Patent Application
20230272526
Conventional coatings that repel oils and water are composed of heavily-fluorinated or perfluorinated compounds, or compounds and polymers that contain at least 60 percent by weight fluorine as part of their chemical formula. These compounds have been found to be persistent and bioaccumulative in the environment and cause irreparable harm to aquatic life and human consumers.
While most hydrocarbon-based coatings can repel water with varying efficacy, no hydrocarbon-based coating formulation is known to repel oil stains, such as mineral oil, food oils (olive oil, butter, palm oil) and grease stains (hexane, heptane, octane).
In addition to the environmental impact of fluorinated compounds and the failure of others to obtain textiles that repel both water-based and hydrocarbon-based liquids, there is a need for methods of coating electrically conductive yarn, fibers or fabric that preserve electrical conductivity, are mechanically robust, and can withstand multiple washings.
Therefore there is a need to develop coatings that can repel water, grease, and oil while containing less than 30 weight percent fluorine, or, ideally, no fluorine component whatsoever. A prevailing need in the field also exists for improved processes to produce such yarns, fibers and fabrics that are both hydrophobic and oleophobic, including those that are compatible with electrically conductive materials.
Additionally, large-scale production of coatings by chemical vapor deposition have been limited by the need to use batch processes and/or challenges in maintaining a vacuum in continuous process chambers. Therefore, there is also a need for improved vapor deposition systems and methods for the continuous production of coated substrates.
Therefore, in one embodiment, a system comprises a first process chamber for coating a flexible substrate (such as yarn, fiber, fabric, a textile, metal foil or metalized plastic), resulting in a liquid repellant substance. In some embodiments, liquid repellant coatings are applied on the substrate under and/or over an electrically conductive substance to produce an electrically conductive material, such as an electrically conductive yarn, fiber or fabric. Depending on the embodiment, the system comprises a second process chamber for encapsulating the electrically conductive material with an encapsulating substance. Both continuous and non-continuous coatings are contemplated. Additionally, coatings may penetrate into the substrate or not depending on the properties of the coating substance and substrate, e.g., porosity and wettability.
In another embodiment, a device is provided for printing an encapsulated electrically conductive substance onto any flat or smooth substrate (e.g., plastic, paper, transparent conducting oxide or metal oxide surface, or nonwoven, prewoven or knit fabric surface), including print head(s) for coating and encapsulating a substrate, such as yarn, fiber or fabric. In some embodiments, the electrically conductive substance is completely encapsulated, and in other embodiments, the electrically conductive substance is partially encapsulated.
In some embodiments, the first process chamber comprises one or more load lock chambers at the substrate inlet and/or outlet of the first process chamber. In other embodiments, the second process chamber comprises one or more load lock chambers at the substrate inlet and/or outlet of the second process chamber. In further embodiments, the system has a series of load lock chambers having successively lower pressures are used at the process chamber inlet. In yet further embodiments, a series of load lock chambers having successively increasing pressures are used at the process chamber outlet. In another embodiment, the load lock chamber is a pressure reduction zone or space in which a pressure reduction effect is generated on the substrate during the production of the liquid repellant material.
In some embodiments, a material production system comprises a first support configured to support a spool of flexible substrate, a second support configured to support a plurality of compressing rollers configured to apply a force to a segment of the flexible substrate that extends from the roll. The compressing rollers are positioned and configured to compress the segment, which is located within a space or zone between the compressing rollers. The system also includes a plurality of gas directors, wherein each one of the gas directors is configured to direct a stream of gas that flows at least partially around one of the compressing rollers. The streams cause an air pressure reduction in the zone. In addition, the system has a precursor supply configured to expose the substrate to a precursor, resulting in a coated or protected material. In some embodiments, the material production system also comprises a co-reactant supply configured to expose the substance and the precursor to the co-reactant.
The above embodiments are exemplary only. Other embodiments as described herein are within the scope of the disclosed subject matter.
So that the manner in which the features of the disclosure can be understood, a detailed description may be had by reference to certain embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain embodiments and are therefore not to be considered limiting of its scope, for the scope of the disclosed subject matter encompasses other embodiments as well. The drawings are not necessarily to scale, emphasis generally being placed upon illustrating the features of certain embodiments. In the drawings, like numerals are used to indicate like parts throughout the various views, in which:
Corresponding reference characters indicate corresponding parts throughout several views. The examples set out herein illustrate several embodiments, but should not be construed as limiting in scope in any manner.
The present disclosure relates to methods and processes for producing conductive, coated, protected, and/or liquid repellant materials, such as plastics, metallized plastics, metal foil, and textiles (e.g., fibers, yarns, and fabrics). In one embodiment, polysiloxane coatings are applied to substrates via vapor deposition and condensation of siloxane monomers, dimers, trimers, or other oligomers.
Advantageously, in some embodiments, methods and processes for preparing liquid repellant coatings are integrated with high-throughput processes for producing electrically conductive or liquid repellant materials, such as textiles, fibers, yarns or fabrics resulting from the methods and processes. Further details regarding electrically conductive fabrics and yarns may be found in, PCT Publication No. WO 2021194931A1 (Andrew, Baima and Beach), U.S. Patent Publication No. 2019/0230745A1 (Andrew, Zhang and Baima), published Jul. 25, 2019, and entitled “Electrically-heated fiber, fabric, or textile for heated apparel,” and U.S. Patent Publication No. 2018/0269006A1 (Andrew and Zhang), published Sep. 20, 2018, and entitled “Polymeric capacitors for energy storage devices, method of manufacture thereof and articles comprising the same,” each of which is incorporated herein in its entirety.
Generally stated, provided herein, in one embodiment, is a system for continuously producing protected and/or electrically conductive material (such as electrically conductive yarn, fiber or fabric) by processing a flexible substrate, such as raw or untreated yarn, fiber or fabric. The system comprises a first, second and an optional third process chamber, and spooling mechanisms. For instance, the first process chamber is for coating the substrate with an electrically conductive polymeric substance. The first process chamber introduces a precursor (e.g., a monomer) and an initiator that form the electrically conductive polymeric substance. And the second process chamber is for encapsulating the electrically conductive material with an encapsulating insulating substance. A first spooling mechanism stores the substrate within the first process chamber and flows the substrate through the first process chamber during the coating. A second spooling mechanism accepts the substrate such that the substrate continuously flows in the direction from the first process chamber to the second process chamber. The flow rate of the first and second spooling mechanisms are selected to allow the substrate to be coated with the electrically conductive substance and encapsulated with the encapsulating substance (e.g., a siloxane). The substrate is subsequently spooled after encapsulation to form a spool of electrically conductive, liquid repellant, coated or protected material.
In one embodiment, the first and second process chambers are combined as a single process chamber. For example, separation of the coating and the encapsulating is achieved through one or more of space or a physical barrier within the single process chamber. In another embodiment, the process chamber comprises vapor phase introduction of the precursor and the initiator. For example, the precursor and initiator begin reacting in the vapor phase and the coating is formed conformally around the substrate as a molecular layer. In such a case, the forming process as a molecular layer retains flexibility of the substrate after the coating. In different embodiments, the precursor composition may be 3,4-ethylenedioxythiophene, the electrically conductive substance composition may be p-doped poly(3,4-ethylenedioxythiophene), and the encapsulating substance composition may be an acrylate and/or a siloxane.
In another aspect, a device for printing a pattern of encapsulating and/or electrically conductive polymer onto any flat or smooth substrate (such as plastic, metal foil, metalized plastic (e.g., chip bag substrate), paper, transparent conducting oxide or metal oxide surface, or nonwoven, prewoven or knit fabric surface) includes at least one print head for heating at least one precursor and producing at least one vapor within a target zone of the print head. For instance, the vapor comprises a precursor and an initiator, and the surface is coated with a pattern of an electrically conductive substance and protected with an encapsulating substance when passing within the target zone of the print head.
In one embodiment, the at least one print head comprises a first print head for coating the surface with the electrically conductive substrate, and a second print head for encapsulating the electrically conductive substrate with an encapsulating substance. In another embodiment, the at least one print head comprises a single print head for coating the surface with the electrically conductive substance, and for encapsulating the electrically conductive substrate with an encapsulating substance. Further embodiments use heat-based and/or light-based initiation to coat with the encapsulating substance.
By way of example, the electrically conductive substance composition may comprise p-doped poly(3,4-ethylenedioxythiophene), and the encapsulating substance may comprise a poly(acrylate). In another implementation, the system includes a portable unit, and the system further includes a battery and movable material tanks for storing. In a further implementation, the system further comprises an outlet for delivering a cleaning solution to the substrate.
In the embodiment of
The thickness of the growing polymer film inside the chamber is monitored in real time by a quartz crystal microbalance (QCM) sensor situated near the sample stage. The total deposition rate and film thickness values reported by the QCM sensor during vapor deposition arise from both the polymer film and unreacted EDOT/FeCl3 being deposited onto the sensor surface. Thickest polymer films are obtained after rinsing when the EDOT and FeCl3 flow rates are matched during deposition. Unreacted EDOT or FeCl3 remain trapped in the films if their flow rates are mismatched, which are leached out of the film during rinsing, leading to significantly lower coating thicknesses than measured by the QCM sensor during deposition. Taking this into account, typical polymer growth rates are about 10-15 nm per minute of exposure to the reactive vapor cone, for a substrate stage temperature of 80° C.
Next, the coated substrate is moved to the cleaning chamber 120. A post deposition rinse in the cleaning chamber 120 completely removes residual FeCl3 trapped in the vapor deposited polymer films and yields metal free, PEDOT-Cl coated substrates (e.g., yarns). The post deposition rinse contains a dilute aqueous solution, 0.001-0.1 moles per liter, of an acid, either monoprotic or diprotic, and it will further dope the PEDOT film to improve the conductivity of the resulting coated substrate (e.g., yarns and fabric comprising such yarns). After rinsing, warm air is blown through the substrate (e.g., fabric) to dry it.
Finally and still referring to
With respect to both the coating and encapsulation steps, the coating thickness can be varied from approximately 100 to 1000 nm. Highly-uniform and conformal coatings have been formed on an array of substrate surfaces that are exposed to the reactive vapor in both chambers, without any special pre-treatment or fixing steps. Although pre-treatment (e.g., plasma treatment) and/or fixing steps are also contemplated. Further, polymer films are uniformly deposited (macroscopically) over the surface while also conformally wrapping (microscopically) the curved surface of each exposed fibril of the threads constituting the substrate. The high conformality of the conductive coating is particularly apparent in the SEM image of PEDOT-Cl coated wool gauze, where the PEDOT-Cl film contours to all the exposed surface features of the substrate with high fidelity over multiple length scales. Cross-section SEM studies have confirmed that the PEDOT and protective acrylate films are purely surface coatings and that the bulk of fibrils/threads are not swelled or dyed by the polymers. Successful vapor coatings have been carried out without any pre-treatment steps, regardless of surface chemistry, thread/yarn composition and weave density. The polymer coatings did not change the feel of any of the substrates, as determined by touching the substrates with bare hands before and after coating. Further, the coatings did not increase the weight of the substrates by more than 2%.
In order to increase the coating thickness and throughput, the total dwell time in a deposition zone and the stage temperature are the two variables requiring evaluation. A meandering loop design is used to increase the total dwell time experienced by a unit length of yarn as it passes through the deposition zones in each of the two polymer deposition chambers. Stage temperatures are more difficult since there will be a 2D distribution across the plate, however, thermocouples will be instrumented across the stage to compare the ‘local’ temperatures to the quality of coat. The local temperatures and corresponding regions of yarn can be used to correlate the effect of temperature with better resolution. Chamber pressures can also be used to tightly-control coating uniformity while increased throughput speed. Increased (>300 mTorr) chamber pressures then result in shorter mean free paths for the chemical species responsible for polymer chain growth in the chamber, which, in turn, afford greater surface coverage due to a higher frequency of surface-restricted reactions and suppression of line-of-sight deposition events.
By way of further explanation, in one embodiment, the poly(3,4-ethylenedioxythiophene) film formed from vapor phase polymerization using an iron salt is advantageous. In one embodiment, the dopant is uniformly distributed through the p-doped PEDOT film. In an embodiment, the poly(3,4-ethylenedioxythiophene) is uniformly doped having a dopant concentration of 1010 atoms per cm3 to 1020 atoms per cm3 and a concentration variation of ±103 atoms per cm3.
The 3,4-ethylenedioxythiophene has the structure of formula (1):
Upon polymerization, this has the structure of formula (2):
where “n” is the number of repeat units.
In an embodiment, n (the number of repeat units) may be greater than 20, preferably greater than 30, and more preferably greater than 40. In an embodiment, n is 20 to 10,000, preferably 50 to 9000, and more preferably 100 to 8500.
The iron salt may be any salt that can be vaporized (either by boiling or sublimation) at the reaction temperature. The iron salts may be divalent iron salts, trivalent iron salts, or a combination thereof. It is generally desirable for the iron salts to be trivalent iron salts. Examples of salts are iron (III) chloride, iron (III) bromide, iron (III) acetylacetonate, iron (III) sulfate, iron (III) acetate, iron(III) p-toluenesulfonate, or the like, or a combination thereof.
The amount of the 3,4-ethylenedioxythiophene vapor in the reactor is 20 to 80 volume percent, preferably 40 to 60 volume percent relative to the volume of the sum of the vapors of 3,4-ethylenedioxythiophene and the iron-salt. The amount of iron salt in the reactor is 20 to 80 volume percent, preferably 40 to 60 volume percent relative to the volume of the sum of the vapors of 3,4-ethylenedioxythiophene and the iron-salt. Other inert gases such as nitrogen and argon may be present in the reactor during the reaction.
The substrate upon which the film is disposed is an electrically insulating substrate. Electrically conducting substrates are those that have an electrical volume resistivity of less than or equal to 1×1011 ohm-cm, while electrically conducting substrates are those that have an electrical volume resistivity of greater than 1×1011 ohm-cm. The substrate may be in the form of a slab, a thin film or sheet having a thickness of several nanometers to several micrometers (e.g., 10 nanometers to 1000 micrometers), woven or non-woven fibers, yarns, a fabric, a gel, a pixel, a particle, or the like. The substrate may have a smooth surface (e.g., not deliberately textured) or may be textured.
The substrate may have a surface area of a few square millimeters to several thousands of square meters. In an embodiment, the surface of the substrate may have a surface area of 10 square nanometers to 1000 square meters, preferably 100 square nanometers to 100 square meters, preferably 1 square centimeter to 1 square meter.
In an embodiment, electrically insulating substrates may include ceramic substrates, or polymeric substrates. Ceramic substrates include metal oxides, metal carbides, metal nitrides, metal borides, metal silicides, metal oxycarbides, metal oxynitrides, metal boronitrides, metal carbonitrides, metal borocarbides, or the like, or a combination thereof. Examples of ceramics that may be used as the substrate include silicon dioxide, aluminum oxide, titanium dioxide, zirconium dioxide, cerium oxide, cadmium-oxide, titanium nitride, silicon nitride, aluminum nitride, titanium carbide, silicon carbide, titanium niobium carbide, stoichiometric silicon boride compounds (SiBn, where n=14, 15, 40, and so on) (e.g., silicon triboride, SiB3, silicon tetraboride, SiB4, silicon hexaboride, SiB6, or the like), or the like, or a combination thereof.
Organic polymers that are electrically insulating may also be used as the substrate and may be selected from a wide variety of thermoplastic polymers, blend of thermoplastic polymers, thermosetting polymers, or blends of thermoplastic polymers with thermosetting polymers. The organic polymer may also be a blend of polymers, copolymers, terpolymers, or combinations comprising at least one of the foregoing organic polymers. The organic polymer can also be an oligomer, a homopolymer, a copolymer, a block copolymer, an alternating block copolymer, a random polymer, a random copolymer, a random block copolymer, a graft copolymer, a star block copolymer, a dendrimer, a polyelectrolyte (polymers that have some repeat groups that contain electrolytes), a polyampholyte (a polyelectrolyte having both cationic and anionic repeat groups), an ionomer, or the like, or a combination comprising at last one of the foregoing organic polymers. The organic polymers have number average molecular weights greater than 10,000 grams per mole, preferably greater than 20,000 g/mole and more preferably greater than 50,000 g/mole.
Examples of the organic polymers are polyacetals, polyolefins, polyacrylics, polycarbonates, polystyrenes, polyesters, polyamides, polyamideimides, polyarylates, polyarylsulfones, polyethersulfones, polyphenylene sulfides, polyvinyl chlorides, polysulfones, polyimides, polyetherimides, polytetrafluoroethylenes, polyetherketones, polyether etherketones, polyether ketone ketones, polybenzoxazoles, polyphthalides, polyanhydrides, polyvinyl ethers, polyvinyl thioethers, polyvinyl alcohols, polyvinyl ketones, polyvinyl halides, polyvinyl nitriles, polyvinyl esters, polysulfonates, polysulfides, polythioesters, polysulfones, polysulfonamides, polyureas, polyphosphazenes, polyethylene terephthalate, polybutylene terephthalate, polyurethane, polytetrafluoroethylene, perfluoroelastomers, fluorinated ethylene propylene, perfluoroalkoxyethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polysiloxanes, or the like, or a combination thereof.
Examples of polyelectrolytes are polystyrene sulfonic acid, polyacrylic acid, pectin, carrageenan, alginates, carboxymethylcellulose, polyvinylpyrrolidone, or the like, or a combination thereof.
Examples of thermosetting polymers include epoxy polymers, unsaturated polyester polymers, polyimide polymers, bismaleimide polymers, bismaleimide triazine polymers, cyanate ester polymers, vinyl polymers, benzoxazine polymers, benzocyclobutene polymers, acrylics, alkyds, phenol-formaldehyde polymers, novolacs, resoles, melamine-formaldehyde polymers, urea-formaldehyde polymers, hydroxymethylfurans, isocyanates, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, unsaturated polyesterimides, or the like, or a combination thereof.
The polymers and/or ceramics may be in the form of films, fibers, single strands of fiber, woven and non-woven fibers, woven fabrics, slabs, or the like, or a combination thereof. The fibers may be treated with surface modification agents (e.g., silane coupling agents) to improve adhesion if desired.
In addition to fibers, fabrics, yarns and textiles, the present technique may be used to coat and/or encapsulate other substrates of interest for other applications. For instance, exemplary substrates are flat sheets, such as paper, foil, Tyvek, polymeric sheets including the polymer sheets listed above, porous, planar membranes, such as CELGARD®, or cylindrical or curved objects, such as monofilament NYLON® thread, single-ply silk thread, or monofilament fiberglass thread.
Suitable substrates further comprise plastics, metallized plastics, and metal foils. Exemplary substrates comprise greater than 80%, 70%, 60%, 50%, or 40% by atomic composition of metals. The contemplated thickness of the metal layers of exemplary metallized plastics (e.g., metallized plastics used in chip bags) comprise less than 100 nm coating of metals on a plastic substrate.
Optionally, substrates are pre-treated, e.g., by exposure to an inert gas plasma, to activate the surface and increase bonding between the substrate and the deposited material.
In one embodiment, liquid repellant substance is deposited on a substrate to which an electrically conductive polymer has already been deposited. In another embodiment, liquid repellant substance is deposited on a substrate to which no electrically conductive polymer has been applied. In a further embodiment, an electrically conductive polymer is deposited on the liquid repellant substance as described above. Optionally, a substrate to which liquid repellant polymer and electrically conductive polymer have been applied is coated with another layer of liquid repellant substance, e.g., sandwiching the electrically conductive polymer between layers of liquid repellant material. It should be appreciated that the coatings and layers disclosed herein need not be continuous and may or may not penetrate into the substrate and any previously applied coating materials.
In regard to liquid repellant substances, in one embodiment, the liquid repellent substance comprises polysiloxane. Examples of polysiloxanes include those resulting from the condensation of an alkylhalosiloxane, e.g., chlorosilane, dichlorosilane and/or trichlorosilane monomer with a diol and/or water as shown in Scheme 1. In some embodiments, the silane monomer and diol are vaporized and mixed at the time of coating. Exemplary chlorosilanes comprise one, two, or three alkyl groups bonded to each silicon atom. In further examples, halosilanes, such as bromo-, iodo-, and fluorosilanes are used as monomers. Exemplary alkyl groups (“R”) include methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, hexyl, octyl or greater. It should be appreciated that alkyl groups may be branched or unbranched. Exemplary silanes comprise two alkyl groups that are the same (e.g., dimethyldichlorosilane, diethyldichlorosilane, diisopropyldichlorosilane), and in another embodiment, the silane includes two alkyl groups that are different (e.g., n-propylmethyldichlorosilane), As shown in Scheme 1, monomers may comprise dihalosilane (e.g., dichlorosilane) dimers, trimers, tetramers, pentamers, hexamers, heptamers, octomers and/or other oligomers.
Exemplary diols include alkyl diols having one to eight carbon atoms, which may be linear or branched (e.g., dihydroxymethane, ethyleneglycol, propylene glycol, etc.) as shown in Scheme 1. Examples of diols also comprise polyethylene glycols having between one and eight ethylene units. Use of polypropylene glycols is also contemplated.
In some examples, a ratio of silane monomer to water and/or diol is about 1:10, about 1:9, about 1:8, about 1:7, about 1:6, about 1:5, about 1:4, about 1:3, about 1:2, about 1:1, or about 1:0.5 by volume.
Silane monomers react with water and/or a diol in one of the chambers disclosed herein (e.g., 110, 130, 210, 230, 410, 630A, 630B, 300A, 300B). In some embodiments, the formulation includes a disiloxane or trisiloxane monomer that is vaporized at the time of coating, and mixed at the time of coating with vapors of an aryl or diarylketone photoinitiator, and ultraviolet light of any wavelength lower than 400 nm. In other embodiments, the formulation includes a disiloxane or trisiloxane monomer that is vaporized at the time of coating and mixed at the time of coating with vapors of a diol, glycol and/or water in the presence of an electrically generated reactive ion plasma, such as an argon ion plasma. In all embodiments, a vacuum chamber with a plurality of ports needs to be used to mix and therefore induce a reaction between vapors of the silane or siloxane monomer and the co-reactant to form a polymer coating directly on the surface of any desired substrate. Substrates can comprise, paper, yarns, fibers and textiles that are woven, knit or nonwoven, plastics (e.g., polyethylene terephthalate (PET), polylactic acid (PLA), and polyethylene naphthalate (PEN), or any of the polymers disclosed herein and mixtures thereof), metallized plastics, and other composite materials. The reaction time, as defined as the total duration of time wherein the vapors of the monomers and various co-reactants are allowed to mix within the process chamber controls the thickness of the polysiloxane coating that is formed on the substrate surface. Exemplary reaction times include 1 minute, 2 minutes, 5 minutes, 7.5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, 65 minutes, 70 minutes, 75 minutes, 80 minutes, 85 minutes, 90 minutes, 95 minutes, 100 minutes, 105 minutes, 110 minutes, 115 minutes, or 120 minutes.
Polysiloxane coating thicknesses of less than one hundred micrometers result in liquid repellent textiles and yarns. The relative ratio of the siloxane monomer and co-reactant vapors can be controlled to increase or decrease the degree of polycondensation between polymer chains i.e., the crosslink density, and to increase or decrease the average polymer molecular weight of the polysiloxane coating. The crosslink density and polymer molecular weight can also be increased by introducing optional ultraviolet light or an electrically-generated reactive ion plasma into the process chamber at the same time as the monomer and co-reactant vapors are introduced into the chamber.
In further regard to liquid repellant substances, in one embodiment, the liquid repellent substance comprises poly(acrylate). In one embodiment, a method of coating a substrate with a liquid repellent polymer comprises vaporizing an acrylate, vaporizing a diacrylate, vaporizing an initiator, and initiating the polymerization of the acrylate and the diacrylate on a substrate.
Exemplary acrylates comprise fluoroalkyl acrylates, such as 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl methacrylate, and 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl acrylate, and siloxyalkyl acrylates, such as 3-[Tris(trimethylsiloxy)silyl]propyl methacrylate. In one embodiment, the acrylate comprises 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl acrylate.
Exemplary diacrylates comprise alkyldiol diacrylates, such as 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate and 1,6-hexanediol diacrylate. In one embodiment, the diacrylate comprises 1,4-butanedioldiacrylate.
Polymerization may be initiated by heat and/or light. In one embodiment, the initiator comprises a photoinitiator, e.g., 2-hydroxy-2-methylpropiophenone.
In one example, the vacuum can be maintained using self-induced friction amplification, in which pulling the substrate in a given direction causes the opening to clamp tighter on the substrate to create a seal. A well-known example of this type of sealing is the popular finger trap toy or towing stock device. In another example, an external vacuum housing similar to a glove box could also be implemented to maintain vacuum while feeding substrate into the deposition chamber(s).
In yet another example, a single chamber could be used that includes all of the functions of the three chambers 210, 220, 230 e.g., in large scale factory production.
In the embodiment of
In the embodiment of
In the embodiment of
In the embodiment of
With respect to the print head embodiment described above, conventional print heads are known for printing using liquid inks. For example, conventional inkjet printer propel a liquid ink onto paper in order to produce a pattern using either heat, pressure, or a combination thereof in a conventional manner that is well understood and well known to the ordinary artisan in the field. But conventional print heads are incapable of delivering two components that are supposed to react, and even further lack the concept of having an initiation means, such as heat or light, to cause such as reaction. Conventional print heads are designed for speed, and printing onto flat paper only, have no facility for initiating chemical reactions, and thus cannot be used to create an electrically conductive polymer coating as described herein. A person of ordinary skill in the art will understand that conventional ink jet printers include both one or more print heads and a control mechanism that allows the print heads, which include may include numerous output nozzles for different color inks, to move back and forth along a sheet of paper in order to print the required pattern. Such control mechanisms may be used with the present technique so that the presently described innovative print heads may move back and forth over any of the types of substrates described herein to form an electrically conductive and encapsulated coating on those substrates.
Advantageously, the presently disclosed vapor deposition print head includes light initiated or heat initiated polymerization of a monomer and an initiator so that an electrically conductive material such as PEDOT can be conformally deposited on a substrate such as a yarn, fiber, fabric or textile. The print head can also include another nozzle from which an encapsulating material is delivered. The control mechanism can then time the delivery of the materials so that as the print head moves above the substrate, a fully encapsulated, electrically conductive polymer such as PEDOT is delivered to the substrate in whatever pattern is desired. Because the vapor phase polymerization can occur within a short distance such as a few centimeters, the result is a substrate that is conformally coated and encapsulated with the conductive polymer.
In the embodiment of
In some embodiments, the process chambers (e.g., 110, 130, 210, 230, 410, 630A, 630B) further comprise entry and/or exit load lock chambers as shown in
One embodiment of entry load lock chamber 700A is shown in
In one embodiment a spool 802 of substrate 70 is secured by a support or scaffolding 710. The substrate 70 enters vacuum region 723 through a load lock-vacuum interface, space or zone 804 located between by compressing rollers 731 and 732, which are supported by a frame or support (not shown). Depending on the embodiment, the compressing rollers 731, 732 can be driver rollers that are electromechanically powered to rotate. In an embodiment, the compressing rollers 731 and 732 are configured to freely rotate. The system has a plurality of gas directors 741, 742 associated with the compressing rollers 731, 732, respectively. To allow or cause the compressing rollers 731, 732 to rotate while maintaining the vacuum in the vacuum region/process chamber, each of the gas directors 741, 742 outputs a jet of nitrogen gas, which is streamed at high velocity over a gap between the associated roller and the edges of the vacuum region/process chamber. In an embodiment, gas director 741 generates a gas stream that flows fully or partially around the circumference of compressing roller 731, and gas director 742 generates a gas stream that flows fully or partially around the circumference of compressing roller 732. Without wishing to be bound by a particular hypothesis, the gas streams generate a pressure reduction effect, such as the Bernoulli effect. In an embodiment, the Bernoulli effect is used to maintain an intermediate vacuum (between about 760 Torr and about 1 Torr) between ambient pressure region 721 and vacuum region 723. In one embodiment, an ultrahigh nitrogen gas flow (“nitrogen knife”) 741 and 742 pushes out ambient gases and maintains a pressure differential between the ambient and the intermediate pressure regions. In one embodiment, the nitrogen gas jets/knives 741 and 742 also apply pressure to rollers 731 and 732 increasing the contact between the rollers and the substrate 70 at the load lock-vacuum interface 804.
One embodiment of exit load lock chamber 700B is shown in
Optionally, in some embodiments, the substrate 70 is wound on spool 75, which may be located outside, inside, or partially inside and partially outside of exit load lock chamber 700B. In one embodiment, the bolt of substrate 70 on spool 75 is located outside entry load lock chamber 700B to facilitate changing spool 75 while maintaining the vacuum in exit load lock chamber 700B and in the connected process chamber. In one embodiment spool 75 is secured by scaffolding 711.
In some embodiments, rollers 731, 732, 733, and 734 comprise silicone and separate the intermediate region from the vacuum region. Exemplary rollers have diameters of about 0.5 inches to about 1 inch, about 1 inch to about 1.5 inches, about 1.5 inches to about 2 inches, about 2 inches to about 2.5 inches, about 2.5 inches to about 3 inches, about 3 inches to about 3.5 inches, about 3.5 inches to about 4 inches, about 4 inches to about 4.5 inches, about 4.5 inches to about 5 inches, about 5 inches to about 5.5 inches, about 5.5 inches to about 6 inches, about 6 inches to about 6.5 inches, about 6.5 inches to about 7 inches, about 7 inches to about 7.5 inches, about 7.5 inches to about 8 inches, about 8 inches to about 8.5 inches, about 8.5 inches to about 9 inches, about 9 inches to about 9.5 inches, about 9.5 inches to about 10 inches, or larger.
In some embodiments, the vacuum region/process chamber (e.g., 110, 130, 210, 230, 410, 630A, 630B) is connected to a mechanical pump that maintains the vacuum chamber at between 1-1000 millitorr and the silicone rollers allow this vacuum level to be maintained by prevent gas bleed-through from the intermediate region to the vacuum region.
The following table provides exemplary embodiments of substrates coated with water and/or oil repellant substances produced using the systems and methods described herein. Water repellency was tested using ISO 4920:2012 Textile fabrics—Determination of resistance to surface wetting (spray test). “Yes” corresponds to coatings that repel water for 8 hours or more. Oil Repellency was measured using ISO 14419:2010 Textiles—Oil repellency—Hydrocarbon resistance test, where ISO 0 corresponds to no oil repellency and ISO 8 corresponds to maximum oil repellency. Additionally, the exceptional conformality of the coating of Sample Nos. 20 and 21 are illustrated in the SEM images presented in
Many examples of the utility of the present disclosure have been contemplated by the inventors, including heated gloves, hats, and other clothing, printed circuits that are embedded onto clothing to form wearable devices, etc. Various other applications of the present disclosure have been contemplated, including wearables that provide heat to a user, monitor the users health by measuring electric signals and temperatures, allow for mounting of other components such as blood pressure or oxygen sensors, etc.
Therefore, and as discussed above, generally stated, provided herein are a variety of techniques for coating electrically conductive polymer onto substrates including flat or smooth plastic, paper, transparent conducting oxide or metal oxide surface, or nonwoven, prewoven or knit fabric surface that is encapsulated with an insulating material. The various components
The fact that one or more specific embodiments for coating, cleaning and encapsulating have been used to illustrate the concepts of the present technique are not meant to limit the disclosure in any manner. Indeed, as noted above, the concepts disclosed herein are not limited to the disclosed substrates (e.g., textiles, yarns, fibers or fabrics). For example, many other applications of the different processes described herein have been envisaged by the inventors and are included within the scope of this disclosure. The presentation of a specific set of claims herein is not meant to limit scope, but is only done to illustrate some of the example embodiments which are covered by this disclosure. For example, the techniques described herein may be scaled in size from a large factory embodiment measuring many yards in each direction down to a smaller table-top apparatuses that are only a few feet in size. In addition to fiber, fabric, and yarn embodiments, the present disclosure could be used for producing circuits that are printed on any of the substrates identified above, and the coating and encapsulation process can be used to form the conductive lines of the circuit. By adding other electrical or semiconductor elements in a manner known in the art, the end product would be a wearable or non-wearable circuit or electronic device that could be conformed to any surface or configuration, providing great advantages compared to flat circuit boards presently used in the field.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/049648 | 11/11/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63278327 | Nov 2021 | US |
