JP2011527809A - Improved CNT / topcoat process - Google Patents

Abstract

  We comprise coating a substrate with a dispersion or solution comprising a nanostructure selected from the group consisting of carbon nanotubes, fullerenes, graphene flakes / sheets, nanowires, and two or more thereof Disclosed is a method for making an optically transparent, electrically conductive nanostructured film. The film may also comprise a dopant in the dispersion or solution as well as the capsule or topcoat.

Description

  Field of Invention

  The present invention relates generally to nanostructured films, and more specifically to their fabrication methods.

  Background of the Invention

  Many modern and / or emerging applications require at least one device electrode that has not only high electrical conductivity, but also high optical transparency as well. Such applications include touch screens (eg analog, resistive, four wire resistive, five wire resistive, surface capacitive, projected capacitive , Multi-touch, etc.), display (eg flexible, rigid, electrophoretic, electroluminescent, electrochromatic, liquid crystal (LVD), plasma (PDP), organic light emitting diodes (OLED), etc.), solar cells (eg, silicon (amorphous, polycrystalline, nanocrystalline), cadmium telluride (CdTe)) Gallium indium copper selenide (COGS), indium copper selenide (CIS), gallium arsenide (GaAs), light absorbing dyes, quantum dots, organic semiconductors (eg heavy Bodies, small molecule compounds)), solid state lighting fixtures, optical fiber communications (eg electro-optics and opto-electric modulators), and microfluidics (eg electro-wetting on dielectrics). (EWOD)), but is not limited thereto.

  As used herein, a layer of one material or a sequence of several layers of different materials allows the layer to transmit at least 50% of ambient electromagnetic radiation at the relevant wavelength through the layer. It is said to be “transparent” when it is allowed. Similarly, layers that allow some of the ambient electrical radiation at the relevant wavelengths, but less than 50%, are said to be "translucent".

  At present, the most common transparent electrode is a transparent conductive oxide (TCO), specifically indium tin oxide (ITO) on glass. However, ITO can be an unsuitable solution for many of the applications mentioned above (eg thanks to its relatively brittle nature, correspondingly poor flexibility and abrasion resistance) and Indium constituents of ITO are rapidly becoming scarce products. In addition, ITO deposition typically requires expensive high temperature sputtering, which can be incompatible with many device process flows. Thus, more robust, abundant and easily deposited transparent conductor materials are being explored.

  Summary of the Invention

The present invention describes a nanostructured film. Nanostructures have attracted a lot of recent attention thanks to their exceptional properties. Nanostructures are nanotubes (eg.
Single walled carbon nanotube (SWNT), multiple walled carbon nanotube (MWNT), double walled carbon nanotube (DWNT), few walled carbon nanotube (FWNT)), other fullerenes (eg, buckyball), graphene flakes / sheets, and / or nanowires (eg, metal (eg, Ag, Ni, Pt, Au), semi-conductive ( Examples include, but are not limited to, InP, Si, GaN), dielectric materials (eg, SiO ₂ , TiO ₂ ), organic materials, and inorganic materials. Nanostructured films may comprise at least one interconnected network of such nanostructures and may exhibit exceptional material properties as well. For example, a nanostructured film comprising substantially at least one interconnected network of carbon nanotubes (CNTs) (eg, where the density of nanostructures is above the penetration threshold) It can present not only efficient heat conduction and substantial optical transparency, but also extraordinary strength and electrical conductivity. As used herein, “substantially” shall mean that at least 40% of the components are of a given type.

  In one embodiment, an encapsulated nanostructured film according to the present invention may be fabricated using a series of coating, drying, washing, and baking stations. In one embodiment, the substrate is passed through a leaning / drying station, coated with a dispersion of CNTs, dried, washed, re-dried, capsule / topcoat (eg. May be coated with a slot die coated crosslinked polymer) and then baked. In another embodiment, the washing and second drying step is performed to reduce tact time and equipment costs (ie, the dried CNT coating is encapsulated without an intermediate washing and drying step). / To be removed (as coated with topcoat). In another and / or further embodiment, a dual-head slot die configuration (eg, two dies in a single coater) can have a tact time (eg, by allowing removal of separate topcoat stations) and Sometimes used to reduce equipment costs.

  In another embodiment, encapsulated nanostructured films according to the present invention may be fabricated using different series of coating, drying, washing, and baking stations. In another embodiment, the substrate is coated with a dispersion of CNTs and a capsule / topcoat (eg, slot die coated cross-linked polymer) mixture that is passed through a cleaning / drying station. It may be baked, washed and then dried. In this embodiment, a single slot die configuration (e.g., by allowing removal of a separate topcoat station and by using a single slot head die rather than a dual head slot die configuration). ) Sometimes used to reduce tact time and equipment costs.

  In another embodiment, encapsulated nanostructured films according to the present invention may be fabricated using different series of coating, drying, washing, and baking stations, and In particular, the substrate is coated, baked, coated with a mixture of CNT and polymer mixed solution (eg slot die coated cross-linked polymer) that is passed through a cleaning / drying station. , Washed, and then dried. In another embodiment, the substrate is passed through a cleaning / drying station and CNTs without one or more of the steps that follow baking, washing, and drying. And may be coated with a mixture of polymer mixed solutions (eg, slot die-coated cross-linked polymers).

  In another embodiment, encapsulated nanostructured films according to the present invention may be fabricated using different series of coating, drying, washing, and baking stations, and In particular, the substrate is passed through a cleaning / drying station, coated with a primer layer (eg by spray, slot, SAM-dip, etc.), coated with a coating of CNT (eg with a slot die). May be coated with a top coat, baked, washed and dried. In another embodiment, the substrate is coated with a primer layer (eg, by a method such as spray, slot, SAM-dip, etc.) that is passed through a cleaning / drying station (eg, by a method such as spray, slot, SAM-dip, etc.) CNT And may be coated with a top coat without one or more steps following baking, washing, and drying.

  Other features and advantages of the invention will be apparent from the accompanying drawings and from the detailed description. One or more of the embodiments disclosed above are provided in further detail below with reference to the accompanying figures, in addition to certain alternatives. The invention is not limited to any particular embodiment disclosed; the invention is not only in the application of transparent conductive films, but also in other nanostructure applications (eg, opaque (E.g., poles, transistors, diodes, conductive composites, electrostatic shields, etc.).

FIG. 1A is a scanning electron microscope (SEM) image of a nanostructured film according to one embodiment of the present invention. FIG. 1B shows the transmittance and associated wavelengths of a number of nanostructured films according to one or more embodiments of the present invention. FIG. 2 is a schematic representation of an apparatus for producing a nanostructured film according to one embodiment of the present invention. FIG. 3 is a schematic representation of a nanostructured film fabrication apparatus according to one embodiment of the present invention, in which a dual head slot die is used. FIG. 4A is a schematic representation of a nanostructured film coated on a primer / promotion layer, according to one embodiment of the present invention. FIG. 4B is a schematic representation of a method for patterning a nanostructured film according to an embodiment of the present invention. FIG. 5 is a schematic representation of a method for patterning a nanostructured film according to an embodiment of the present invention.

  A brief description of the drawing

  The invention will be better understood from reading the detailed description that follows preferred embodiments with reference to the accompanying drawings, in which:

  FIG. 1A is a scanning electron microscope (SEM) image of a nanostructured film according to one embodiment of the present invention;

  FIG. 1B shows the transmittance and associated wavelengths of a number of nanostructured films according to one or more embodiments of the present invention;

  FIG. 2 is a schematic representation of an apparatus for producing a nanostructured film according to one embodiment of the present invention;

  FIG. 3 is a schematic representation of a nanostructured film fabrication apparatus according to one embodiment of the present invention, in which a dual head slot die is used;

  FIG. 4A is a schematic representation of a nanostructured film coated on a primer / promotion layer, according to one embodiment of the invention;

  4B and 5 are schematic representations of a method of patterning a nanostructured film according to an embodiment of the invention.

  Features, elements, and aspects of an invention that are referenced by the same numbers in different figures may represent the same, equivalent, or similar features, elements, or aspects consistent with one or more embodiments of the system. To express.

  Detailed description of embodiments

Referring to FIG. 1, a nanostructured film according to one embodiment of the present invention comprises at least one interconnected network of carbon nanotubes (SWNT) surrounded by a single wall. Such films may additionally or alternatively include other nanotubes (eg, MWNT, DWNT), other fullerenes (eg, buckyballs), graphene flakes / sheets, and / or nanowires (eg, those of metals) (Eg, Ag, Ni, Pt, Au), semiconductor materials (eg, InP, Si, GaN), dielectric materials (eg, SiO ₂ , TiO ₂ ), organic materials, inorganic materials) There is.

Such nanostructured films may further comprise at least one functionalized material bonded to the nanostructured film. For example, a dopant attached to a nanostructured film may increase the electrical conductivity of the film by increasing the concentration of carriers. Such dopants include iodine (I ₂ ), bromine (Br ₂ ), polymer supported bromine (Br ₂ ), antimony pentafluoride (SbF ₅ ), phosphorus pentachloride (PCl ₅ ), oxytrifluoride. Vanadium chloride (VOF ₃ ), silver fluoride (II) (AgF ₂ ), 2,1,3-benzooxadiazole-5-carboxylic acid, 2- (4-biphenylyl) -5-phenyl-1,3, 4-oxadiazole, 2,5-bis- (4-aminophenyl) -1,3,4-oxadiazole, 2- (4-bromophenyl) -5-phenyl-1,3,4-oxadi Azole, 4-chloro-7-chlorosulfonyl-2,1,3-benzooxadiazole, 2,5-diphenyl-1,3,4-oxadiazole, 5- (4-methoxyphenyl) -1,3 , 4-oxadiazole- -Thiol, 5- (4-methylphenyl) -1,3,4-oxadiazole-2-thiol, 5-phenyl-1,3,4-oxadiazole-2-thiol, 5- (4-pyridyl ) -1,3,4-oxadiazole-2-thiol, methylviologen = chloride hydrate, fullerene-C60, N-methylfulleropyrrolidine, N, N′-bis (3-methylphenyl) -N, N'-diphenylbenzidine, triethylamine (TEA), triethanolamine (TEA) -OH, trioctylamine, triphenylphosphine, trioctylphosphine, triethylphosphine, trinaphthylphosphine, tetradimethylaminoethene, tris (diethylamino) phosphine, Pentacene, tetracene, N, N′-di-[(1-naphthyl) -N, N ′ Sublimated grades of diphenyl] -1,1'-biphenyl) -4,4'-diamine, 4- (diphenylamino) benzaldehyde, di-p-tolylamine, 3-methyldiphenylamine, triphenylamine, tris [4- (Diethylamino) phenyl] amine, tri-p-tolylamine, acridine orange base, 3,8-diamino-6-phenylphenanthridine, 4- (diphenylamino) benzaldehyde, diphenylhydrazone, poly (9-vinylcarbazole) ), Poly (1-vinylnaphthalene), poly (2-vinylpyridine) n-oxide, triphenylphosphine, 4- (carboxybutyl) triphenylphosphonium bromide, tetrabutylammonium benzoate, tetrabutylammonium hydroxy 30 hydrate, tetrabutylammonium triiodide, tetrabutylammonium bis - trifluoromethanesulfonic imidate, tetraethylammonium = trifluoromethanesulfonate, fuming sulfuric acid _{(H 2 SO 4 -SO 3)} , triflic acid, and / or magic May include at least one acid.

  Such dopants may be covalently or non-covalently bound to the film. Moreover, the dopant is bound directly to the film or indirectly through and / or in connection with another molecule, such as a stabilizer that reduces the detachment of the dopant from the film. Sometimes. The stabilizer may be a relatively weak reducing agent (electron donor) or oxidizing agent (electron acceptor), where the dopant is a relatively strong reducing agent (electron donor) or oxidizing agent. (Ie, the electron acceptor) (ie, the dopant has a greater doping potential compared to the stabilizer). Additionally or alternatively, the stabilizer and dopant comprise a Lewis base and a Lewis acid, respectively, or a Lewis acid and a Lewis base, respectively. Exemplary stabilizers include aromatic amines, other aromatic compounds, other amines, imines, triazenes, boranes, other boron-containing compounds, and polymers of preceding compounds, but However, it is not limited to them. Specifically, poly (4-vinylpyridine) and / or triphenylamine is substantially stabilized in accelerated atmospheric testing (eg, 1000 hours at 65 ° C. and 90% relative humidity). The behavior to be displayed has been displayed.

  Stabilization of the dopant bound to the nanostructured film may also or alternatively be improved through the use of capsules. The stability of non-functionalized or otherwise functionalized nanostructured films may also be improved through the use of capsules. Accordingly, yet another embodiment of the present invention comprises a nanostructured film coated with at least one layer of encapsulation. This layer of encapsulation preferably provides increased stability and environmental (eg, heat, humidity, and / or atmospheric gas) resistance. Multiple layers of encapsulation (eg, having different compositions) may be advantageous in tailoring the properties of the capsule. Exemplary capsules are fluoropolymer, acrylic, silane, polyimide, and / or polyester capsules (eg, PVDF (Hylar CN, Solvay), Teflon AF, polyvinyl fluoride (PVF), polychlorotrifluoro). At least one of ethylene (PCTFE), poly (vinylalkyl = vinyl = ether), fluoropolymer dispersion from Dupont (TE 7224), melamine / acrylic blend, conformal acrylic coating dispersion, etc. Prepare things. Capsules may additionally or alternatively comprise UV and / or thermally crosslinkable polymers (eg poly (4-vinylphenol)).

  The electronic performance of the nanostructured film according to one embodiment can additionally or alternatively be obtained from a metal (eg gold, etc.) to nanotubes (eg by using electroplating and / or electroless plating). It may be improved by combining silver) nanoparticles. Such coupling may occur before, during, and / or after the nanotubes form an interpenetrated network.

  Nanostructured films according to one embodiment may additionally or alternatively include application specific additives. For example, a thin nanotube film can be inherently transparent to infrared radiation, but thus changes the properties of this material (eg, for applications that shield windows). It may be advantageous to add an infrared (IR) absorber to it. Exemplary IR absorbers include, but are not limited to, at least one of cyanine, quinone, metal complex, and photochromic. Similarly, UV absorbers may be used to limit the level of direct UV exposure of nanostructured films.

  Nanostructured films according to one embodiment may be fabricated using a solution based process. In such a process, the nanostructure may be initially dispersed in a solution with a solvent and a dispersant. Exemplary solvents include, but are not limited to, deionized (DI) water, alcohols, and / or benzo-solvents (eg, toluene, xylene). Exemplary dispersants are surfactants (eg, sodium dodecyl sulfate (SDS), Triton X, behentrimonium chloride (BTAC), stearyltrimethylammonium chloride (STAC), distearyldimonium chloride (DSDC). , NaDDBS) and biopolymers (eg, carboxymethyl cellulose (CMC)), but are not limited thereto. Dispersion can be cavitation (eg, using a probe and / or bath sonicator), shear (eg, using a high shear mixer and / or rotor-stator), impact (eg, rotor— Stator) and / or may be further assisted by mechanical agitation, such as by homogenization (eg, using a homogenizer). The coating aids also depend on the desired coating parameters, e.g. May be used in solution to achieve wetting and adhesion to a given substrate; additionally or alternatively, coating aids may be applied to the substrate. Exemplary coating aids include aerosol OT, fluorinated surfactants (eg, Zonyl FS300, FS500, FS62A), alcohols (eg, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, saponin, Ethanol, propanol, butanol and / or pentanol), aliphatic amines (eg primary, secondary (eg dodecylamine), tertiary (eg triethanolamine) Quaternary), TX-100, FT248, Tergirol TMN-10, Olin 10G, and / or APG325, but are not limited thereto.

  The resulting dispersion may be coated onto the substrate using a variety of coating methods. The coating may entail single or multiple pathways, depending on the nature of the dispersion, the nature of the substrate, and / or the nature of the desired nanostructured film. Exemplary coating methods include spray coating, dip coating, drop coating, and / or casting, roll coating, transfer stamping, slot die coating, curtain coating, [micro] gravure printing, flexographic printing, and / or inkjet printing. Including, but not limited to. Exemplary substrates are flexible or rigid and include glass, elastomers (eg, saturated rubber, unsaturated rubber, thermoplastic elastomer (TPE), thermoplastic vulcanizate (TPV)). , Polyurethane rubber, polysulfide rubber, resinin and / or elastin) and / or plastic (eg polymethyl methacrylate (PMMA), polyolefin, polyethylene terephthalate (PET), polyethylene = naphthalate (PEN), polycarbonate (PC) , Polyethersulfone (PES), and / or Arton), but is not limited thereto. Flexible substrates may be advantageous in having compatibility with processing roll-to-roll (also known as reel-to-reel), in which case One roll supports an uncoated substrate while another roll supports a coated substrate. The roll-to-roll process represents a dramatic departure from current manufacturing practices and significantly increases throughput when compared to a batch process that deals with only one component at a time. While increasing, significant equipment and product costs can be reduced. Nanostructured films are examples. To take advantage of roll-to-roll performance, it may be first printed on a flexible substrate and then transferred to a rigid substrate (eg, a flexible substrate is a release liner). And / or other donor substrates or layers of adhesion (eg, A-187, AZ28, XAMA, PVP, CX-100, PU). The substrate may be prepared to improve the adhesion of the nanotube thereto (eg, by first coating a layer of adhesion / promoter to the substrate).

  Once coated onto the substrate, the dispersion may be heated to remove the solvent therefrom so that a nanostructured film is formed on the substrate. Exemplary heating devices include hot plates, heating rods, heating coils, and / or ovens. The resulting film is then washed and / or oxidized (eg baked and / or with water, ethanol, and / or IPA) to remove residual dispersant and / or coating aids. And / or rinsed with an oxidizing agent such as nitric acid, sulfuric acid and / or hydrochloric acid).

Dopants, other additives and / or capsules may be further added to the film. Such materials may be applied to the nanostructures in the film before, during and / or after the formation of the film, and depending on the specific material, , Solid and / or liquid phases (eg, gaseous phase NO ₂ or liquid phase nitric acid (HNO ₃ ) dopant). Moreover, such materials can be applied through controlled techniques, such as the coating techniques listed above in the case of liquid phase materials (eg, slot die coating polymer capsules). May be.

  Nanostructured films according to one embodiment can be produced prior to fabrication on a substrate (eg, using a lift-off method, substrate pre-treated with a pattern) during (eg, patterned transfer). Printing, screen printing (eg using acid paste as etchant with subsequent water washing), ink jet printing) and / or after (eg laser ablation or masking / etching techniques) May be patterned).

  In one exemplary embodiment, an optically transparent and electrically conductive nanostructured film comprising an interconnected network of SWNTs is transparent via a multi-step spray and wash process. And a flexible plastic substrate. The SWNT dispersion was initially formulated by dissolving a commercially available SWNT powder (eg, P3 from Carbon Solutions) in DI water with 1% SDS and 30 at a power of 300W. Sonicate with probe for minutes. The resulting dispersion is then 10 kref (relative centrifuge) for 1 hour to remove large agglomerates of SWNTs and impurities (eg, amorphous carbon and / or residual catalyst particles). It was centrifuged in the separation field. In parallel, the PC substrate was rinsed with Di water and blow dried with nitrogen followed by a solution of silane for approximately 5 minutes (1% weight of 3-aminopropyl trimethylate in DI water). It was immersed in a coating aid comprising ethoxysilane. The resulting pre-treated PC substrate (Tekra 0.03 "thickness with a hard coating) is then heated to a 100 ° C hotplate with the previously prepared dispersion of SWNTs. Spray coated, dipped in DI water for 1 minute, then sprayed again, and dipped again in Di water.This step of spraying and dipping in water is desirable It may be repeated many times until the sheet resistance (eg, film thickness) is achieved.

In a related exemplary embodiment, a doped nanostructured film comprising an interconnected network of SWNTs is obtained using the method described in the previous example, but additionally TCNQF ₄ A dispersion of SWNTs containing the following dopants was fabricated into transparent and flexible substrates. In another related embodiment, the doped nanostructured film was then encapsulated by spin-coating and baking a layer of parylene on it.

In another exemplary embodiment, a dispersion of SWNTs was first prepared by dissolving SWNT powder (eg, P3 from Carbon Solutions) in DI water with 1% SDS and 100 W 15000 ref for 30 minutes so that only the upper 3/4 portion of the centrifuged dispersion is selected for further processing for 16 hours. And then centrifuged. The resulting dispersion is then an alumina filter (0.1-0.2 μm pore size) so that an optically clear and electrically conductive SWNT film is formed on the filter. Vacuum filtered through Watman Inc.). The DI water was then vacuum filtered through the film for several minutes to remove the SDS. The resulting film was then transferred to a PET substrate by a PDMS (polydimethylsiloxane) based transfer printing technique, in which a patterned PDMS stamp was first patterned. The patterned film is placed in conformal contact with the film on the filter so that it is transferred from the filter to the stamp, and then the patterned substrate is transferred to the PET substrate so that it is transferred to the PET. Placed in conformal contact and heated to 80 ° C. In related exemplary embodiments, the patterned film may then be doped via immersion in a gaseous NO ₂ chamber. In another related exemplary embodiment, the film may be encapsulated by a layer of PMPV, which, in the case of doped films, reduces dopant desorption from the film. be able to.

  In yet another exemplary embodiment, an optically transparent, electrically conductive, doped and encapsulated nanostructured film comprising an interconnected network of FWNTs is transparent Fabricated on flexible and flexible substrates. FWNT grown in CVD (OE grade from Unidim, Inc.) was first dissolved in DI water with 0.5% Triton-X and at 300W power for one hour Sonicated with interprobe. The resulting dispersion was then slot die coated onto a PET substrate and baked at about 100 ° C. to evaporate the solvent. Triton-X was then removed from the resulting FWNT film by immersing the film in nitric acid (10 molar) for about 15-20 seconds. Nitric acid reduces the sheet resistance of the film from 498 ohm / square to about 131 ohm / square at about 75% transparency and from 920 ohm / square to about 230 ohm / square at 80% transparency in an exemplary film. It may be effective as both an oxidizing agent for removal of surfactants, as well as a doping agent, which is an improvement. In related exemplary embodiments, these films were then coated with triphenylamine, which stabilized the dopant (ie, the film was subjected to accelerated aging conditions (65 ° C. ) Showed less change compared to 10% in 1000 hours after conductivity). In other related exemplary embodiments, the film was then encapsulated with Teflon AF.

  In another exemplary embodiment, the FWNT powder is initially SDS sonicated (eg, 30 minutes bath sonication followed by 30 minutes probe sonication). (E.g. 1%) dispersed in water with surfactant; 1-dodecanol (e.g. 0.4%) was then sonicated (e.g. The resulting dispersion was added to the dispersion by probe sonication) and the Meyer rod coated onto the PEN substrate. The SDS was then removed by rinsing the film with DI water and 1-dodecanol was removed by rinsing with ethanol. The resulting optically transparent and electrically conductive film passed the industry standard “tape test” (ie, FWNT film is a piece of Scotch tape pressed into the film. And when it was then peeled off, it remained on the substrate); such adhesion between the FWNT film and the PEN was not achieved with SDS dispersions in the absence of the use of coating aids.

  Referring to FIG. 2, an encapsulated nanostructured film according to the present invention may be fabricated using a series of coating, drying, washing, and baking stations. In one embodiment, the substrate is coated with a dispersion of CNTs (eg, as described above) that is passed through a cleaning / drying station, dried, washed, and again. It may be dried, coated with a capsule / topcoat (eg, slot die-coated crosslinked polymer), and then baked.

  In another embodiment, the washing and second drying step is to reduce tact time and equipment costs (i.e., the dried CNT coating has no intermediate washing and drying steps). (As coated with a capsule / topcoat). This step is advantageous in coating substrates such as glass or color filter resins because the dried CNT coating can delaminate from such substrates during the cleaning procedure. (E.g., FWNT film formed by slot die coating and drying a solution of FWNT dispersed in BTAC onto a glass substrate delaminated from the substrate when lightly washed with water. ). It was previously thought that cleaning was essential to achieving good optoelectronic properties (ie, by removing residual surfactant from the film). On the other hand, our experiments have surprisingly shown that omitting the washing step can produce equivalent optoelectronic properties.

  Referring to FIG. 3, in another and / or further embodiment, the dual-head slot die configuration can be used for tact time and equipment costs (eg, by allowing removal of a separate topcoat station). May be used to reduce In this embodiment, drying the dispersion of CNTs to form a CNT film may occur during a short gap between the heads of the slot dies. In another embodiment, a dual slot (eg, a two slot nip in the head) may be used as an alternative to a dual head slot die.

  In another embodiment, encapsulated nanostructured films according to the present invention may be fabricated using different series of coating, drying, washing, and baking stations. In another embodiment, the substrate is coated with a dispersion of CNTs and a mixture of capsule / topcoat (eg, slot die coated cross-linked polymer) that is passed through a cleaning / drying station. May be baked, washed, and then dried. In this embodiment, a single slot die configuration (e.g., by allowing the removal of a separate topcoat station and of a single slot head rather than a dual head slot die configuration). May be used to reduce tact time and equipment costs (by using a die). Since this embodiment can be made in a single coating step, this embodiment facilitates coating in cells (matrix glass) and patterned coatings. Furthermore, this embodiment provides a planarization of the topcoat layer that is definable by light. In a further embodiment, a photoresist coating can be applied to the CNT coating after drying.

  In another embodiment, encapsulated nanostructured films according to the present invention may be fabricated using different series of coating, drying, washing, and baking stations, and In particular, the substrate is coated, baked, coated with a mixture of CNT and polymer mixed solution (eg slot die coated cross-linked polymer) that is passed through a cleaning / drying station. , Washed, and then dried. In a further embodiment, a photoresist coating can be applied to the CNT coating after drying. In another embodiment, the substrate is passed through a cleaning / drying station, and without one or more of the steps that follow baking, washing, and drying, It may be coated with a mixture of CNT and polymer mixed solution (eg, slot die coated cross-linked polymer). Since these embodiments can be made in a single coating step, these embodiments facilitate coating in cells (matrix glass) and patterned coatings.

  In another embodiment, encapsulated nanostructured films according to the present invention may be fabricated using different series of coating, drying, washing, and baking stations, and In particular, the substrate is passed through a cleaning / drying station, coated with a primer layer (eg by spray, slot, SAM-dip, etc.), with a coating of CNTs (eg with a slot die). It may be coated, coated with a topcoat, baked, washed and dried. In a further embodiment, a photoresist coating can be applied to the CNT coating after drying. In another embodiment, the substrate is passed through a cleaning / drying station, coated with a primer layer (eg, by a method such as spray, slot, SAM-dip, etc.), (eg, with a slot die). Coated with a coating of CNTs and may be coated with a top coat without one or more of the steps that follow baking, washing and drying. Furthermore, these embodiments provide for planarization of the topcoat layer that is light definable.

  In addition to the encapsulant / topcoat, the use of surface treatments and / or surface activity may further assist the adhesion of the CNT film to the underlying substrate (eg, HMDS or silane or corona / plasma). processing). In the above embodiments, the encapsulant / topcoat is a thermosetting polymer (eg, so that application of heat creates a network of crosslinked polymers) and / or (eg, UV radiation, The application of visible radiation, electron beam, and / or other radiation may be a UV curable polymer (so as to create a crosslinked polymer network).

  With reference to FIG. 4A, such capsule / topcoat materials may additionally or alternatively be To allow deposition of CNT films on high surface energy substrates (eg, silicon nitride, glass, anti-glare coating, etc.), it may be deposited as a primer / promotion layer, where the CNT films are Otherwise, it will not adhere well when deposited using certain solution-based deposition methods (including some of those described above). For example, a CNT film that would otherwise not adhere to a glass substrate would be a PVP primer / promotion layer (in ethanol) where the glass substrate was first spin-coated (3000 rpm for 30 seconds). It has been shown to pass the industry standard "tape test" when coated with.

  With reference to FIG. 4B, such capsules / topcoats may also be used to pattern nanostructured films. For example, an adhesive layer comprising monomers, polymers, and / or cross-linked polymers that strongly attract CNTs is coated with a CNT film that is coated and patterned on a substrate. And then may be cleaned and / or sonicated so that only the portion of the CNT film that is to be coated on the adhesive layer remains. Exemplary polymeric adhesive layers include poly (4-vinylphenol) (PVP), PVDF, poly (vinyl formal), poly (melamine-co-formaldehyde) methylated, polyimide, COC, Polyurethane latex (including sanure 898, 899, 825, and 835) and urethane / acrylic copolymers. Crosslinkers include Silquest A-187, CX-100, MMF, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and many others. Monomers include acrylate monomers such as methyl methacrylate, n-butyl methacrylate, hydroxyethyl methacrylate, and many others. The adhesive can be a UV curable epoxide such as electro-lite 2728, 2900, and Loctite adhesive. The adhesive layer can be formed, for example, by screen printing through a mask, ink jet printing, photolithography patterning (eg, photoresist (PR) patterning, coating an adhesive on a substrate, and then Lift off the PR), laser ablation, etc. Adhesive layers are examples. May be thin, in the 1-10 nm range for adhesion primer / promotion purposes only. The substrate may be, for example, glass or ST504 without primer coating.

  Referring to FIG. 5, the CNT film is sonicated, taped, and / or mechanically produced to produce a patterned encapsulated CNT film where the unimpregnated portion of the film is patterned. It may be selectively impregnated with a capsule / topcoat so that it can be removed by excessive wear.

  It may be possible to remove the capsule / topcoat (eg, organic solvents may be effective in removing uncrosslinked polymers). For example, 0.01-0.5% PVP in PGMEA was mixed with the crosslinker Silquest A-187 (the weight of A-187 is 1-20% of PVP) and the resulting mixture 20 mL of the solution was drop coated onto a selected portion of the underlying CNT film; the polymer coated CNT film was then baked at 120 ° C. for 10 minutes, and then Washed to remove nanotubes, not encapsulated.

  The present invention has been described above with reference to preferred features and embodiments. However, those skilled in the art will recognize that changes and modifications may be made in these preferred embodiments without departing from the scope of the invention.

Claims (16)

A method for making an optically transparent, electrically conductive nanostructured film comprising:
Coating a substrate with a dispersion or solution comprising a nanostructure selected from the group consisting of carbon nanotubes, fullerenes, graphene flakes / sheets, nanowires, and two or more thereof;
Baking the coating on the substrate;
Cleaning the coating on the substrate; and
Drying the coating on the substrate. The method of claim 1, wherein
The nanostructure is composed of carbon nanotubes (SWNT) surrounded by a single wall, carbon nanotubes surrounded by a large number of walls (MWNT), carbon nanotubes surrounded by a double wall (DWNT), and a small number of walls. Enclosed carbon nanotubes (FWNT), buckyballs, graphene flakes / sheets, metal nanowires, semiconducting nanowires, dielectric nanowires, organic nanowires, inorganic nanowires and their A method selected from the group consisting of two or more. The method of claim 1, wherein
The method, wherein the nanostructured film comprises a network of nanostructures. The method of claim 1, wherein
The method wherein the coating is done in a pattern. The method of claim 4, wherein
The coating is applied prior to coating the substrate with the nanostructured film by a technique selected from the group consisting of substrates pre-treated in a lift-off method and pattern; patterned transfer printing, screen printing, and inkjet Coating the substrate with the nanostructured film by a technique selected from the group consisting of printing; coating the nanostructured film on the substrate with a technique selected from the group consisting of laser ablation or masking / etching techniques Or patterning with two or more before, during, or after coating. The method of claim 1, comprising:
Coating the substrate with a dispersion or solution comprising a capsule. The method of claim 6 wherein:
Coating the dispersion or solution comprising the capsule is performed after coating the dispersion or solution comprising the nanostructure. The method of claim 6 wherein:
Coating the dispersion or solution comprising the capsule is performed prior to coating the dispersion or solution comprising the nanostructure. The method of claim 6 wherein:
The capsules are fluoropolymer, polyacrylate, polysilane, polyimide, polyester, polyvinylidene fluoride (PVDF), polytetrafluoroethylene, polyvinyl chloride (PVF), polychlorotrifluoroethylene (PCTFE), polyvinyl alkyl = vinyl. = From the group consisting of ethers, melamine / acrylic blends, conformal acrylic coating dispersions, UV crosslinkable polymers, heat crosslinkable polymers, poly (4-vinyl-phenol), and mixtures thereof Selected method. The method of claim 1, wherein
Coating the dispersion or solution comprising the nanostructures further comprises a dopant, or the method further comprises coating a dispersion or solution comprising the dopant on a substrate. The method of claim 10, wherein:
The dopant is iodine (I ₂ ), bromine (Br ₂ ), polymer-supported bromine (Br ₂ ), antimony pentafluoride (SbF ₅ ), phosphorus pentachloride (PCl ₅ ), vanadium oxytrifluoride. (VOF ₃ ), silver fluoride (II) (AgF ₂ ), 2,1,3-benzooxadiazole-5-carboxylic acid, 2- (4-biphenylyl) -5-phenyl-1,3,4 Oxadiazole, 2,5-bis- (4-aminophenyl) -1,3,4-oxadiazole, 2- (4-bromophenyl) -5-phenyl-1,3,4-oxadiazole, 4-chloro-7-chlorosulfonyl-2,1,3-benzooxadiazole, 2,5-diphenyl-1,3,4-oxadiazole, 5- (4-methoxyphenyl) -1,3,4 -Oxadiazol-2-thi 5- (4-methylphenyl) -1,3,4-oxadiazole-2-thiol, 5-phenyl-1,3,4-oxadiazole-2-thiol, 5- (4-pyridyl) ) -1,3,4-oxadiazole-2-thiol, methylviologen = chloride hydrate, fullerene-C60, N-methylfulleropyrrolidine, N, N′-bis (3-methylphenyl) -N, N'-diphenylbenzidine, triethylamine (TEA), triethanolamine (TEA) -OH, trioctylamine, triphenylphosphine, trioctylphosphine, triethylphosphine, trinaphthylphosphine, tetradimethylaminoethene, tris (diethylamino) phosphine, Pentacene, tetracene, N, N′-di-[(1-naphthyl) -N, N′-diph Nyl] -1,1′-biphenyl) -4,4′-diamine, sublimated grade, 4- (diphenylamino) benzaldehyde, di-p-tolylamine, 3-methyldiphenylamine, triphenylamine, tris [4- (Diethylamino) phenyl] amine, tri-p-tolylamine, acridine orange base, 3,8-diamino-6-phenylphenanthridine, 4- (diphenylamino) benzaldehyde, diphenylhydrazone, poly (9-vinylcarbazole) ), Poly (1-vinylnaphthalene), poly (2-vinylpyridine) n-oxide, triphenylphosphine, 4- (carboxybutyl) triphenylphosphonium bromide, tetrabutylammonium benzoate, tetrabutylammonium hydroxide 30 Hydrate, tetrabutylammonium triiodide, tetrabutylammonium bis - trifluoromethanesulfonic imidate, tetraethylammonium = trifluoromethanesulfonate, fuming sulfuric acid _{(H 2 SO 4 -SO 3)} , triflic acid, magic acid, and their A method selected from the group consisting of two or more. The method of claim 1, wherein
The substrate is made of glass, elastomer, saturated rubber, unsaturated rubber, thermoplastic elastomer (TPE), thermoplastic vulcanizate (TPV), polyurethane rubber, polysulfide rubber, resin, elastin, plastic, polymethyl methacrylate. Rates (PMMA), polyolefins, polyethylene = terephthalate (PET), polyethylene = naphthalate (PEN), polycarbonate (PC), polyethersulfone (PES), cyclic olefin polymers, and two or more of them A method selected from the group consisting of things. The method of claim 1, wherein
The method wherein the substrate is flexible and the coating step is performed using roll-to-roll processing. The method of claim 1, wherein
Heating is performed by using a hot plate, a heating rod, a heating coil, an oven, or two or more of them. The method of claim 1, wherein
The method wherein the washing is performed with water, ethanol, isopropyl alcohol, or two or more of them. The method of claim 1, comprising:
Rinsing the coated substrate with an oxidizing agent selected from the group consisting of nitric acid, sulfuric acid, hydrochloric acid, and two or more thereof.

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