, all numerical values may be approximate.
The terms “first”, “second”, and the like are used herein to describe various features or elements, but these features or elements should not be limited by these terms. These terms are only used to distinguish one feature or element from another feature or element. Thus, a first feature or element discussed below could be termed a second feature or element, and similarly, a second feature or element discussed below could be termed a first feature or element without departing from the teachings of the present disclosure.
A fiber coated with a functional nanostructure is provided (“coated fiber”), which includes (a) the fiber substrate, (b) a reactive dye conjugating moiety covalently bound to the fiber substrate, (c) a bonding agent covalently bound to the reactive dye conjugating moiety, and (d) the functional nanostructure conjugated to the bonding agent.
The bonding agent may be bound to the functional nanostructure via any type of chemical bond. In some embodiments of the coated fiber, the functional nanostructure is covalently bound to the bonding agent. Such embodiments have the advantage of providing extremely tenacious bonding between the functional nanostructure and the bonding agent.
In some embodiments of the coated fiber, the functional nanostructure is a metal-organic framework (MOF). An MOF refers to a coordination network with organic ligands containing potential voids. In this context a coordination network comprises (1) a coordination compound extending, through repeating coordination entities, in one dimension, but with cross-links between two or more individual chains, loops, or spiro-links; or (2) a coordination compound extending through repeating coordination entities in multiple dimensions. The “coordination compound” is any compound that contains an ion or neutral molecule that is composed of a central atom, such as but not limited to a metal, to which is attached a surrounding array of atoms or groups of atoms, each of which is called a ligand. The term organic ligand is an ion or molecule attached to a coordination compound. In some embodiments of the coated fiber, the MOF is conjugated to an organic linker.
The MOF may be any known in the art. In a specific embodiment of the coated fiber, the MOF is a copper-1,3,5-benzenetricarboxylic acid (Cu-BTC) framework. Cu-BTC frameworks have a variety of useful applications, such as the ability to efficiently scrub contaminants such as ethane, ethylene, and ammonia from gas streams.
The bonding agent is a molecule with at least one reactive functional group, which allows the bonding agent to form a bond with the fiber substrate or the functionalized nanostructure. Some embodiments of the bonding agent comprise at least two reactive functional groups, which allow the bonding agent to form a bond with the fiber substrate and the functionalized nanostructure. In some embodiments of the coated fiber the bonding agent is organic. In further embodiments, the bonding agent is an organic molecule with two or more reactive functional groups, wherein the first functional group covalently binds to the reactive dye conjugating moiety and the second functional group binds to the functional nanostructure.
In some embodiments of the coated fiber, the bonding agent may include a thiol group bound to the functional nanostructure and a primary amine group bound to the reactive dye conjugating moiety. Thiol groups have the advantage of being highly reactive, for example forming strong bonds with metals and other functional groups. Primary amine groups have the advantage of reacting with organohalide compounds, such as certain reactive dye conjugating moieties. Because many fibers lack chlorine atoms, the primary amine allows the bonding agent to selectively react with organohalide reactive dye conjugating moieties, but not with the substrate fiber itself. In some embodiments of the coated fiber, the bonding agent may include a thiol group bound to the functional nanostructure and a primary amine group bound to the reactive dye conjugating moiety.
In some embodiments of the coated fiber, the bonding agent comprises: (1) an SH group; (2) an alkyl group; and (3) one or more functional groups capable of reacting with the reactive dye conjugating moiety. In some embodiments of the coated fiber, the bonding agent may have the formula H2N—R—SH, in which R is a substituted or unsubstituted alkyl group. In a specific embodiment, R is an unsubstituted alkyl group. In some such embodiments, the R group is no more than 60 carbons in length. In further embodiments, the R group is 1-40 carbons in length, 1-10 carbons in length, 1-6 carbons in length, 1-3 carbons in length; 6 carbons in length; or 3 carbons in length.
In some embodiments of the coated fiber, R is an unbranched and unsubstituted alkyl group, having the formula (CH2)n. In such embodiments, n indicates the length of the alkyl chain, and may be for example 1-60. In other embodiments of the binding agent n may be 1-40, 1-10, 1-6, 1-3, 6, or 3.
In some embodiments of the coated fiber, the bonding agent is cysteamine (H2NCH2CH2SH) or cysteamine hydrochloride (H2NCH2CH2SH*HCl). These two compounds are widely available commercially, are inexpensive, and pose few hazards to workers or the environment. They also effectively bind some reactive dye conjugating moieties, such as halotriazine moieties.
“Substituted or unsubstituted” or “optionally substituted” means a group such as, for example, but not limited to: alkyl, aryl, heterocyclyl, cycloalkyl, arylalkyl, heteroaryl, heteroarylalkyl, and the like, unless specifically noted otherwise, may be unsubstituted, or may be substituted with 1 or 2 substituents. The term “carbocycle” (or carbocyclyl) as used herein refers to monocyclic, saturated, partially unsaturated or aromatic ring. Carbocycles may be optionally substituted. Non-exclusive examples of carbocycles include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclopentene, cyclohexene, cyclooctene, cycloheptene, benzyl, naphthalene, anthracene, phenanthrene, biphenyl, and pyrene. The term “hetereocyclyl” or “heterocycle” is a carbocycle group wherein one or more of the atoms forming the ring is a heteroatom that is N, O, or S. The heterocycle may be saturated, partially saturated, or aromatic. Heterocycles may be optionally substituted. Non-exclusive examples of heterocyclyl (or heterocycle) include: piperidyl, 4-morpholyl, 4-piperazinyl, pyrrolidinyl, 1,3-dioxanyl, thiophenyl, furanyl, pyrrolyl, pyrazolyl, pyridinyl, pyrimidinyl, pyranyl, and the like. “Halogenated” or “halo” means fluorine, chloride, bromine or iodine.
Any of a wide variety of functional nanostructures can be included. Such functional nanostructures may include: a nanoparticle of less than about 50 nm diameter, a metal atom, a zero valent metal atom, a single metal atom, a metal ion, a single metal ion, a metalloid atom, a single metalloid atom, a metalloid ion, a single metalloid ion, a quantum dot, a polyoxometalate, a polymer of intrinsic microporosity, a metal-organic framework, a zeolitic imidazolate framework, a graphene oxide framework, a fluorophore, a chromophore, a polypeptide, a protein, an enzyme, a nucleic acid, a carbohydrate, a monosaccharide, a disaccharide, a polysaccharide, cyclodextrin, an organic linker of a metal-organic framework, an antimicrobial compound, an antimicrobial ion, an antimicrobial metal, a quaternary ammonium salt, a metal hydroxide, an amino acid, a monomer, and an antibody.
A nanoparticle of less than about 50 nm diameter has distinct advantages over large particles, specifically that nanoparticles of less than about 50 nm have very large surface areas that enable nanofunctionality, as is known in the art. In some embodiments of the coated fiber, the nanoparticle may include a metal, a metalloid, gold, gold (III), gold chloride, gold (III) chloride, silver, a metal oxide, a metal salt, a magnetic metal, a zeolite, a polymer, silica, graphene, graphite. More specific embodiments of the nanoparticle are a metal atom, a zero valent metal atom, a single metal atom, a metal ion, or a single metal ion selected from the group consisting of: gold, gold (III), silver, mercury, and iron. In an alternative embodiment of the coated fiber, the functional nanostructure is a quantum dot.
Zero valent metals (ZVM) have the advantage of very high thermal conductivity and electrical conductivity. Many ZVM are hard, tough, wear resistant, corrosion resistant, heat resistant, and resistant to deformation at high temperatures. Part of the coated fiber, such as threads or bundles of threads, having the ZVM creates the possibility of enabling the surface metal to act as an electrical or thermal conductor (for example, using zero valent copper or gold). Such a thread with a fiber core and conductive outer layer has a myriad of potential uses in the electronics industry, the textile industry, biomedical device development, and the aerospace field. Such conductive fibers would have significant strength, high conductivity and much lower mass than bulk metal wires used in power transmission and signal transmission.
The reactive dye conjugating moiety is a group from a reactive dye that functionalizes the dye for binding to the fiber. A reactive dye comprises a chromophore and a structure with a reactive group, which structure is referred to in this disclosure as the conjugating moiety. The conjugating moiety reacts with the fiber to form a covalent bond, resulting in very colorfast dying of the fiber. Various reactive dyes and their conjugating groups are known. Any known reactive dye conjugating moiety may be used. In some embodiments of the coated fiber, the reactive dye conjugating moiety may include a reactive binding group selected from the group consisting of: chloride, fluoride, thiol, sulfide, sulfone, and amide. In some embodiments of the coated fiber, the reactive dye conjugating moiety may include at least two reactive binding groups, each independently selected from the group consisting of: chloride, fluoride, thiol, sulfide, sulfone, and amide. In some embodiments of the coated fiber, the reactive dye conjugating moiety is a halorotriazine moiety. In some embodiments of the coated fiber, the reactive dye conjugating moiety is a mono-, di-, or trichlorotriazine moiety. In further embodiments of the coated fiber, the reactive dye conjugating moiety is selected from the group consisting of: cyanuric chloride, monochlorotriazine, monofluorochlorotriazine, dichlorotriazine, monofluorodichlorotriazine, and difluoromonochlorotriazine. In a specific embodiment of the coated fiber, the reactive dye conjugating moiety is a 2,4,6-trichloro-1,3,5-triazine(cyanuric chloride) moiety. The halotriazines have the advantage of excellent fiber binding chemistry in reactive dyes. In alternative embodiments of the coated fiber, the reactive dye conjugating moiety is a vinyl sulfone moiety. Other examples of the reactive dye conjugating moiety include haloquinoxaline moieties and halo pyrimidine moieties.
In some embodiments of the coated fiber, the functional nanostructure is a gold nanoparticle that may further include a functionalized thiol bound to gold in the nanostructure. In some embodiments of the coated fiber, the functional nanostructure that is a gold nanoparticle, a gold atom, gold(III) chloride, or gold (III) chloride hydrate, may further include a functionalized thiol compound bound to the gold nanoparticle. In such embodiments the functional nanostructure may serve as a general substrate for the addition of further groups to the coated fiber.
In some embodiments of the coated fiber, the first functional nanostructure may be conjugated to a second functional nanostructure via a functionalized thiol. As stated above, the first functional nanostructure may be a gold nanoparticle that may further include a functionalized thiol compound bound to a second functional nanostructure. In some embodiments of the coated fiber, the first functional nanostructure is a gold nanoparticle that may further include a functionalized thiol compound bound to a second functional nanostructure, wherein that second functional nanostructure is a gold nanoparticle.
The second functional nanostructure may be any known in the art. In some embodiments of the coated fiber, the functionalized thiol may be conjugated to a second functional nanostructure selected from the group consisting of: a self-assembled monolayer forming compound, gold, silver, metal nanoparticles, bulk metal particles, metal salts, metalloids, metal alloys, quantum dots, adsorbents, catalysts, metal oxides, magnetic nanoparticles, polyoxometalates (POMS), polymers, polymers of intrinsic microporosity (PIMS), metal organic frameworks (MOFs), an organic linker of a MOF, zeolites, covalent organic frameworks (COFs), zeolites, zeolitic imidazolate frameworks (ZIFs), graphene oxide frameworks (GOFs), colloidal particles, silicas, carbons, graphene, graphite, antibiotics, antibodies, fluorescent molecules, enzymes, and proteins.
Any of various fibers may serve as the substrate. In some embodiments of the coated fiber, the fiber substrate is a synthetic fiber, a vegetable fiber, or an animal fiber. Synthetic fibers include nylon, modacrylic, olefin, acrylic, polyester, carbon fiber, rayon, vinyon, saran, spandex, vinalon, araminds, modal, dyneema, specrtra, polybenzimidazole, sulfar, lyocell, PLA, M-5, orion, zylon, vectran, derclon, glass fibers, glass wool, glass reinforced plastics, rayon, diacetate, triacetate, polyamide, aliphatic polyimide, polyphthalamide, and an aramide. Such synthetics are commercially available under tradenames such as nylon, technyl, rilsan, rilsamid, trogamid, amodel, Kevlar, Nomex, Teijinconex, Twaron, Technora, Kermel, and Spectra. In further embodiments of the coated fiber, the fiber substrate is a vegetable fiber. Vegetable fibers include cellulosic fibers, cotton, hemp, jute, flax, ramie, sisal, bagasse, pina, esparto, Indian hemp, hoopvine, kenaf, linden bast, nettle bast, papyrus, Manila hemp, bowstring hemp, henequen, phormium, yucca, coir, kapok, milkweed, luffa, wood fiber, or bamboo fiber. In further embodiments of the coated fiber, the fiber substrate is an animal fiber. The animal fiber may be, for example proteinaceous, silkworm silk, spider silk, sinew, catgut, wool, sea silk, hair, cashmere wool, mohair, angora, sheep pelt, rabbit pelt, mink pelt, fox pelt, beaver pelt, angora, bison, qiviut, horsehair, chiengora, alpaca wool, vicuña wool, merino wool, yak down, camel down, guanaco wool, llama wool, or chinchilla.
Some embodiments of the coated fiber display extremely durable attachment of the functionalized nanostructure to the fiber substrate. In some embodiments of the coated fiber, no significant loss of the functional nanostructure occurs upon vigorous washing. In some embodiments of the coated fiber, no significant loss of the functional nanostructure occurs upon vigorous washing with one or more of: chloroform, water, soap and water, tetrahydrofuran, hexane, and acetone. In some embodiments of the coated fiber, no significant loss of the functional nanostructure occurs upon vigorous washing with all of: chloroform, water, soap and water, tetrahydrofuran, hexane, and acetone. Although the act of “vigorous washing” is well understood by those in the art, where necessary to definitely establish the meaning of such term, the vigorous washing may be construed to be the washing process described below, in the “Materials and Methods” section of the Working Example In various embodiments of the coated fiber, the vigorous washing described above results no significant loss, that is less than 25% loss of the functional nanostructure. In further embodiments the not significant loss is less than 20%, 15%, 10%, 5%, and 1%. In a specific embodiment the loss is about 0%. In still further embodiments, no loss of the functionalized nanostructure to the fiber substrate can be detected by unassisted visual observation.
A method of attaching a functional nanostructure to a fiber substrate using a reactive dye is provided, including the following steps in any order: (a) covalently binding the reactive dye conjugating moiety to the fiber substrate, (b) covalently binding a bonding agent to the reactive dye conjugating moiety, and (c) binding the functional nanostructure to the bonding agent. A specific embodiment of the method includes performing step (a) prior to steps (b) and (c), and then performing step (b) prior to step (c). In some embodiments, step (c) may include covalently binding the functional nanostructure to the bonding agent. Such embodiments have the advantage of providing a durable bond between the functional nanostructure and the bonding agent.
In some embodiments, the functional nanostructure is a metal-organic framework (MOF). In some such embodiments, step (c) may include binding a metal ion to the bonding agent. In further embodiments in which the functional nanostructure is a MOF, the method may include conjugating the metal ion to an organic linker.
The reactive dye conjugating moieties, bonding agents, and functional nanostructures used in the method may be any of the reactive dye conjugating moieties, bonding agents, and functional nanostructures disclosed as suitable for use in the coated fiber above.
In embodiments of the method in which the functional nanostructure comprises a metal atom or ion, the method may further comprise reducing the metal atom or ion to a zero valent state. The atom or ion may be reduced chemically, electrochemically or thermally to yield a zero valent metal atom that remains attached to the surface through the bonding agent and the reactive dye conjugation moiety. In some embodiments the method comprises reducing an atom or ion of gold; however, any metal atom or ion that can be attached would also be reducible by these means (e.g. Cu2+, Cu+, Ag+, Fe2+, Fe3+, Zn2+, Ti4+, Pd2+, Pt2+, Zr4+, Al3+, etc.). Such ZVM coatings has numerous advantages and uses as described above.
A fiber coated with a functional nanostructure is provided that is the product of any of the processes disclosed above. In some embodiments of the coated fiber, no significant loss of the functional nanostructure occurs upon vigorous washing. In some embodiments of the coated fiber, no significant loss of the functional nanostructure occurs upon vigorous washing with one or more of: chloroform, water, soap and water, tetrahydrofuran, hexane, and acetone. In some embodiments of the coated fiber, no significant loss of the functional nanostructure occurs upon vigorous washing with all of: chloroform, water, soap and water, tetrahydrofuran, hexane, and acetone. In various embodiments of the clothing or textile, the vigorous washing described above results in less than 25% loss of the functional nanostructure. In further embodiments the loss is less than 20%, 15%, 10%, 5%, and 1%. In a specific embodiment the loss is about 0%.
A manufactured article is provided, comprising any of the coated fibers disclosed above. Such article may include a wooden article; in some embodiments of the wooden article, the fiber substrate is a wood fiber. Other examples of the article include a paper article, and a textile (which may be a woven or knit textile). In embodiments of the article that are a textile, the textile may be for example cambric, chino, corduroy, denim, seersucker, or terrycloth.
The article may also be an item of clothing that includes the textile. Some embodiments of the clothing or textile display extremely durable attachment of the functionalized nanostructure to the fiber substrate. In some embodiments of clothing or textile, no significant loss of the functional nanostructure occurs upon vigorous washing. In some embodiments of clothing or textile, no significant loss of the functional nanostructure occurs upon vigorous washing with one or more of: chloroform, water, soap and water, tetrahydrofuran, hexane, and acetone. In some embodiments of clothing or textile, no significant loss of the functional nanostructure occurs upon vigorous washing with all of: chloroform, water, soap and water, tetrahydrofuran, hexane, and acetone. Although the act of “vigorous washing” is well understood by those in the art, where necessary to definitely establish the meaning of such term, the vigorous washing may be construed to involve . . . . In various embodiments of the clothing or textile, the vigorous washing described above results in less than 25% loss of the functional nanostructure. In further embodiments the loss is less than 20%, 15%, 10%, 5%, and 1%. In a specific embodiment the loss is about 0%.
Therefore, the purpose of the examples below is to demonstrate that reactive dye coordinating moieties, such as but not limited to cyanuric chloride, used commercially to add color to fabrics and fibers, can also be used as a generic platform to attach functional nanostructures to substrates. The example utilizes fibers as a substrate and cyanuric chloride as a reactive dye conjugating moiety. Several functional groups bound to the substrate are considered and the growth of a monolayer after functionalizing a substrate is demonstrated.
The utilization of reactive dye chemistry as a method to functionalize fibers provides a robust and cost-effective platform to build or incorporate nanostructures into commercially available fiber products. A general platform approach is illustrated in
Specifically, a reactive dye conjugating moiety, cyanuric chloride, was selected as a method to anchor nanostructures to the fiber substrate, as shown in
The results of this process are shown in
It is important to note that prior to taking the FESEM images, the fabric samples were rigorously washed first with chloroform, water, then commercial hand soap and water, and lastly acetone. The presence of the gold after rigorous washing highlights the robust chemical attachment of the metal to the surface of the particles. The ability of the gold nanoparticles to remain bound to the fiber substrate even with vigorous washing was in stark contrast with the fabric samples that were incubated with gold without the use of reactive dye chemistry, as shown in
To ensure that the coating observed on the fabric was gold, scanning electron microscopy energy dispersive x-ray spectroscopy (SEM-EDS) data were gathered and confirmed the presence of not only gold, but also sulfur, and chlorine. The presence of these elements is consistent with the reaction chemistry reflecting a thiol of cysteamine and residual chlorine of cyanuric chloride. SEM-EDS data on the gold modified samples were taken without gold sputtering, and additional SEM-EDS data are presented in the figures.
A distinct pink color, consistent with properties of gold, was observed when the nylon was functionalized with 40 nm gold as shown in
The reactive dye method (RDM) was also used to modify cellulose (cotton) swatches with 20 and 40 nm gold particles and produced similar results as the nylon samples. Images of cotton modified with gold are provided in
To quantify the total gold loading, microwave plasma atomic emission spectroscopy (MP-AES) measurements were completed on representative 40 nm gold-modified cotton and gold-modified nylon samples that were prepared. The gold loadings of these samples was nominally 0.077 wt. % for gold-modified cotton and 0.081 wt. % for gold-modified nylon.
Two similar processes were developed to bind gold to the surface of the fabric; one using cysteamine hydrochloride and the second using cysteamine. This modification is noted because the two processes produced similar results and the cysteamine hydrochloride salt is available at a significantly reduced price relative to the pure cysteamine reagent. The synthesis section of the work identifies these differences and highlights when each method was used. In this example the cysteamine has taken the place of the traditional chromophores and is available for additional reaction; however, other thiols, such as 6-amino-1-hexanethiol, could have also been used.
It is important to highlight that the fabric swatch was cut from a sample of nylon purchased from Jo-Ann's Fabric and Craft store, which illustrates that it is not necessary to have laboratory grade nylon and that this approach can be applied to currently industrially-produced fabrics. The RDM was also used to modify 0.5″ (1.27 cm) cellulose swatches. As was done for the nylon sample, a commercially available cellulose sample was obtained, in this case a T-shirt purchased from Wal-Mart (Faded Glory brand) reflecting the ease of application of this approach to existing commercially available fibers. Also, reactive dye chemistry is known to be applicable to wool and silk and in this work cellulose was selected as a representative example of these natural fibers. Likewise, illustration of the RDM to cellulose is broadly applicable to fabrics as well as other cellulose materials, such as wood or paper.
With the FESEM illustrating gold covering a large portion of the fiber surface (
The materials show high surface area with approximately 976 and 680 m2/g for cotton and nylon respectively, and X-ray diffraction (XRD) patterns consistent with Cu-BTC. As a control, Cu-BTC was prepared without the presence of fabric and resulted in a sample with 1778 m2/g. Compared to the pure Cu-BTC powder, the cotton and nylon have 55 and 38% of the pure powder surface area, respectively. Additionally, the presence of the fabric swatch functionalized to bind copper on the fabric did not impact the formation of MOF in the reaction solution. Specifically, Cu-BTC powder that formed in the reaction solution but was not attached to the fabric produced a sample containing 1760 m2/g of surface area.
To illustrate the viability of the bound nanostructure to perform industrially relevant separations, ethane and ethylene single component gas adsorption isotherms were measured and are shown in
Also, the ability of the material to remove ammonia from air was evaluated by passing a humid air stream containing ammonia across the fabric and monitoring the effluent gas concentration in a gas breakthrough experiment (46). The data shows that the material readily captures ammonia from a flowing stream of humid air. Specifically, the cotton Cu-BTC sample adsorbed 2 mol/kg of ammonia in a 25° C. (50% relative humidity) air stream, and the nylon Cu-BTC sample produced a lower 0.5 mol/kg loading, which is consistent with the lower surface area of the Cu-BTC nylon sample.
To illustrate the application of RDM technology to optical nanostructures and surfaces, 6 nm CdSeS/ZnS alloyed quantum dots with a fluorescence of 505 nm were added to cellulose and nylon. FESEM images of these samples were completed; however, given the small size of the quantum dots it was difficult to see the particles using FESEM, as shown in
To observe the loading of the quantum dots on the fabric, maximum intensity confocal microscopy images were gathered as shown in
A second sample was prepared using cysteamine hydrochloride (process 3b) and the results are shown in
Although these two samples showed variance in how the quantum dots load the nylon fibers, both produced nylon swatches with bound quantum dots and florescence consistent with the stock quantum dot solution.
The optical measurements also confirmed that the observed fluorescence of the quantum dots in solution has not changed upon binding to the fiber surface. Specifically, a sample of the solution that was used as the source of the quantum dots for the experiments shown in
The RDM was repeated using quantum dots with fluorescence wavelengths of 525, 575, 630, and 665 nm producing fabrics of different colors as shown
To demonstrate the viability of attaching a metal ion to the fiber using the reactive dye chemistry, and subsequently reducing the ion to a ZVM, cotton was coated with gold ions. A roll of cotton fabric was exposed to gold ions after pretreatment with the reactive dye method. Another cotton fabric sample was pretreated with the reactive dye method, exposed to gold ions, washed with water, and then reduced to form zero valent gold. A slight pink color was present in the reduced sample, indicating zero valent gold on the fabric.
The results discussed illustrate the use of reactive dye chemistry to attach nanostructures to fibers. The approach is applicable to synthetic and natural fibers and can be used as a starting point for the assembly of complex nanostructures, such as MOFs on fibers. Likewise, the gold in the modified fibers is available for surface chemistry reactions and provides a starting point for applying other gold-based nanotechnology, such as self-assembled monolayers, to fibers. The MOF-modified fibers show selectivity for ethylene over ethane and can remove ammonia from a humid air stream. The quantum dot fibers fluoresce with the same wavelength of the bulk solution even though the particles are bound to the surface. The gold and quantum dot examples provided survive not only solvent washes, such as acetone, chloroform, and hexane, but also soap and water. The MOF modified fibers survive washes with solvents, but were not washed with water due to Cu-BTC instability. These results provide three examples of utilizing reactive dyes to modify synthetic and natural fibers, and provide a route to move nanotechnology from a lab practice to commercially available substrates, such as fabrics, papers, and plastics.
Although other dyes can be used, in the cases shown, cyanuric chloride was covalently attached to the fiber substrate. Then the attached cyanuric chloride was modified with an amino thiol bonding agent, and lastly a functional nanostructure such as a metal, metal salt, or quantum dot, was added to the modified fiber. The order of these steps can vary and may impact the quality and properties of the product produced.
Two variants of this method were used to prepare most of the fabrics. The processes are similar with the first process using cysteamine hydrochloride as the bonding agent and the second process using cysteamine as the bonding agent. Two methods were examined because cysteamine hydrochloride is less expensive than pure cysteamine. Both methods produced similar results. The use of cysteamine hydrochloride was illustrated by modifying nylon with gold as detailed in process 1b, nylon modified with MOF as described in 2b, and nylon modified with quantum dots as detailed in process 3b. The gold was purchased as nanoparticles in solution from Strem Chemicals Inc. and used as received.
In all cases these materials were prepared separately (nylon and cellulose were not placed together in the reaction vials). Cellulose was prewashed with soap and water and then rinsed with chloroform. The nylon was not prewashed but the other processing steps are the same for both cellulose and nylon.
The following protocol was followed to observe the persistence of the nanostructure on the fiber substrate after washing. Washing of the nanostructure-modified fabric was completed with enough solvent to completely submerge the fabric in solvent. The solvent and fabric swatch were mixed using a scapula. If color was observed in the solvent upon washing, the fabric was subsequently rinsed with more solvent using a wash bottle and washed again. Solvents, water, and soap were washed at room temperature. When hot THF was used the temperature was 40-50° C. Washing of the nanostructure modified fabric was completed with enough solvent to completely submerge the fabric in solvent. The solvent and fabric swatch were mixed using a microspatula. If color was observed in the solvent upon washing, the fabric was subsequently rinsed with more solvent using a wash bottle and washed again. To complete a wash using soap the fabric swatch was placed in the palm of the hand and hand soap applied; the fabric was then rubbed against the palm of the hand with one's index finger. Different solvent washes were used for different attached structures (optimized to try to remove the attached structure). For gold the washings were completed using hot THF (40-50° C.), water, soap (hand soap), and acetone. In some cases for gold the washings were water, chloroform, soap, water, and acetone. STOKO hand soap was used to wash the fabrics. STOKO hand soap contains: water, sodium laureth sulfate, cocamidopropyl betaine, PEG-200, hydrogenated glyceryl palmate, PEG-7, Glyceryl Cocoate, Undecylenamidopropyltrimonium, methosulfate, fragrance, benzyl alcohol, methylchloroisothiazolinone, methylisothiazolinone, citric acid, and blue 1.
Per the manufacture, the gold nanoparticles solutions are supplied at an optical density of 1 in a solution stabilized with citrate buffer (0.1 mg/ml). The concentration of the gold particles at these conditions are 6.94×10−2, 5.31×10−2, and 4.65×10−2 mg/ml for 5, 20, and 40 nm particle solutions, respectively.
Process 1a: Modification of Nylon or Cellulose with Gold Via Cysteamine
The procedure below applies to both cellulose and nylon. This process was used to produce the sample shown in
Process 1b: Modification of Nylon with Gold Via Cysteamine Hydrochloride
This process was used to produce the sample shown in
In an Erlenmeyer flask, 40 mL of tetrahydrofuran (THF) was heated (approximately 40-50° C.) and 1.13 g cysteamine hydrochloride added. Once the cysteamine hydrochloride dissolved, the heat was removed and 0.92 g of cyanuric chloride was added. In a beaker, a solution of 0.4 g of sodium carbonate in 4 mL of water was prepared, added to the THF mixture, and allowed to sit overnight. The next day two swatches of the nylon were pretreated in a solution of 5 g sodium carbonate and 50 mL of water at 60° C. for 5-10 minutes. After pretreatment, the fabric swatches were added to the THF mixture and allowed to sit for 3 days. Next, one of the three pieces was washed with hot THF and water. A gold (5 nm) solution was added to the fabric in a beaker and the solution was allowed to sit overnight covered. Gold nanoparticles were added to the fabric in excess such that the gold solution submerged the fabric. The next day the fabric was removed from the gold solution and washed with hot THF and water. A second swatch of fabric that was stirred for 3 days was collected from the reaction solution and washed with hot THF, water, soap and acetone; then 5 nm gold solution was added to the fabric, and the fabric/gold mixture was allowed to sit covered overnight. Lastly the second fabric swatch was then washed with hot THF, water, soap, and acetone. The results of this process are shown in
The same reaction process was repeated to produce the results shown in
Process 2a: Modification of Nylon and Cellulose with a MOF Via Cysteamine
This process was used to produce the cellulose modified samples shown in
The nylon and cellulose fabric was pretreated by stirring the fabric in a solution of 50 mL of water and 5 g of sodium carbonate for 5-10 minutes at approximately 60° C. Separately, 40 mL of chloroform and 1.84 g of cyanuric chloride were added to an Erlenmeyer flask; the fabric was then removed from the pretreatment solution and placed in the Erlenmeyer flask. The flask was capped with a rubber stopper and needle for ventilation and allowed to stir for one hour. Then in another flask 20 mL of water and 0.43 g cysteamine were mixed. After mixing in the cyanuric chloride solution for an hour, the fabric was removed from the flask and placed in the cysteamine solution and allowed to stir for 22 hours. Afterwards, the fabric was removed and washed with chloroform and water. In a separate 20 mL vial, 0.8 g of copper nitrate trihydrate was added to 6.6 mL of water and stirred until copper (II) nitrate was dissolved. Then the fabric was added to the copper (II) nitrate solution and the mixture was allowed to sit for approximately 24 hours.
A Cu-BTC solution of 1,3,5-benzenetricarboxylic acid (0.4 g), copper nitrate (0.8 g), and 6.6 mL each of water, ethanol, and N,N-dimethylformamide was prepared and allowed to stir for 15 minutes. The Cu-BTC solution was separated into two 20 mL vials, each containing approximately half the solution volume. A fabric swatch was removed from the copper nitrate solution and placed in one of the vials containing the Cu-BTC reaction solution. A second swatch was removed from the copper nitrate solution and placed in the other Cu-BTC reaction solution vial. The Cu-BTC vials were tightly sealed and baked in the oven for 20 hours at 85° C. The vials were removed from the oven, the contents of the two vials were combined into one vial, and then allowed to sit to settle the MOF powder from the solution, and lastly the solvent was removed leaving the crystals and fabric. Dichloromethane was then added to the vial and allowed to sit overnight (solvent exchange). The solvent exchange process was repeated 3 times, each time removing the majority of the dichloromethane solvent and replacing it with fresh dichloromethane.
Process 2b: Modification of Nylon with an MOF Via Cysteamine Hydrochloride
A 0.5″ (1.27 cm) size swatch of nylon (approximately 0.0148 g) was cut from a yard of nylon. Next, 40 mL of chloroform and 1.84 g of cyanuric chloride were placed in an Erlenmeyer flask. Then an aqueous Na2CO3 solution was prepared (0.8 g sodium carbonate in 8 mL water). In a second beaker, an aqueous cysteamine solution was prepared (1.2 g cysteamine hydrochloride in 5 mL water). The Na2CO3 solution was added to the cysteamine hydrochloride solution. This mixture was then added dropwise to the stirring solution of cyanuric chloride over 10 min and the solution was stirred overnight. The next day the nylon was pretreated by stirring the fabric in a solution of 50 mL of water and 5 g of sodium carbonate for 5-10 minutes at approximately 60° C. The pretreated nylon was then added to the cyanuric chloride mixture and allowed to stir in the reaction mixture for 4 days. The fabric was then taken out of the mixture, washed with water and chloroform. In a separate 20 mL vial, 0.8 g of copper (II) nitrate trihydrate was added to 6.6 mL of water and stirred until copper nitrate was dissolved. Then the fabric was added and allowed to sit for approximately 24 hours.
A Cu-BTC solution of 0.4 g 1,3,5-benzenetricarboxylic acid, 0.8 g copper nitrate, and 6.6 mL each of water, ethanol, and N,N-dimethylformamide was prepared and stirred for 15 minutes. The Cu-BTC solution was separated into two 20 mL vials each containing approximately half the solution volume. A fabric swatch was taken out of the water and copper nitrate solution and was placed in one of the vials containing the Cu-BTC reaction solution. A second swatch was removed from the water copper nitrate solution and placed in the other Cu-BTC reaction solution vial. The Cu-BTC vials were tightly sealed and baked in the oven for 20 hours at 85° C. The vials were removed from the oven and combined into one vial. After the crystals had settled to the bottom of the vial, the solvent was pipetted off of the crystals and fabric. Dichloromethane was then added to the vials and allowed to sit overnight (solvent exchange). The solvent exchange process was repeated 3 times with each time removing the majority of the dichloromethane solvent and replacing it with fresh dichloromethane. This process was used to produce the samples shown in
Process 3a: Modification of Nylon and Cellulose with Quantum Dots Via Cysteamine
This process was used to produce the sample shown in
Cellulose and nylon were pretreated in 50 mL water and 5 g of sodium carbonate at 65° C. for 5-10 minutes. The fabric was then added to an Erlenmeyer flask containing 40 mL of chloroform and 1.84 g of cyanuric chloride, and the flask was covered with a rubber stopper that contained a needle for ventilation and stirred for one hour. After one hour of stirring, the fabric was moved to a new flask that contained 0.45 g of cysteamine dissolved in 20 mL of water. The flask was covered with a rubber stopper that contained a needle for ventilation and allowed to stir for 22 hours. After 22 hrs, the fabric was taken out, put in a beaker, and washed with chloroform and water. Quantum dots were then added to the fabric in excess such that the quantum dot solution submerged the fabric. The vial containing the fabric and quantum dots was covered with paraffin film. The paraffin film contained a small hole to allow for evaporation, and the fabric sat at ambient conditions until all liquid had evaporated (approximately 5 days). The fabric was then washed with n-hexane, water, and chloroform. After washing, the fabric was cut in half, and one half was saved in a 20 mL vial and the other half was washed with soap, water and acetone and lastly placed in a 20 mL vial to dry.
Process 3b: Modification of Nylon with Quantum Dots Via Cysteamine Hydrochloride
This process was used to produce the sample shown in
Hand soap was used to wash the fabrics. The soap contains: water, sodium laureth sulfate, cocamidopropyl betaine, PEG-200, hydrogenated glyceryl palmate, PEG-7, Glyceryl Cocoate, Undecylenamidopropyltrimonium, methosulfate, fragrance, benzyl alcohol, methylchloroisothiazolinone, methylisothiazolinone, citric acid, and blue 1.
Gas phase adsorption isotherms were completed using a Micromeritics ASAP 2020. The Cu-BTC fabric samples were outgassed at 170° C. temperature at 1.0° C./min ramp rate overnight under vacuum on a Schlenk line. Ethylene and ethane adsorption isotherms were completed at 298 K by using a closed loop recirculating water bath to maintain a constant 25° C. temperature on the adsorption sample cell.
Samples were imaged using an A1 laser-scanning confocal microscope equipped with a spectral detector (Nikon Instruments), using a 20× objective (Plan Fluor 20× MImm DIC N2, Nikon Instruments). Fluorescence was excited using a 405 nm laser, and spectral emission was detected from 410-720 nm, in 10 nm increments. A laser power of 0.9 (out of 100), a spectral detector high voltage (HV) of 150, and a confocal pinhole diameter of 3.0 airy disc units were used. A pixel size of 1.24 μm/pixel was used in the x, and y directions, with a scan size of 1024×1024 pixels, and a scan speed of 0.5 frames/second (pixel dwell time of 1.1 μs). For each fabric sample, three-dimensional image stacks (Z-stacks) were acquired using a step size of 2.5 μm. Samples of unlabeled nylon and cellulose fabrics, as well as quantum dots in solution, were acquired and used as single-label controls for linear unmixing (described below). Images were saved in lossless, nd2 file format.
Spectral image stacks were linearly unmixed using NIS Elements software (Nikon Instruments). Prior to unmixing, pure (end-member) spectra of each fluorescent species was measured from a field of view from each single-label control sample (cellulose, nylon, and quantum dots in solution). Linear unmixing was applied to each fabric-quantum dot sample using a spectral library containing either nylon and quantum dot spectra (for treated nylon fabrics) or cellulose and quantum dot spectra (for treated cellulose fabrics). Unmixed Z-stacks were then processed using a maximum intensity projection. Maximum intensity projections were saved in lossless format as both nd2 and tiff files.
An Agilent 4100 MP-AES microwave plasma atomic emission spectrometer was used for the elemental analysis. The instrument features a magnetically excited microwave plasma source operating on nitrogen gas, and an onboard argon bottle for plasma ignition. The nitrogen gas is provided by means of an Agilent 4107 nitrogen generator. An Agilent G8480A, SPS-3, 180 position auto-sampler was used to hold blanks, standards and samples. A blank (deionized water) and three gold standard samples, with a concentration of 10, 1, and 0.1 ppm, were used as calibration standards.
A gold dyed fabric swatch was cut up into small pieces, weighed, and then put in a beaker. Then 5 mL of deionized water and 5 mL of concentrated nitric acid were added. A glass dish was put over the beaker and it was put on a hot plate and allowed to boil for approximately 15 minutes. The beaker was then removed from the hot plate and an additional 5 mL of concentrated nitric acid was added. The beaker was returned to the hot plate and the solution boiled for approximately 15 minutes. Then 5 mL of concentrated nitric acid was added to the beaker, the beaker was placed back on the hot plate, and allowed to boil for approximately 15 minutes. The beaker was taken off the hot plate to cool. Upon cooling, 5 mL hydrogen peroxide (30%) was added slowly to the cellulose. The beaker was brought back to boil for 15 minutes. Then 5 mL of hydrochloric acid was added to the cellulose and boiled for 15 minutes. Both fabric solutions were filtered and added to a 100 mL volumetric flask. Deionized water was added until the solution reached the 100 mL line. The flask was shaken and then moved to a bottle to store. This process was used for both the plain fabric swatches and the fabric swatches with gold attached to them.
A gold dyed fabric swatch was cut up into small pieces, weighed, and then put in a beaker. Then 5 mL of deionized water and 5 mL of concentrated nitric acid were added. A glass dish was put over the beaker and the mixture was boiled for approximately 15 minutes. The beaker was then removed from the hot plate and an additional 5 mL of concentrated nitric acid was added. The beaker was returned to the hot plate and the solution boiled for approximately 15 minutes. Then 5 mL of concentrated nitric acid was added to the beaker. Then 5 mL of hydrochloric acid was added to the nylon. Unlike the cellulose, it was not necessary to boil the solution another 15 minutes after the addition of the last portion of concentrated nitric acid or hydrochloric acid. Both fabric solutions were filtered and added to a 100 mL volumetric flask. Deionized water was added until the solution reached the 100 mL line. The flask was shaken and then moved to a bottle to store. This process was used for both the plain fabric swatches and the fabric swatches with gold attached to them.
Samples were prepared by cutting sub-samples from each sample, mounting on double-stick carbon tape and gold sputter coating. Images of gold modified fabrics were analyzed uncoated by low vacuum SEM and SEM-EDS. SEM-EDS was performed using a JEOL JSM-6490LV scanning electron microscope coupled to a Thermo Scientific Noran System SIX energy dispersive x-ray spectrometer system operating in low vacuum mode.
Powder X-ray diffraction (PXRD) data were recorded using a Rigaku MiniFlex600 with a Dtex detector. Samples were scanned at 40 kV and 15 mA using Cu Kα radiation and a scan step size of 2θ=0.02° over a range of 3-60° 2θ.
Ammonia microbreakthrough experiments were run on fabric samples to determine the efficiency of deposition of the MOF onto the substrate. As a comparison, a packed bed of Cu-BTC powder was also evaluated. The microbreakthrough setup has previously been described elsewhere(44). Briefly, powder was packed approximately 4 mm deep into a 4 mm ID glass fritted tube, while fiber swatches were packed into the tube and compressed to achieve maximum residence time. All samples were evaluated as-received, previously being activated at 170° C. at 1° C./min under vacuum on a Schlenk line. An ammonia feed gas was established from a pressurized ballast mixed with a humidified stream, resulting in a concentration of 1,000 mg/m3 and a relative humidity of 50% at room temperature. The total flow through the glass tube was 20 cc/min. The effluent gas was monitored with a photoionization detector as a function of time. The loading was calculated by integrating effluent curve and subtracting from the challenge concentration, and then dividing by the mass of the sample as detailed previously. (44)
Pictures of the fabric samples were taken using a Nikon D600, full frame, SLR, digital camera with a fixed focal length 50 mm AF-S Nikkor 1:1.8 G lens. The camera white balance was calibrated using a white balance cap and the images were captured in .raw format. Pictures are shown without any additional image processing. The .raw files were converted to .tiff file format using Adobe Photoshop CS6.
Shown in
Shown in
Specifically, shown in
Likewise, cellulose samples shown as
Additional images of the quantum dot modified fabrics are shown in
All fabrics, included gold, copper, and quantum dots, were dyed only once with the exception of the cotton fabric swatch shown in
Shown in
Materials synthesis was completed at the University of South Alabama and XRD characterization at the Edgewood Chemical Biological Center (ECBC). The shipping of the samples for XRD characterization may have resulted in this minor impurity as a result of air exposure.
Several control experiments were also completed. As described in the synthesis section, the fabric was first treated with the reactive dye chemistry and then exposed to a Cu(NO3)2 solution overnight prior to adding the BTC link and beginning the MOF synthesis. During this process, Cu-BTC powder that formed was both attached to the fabric and precipitated from the solution not attached to the fabric. The surface area of the Cu-BTC that collected at the bottom of the synthesis vial unattached to the fabric was collected and the surface area was determined as 1484 and 1763 m2/g for cellulose and nylon respectively. The purpose of this control was to show that the presence of fabric modified with reaction chemistry does not significantly impact the formation of MOF materials. The high surface area of the crystals collected supports this conclusion.
As a control, fabric samples of both nylon and cellulose without RDM chemistry were added to a reaction vial of a traditional Cu-BTC synthesis process. The purpose of this control was to verify that the simple addition of fabric to a MOF synthesis process would not produce fabric with MOF attached on the fabric. The surface area of the cellulose and nylon samples prepared with this method was 326 and 420 m2/g respectively. The lower surface area of these materials shows that the reactive dye chemistry allows for more MOF material to be added to the fabric, as seen with a higher surface area than this control group.
During the RDM the reactive dye modified fabric sample was exposed to Cu(NO3)2 overnight prior to beginning MOF synthesis. Therefore, to determine if diffusion of Cu into the fibers of the material was simply time limited during a typical Cu-BTC synthesis, nylon and cellulose materials were exposed to Cu(NO3)2 overnight without reactive dye attachment chemistry. After exposure to Cu overnight, the MOF synthesis procedure was started. In this control, exposing the fabric to Cu for a longer period of time resulted in a surface area of 419 m2/g for cellulose. However, when this process was repeated and the sample was then washed with solvents, the surface area was 95 m2/g, which is significantly lower than without washing indicating a large portion of the MOF was physically attached to the material and not chemically bound to the fabric surface. In either case, with or without washing, both controls produced areas that are lower than the reactive dye chemistry based samples.
The results of each of these control runs are summarized in Tables 1-3. The Cu-BTC sample used to produce the ethane and ethylene isotherms shown in
Results of the microbreakthrough experiments are shown in
The fabric samples each showed lower loadings of ammonia than the pure Cu-BTC sample, which is consistent with the lower surface area of the fabrics relative to the pure Cu-BTC. Also, the performance of the fabric swatches is impacted by the weight of the inactive cellulose or nylon fiber substrate. The cellulose sample produced a loading of 1.97 mol/kg and the nylon 0.49 mol/kg. Desorption was not calculated.
It is to be understood that any given elements of the disclosed embodiments of the invention may be embodied in a single structure, a single step, a single substance, or the like. Similarly, a given element of the disclosed embodiment may be embodied in multiple structures, steps, substances, or the like.
The foregoing description illustrates and describes the processes, machines, manufactures, compositions of matter, and other teachings of the present disclosure. Additionally, the disclosure shows and describes only certain embodiments of the processes, machines, manufactures, compositions of matter, and other teachings disclosed, but, as mentioned above, it is to be understood that the teachings of the present disclosure are capable of use in various other combinations, modifications, and environments and are capable of changes or modifications within the scope of the teachings as expressed herein, commensurate with the skill and/or knowledge of a person having ordinary skill in the relevant art. The embodiments described hereinabove are further intended to explain certain best modes known of practicing the processes, machines, manufactures, compositions of matter, and other teachings of the present disclosure and to enable others skilled in the art to utilize the teachings of the present disclosure in such, or other, embodiments and with the various modifications required by the particular applications or uses. Accordingly, the processes, machines, manufactures, compositions of matter, and other teachings of the present disclosure are not intended to limit the exact embodiments and examples disclosed herein. Any section headings herein are provided only for consistency with the suggestions of 37 C.F.R. §1.77 or otherwise to provide organizational queues. These headings shall not limit or characterize the invention(s) set forth herein.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2015/054741 | 10/8/2015 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62122023 | Oct 2014 | US | |
| 62131607 | Mar 2015 | US |
