US20080199626A1 - Method for assembling nano objects - Google Patents

Method for assembling nano objects Download PDF

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US20080199626A1
US20080199626A1 US11441261 US44126106A US2008199626A1 US 20080199626 A1 US20080199626 A1 US 20080199626A1 US 11441261 US11441261 US 11441261 US 44126106 A US44126106 A US 44126106A US 2008199626 A1 US2008199626 A1 US 2008199626A1
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substrate
method
nano objects
suspension
nano
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US11441261
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Otto Z. Zhou
Hideo Shimoda
Soojin Oh
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University of North Carolina at Chapel Hill
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University of North Carolina at Chapel Hill
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B82NANOTECHNOLOGY
    • B82YSPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00Nanotechnology for materials or surface science, e.g. nanocomposites
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00Processes for applying liquids or other fluent materials
    • B05D1/18Processes for applying liquids or other fluent materials performed by dipping
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00Processes for applying liquids or other fluent materials
    • B05D1/18Processes for applying liquids or other fluent materials performed by dipping
    • B05D1/20Processes for applying liquids or other fluent materials performed by dipping substances to be applied floating on a fluid
    • B05D1/202Langmuir Blodgett films (LB films)
    • B05D1/204LB techniques
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B82NANOTECHNOLOGY
    • B82YSPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00Manufacture or treatment of nanostructures
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S427/00Coating processes
    • Y10S427/102Fullerene type base or coating
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00Nanotechnology
    • Y10S977/84Manufacture, treatment, or detection of nanostructure
    • Y10S977/842Manufacture, treatment, or detection of nanostructure for carbon nanotubes or fullerenes
    • Y10S977/847Surface modifications, e.g. functionalization, coating
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00Nanotechnology
    • Y10S977/84Manufacture, treatment, or detection of nanostructure
    • Y10S977/842Manufacture, treatment, or detection of nanostructure for carbon nanotubes or fullerenes
    • Y10S977/848Tube end modifications, e.g. capping, joining, splicing
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00Nanotechnology
    • Y10S977/84Manufacture, treatment, or detection of nanostructure
    • Y10S977/882Assembling of separate components, e.g. by attaching

Abstract

A method for the self assembly of a macroscopic structure with a pre-formed nano object is provided. The method includes processing a nano object to a desired aspect ratio and chemical functionality and mixing the processed nano object with a solvent to form a suspension. Upon formation of the suspension, a substrate is inserted into the suspension. By evaporation of the solvent, changing the pH value of the suspension, or changing the temperature of the suspension, the nano objects within the suspension deposit onto the substrate in an orientational order. In addition, a seed crystal may be used in place of the substrate thereby forming single-crystals and free-standing membranes of the nano-objects.

Description

    RELATED APPLICATIONS
  • This application is a divisional patent application from and which claims the benefit to the filing date of U.S. patent application Ser. No. 10/103,803, filed Mar. 25, 2002, the disclosure of which is incorporated herein by reference in its entirety.
  • GOVERNMENT INTEREST
  • At least some aspects of this subject matter were made with Government support under the sponsorship of the Office of Naval Research, Contract No. N00014-98-1-0597 and by a grant from the National Aeronautics and Space Administration (NAG-1-01061). The Government may have certain rights in this subject matter.
  • TECHNICAL FIELD
  • The present subject matter relates generally to methods to assemble nano objects into functional structures.
  • BACKGROUND ART
  • In the description of the background of the present subject matter that follows reference is made to certain structures and methods. Such references should not necessarily be construed as an admission that these structures and methods qualify as prior art under the applicable statutory provisions. Applicants reserve the right to demonstrate that any of the referenced subject matter does not constitute prior art with regard to the present subject matter.
  • The term “nanostructure” material is used by those familiar with the art to designate materials including nanoparticles such as C60 fullerenes, fullerene-type concentric graphitic particles; inorganic and organic nanowires/nanorods composed of either single or multiple elements such as Si, Ge, metals, oxides such as SiOx, GeOx; carbides such as silicon carbides; nitrides, borides, or hollow nanotubes composed of either single or multiple elements such as carbon, BxNy, CxByNz MoS2, and WS2. One of the common features of nanostructure materials is the dimension of their basic building blocks. A single nanoparticle or a nanotube or a nanowire has a dimension that is less than 1 micron in at least one direction. These types of materials have been shown to exhibit certain properties that have raised interest in a variety of applications and processes.
  • U.S. Pat. No. 6,280,697 to Zhou et al. entitled “Nanotube-Based High Energy Material and Method,” the disclosure of which is incorporated herein by reference, in its entirety, discloses the fabrication of carbon-based nanotube materials and their use as a battery electrode material.
  • application Ser. No. 09/296,572 entitled “Device Comprising Carbon Nanotube Field Emitter Structure and Process for Forming Device” the disclosure of which is incorporated herein by reference, in its entirety, discloses a carbon nanotube-based electron emitter structure.
  • application Ser. No. 09/351,537 entitled “Device Comprising Thin Film Carbon Nanotube Electron Field Emitter Structure,” the disclosure of which is incorporated herein by reference, in its entirety, discloses a carbon-nanotube field emitter structure having a high emitted current density.
  • U.S. Pat. No. 6,277,318 to Bower et al. entitled “Method for Fabrication of Patterned Carbon Nanotube Films,” the disclosure of which is incorporated herein by reference, in its entirety, discloses a method of fabricating adherent, patterned carbon nanotube films onto a substrate.
  • U.S. Pat. No. 6,334,939 to Zhou et al. (application Ser. No. 09/594,844) entitled “Nanostructure-Based High Energy Material and Method,” the disclosure of which is incorporated herein by reference, in its entirety, discloses a nanostructure alloy with alkali metal as one of the components. Such materials are described as being useful in certain battery applications.
  • application Ser. No. 09/679,303 entitled “X-Ray Generating Mechanism Using Electron Field Emission Cathode,” the disclosure of which is incorporated herein by reference, in its entirety, discloses an X-ray generating device incorporating a nanostructure-containing material.
  • application Ser. No. 09/817,164 entitled “Coated Electrode With Enhanced Electron Emission And Ignition Characteristics” the disclosure of which is incorporated herein by reference, in its entirety, discloses an electrode including a first electrode material, an adhesion-promoting layer and a carbon nanotube-containing material disposed on at least a portion of the adhesion promoting layer, as well as associated devices incorporating such an electrode.
  • application Ser. No. 09/881,684 entitled “Method of Making Nanotube-Based Material With Enhanced Field Emission” the disclosure of which is incorporated herein by reference, in its entirety, discloses a technique for introducing a foreign species into the nanotube-based material in order to improve the emission properties thereof.
  • As evidenced by the above, nanostructure materials, such as carbon nanotubes, possess promising properties. Carbon nanotubes (CNTs) are one type of nano objects. CNTs are cylindrical carbon structures with a length between 0.1 μm and 100 μm and a diameter between 0.4 nm and 50 nm (see, e.g. M. S. Dresselhaus, G. Dresselhaus, and P. Avouris, eds. Carbon Nanotubes: Synthesis, Structure, Properties, and Applications. Topics in Applied Physics. Vol. 80. 2000, Springer-Verlag). CNTs can have either a single graphite shell per nanotube in which case CNTs are called single-wall carbon nanotubes (SWNTs). CNTs may also have concentric multi-shell graphite structures in which case CNTs are called multi-wall carbon nanotubes (MWNTs). Carbon nanotubes have exceptional mechanical properties with high elastic modulus, high ductility, high electrical and high thermal conductivity, thermal stability and chemical stability. CNTs are excellent electron field emitters since CNTs have a large aspect ratio and a sharp tip. (See, e.g. P. M. Ajayan and O. Zhou, in “Topics in Applied Physics, 80,” M. S. Dresselhaus, G. Dresselhaus, and P. Avouris, Editors. 2000, Springer-Verlag). In particular, carbon-nanotube materials exhibit low emission threshold fields as well as large emission current densities. Such properties make them attractive electron field emitters for microelectronic applications, such as lighting elements, field emission flat panel displays, gas discharge tubes for over voltage protection and x-ray generating devices. Other applications of carbon nanotubes include but limited to: sensors, composites, shielding materials, detectors, electrodes for batteries, fuel cells, small conduction wires, small cylinders for storage, etc.
  • Carbon nanotubes, nanowires and nanorods, nanoparticles are typically fabricated by techniques such as laser ablation, arc discharge, and chemical vapor deposition methods. In some cases they can also be made via solution or electrochemical synthesis. However, in most cases, the as-synthesized materials cannot be utilized without further processing. For example, carbon nanotubes produced by the laser ablation and arc discharge techniques are in the form of porous mats and powders. Device applications require assembling these nano objects into ordered, patterned films, membranes, crystals on desired supporting surfaces and the pre-determined locations. In addition, it is often advantageous to assemble elongated nano objects such as the carbon nanotubes into orientationally ordered macroscopic structures which provide properties such as anisotropic electrical, mechanical, thermal, magnetic and optical properties.
  • The conditions used to assemble the nano objects need to be compatible with the conditions used for device fabrications. For example, nano objects which are to be used as field emission cathodes in field emission displays should not have a fabrication temperature which exceeds the melting point of glass substrates (about 650° C.). Also, the temperature should be substantially lower when supporting surfaces of the nano objects are polymer. For such applications, direct growth of nano objects using chemical vapor deposition (CVD) techniques are not feasible since CVD techniques generally require relatively high temperatures (800° C.-1200° C.) as well as reactive environments. In addition, CVD techniques often result in defective multi-wall carbon nanotubes.
  • As such, a more desirable approach for fabrication of macroscopic structures of nano objects for applications is post-processing which includes synthesis of nano objects by arc discharge, laser ablation, or chemical vapor deposition techniques and assembly of these “pre-formed” nano objects into a macroscopic structure. Post-deposition processes that have been employed in the past include screen printing. (see, e.g. W. B. Choi, et al., Appl. Phys. Lett., 75, 3129 (1999)), spraying, and electrophoretic deposition (see, e.g. B. Gao et al. Adv. Mater., 13 (23), 1770, 2001) However, such techniques pose certain drawbacks. For instance, screen printing includes admixture of pre-formed nano objects with an organic or inorganic paste in order to form a thick paste. The thick paste is then placed on a substrate. After placement of the thick paste onto the substrate, the organic binder resides at an exposed surface of the paste. Therefore, an additional step is required to expose the nano objects within the thick paste. Typically, a plasma etching process or similar chemical process is used to expose the nano objects. In addition, the use of thick paste limits the size of a structure can be formed. In general it is difficult to form structures less than 20 microns-50 microns using the screen printing methods. Furthermore, screen printing methods requires considerable amount of materials. Spraying can be inefficient and is not practical for large-scale fabrication. Neither of these processes can control the orientation of the nano objects.
  • Therefore, a need exists for a process/method to assemble nano objects with a controlled structure, morphology, thickness, orientation, and ordering. In addition, a need exists for a method that operates at mild conditions acceptable for device fabrications. In addition, a need exists for an efficient and scalable assembly process.
  • SUMMARY
  • The present subject matter provides a method for forming microscopic and macroscopic structures using nano objects. The method of the present subject matter allows self assembly of nano objects onto a supporting surface, into a freestanding structure, or into a crystal. In addition, the present subject matter provides a method for assembling the nano objects into patterned structures with a controlled thickness, density and a controlled orientation of the nano objects. In addition, the present subject matter provides an efficient process to assemble pre-formed nano objects under mild conditions that are acceptable for a wide range of substrates and devices. The resulting structures are useful in a variety of devices including electron field emission cathodes for devices such as field emission displays, cold-cathode x-ray tubes, microwave amplifiers, ignition devices; electrodes batteries, fuel cells, capacitors, supercapacitors; optical filters and polarizers; sensors; and electronic inter-connects.
  • In one embodiment of the present subject matter, a method for assembling a macroscopic structure with pre-formed nano objects is disclosed. The method comprises processing the nano objects such that they form a stable suspension or solution in a solvent. Once the nano objects are processed, the nano objects are admixed with a solvent to form a stable suspension or a solution. Upon formation of the stable suspension or solution, a substrate is submersed into the suspension or solution. Upon changing either the concentration, temperature, or pH value of the suspension, the nano objects deposit on the surface of the substrate.
  • In a further embodiment of the present subject matter, a method for assembling pre-formed nano objects into a patterned structure is disclosed. The method comprises processing pre-formed nano objects such that they form a stable suspension or solution in a suitable solvent. After processing the nano objects, the processed pre-formed nano object is mixed with a solvent to form a stable suspension or a solution. A patterned substrate is then inserted into the liquid. Upon changing either the concentration, temperature, or the pH value of the liquid, the nano objects assemble on certain regions of the substrate surface to form a patterned structure comprising the nano objects.
  • In yet another embodiment of the present subject matter, a method for assembling pre-formed nano objects into a crystal or a membrane is disclosed. The method comprises processing the nano objects so that they form a stable suspension or solution in a solvent. The processed nano objects are mixed with a solvent to form a suspension or a solution in a container that does not attract the nano objects. Upon changing a concentration, temperature or a pH value of the liquid, the nano objects crystallize in the liquid. In this embodiment of the present subject matter, a seed crystal may be used to form the crystal.
  • In another embodiment of the present subject matter, a method for assembling pre-formed nano objects into multi-layered structures is disclosed. The method comprises first processing the nano objects so that they form a stable suspension or solution in a solvent. The processed nano object is then mixed with a solvent to form a suspension or a solution. After formation of the stable suspension or solution, a substrate is submersed into the suspension or solution. Upon changing the concentration, temperature or the pH value of the suspension or solution, the nano objects assemble on the surface of the substrate. The substrate is then removed from the suspension or solution. After removal, a second type of material is coated on the surface of the self-assembled nano objects on the substrate. The substrate is then submersed into the suspension or solution containing the nano objects. The process is repeated until a multi-layer structure with a desired thickness and number of repeating layers are obtained.
  • In yet another embodiment of the present subject matter, a method for assembling elongated nano objects into orientational ordered structures is disclosed. The method comprises forming a stable suspension or solution of the nano objects in a suitable solvent. A substrate is then submersed into the liquid and the solvent gradually evaporated. Upon evaporation of the solvent, the nano objects deposit on the surface of the substrate such that longitudinal axes of the nano objects align parallel to the substrate surface. The process can further comprise the use of an external field such as either an AC or a DC electrical field or a magnetic field during the assembly process.
  • In a further embodiment of the present subject matter, a method for assembling elongated nano objects into a vertically aligned structure on a supporting surface is disclosed. The method comprises first processing the nano objects such that a tail and a body of the nano objects have different affinities toward certain types of solvents. For example, the tails are hydrophobic and the bodies are hydrophilic. The processed nano objects are dispersed in a suitable solvent where the solvent has an affinity towards the tails of the nano objects. A substrate with one of the surfaces having the same affinity towards the solvent and the tails of the nano objects is submersed into the liquid. Upon changing the concentration, temperature, or pH value of the solvent, the nano objects deposit on the substrate with their tails bonded to the surface and longitudinal axes of the nano objects vertically aligned with respect to the surface of the substrate.
  • As may be appreciated, the present subject matter provides a method for self assembly of nano objects, such as carbon nanotubes, nanowires and nanorods, onto a substrate, into free-standing membranes, into a crystal, or a into multi-layer structure. The nano objects form into functional structures having long range ordering. In addition, the present subject matter provides a method for controlling the functionality of formed macroscopic structures. Some of the objects of the subject matter having been stated hereinabove, and which are addressed in whole or in part by the present subject matter, other objects may become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • Objects and advantages of the subject matter may become apparent from the following detailed description of preferred embodiments thereof in connection with the accompanying drawings in which like numerals designate like elements and in which:
  • FIG. 1A illustrates a substrate within a suspension where the suspension includes nano objects for deposition onto the substrate in accordance with an embodiment of the present subject matter.
  • FIG. 1B shows an embodiment of the present subject matter where the substrate shown with reference to FIG. 1A includes hydrophobic regions and hydrophillic regions.
  • FIG. 2 illustrates the evaporation of the suspension during submersion of the substrate shown with respect to FIG. 1A in accordance with an embodiment of the present subject matter.
  • FIG. 3 is an embodiment of the present subject matter illustrating a air/liquid/substrate triple line on the substrate shown with respect to FIG. 1A where nano objects deposit on the substrate along the air/liquid/substrate triple line.
  • FIG. 4 illustrates the deposition of nano objects onto a substrate to form a nano object film, in accordance with an embodiment of the present subject matter.
  • FIG. 5 illustrates a method 200 assembling a macroscopic structure with preformed carbon nanotubes onto a substrate in accordance with an embodiment of the present subject matter.
  • FIG. 6A illustrates a method of submersing a seed crystal into a solution for assembling nano objects into a crystal in accordance with an embodiment of the present subject matter.
  • FIG. 6B is an embodiment of the present subject matter illustrating the formation of a crystal formed with the nano objects shown with reference to FIG. 6A.
  • FIG. 7A illustrates a method of assembling elongated nano objects on a surface such at they are aligned vertically in respect to the supporting surface in accordance with an embodiment of the present subject matter.
  • FIG. 7B shows nano objects shown with respect to FIG. 7A in accordance with an embodiment of the present subject matter.
  • FIG. 8A illustrates a multi-layer structure fabricated in accordance with an embodiment of the present subject matter.
  • FIG. 8B shows a tri-layer multi-layer structure made in accordance with an embodiment of the present subject matter.
  • FIG. 9A illustrates a glass substrate patterned with photoresist and hydrophilic regions in accordance with an embodiment of the present subject matter.
  • FIG. 9B illustrates an embodiment of the present subject matter where the substrate shown with respect to FIG. 9A includes a SWNTs.
  • FIG. 9C shows a phosphor screen for placement over the glass substrate shown with reference to FIG. 9B in accordance with an embodiment of the present subject matter.
  • DETAILED DESCRIPTION
  • The present subject matter discloses a method for assembling nano objects. The nano objects formed in accordance with the present subject matter may be formed onto a supporting surface, into free-standing membranes and into multi-layer structures. The nano objects may be a variety of materials, including hollow nano tubes which are composed of single or multiple elements. The single or multiple elements may be carbon, boron, nitrogen, solid inorganic or organic nanowires/nanorods. Prior to assembling the nano objects, the nano objects are processed such that they form a stable suspension or a solution in a suitable solvent. The processing operation includes attaching chemical groups to the surface of the nano objects and reducing aspect ratios of elongated nano objects. After processing, a suspension or a solution is formed by admixture of the processed nano objects with a solvent. Upon formation of the suspension, a substrate, such as glass, is submersed into the substrate. After submersion of the substrate, the nano objects self assemble into uniform thin films on the substrate. The nano objects self assemble when either of the following occurs: evaporation of the suspension, a concentration change of the suspension, a temperature change of the suspension or a pH level change of the concentration. The nano objects which self assemble onto the uniform film may be any nano object, such as carbon nanotubes, silicon nanowires or the like.
  • Now making reference to the Figures, and more particularly FIG. 1A, FIG. 1A illustrates a substrate 100 within a suspension 102 having nano objects 104, in accordance with an embodiment of the present subject matter. The substrate 100 may be any substrate which allows deposition of nano objects such as carbon nanotubes onto the substrate, such as hydrophilic glass, gold (Au), a silicon wafer, aluminum, chromium, tin, a polymer, a metal or the like. In accordance with an alternative embodiment of the present subject matter, the substrate may include regions with alternating chemical properties such as hydrophilic and hydrophobic regions, as shown in greater detail with reference to FIG. 1B.
  • FIG. 1B illustrates an embodiment of the present subject matter where the substrate 100 includes hydrophobic regions 100 a and hydrophilic regions 100 b. In this embodiment, the nano objects deposit on one of these regions. Where the nano objects deposit depend on the properties of the nano objects and how they are processed. In the case where nano objects are hydrophilic, the nano objects deposit on the hydrophilic regions 100 b and resist the hydrophobic regions 100 a during deposition. Therefore, a user may control deposition formation on a substrate and functionality of the substrate by controlling the location of hydrophilic and hydrophobic regions on the surface of the substrate. As may be appreciated, controlling the functionality of the substrate enables the fabrication of patterned nano object films. It should be noted that the hydrophobic regions 100 a may be formed using any suitable technique, such as spin coating a thin layer of hydrophobic polymers such as polystyrene over the surface of the substrate 100, by deposition of a monolayer of hydrophobic chemical groups or the like. Moreover, after nano object deposition, the hydrophobic regions 100 a may be removed by washing the substrate 100 in any suitable solvent, such as acetone, methanol, ethanol, buffered hydrofluoric acid or the like. Therefore a user may pattern the substrate such that the formed carbon nanotube film may have different uses, such as the basic field emission pixels for field emission displays.
  • Returning attention to FIG. 1A, the substrate 100 is submersed into the suspension 102. The suspension 102 includes nano objects 104 admixed with suitable solvents. In the case of processed carbon nanotubes, the solvent can be either de-ionized water or alcohol. Some of the nano objects 104 may be dispersed or dissolved in a suitable solvent after fabrication without further processing. Other materials, such as carbon nanotubes or Si nanowires, are processed in order to form a stable suspension. The processing operation includes the following: attaching chemicals to the surfaces of the nano objects and/or reducing the aspect ratios of the elongated nano objects. In one embodiment of this subject matter, the nano objects 104 are single-wall carbon nanotube (SWNT) bundles which are produced by either arc-discharge, laser ablation, or other suitable techniques. They are then purified by a refluxing operation in hydrogen peroxide and filtration. After purification, the nano objects 104 are etched to uniform lengths. The nano objects 104 can be cut by a variety of techniques including sonication in concentrated acids such as sulfuric and nitric acids, or a mechanical process such as ball-milling or mechanical cutting. Upon etching, the SWNT bundles are rinsed in de-ionized water and annealed at 200° C. in a 10−6 torr dynamic vacuum. The etching operation changes a morphology of the SWNT bundles from highly entangled to a rigid-rod structure after reducing the aspect ratio of the SWNT bundles to less than 100. In one embodiment of the present subject matter, SWNT bundles processed for 30 hours had an indicated bundle length of 0.5 μm. Moreover, the etched SWNTs are metallic like and have less than 2.0% hydrogen (H). In addition, the above method used for processing the SWNT bundles maintains the frequency of a Raman-active SWNT breathing mode at a same amount while reducing the aspect ratio and changing the morphology of the SWNT bundles. In accordance with an alternative embodiment of the present subject matter, the nano objects 104 may also be multi-walled nano tube bundles and nanowires/nanorods.
  • Upon processing to the form of the nano objects, the nano objects 104 are admixed with a solution such as de-ionized water to form the suspension 102. In this embodiment, when the nano objects 104 are carbon nanotubes etched using the method described above, the nano objects 104 and the de-ionized water admix to form a homogeneous suspension which is stabilized with a carbon nanotube concentration up to 1.0 mg/mL without flocculation for several days. In accordance with alternative embodiments of the present subject matter, other solvents, such as alcohol, may also be used in the suspension 102.
  • Upon insertion of the substrate 100 into the suspension 102, the solvent 102 evaporates as shown with reference to FIG. 2. FIG. 2 illustrates the evaporation of the suspension 102 during submersion of the substrate 100 in accordance with an embodiment of the present subject matter. As may be seen with reference to FIG. 2, the nano objects 104 transfer to the substrate as the suspension 102 evaporates. In some cases, deposition occurs along an air/liquid/substrate line or triple line 106, as shown with reference to FIG. 3. In accordance with an embodiment of the present subject matter, the triple line 106 is an area on the substrate 100 where the suspension 102 ends on the substrate 102 as indicated by a point A. As may be appreciated, the point A moves in a downward direction Y along the substrate 100 as the suspension 102 evaporates. It should be noted that the rate of evaporation may be controlled through controlling the ventilation of an area immediately surrounding the substrate 100 and the suspension 102 and increasing or decreasing the temperature of the suspension 102. It should also be noted that in an embodiment of the present subject matter, the suspension evaporates at room temperature.
  • Now turning attention to FIG. 4, FIG. 4 illustrates the deposition of the nano objects 104 onto the substrate 100 to form a macroscopic structure, such as a film 108 in accordance with an embodiment of the present subject matter. As the triple line 106 moves in the downward direction Y (shown with reference to FIG. 3), the nano objects 104 continue to deposit on the substrate 102 forming the film 108. In this embodiment, the film 108 has a uniform thickness, as demonstrated by the image shown in FIG. 1, which varies in a range between about 1 nm to about 10 microns. The thickness of the deposited film may be controlled through controlling the concentration of the nano objects 104 in the suspension 102. To further illustrate, for a carbon nanotube film thickness of 0.1 micron, a concentration in a range preferably between about of 0.2 mg/mL of nanotube/water and about 0.5 mg/mL of nanotube/water suspension may be used. When a carbon nano object film having a thickness of 1.0 micron is desired, a concentration preferably in a range between about 0.5 mg/mL and about 1 mg/mL may be used.
  • It should be noted that carbon nanotube film deposition occurs for the film 108 when the suspension 102 is super saturated. To further illustrate, when a concentration Co of the suspension 102 is less than a critical concentration C* of the suspension 102, deposition occurs during evaporation of the suspension, as previously described. For example, if the concentration C* of the suspension is 0.5 mg/mL and the critical concentration C* of the suspension 102 is 1 mg/mL deposition occurs at the triple line 106. Nonetheless, if the concentration Co of the suspension 102 is substantially smaller than a critical concentration of the suspension, even when the suspension 102 has a high evaporation rate (i.e., an evaporation rate of 1 mm/hour), the nano objects 104 may not deposit on the substrate. For example, when Co<0.1 mg/mL and Co=1 mg/mL, no deposition of SWNTs occurs on the glass substrate.
  • The nano objects 104 in the self-assembled film 108 are orientationally ordered such that longitudinal axes of the nano objects 104 which deposit on the substrate 100 lie along the triple line 106 direction. This is demonstrated in FIG. 4, which shows a TEM image of the aligned SWNT bundles after assembly. Moreover, a degree of ordering of the nano objects in the film 108 maybe controlled by length and length distribution of the nano objects 104 and the thickness of the film 108 deposited on the substrate 100. To further illustrate, when the nano objects 104 are preferably in a range between about 0.01 μm and about 1 μm with a thin deposited film 108 in a range preferably between about 10 nm and about 1 micron, the film 108 has a higher degree of ordering. Furthermore, if the nano objects 104 are longer (i.e. 2 μm or more in length), a nano object film having a polycrystalline structure tends to form with well-ordered domains and partial alignment of neighboring domains.
  • Upon formation, the carbon nanotube film 108 displays anisotropic polarization of individual carbon nanotubes. The individual carbon nanotubes also demonstrate long-range orientational ordering. As those skilled in the art will appreciate, the electrical conductivity of the film 108 is higher when measured parallel to the alignment direction as opposed to being perpendicular with the alignment direction.
  • In addition, the substrate 100 may have a plurality of shapes in addition to the planar configuration shown with respect to the Figures. For example, the substrate 100 may also include a curved surface, a sandwich structure or the like. In embodiments where a multi-planar substrate is used, electrophoresis may be used to deposit the film 108 onto the substrate 100, as more fully discussed with reference to commonly owned application Ser. No. 09/996,695 filed on Nov. 30, 2001, the specification of which is herein incorporated by reference in its entirety.
  • One advantage of present subject matter includes strong bonding and selectivity of the nano objects 104 to the substrate 100. The nano objects 104 are both mechanically and chemically stable in certain solvents. The stability and selectivity of the self assembled nano objects are attractive from a fabrication standpoint and for use in device applications. To further illustrate, when nano tubes are carbon nanotubes and a substrate which includes glass and chromium is used, the nano objects bond strongly to the substrate. In this example, the nano objects may not be removed by mechanical scratching or through the use of a solvent such as acetone. Nonetheless, the nano objects may be removed by washing or sonication in water. When the nano objects are removed through the use of water, water is stirred into a suspension, such as the suspension 102, and the nano objects, such as the film 108, separate into smaller free standing membranes which float on a surface of the water.
  • Now with reference to FIG. 5, FIG. 5 illustrates a method 200 for assembling a macroscopic structure with pre formed carbon nanotubes onto a substrate in accordance with an embodiment of the present subject matter. Initially, in an operation 202, starting materials used for forming the macroscopic structures are processed. For example, turning attention to FIG. 1A and both the suspension 102 and the nano objects 104 shown with respect to the Figure, prior to forming the suspension 102, a user processes the nano objects 104 and the substrate 100. During the operation 202, the SWNT bundles 104 are etched to controlled lengths by sonication in concentrated sulfuric and nitric acids after purification by reflux in hydrogen peroxide and filtration. Upon etching, the SWNT bundles are rinsed in de-ionized water and annealed at 200° C. in a 10 −6 torr dynamic vacuum to form the nano objects 104. It should also be noted that if the user desires to pattern the carbon nano object film deposition onto a substrate, the user patterns hydrophobic regions and hydrophilic regions onto the substrate, as discussed with reference to FIG. 1B and the substrate 100. Once a user processes the starting materials to be used for the formation of the carbon nano object film, an operation 204 is performed, as shown with reference to FIG. 5.
  • During the operation 204, the suspension is formed with the starting materials. The user admixes the processed starting materials at a given concentration with a solution in order to form the suspension. Returning to the example and FIG. 1A, the user admixes the nano objects 104 with de-ionized water such that the concentration of the nano objects 104 within the suspension 102 is 1.0 mg/mL in this example. Upon formation of the suspension with the starting materials, the method 200 performs an operation 206.
  • During the operation 206, a user inserts a substrate into the suspension. Once the user inserts the substrate into the suspension, an operation 208 is performed. During the operation 208, the suspension evaporates, thereby forming a nano object film on a surface of the substrate. Turning back to the example and FIG. 2, upon submersion of the substrate 100 into the suspension 102 in the operation 206, the suspension 102 begins evaporation in the operation 208. As previously discussed, as the suspension 102 evaporates, the film 108 deposits on the substrate 100, thereby forming a macroscopic structure with the preformed nano objects 104 in accordance with an embodiment of the present subject matter. In one embodiment of the present subject matter, the substrate 100 may be annealed in a vacuum at a temperature in a range preferably between 100° C. and about 500° C.
  • Now making reference to FIG. 6A, FIG. 6A illustrates a method for assembling pre-formed nano objects into a crystal or a membrane in accordance with an embodiment of the present subject matter. The method comprises processing the nano objects so that they form a stable suspension or solution in a suitable solvent as discussed earlier. A processed nano object 610 is mixed with a solvent 600 to form a suspension or a solution in a container 620 that does not attract the nano objects 610, such as TEFLON® or the like if the nano objects are hydrophilic. Preferably, a seed crystal 630 comprising the same nano objects or similar materials as the nano object 610 is either submersed in the solution or touches the surface of the solution. When the processed nano objects 610 are carbon nanotubes, the solvent 600 can be water and preferably de-ionized water. The temperature or the pH value of the suspension or solution is changed after contact of the seed crystal 620 with the solution to bring it to super-saturation. The nano objects assemble in the liquid or around the seed crystal 630 to form a crystal 640 (shown with reference to FIG. 6B). It should be noted that when a seed crystal is used, the seed crystal may be slowly withdrawn from the solution such that nano objects in the solution assemble around a lower surface of the seed crystal 630. The nano objects 610 assemble around the seed crystal 630 thereby forming a crystal 640, as shown with respect to FIG. 6B. The nano objects 610 form around the seed crystal 630 such that a structure of the crystal 640 is the same as a structure of the seed crystal 630. Additionally, the crystal 640 may have a thickness in a range preferably between about 1 nanometer and about 10 microns. Moreover, the area of the freestanding membrane is in a range between 1 micron.times.1 micron and 10 cm.times.10 cm.
  • In a further embodiment of the present subject matter, nano objects may be formed in a vertical structure, as shown with reference to FIG. 7A. FIG. 7A illustrates a method for vertically aligning nano objects 711 into a vertically aligned structure on a substrate surface 760. In this embodiment, nano objects 711 are processed such that the nano objects 711 have a tail 720 and a body 710 which have different affinities toward certain types of solvents. For example, the tails 720 are hydrophobic and the bodies 710 are hydrophilic. In an embodiment of the present subject matter, the tails 720 may be a chemical group comprising hydrocarbons such as C17H35. Additionally, the bodies 710 may be a chemical group comprising carboxylic acid —CO2H. The processed nano objects 711 are dispersed in a solvent 750 which attracts the tail 720 but repels the bodies 710 of the nano objects 711. As such, the nano objects float on a surface of the solvent 750 and more preferably with the tails 720 in contact with the solvent and bodies 710 away from the solvent 750. An example of a solvent which may be used when the tail 720 is composed of hydrocarbons is toluene or the like. It is also possible through applying pressure or external electrical or magnetic field to assist with the assembly of the nano objects 711 on the surface of the solvent 750.
  • Upon dispersion of the nano objects 711 within the solvent 750, a substrate 760 with a surface 730 having the same affinity as the tails 720 is submersed into a container 740 that includes the solvent 750. After submersing the substrate 760 into the solvent 750, the substrate 760 is withdrawn from the solvent 750. Upon withdrawing the substrate 760 from the solvent 750, the nano objects 711 deposit on the substrate 760 with the tails 720 bonded to the surface 730 and longitudinal axes of the nano objects 711 vertically aligned with respect to the surface 730 of the substrate 760.
  • In one example, the nano objects 711 can be carbon nano tubes made hydrophilic by oxidation in acid. A hydrophobic chemical group can be attached to the ends of the carbon nano tubes 711 that are open after the oxidation process. In this example, the substrate may be glass coated with a layer of hydrophobic chemicals such that the carbon nano tubes vertically align with the structure. The vertically aligned structure is useful, for example, as sensors which detect biological systems, chemicals or gases. The vertically aligned structure may also be useful as an electron field emission cathode. It should be noted that it is also possible to make bodies of carbon nanotubes hydrophobic and tails of carbon nanotubes hydrophilic. A vertically aligned structure can also be formed using this type of carbon nanotube. In addition, in this embodiment, the solvent 650 may be hydrophilic. Thus, the hydrophilic tails attach to the surface 730 such that longitudinal axes of the nano objects are perpendicular to the surface 730.
  • Now turning attention to FIG. 8A, FIG. 8A discloses assembled preformed nano objects which form a multi-layered structure in accordance with an embodiment of the present subject matter. A self-assembled nano object film 810A is first deposited on a substrate 830. After deposition, the substrate 830 is removed from a solution having nano objects which formed the self-assembled nano object film 810A. A second material 820A is then coated on the surface of the self-assembled nano objects 810A on the substrate. The second material may be coated onto the self assembled nano object film 810A using a variety of techniques such as spin-coating, spray, electrophoresis, evaporation or sputtering. The material 820A has the same affinity to the self-assembled nano object film 810A as a surface of the substrate. An example of the type of material which may be used for the material 820A includes polymers, metals, ceramics, semiconductors, inorganic materials, organic materials, biological materials or the like.
  • The substrate 830 is re-submersed into the solution containing the nano objects to form a nano object film 810B similar to the nano object film 810A. The process is repeated until a multi-layer structure with a desired thickness and a desired number of repeating layers, e.g., layers 820B and 810C, are obtained as shown with reference to FIG. 8A. Alternatively, a third material 860 can be deposited on top of the second layer 850 to form a tri-layer structure as shown with respect to FIG. 8B, the structure of which may be used as a thin film re-chargeable battery.
  • A first layer electrode of the re-chargeable battery is carbon nanotubes 840 which are deposited on a conducting surface 830. The second layer 850 is an electrolyte material that can be deposited over the carbon nanotubes 840 using any suitable technique such as evaporation, pulsed laser deposition, sputtering or the like. A third layer 860 is a second electrode of the rechargeable battery which can be LixMnO4 or LixCO2. The third layer 860 can be deposited by any suitable technique including evaporation, pulsed laser deposition, sputtering or the like. The multi-layer structure can then be used as a re-chargeable battery or as a fuel cell.
  • In another embodiment of this subject matter, carbon nanotubes are assembled into a structure which can be used as an electron field emission cathode for applications such as field emission flat panel displays. SWNTs are first synthesized by the laser ablation method and then raw materials are purified. The average bundle length is then reduced from >10 μm to ˜0.5 μm by, for example, sonication in a mixture of HNO3 and H2SO4 for 30 hours. The short SWNTs are then rinsed in deionized water and annealed at 200° C. in 106 torr dynamic vacuum before use. A homogeneous suspension of shortened SWNTs is stabilized in de-ionized water at a nanotube concentration of 1.0 mg/mL.
  • Now making reference to FIG. 9A, FIG. 9A illustrates a patterned substrate 900 in accordance with an embodiment of the present subject matter. Initially, a thin layer of photoresist is spin-coated onto a top surface of the glass slide 900. A photo mask with periodic lines (less than 100 micron width) is placed on top of the glass surface coated with the photoresist. After placement of the photo mask over the glass surface, an ultraviolet light source is used to expose the glass. The exposed glass is then developed in chemicals to remove the photoresist materials that are exposed to UV light. The developed glass forms a patterned glass substrate with periodic hydrophobic regions which are covered by the photoresist 910 and hydrophilic regions 920 which are free of the photoresist. The glass with patterned hydrophobic and hydrophilic regions is submersed into the previously described SWNT/water suspension at room temperature. It should be noted that SWNTs having an aspect ratio preferably of about 10 and a bundle length in a range preferably between about 300 nm and about 1 micron may be used. As the water evaporates, SWNTs 930 deposit on the hydrophilic region of the glass slide.
  • In a next operation, the glass slide coated with the SWNTs 930 is washed in a suitable solvent such as acetone, methanol, ethanol, buffered hydrochloric acid or the like. During the washing process, the remaining photoresist is removed and the SWNTs 930 remain on the glass surface. After removing from the remaining photoresist, the glass slide is heated in either air or vacuum at 200° C. to remove the residual solvent to achieve SWNTs 930, as shown with reference to FIG. 9B. The width of the SWNTs 930 can be as small as 0.1 micron and as wide as 1 cm or larger. It should be noted that the SWNTs 930 may have other patterns in addition to that shown with reference to FIG. 9B, such as squares, circles, dots or any other geometry that can be patterned by photolithography.
  • Electrical contacts 950 are coupled with each of the SWNTs 930 on the glass substrate 900 as shown with reference to FIG. 9B. When the structure shown with respect to FIG. 9B is placed inside a vacuum system and subjected to an electrical field in the order of 1-10V/micron, electrons emit from the carbon nanotubes 930. When a phosphor screen 960 (FIG. 9C) is placed above the carbon nanotube structure, images can be obtained by controlling where the electrons emit and at which location the electrons strike the phosphor thereby forming a field emission flat display. It should be noted that a field emission cathode formed in accordance with the present subject matter may have a threshold electrical field in a range between about 1V/micron to about 5V/micron for an emission current density of 1 mA/cm2.
  • The present subject matter provides a method for the self assembly of preformed nano objects onto a substrate. As may be appreciated, the present subject matter allows for higher packing densities than those techniques used in the prior art. Forming nano structures with filtration techniques form nanotube papers which have a lower packing density than that of nano structures formed in accordance with the present subject matter. In addition, the present subject matter may be performed at room temperature as previously mentioned. The efficient room temperature deposition process provides an attractive alternative to chemical vapor deposition techniques, more specifically in display applications having low melting temperatures.
  • Variations of the above-described exemplary method, as well as additional methods, are evident in light of the above-described devices of the present subject matter. Although the present subject matter has been described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without department from the spirit and scope of the subject matter as defined in the appended claims. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation.

Claims (49)

  1. 1. A method for assembling nano objects onto a macroscopic structure, the method comprising:
    (a) processing nano objects to a desired aspect ratio and chemical functionality;
    (b) admixing the processed nano objects with a solvent to form a suspension, the suspension having a concentration, a temperature and a pH level;
    (c) submersing a substrate into the suspension; and
    (d) changing the concentration to control deposition of the nano objects onto the substrate, thereby assembling the macroscopic structure onto the substrate.
  2. 2. The method of claim 1, wherein the nano objects comprise single wall carbon nanotubes (SWNTs) or single wall carbon nanotube bundles.
  3. 3. The method of claim 1, wherein the nano objects comprise multi wall carbon nanotubes (MWNTs).
  4. 4. The method of claim 1, wherein the nano objects comprise a mixture of single wall carbon nanotubes (SWNTs) and multi wall carbon nanotubes (MWNTs).
  5. 5. The method of claim 2, wherein the operation of processing the nano objects further comprises:
    (e) synthesizing the carbon nanotubes;
    (f) purifying the carbon nanotubes; and
    (g) modifying both a length of the carbon nano tubes and at least one chemical property of the carbon nano tubes.
  6. 6. The method of claim 2, wherein the operation of processing the nano objects further comprises:
    (e) synthesizing the SWNTs by a process selected from the group consisting of laser ablation, arc discharge, chemical vapor deposition, and pyrolysis;
    (f) purifying the SWNTs by selective oxidation and/or filtration; and
    (g) reducing an aspect ratio of the SWNTs by sonication in acid or mechanical cutting.
  7. 7. The method of claim 2, wherein the operation of processing the nano objects further comprises:
    (e) synthesizing the SWNTs by a process selected from the group consisting of laser ablation, arc discharge, chemical vapor deposition, and pyrolysis;
    (f) purifying the SWNTs by selective oxidation and/or filtration; and
    (g) chemically modifying the SWNTs.
  8. 8. The method of claim 6, wherein a length of the processed SWNTs is in a range between about 0.1 micron and about 10 microns.
  9. 9. The method of claim 2, wherein the solvent is selected from the group consisting of water, alcohol, and combinations thereof.
  10. 10. The method of claim 9, wherein the concentration of the suspension of carbon nanotubes in water is in a range between about 0.01 grams of carbon nanotube per liter of water and about 10.0 grams of carbon nanotube per liter of water.
  11. 11. The method of claim 2, wherein the substrate comprises a hydrophilic region and a hydrophobic region such that the SWNTs deposit on the hydrophilic region of the substrate.
  12. 12. The method of claim 11, wherein the substrate comprises hydrophilic glass patterned with a hydrophobic material.
  13. 13. The method of claim 12, wherein the hydrophobic material is selected from the group consisting of a polystyrene, a photoresist, a mono-layer of hydrophobic functional groups, and combinations thereof.
  14. 14. The method of claim 1, wherein the method further comprises patterning a surface of the substrate such that the substrate surface comprises a first region and a second region where the first region has an affinity to the nano objects and the second region has no affinity to the nano objects, where changing the concentration of the suspension deposits the nano objects on the first region of the substrate surface.
  15. 15. The method of claim 1, wherein the substrate has a planar configuration.
  16. 16. The method of claim 1, wherein the substrate has a curved configuration.
  17. 17. The method of claim 1, wherein the operation of changing the concentration of the suspension further comprises changing the concentration of the suspension by gradual evaporation of the solvent such that the nano objects deposit on the substrate along an air/liquid/substrate triple line of the substrate.
  18. 18. The method of claim 17, wherein the operation of submersing the substrate into the suspension further comprises submerging the substrate into the suspension in a vertical orientation relative to the suspension.
  19. 19. The method of claim 18, wherein longitudinal axes of the nano objects align in a direction of the air/liquid/substrate triple line.
  20. 20. The method of claim 1, further comprising:
    (e) removing the substrate from the suspension;
    (f) depositing a second material onto the nano objects assembled on the substrate; and
    (g) repeating operations (c) through (e) thereby forming a multi layer structure.
  21. 21. The method of claim 20, wherein the second material is selected from the group consisting of a metal, a semiconductor, a polymer, an inorganic material, an organic material, a biological material, and combinations thereof.
  22. 22. A multilayer structure prepared by the method of claim 20.
  23. 23. The multilayer structure of claim 22, wherein the multi layer structure is selected from the group consisting of an electrode, an electrolyte for a battery, and a fuel cell.
  24. 24. The multilayer structure of claim 22, wherein the multi-layer structure is selected from the group consisting of a capacitor, a super-capacitor, an electronic device, and a sensor.
  25. 25. A method for assembling pre-formed nano objects into a macroscopic structure, the method comprising:
    (a) processing the nano objects, wherein the processing of the nano object comprises:
    (i) synthesizing the pre-formed nano objects, where the pre-formed nano objects are single wall carbon nanotube (SWNT) bundles;
    (ii) purifying the SWNT bundles by reflux in a hydrogen peroxide solution and filtering the SWNT bundles; and
    (iii) cutting the purified SWNT bundles by reacting the SWNTs with HNO3 and/or H2SO4, and with ultra-sonication;
    (b) forming a suspension by admixture of the nano objects with a solution;
    (c) inserting a substrate into the suspension; and
    (d) gradually removing the substrate from the suspension during which the nano objects from the suspension deposit on the surface of the substrate.
  26. 26. The method of claim 25, wherein the substrate comprises a material selected from the group consisting of glass, quartz, aluminum, chromium, tin, and silicon or any other substrate with a hydrophilic coating on a surface of the substrate.
  27. 27. The method of claim 25, the substrate further comprising a hydrophobic coating, the hydrophilic coating and the hydrophobic coating forming a pattern on the substrate wherein the processed pre-formed nano objects form onto the substrate at the hydrophilic coating thereby forming a pattern corresponding to the pattern formed by the hydrophilic coating and the hydrophobic coating.
  28. 28. A method for assembling pre-formed nano objects into a macroscopic structure, the method comprising:
    (a) processing the nano objects;
    (b) forming a suspension by admixture of the nano objects with a solution;
    (c) inserting a substrate into the suspension; and
    (d) gradually removing the substrate from the suspension during which the nano objects from the suspension deposit on the surface of the substrate, wherein the nano objects form on an air/liquid/substrate triple line of the substrate.
  29. 29. A method for assembling nano objects into a free-standing macroscopic structure, the method comprising:
    (a) processing the nano objects such that the nano objects disperse or dissolve in a solvent;
    (b) admixing the processed nano objects with the solvent to form a stable suspension or a solution in a container that does not attract the processed nano objects;
    (c) submersing a seed-crystal into the suspension; and
    (d) changing a concentration of the suspension to bring the suspension into super-saturation such that the processed nano objects assemble into a free-standing macroscopic structure.
  30. 30. The method of claim 29, wherein the nano objects assemble into the macroscopic structure around the seed crystal such that a structure of the macroscopic structure is the same as a structure of the seed crystal.
  31. 31. The method of claim 29, wherein a thickness of the freestanding macroscopic structure is in a range between about 1 nanometer to about 10 microns.
  32. 32. The method of claim 29, wherein an area of the free-standing macroscopic structure is in a range between about 1 micron×1 micron and about 10 cm×10 cm.
  33. 33. The method of claim 29, wherein the nano objects are selected from the group consisting of single wall carbon nanotubes and multi wall carbon nanotubes.
  34. 34. The method of claim 29, wherein the nano objects comprise nanowires/nanorods, and wherein the nanowires/nanorods comprise at least one material selected from the group consisting of carbon, silicon, germanium, oxygen, boron, nitrogen, sulfur, phosphorus, and metal.
  35. 35. A free-standing macroscopic structure assembled by the method of claim 29.
  36. 36. A method for fabricating electron field emission cathodes by self-assembly of pre-formed nano objects, the method comprising:
    (a) processing the nano objects such that the nano objects disperse or dissolve in a solvent;
    (b) admixing the processed nano objects with the solvent to form a suspension;
    (c) submersing a substrate into the suspension; and
    (d) changing a concentration of the suspension to assemble the processed nano objects on certain regions of the substrate surface thereby fabricating the electron field emission cathode,
    wherein the substrate comprises a region A and a region B where the region A attracts the processed nano objects and the region B does not attract the processed nano objects where the nano objects deposit on the region A upon changing the concentration of the suspension.
  37. 37. The method of claim 36, wherein the nano objects comprise carbon nanotubes.
  38. 38. The method of claim 36, wherein a smallest lateral dimension of the region A is at least about 100 nm.
  39. 39. The method of claim 36, wherein the substrate comprises hydrophilic glass.
  40. 40. The method of claim 39, further comprising coating the substrate with a region of a hydrophobic polymer such that the region of the hydrophobic polymer forms the region B and an uncoated region of the substrate forms the region A.
  41. 41. The method of claim 40, further comprising removing the region of the hydrophobic polymer after deposition of the nano objects.
  42. 42. The method of claim 40, wherein the hydrophobic polymer is removed by washing in a solvent selected from the group consisting of acetone, methanol, ethanol, buffered hydrofluoric acid, and combinations thereof.
  43. 43. The method of claim 36, wherein the process further comprises annealing the substrate deposited with the nano-objects at a temperature in a range between about 100° C. and about 500° C. in a vacuum.
  44. 44. The method of claim 36, wherein the nano objects are single wall carbon nanotube bundles with an aspect ratio larger than about 10 and a bundle length in a range between about 300 nm and about 1 micron.
  45. 45. The method of claim 36, wherein the field emission cathode has a threshold electrical field in a range between about 1 V/micron and about 5V/micron for an emission current density of about 1 mA/cm2.
  46. 46. A field emission cathode fabricated by the method of claim 36.
  47. 47. A method for assembling nano objects onto a macroscopic structure, the method comprising:
    (a) processing nano objects to a desired aspect ratio and chemical functionality;
    (b) admixing the processed nano objects with a solvent to form a suspension, the suspension having a concentration, a temperature and a pH level; and
    (c) coating the suspension onto a substrate thereby assembling the macroscopic structure onto the substrate.
  48. 48. The method of claim 47, wherein the operation of coating the suspension onto a substrate further comprises a coating procedure selected from the group consisting of spin coating, spraying, and electrophoresis.
  49. 49. The method for assembling nano objects onto a macroscopic structure as recited in claim 47, wherein the substrate has a first region and a second region where the first region attracts the nano objects and the second region does not attract nano objects.
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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070243493A1 (en) * 2006-04-13 2007-10-18 Tatung Company Method for manufacturing field emission substrate
US20080102213A1 (en) * 2006-01-03 2008-05-01 International Business Machines Corporation Selective placement of carbon nanotubes through functionalization
US20080102201A1 (en) * 2006-10-30 2008-05-01 Samsung Electronics Co., Ltd. Method For Dispersing Nanoparticles and Methods for Producing Nanoparticle Thin Films By Using The Same
WO2011127207A2 (en) * 2010-04-07 2011-10-13 California Institute Of Technology Simple method for producing superhydrophobic carbon nanotube array
WO2012178216A1 (en) * 2011-06-24 2012-12-27 U.S. Army Corps Of Engineers Meso-scale carbon nanotube self-assembled tube structures
US8976507B2 (en) 2011-03-29 2015-03-10 California Institute Of Technology Method to increase the capacitance of electrochemical carbon nanotube capacitors by conformal deposition of nanoparticles
US20150102284A1 (en) * 2012-04-12 2015-04-16 Sol Voltaics Ab Methods of nanowire functionalization, dispersion and attachment
US9050444B2 (en) 2007-07-10 2015-06-09 California Institute Of Technology Drug delivery and substance transfer facilitated by nano-enhanced device having aligned carbon nanotubes protruding from device surface
US9349543B2 (en) 2012-07-30 2016-05-24 California Institute Of Technology Nano tri-carbon composite systems and manufacture
US9368723B2 (en) 2014-02-11 2016-06-14 Wisconsin Alumni Research Foundation Dose-controlled, floating evaporative assembly of aligned carbon nanotubes for use in high performance field effect transistors
US9425405B1 (en) 2015-02-11 2016-08-23 Wisconsin Alumni Research Foundation Continuous, floating evaporative assembly of aligned carbon nanotubes
US9449816B2 (en) 2010-12-10 2016-09-20 California Institute Of Technology Method for producing graphene oxide with tunable gap
US9484543B2 (en) 2007-07-10 2016-11-01 California Institute Of Technology Fabrication of anchored carbon nanotube array devices for integrated light collection and energy conversion

Families Citing this family (143)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6835591B2 (en) * 2001-07-25 2004-12-28 Nantero, Inc. Methods of nanotube films and articles
US7335395B2 (en) * 2002-04-23 2008-02-26 Nantero, Inc. Methods of using pre-formed nanotubes to make carbon nanotube films, layers, fabrics, ribbons, elements and articles
US6706402B2 (en) 2001-07-25 2004-03-16 Nantero, Inc. Nanotube films and articles
US7252749B2 (en) * 2001-11-30 2007-08-07 The University Of North Carolina At Chapel Hill Deposition method for nanostructure materials
US20070014148A1 (en) * 2004-05-10 2007-01-18 The University Of North Carolina At Chapel Hill Methods and systems for attaching a magnetic nanowire to an object and apparatuses formed therefrom
US7455757B2 (en) * 2001-11-30 2008-11-25 The University Of North Carolina At Chapel Hill Deposition method for nanostructure materials
US7147894B2 (en) * 2002-03-25 2006-12-12 The University Of North Carolina At Chapel Hill Method for assembling nano objects
US8907323B2 (en) * 2002-04-23 2014-12-09 Philip D. Freedman Microprocessor assembly
US7037319B2 (en) * 2002-10-15 2006-05-02 Scimed Life Systems, Inc. Nanotube paper-based medical device
GB2395059B (en) 2002-11-05 2005-03-16 Imp College Innovations Ltd Structured silicon anode
JP2006513048A (en) * 2002-12-09 2006-04-20 ザ ユニバーシティ オブ ノース カロライナ アット チャペル ヒルThe University Of North Carolina At Chapel Hill The methods and related articles to collect material comprising nanostructures and classification
US7419601B2 (en) * 2003-03-07 2008-09-02 Seldon Technologies, Llc Nanomesh article and method of using the same for purifying fluids
US20100098877A1 (en) * 2003-03-07 2010-04-22 Cooper Christopher H Large scale manufacturing of nanostructured material
CN1867392B (en) 2003-03-07 2010-06-09 塞尔顿技术公司 Purification of fluids with nanomaterials
US6969690B2 (en) * 2003-03-21 2005-11-29 The University Of North Carolina At Chapel Hill Methods and apparatus for patterned deposition of nanostructure-containing materials by self-assembly and related articles
US7803574B2 (en) 2003-05-05 2010-09-28 Nanosys, Inc. Medical device applications of nanostructured surfaces
US20060122596A1 (en) * 2003-04-17 2006-06-08 Nanosys, Inc. Structures, systems and methods for joining articles and materials and uses therefor
US7972616B2 (en) 2003-04-17 2011-07-05 Nanosys, Inc. Medical device applications of nanostructured surfaces
US7985475B2 (en) * 2003-04-28 2011-07-26 Nanosys, Inc. Super-hydrophobic surfaces, methods of their construction and uses therefor
US7375369B2 (en) * 2003-09-08 2008-05-20 Nantero, Inc. Spin-coatable liquid for formation of high purity nanotube films
US7858185B2 (en) 2003-09-08 2010-12-28 Nantero, Inc. High purity nanotube fabrics and films
US7504051B2 (en) * 2003-09-08 2009-03-17 Nantero, Inc. Applicator liquid for use in electronic manufacturing processes
US20050079552A1 (en) * 2003-10-08 2005-04-14 Hitachi Software Engineering Co., Ltd. Beads with immobilized amphiphilic molecules, method of fabrication thereof, and method of arraying beads for capillary beads-array
US7790331B1 (en) * 2003-10-31 2010-09-07 Hewlett-Packard Development Company, L.P. Fuel cell with film having nanowires therein
US8025960B2 (en) 2004-02-02 2011-09-27 Nanosys, Inc. Porous substrates, articles, systems and compositions comprising nanofibers and methods of their use and production
US7276389B2 (en) * 2004-02-25 2007-10-02 Samsung Electronics Co., Ltd. Article comprising metal oxide nanostructures and method for fabricating such nanostructures
US7671398B2 (en) * 2005-02-23 2010-03-02 Tran Bao Q Nano memory, light, energy, antenna and strand-based systems and methods
US8632699B2 (en) * 2004-04-07 2014-01-21 Eikos, Inc. Fugitive viscosity and stability modifiers for carbon nanotube compositions
JP2007534588A (en) * 2004-04-07 2007-11-29 エイコス・インコーポレーテッド Temporary viscosity for the carbon nanotube composition and stability modifiers
KR20050104840A (en) * 2004-04-29 2005-11-03 삼성에스디아이 주식회사 A carbon nanotube, an emitter comprising the carbon nanotube and an electron emission device comprising the emitter
US7658869B2 (en) 2004-06-03 2010-02-09 Nantero, Inc. Applicator liquid containing ethyl lactate for preparation of nanotube films
US7556746B2 (en) 2004-06-03 2009-07-07 Nantero, Inc. Method of making an applicator liquid for electronics fabrication process
US7879410B2 (en) * 2004-06-09 2011-02-01 Imra America, Inc. Method of fabricating an electrochemical device using ultrafast pulsed laser deposition
CN1313364C (en) * 2004-06-16 2007-05-02 东元奈米应材股份有限公司 Nano carbon tube suspensoid and its manufacturing method
US9346673B2 (en) 2004-06-23 2016-05-24 Samsung Sdi Co., Ltd. Electrode for fuel cell, membrane-electrode assembly for fuel cell comprising the same, fuel cell system comprising the same, and method for preparing the electrode
KR20070030282A (en) * 2004-06-23 2007-03-15 하이페리온 커탤리시스 인터내셔널 인코포레이티드 Functionalized single walled carbon nanotubes
JP2006011296A (en) * 2004-06-29 2006-01-12 Toshiba Corp Polarizing element, method for manufacturing polarizing element, and method for evaluating exposing device
US20060040168A1 (en) * 2004-08-20 2006-02-23 Ion America Corporation Nanostructured fuel cell electrode
KR100578981B1 (en) 2004-09-08 2006-05-12 삼성에스디아이 주식회사 Electrode for fuel cell and the fuel cell system comprising the same
KR20060024564A (en) * 2004-09-14 2006-03-17 삼성에스디아이 주식회사 Method for aligning carbon nanotubes and method of manufacturing field emission device using the same
WO2006121461A3 (en) 2004-09-16 2008-09-25 Claude L Bertin Light emitters using nanotubes and methods of making same
US7717001B2 (en) 2004-10-08 2010-05-18 Sdc Materials, Inc. Apparatus for and method of sampling and collecting powders flowing in a gas stream
US20060091123A1 (en) * 2004-10-28 2006-05-04 Hon Hai Precision Industry Co., Ltd. Method for hydrophilic treatment of a surface of a material
CN100557842C (en) 2004-11-01 2009-11-04 毫微纤维公司 Soft lift-off of organic nanofibres
US7553341B2 (en) * 2004-11-24 2009-06-30 The Regents Of The University Of California High power density supercapacitors with carbon nanotube electrodes
KR100658675B1 (en) 2004-11-26 2006-12-15 삼성에스디아이 주식회사 Electrode for fuel cell, fuel cell comprising the same, and method for preparing the smme
CA2590684A1 (en) * 2004-12-16 2006-06-22 Nantero, Inc. Aqueous carbon nanotube applicator liquids and methods for producing applicator liquids thereof
US7635518B1 (en) 2005-02-04 2009-12-22 University Of Louisiana At Lafayette Dendritic magnetic nanostructures and method for making same
WO2006084413A1 (en) * 2005-02-14 2006-08-17 Tex-A-Tec Ag Method for coating support materials with nanoparticle-containing dispersions
US7597950B1 (en) * 2005-02-28 2009-10-06 Massachusetts Institute Of Technology Nanoparticles having sub-nanometer features
US7218004B2 (en) * 2005-03-11 2007-05-15 Hewlett-Packard Development Company, L.P. Fusing nanowires using in situ crystal growth
WO2006101659A3 (en) * 2005-03-17 2006-11-23 Jiajie Diao Method of making nanoparticle wires
US8155262B2 (en) 2005-04-25 2012-04-10 The University Of North Carolina At Chapel Hill Methods, systems, and computer program products for multiplexing computed tomography
CN101296658B (en) * 2005-04-25 2011-01-12 北卡罗来纳大学查珀尔希尔分校 X-ray imaging system using temporal digital signal processing
US20060240218A1 (en) * 2005-04-26 2006-10-26 Nanosys, Inc. Paintable nonofiber coatings
US7479654B2 (en) 2005-05-09 2009-01-20 Nantero, Inc. Memory arrays using nanotube articles with reprogrammable resistance
WO2006138263A3 (en) * 2005-06-13 2007-10-18 Electrox Corp System and method for the manipulation, classification sorting, purification, placement, and alignment of nano fibers using electrostatic forces and electrographic techniques
US7118784B1 (en) * 2005-06-27 2006-10-10 The Regents Of The University Of California Method and apparatus for controlling nucleation in self-assembled films
KR100684797B1 (en) 2005-07-29 2007-02-20 삼성에스디아이 주식회사 Electrode for fuel cell, membrane-electrode assembly comprising same and fuel cell system comprising same
KR100818383B1 (en) * 2005-08-05 2008-04-01 마이티테크, 인코퍼레이티드. Method for Preparing a nanostructured composite electrode through electrophoretic deposition and a product prepared thereby
JP4544530B2 (en) * 2005-09-05 2010-09-15 ジャパンスーパーコンダクタテクノロジー株式会社 Method of manufacturing a Cnt array material
EP1964188A4 (en) * 2005-09-06 2010-06-16 Nantero Inc Carbon nanotubes for the selective transfer of heat from electronics
CN100482583C (en) * 2005-09-09 2009-04-29 鸿富锦精密工业(深圳)有限公司;鸿海精密工业股份有限公司 Method of processing carbon nano tube
KR100776359B1 (en) * 2005-10-18 2007-11-15 부산대학교 산학협력단 Manufacturing method of field emission display which composing carbon nanotubes field emitter array
KR100682381B1 (en) * 2005-11-16 2007-02-07 광주과학기술원 Single-wall carbon nanotube-egg white protein composite and preparation thereof
GB0601318D0 (en) 2006-01-23 2006-03-01 Imp Innovations Ltd Method of etching a silicon-based material
GB0601319D0 (en) 2006-01-23 2006-03-01 Imp Innovations Ltd A method of fabricating pillars composed of silicon-based material
US20090278556A1 (en) * 2006-01-26 2009-11-12 Nanoselect, Inc. Carbon Nanostructure Electrode Based Sensors: Devices, Processes and Uses Thereof
WO2007089550A2 (en) 2006-01-26 2007-08-09 Nanoselect, Inc. Cnt-based sensors: devices, processes and uses thereof
KR100739943B1 (en) 2006-01-31 2007-07-09 삼성에스디아이 주식회사 Fabrication method of electrode conducting material for a rechargeable battery and lithium rechargeable battery including the conducting material
JP4982676B2 (en) * 2006-02-15 2012-07-25 ニッタ株式会社 Electron emitter
US8628819B2 (en) 2006-02-24 2014-01-14 GM Global Technology Operations LLC Method of depositing a nanoparticle coating on a bipolar plate and removing the nanoparticle coating from the lands of the bipolar plate
US20070207182A1 (en) * 2006-03-06 2007-09-06 Jan Weber Medical devices having electrically aligned elongated particles
JP4163250B2 (en) * 2006-03-10 2008-10-08 松下電器産業株式会社 How to Mount an anisotropic shape member
JP5108240B2 (en) * 2006-03-20 2012-12-26 トヨタ自動車株式会社 Method for manufacturing a fuel cell and a fuel cell
US8343581B2 (en) * 2006-04-28 2013-01-01 Regents Of The University Of California Synthesis of pure nanotubes from nanotubes
US8189893B2 (en) 2006-05-19 2012-05-29 The University Of North Carolina At Chapel Hill Methods, systems, and computer program products for binary multiplexing x-ray radiography
US7393699B2 (en) 2006-06-12 2008-07-01 Tran Bao Q NANO-electronics
US20110255212A1 (en) * 2006-09-01 2011-10-20 Battelle Memorial Institute Carbon Nanotube Nanocomposites, Methods of Making Carbon Nanotube Nanocomposites, and Devices Comprising the Nanocomposites
CN1987454B (en) 2006-10-31 2011-01-12 成都夸常医学工业有限公司 Nano structure component containing oriented nano structure functional zone and its preparing and applying method
CN101632185B (en) * 2007-02-12 2011-05-18 毫微纤维公司 Storage and transfer of organic nanofibers
US8893651B1 (en) 2007-05-11 2014-11-25 SDCmaterials, Inc. Plasma-arc vaporization chamber with wide bore
GB0709165D0 (en) 2007-05-11 2007-06-20 Nexeon Ltd A silicon anode for a rechargeable battery
JP2008300190A (en) * 2007-05-31 2008-12-11 Fuji Heavy Ind Ltd Manufacturing method of electrode
GB0713895D0 (en) 2007-07-17 2007-08-29 Nexeon Ltd Production
GB0713896D0 (en) 2007-07-17 2007-08-29 Nexeon Ltd Method
GB0713898D0 (en) 2007-07-17 2007-08-29 Nexeon Ltd A method of fabricating structured particles composed of silcon or a silicon-based material and their use in lithium rechargeable batteries
JP2009057249A (en) * 2007-08-31 2009-03-19 Sumitomo Electric Ind Ltd Carbon structure, composite member and its production method
JP2010537793A (en) * 2007-09-06 2010-12-09 ボストン サイエンティフィック リミテッド Medical devices containing silicates and carbon particles
US8575059B1 (en) 2007-10-15 2013-11-05 SDCmaterials, Inc. Method and system for forming plug and play metal compound catalysts
CN101425380B (en) * 2007-11-02 2013-04-24 清华大学 Super capacitor and preparing method therefor
US8319002B2 (en) 2007-12-06 2012-11-27 Nanosys, Inc. Nanostructure-enhanced platelet binding and hemostatic structures
CN101883545B (en) 2007-12-06 2013-08-07 纳诺西斯有限公司 Resorbable nanoenhanced hemostatic structures and bandage materials
US8308930B2 (en) * 2008-03-04 2012-11-13 Snu R&Db Foundation Manufacturing carbon nanotube ropes
WO2009128800A1 (en) * 2008-04-17 2009-10-22 The Board Of Trustees Of The University Of Illinois Silicon nanowire and composite formation and highly pure and uniform length silicon nanowires
CA2723486A1 (en) * 2008-05-07 2010-04-01 Nanocomp Technologies, Inc. Nanostructure composite sheets and methods of use
USD627900S1 (en) 2008-05-07 2010-11-23 SDCmaterials, Inc. Glove box
CA2765337C (en) * 2008-06-13 2016-05-17 Fablab Inc. A system and method for fabricating macroscopic objects, and nano-assembled objects obtained therewith
US8673258B2 (en) * 2008-08-14 2014-03-18 Snu R&Db Foundation Enhanced carbon nanotube
US8357346B2 (en) * 2008-08-20 2013-01-22 Snu R&Db Foundation Enhanced carbon nanotube wire
US8021640B2 (en) * 2008-08-26 2011-09-20 Snu R&Db Foundation Manufacturing carbon nanotube paper
US7959842B2 (en) * 2008-08-26 2011-06-14 Snu & R&Db Foundation Carbon nanotube structure
GB2464158B (en) 2008-10-10 2011-04-20 Nexeon Ltd A method of fabricating structured particles composed of silicon or a silicon-based material and their use in lithium rechargeable batteries
GB2464157B (en) 2008-10-10 2010-09-01 Nexeon Ltd A method of fabricating structured particles composed of silicon or a silicon-based material
US7915637B2 (en) * 2008-11-19 2011-03-29 Nantero, Inc. Switching materials comprising mixed nanoscopic particles and carbon nanotubes and method of making and using the same
US8540889B1 (en) 2008-11-19 2013-09-24 Nanosys, Inc. Methods of generating liquidphobic surfaces
US8600003B2 (en) 2009-01-16 2013-12-03 The University Of North Carolina At Chapel Hill Compact microbeam radiation therapy systems and methods for cancer treatment and research
WO2010120813A3 (en) * 2009-04-13 2011-01-13 Applied Materials, Inc. Composite materials containing metallized carbon nanotubes and nanofibers
GB2470056B (en) 2009-05-07 2013-09-11 Nexeon Ltd A method of making silicon anode material for rechargeable cells
GB2470190B (en) 2009-05-11 2011-07-13 Nexeon Ltd A binder for lithium ion rechargeable battery cells
US9853292B2 (en) 2009-05-11 2017-12-26 Nexeon Limited Electrode composition for a secondary battery cell
CN101944403A (en) * 2009-07-08 2011-01-12 群康科技(深圳)有限公司;群创光电股份有限公司 Electric-conducting plate and manufacturing method thereof
KR101564330B1 (en) 2009-10-15 2015-10-29 삼성전자주식회사 Solar cell including organic nanowires
US8545652B1 (en) 2009-12-15 2013-10-01 SDCmaterials, Inc. Impact resistant material
US9039916B1 (en) 2009-12-15 2015-05-26 SDCmaterials, Inc. In situ oxide removal, dispersal and drying for copper copper-oxide
US9149797B2 (en) 2009-12-15 2015-10-06 SDCmaterials, Inc. Catalyst production method and system
US8652992B2 (en) 2009-12-15 2014-02-18 SDCmaterials, Inc. Pinning and affixing nano-active material
US8803025B2 (en) 2009-12-15 2014-08-12 SDCmaterials, Inc. Non-plugging D.C. plasma gun
US8470112B1 (en) 2009-12-15 2013-06-25 SDCmaterials, Inc. Workflow for novel composite materials
US9126191B2 (en) 2009-12-15 2015-09-08 SDCmaterials, Inc. Advanced catalysts for automotive applications
US8557727B2 (en) 2009-12-15 2013-10-15 SDCmaterials, Inc. Method of forming a catalyst with inhibited mobility of nano-active material
US20110203632A1 (en) * 2010-02-22 2011-08-25 Rahul Sen Photovoltaic devices using semiconducting nanotube layers
CN101798115B (en) * 2010-02-26 2012-08-15 中山大学 Preparation method of ternary oxysalt compound micro-nano material
FR2956991B1 (en) * 2010-03-02 2012-11-02 Commissariat Energie Atomique A method of depositing a layer of organized particles on a substrate
GB201005979D0 (en) 2010-04-09 2010-05-26 Nexeon Ltd A method of fabricating structured particles composed of silicon or a silicon-based material and their use in lithium rechargeable batteries
GB201009519D0 (en) 2010-06-07 2010-07-21 Nexeon Ltd An additive for lithium ion rechargeable battery cells
GB201014706D0 (en) 2010-09-03 2010-10-20 Nexeon Ltd Porous electroactive material
US8358739B2 (en) 2010-09-03 2013-01-22 The University Of North Carolina At Chapel Hill Systems and methods for temporal multiplexing X-ray imaging
GB201014707D0 (en) 2010-09-03 2010-10-20 Nexeon Ltd Electroactive material
US8669202B2 (en) 2011-02-23 2014-03-11 SDCmaterials, Inc. Wet chemical and plasma methods of forming stable PtPd catalysts
WO2013028575A1 (en) 2011-08-19 2013-02-28 Sdc Materials Inc. Coated substrates for use in catalysis and catalytic converters and methods of coating substrates with washcoat compositions
CN102502485A (en) * 2011-11-10 2012-06-20 中山大学 Technical process for imaging nano materials
US8764681B2 (en) 2011-12-14 2014-07-01 California Institute Of Technology Sharp tip carbon nanotube microneedle devices and their fabrication
US9156025B2 (en) 2012-11-21 2015-10-13 SDCmaterials, Inc. Three-way catalytic converter using nanoparticles
US9511352B2 (en) 2012-11-21 2016-12-06 SDCmaterials, Inc. Three-way catalytic converter using nanoparticles
CN103227102B (en) * 2013-04-17 2016-06-15 北京大学 One nanoparticle self-assembly method for producing patterned
US20140363643A1 (en) * 2013-06-07 2014-12-11 International Business Machines Corporation Surface-Selective Carbon Nanotube Deposition Via Polymer-Mediated Assembly
WO2015013545A1 (en) 2013-07-25 2015-01-29 SDCmaterials, Inc. Washcoats and coated substrates for catalytic converters
CA2926135A1 (en) 2013-10-22 2015-04-30 SDCmaterials, Inc. Compositions of lean nox trap
JP2016536120A (en) 2013-10-22 2016-11-24 エスディーシーマテリアルズ, インコーポレイテッド Catalyst design for heavy duty diesel combustion engine
US9687811B2 (en) 2014-03-21 2017-06-27 SDCmaterials, Inc. Compositions for passive NOx adsorption (PNA) systems and methods of making and using same
CN104386647B (en) * 2014-10-27 2016-04-13 暨南大学 A method of alignment halloysite nanotube coating and its application
CN105206485B (en) * 2015-08-19 2016-09-07 宁波工程学院 P-doped SiC nanowires application field emission cathode material

Citations (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4249988A (en) * 1978-03-15 1981-02-10 Western Electric Company, Inc. Growing crystals from a melt by controlling additions of material thereto
US5078830A (en) * 1989-04-10 1992-01-07 Mitsubishi Metal Corporation Method for growing single crystal
US5322591A (en) * 1991-03-26 1994-06-21 The United States Of America As Represented By The Secretary Of The Air Force Hydrothermal growth on non-linear optical crystals
US5801092A (en) * 1997-09-04 1998-09-01 Ayers; Michael R. Method of making two-component nanospheres and their use as a low dielectric constant material for semiconductor devices
US5879836A (en) * 1993-09-10 1999-03-09 Hyperion Catalysis International Inc. Lithium battery with electrodes containing carbon fibrils
US6008138A (en) * 1996-03-19 1999-12-28 Robert Bosch Gmbh Process for making micromechanical structures
US6097138A (en) * 1996-09-18 2000-08-01 Kabushiki Kaisha Toshiba Field emission cold-cathode device
US6197399B1 (en) * 1998-03-13 2001-03-06 Kabushiki Kaisha Toshiba Recording medium and method of manufacturing the same
US6250984B1 (en) * 1999-01-25 2001-06-26 Agere Systems Guardian Corp. Article comprising enhanced nanotube emitter structure and process for fabricating article
US6264741B1 (en) * 1998-11-25 2001-07-24 Sandia Corporation Self-assembly of nanocomposite materials
US6277740B1 (en) * 1998-08-14 2001-08-21 Avery N. Goldstein Integrated circuit trenched features and method of producing same
US6277318B1 (en) * 1999-08-18 2001-08-21 Agere Systems Guardian Corp. Method for fabrication of patterned carbon nanotube films
US6280697B1 (en) * 1999-03-01 2001-08-28 The University Of North Carolina-Chapel Hill Nanotube-based high energy material and method
US6297592B1 (en) * 2000-08-04 2001-10-02 Lucent Technologies Inc. Microwave vacuum tube device employing grid-modulated cold cathode source having nanotube emitters
US20010046564A1 (en) * 2000-03-28 2001-11-29 Kotov Nicholas A. Assembly of free-standing films using a layer-by-layer process
US6334939B1 (en) * 2000-06-15 2002-01-01 The University Of North Carolina At Chapel Hill Nanostructure-based high energy capacity material
US6346023B1 (en) * 1998-09-11 2002-02-12 Futaba Denshi Kogyo Kabushiki Kaisha Method of preparing film of carbon nano-tube and film of carbon nano-tube prepared thereby
US6352758B1 (en) * 1998-05-04 2002-03-05 3M Innovative Properties Company Patterned article having alternating hydrophilic and hydrophobic surface regions
US20020085968A1 (en) * 1997-03-07 2002-07-04 William Marsh Rice University Method for producing self-assembled objects comprising single-wall carbon nanotubes and compositions thereof
US6420092B1 (en) * 1999-07-14 2002-07-16 Cheng-Jer Yang Low dielectric constant nanotube
US6426134B1 (en) * 1998-06-30 2002-07-30 E. I. Du Pont De Nemours And Company Single-wall carbon nanotube-polymer composites
US20020122765A1 (en) * 2001-03-02 2002-09-05 Fuji Xerox Co., Ltd. Carbon nanotube structures and method for manufacturing the same
US20020130353A1 (en) * 1999-07-02 2002-09-19 Lieber Charles M. Nanoscopic wire-based devices, arrays, and methods of their manufacture
US20020172639A1 (en) * 2001-05-21 2002-11-21 Fuji Xerox Co., Ltd. Carbon nanotube structures, carbon nanotube devices using the same and method for manufacturing carbon nanotube structures
US20030012723A1 (en) * 2001-07-10 2003-01-16 Clarke Mark S.F. Spatial localization of dispersed single walled carbon nanotubes into useful structures
US20030026754A1 (en) * 2001-07-10 2003-02-06 Clarke Mark S.F. Production of stable aqueous dispersions of carbon nanotubes
US6553096B1 (en) * 2000-10-06 2003-04-22 The University Of North Carolina Chapel Hill X-ray generating mechanism using electron field emission cathode
US20030090190A1 (en) * 2001-06-14 2003-05-15 Hyperion Catalysis International, Inc. Field emission devices using modified carbon nanotubes
US6593166B1 (en) * 1998-03-24 2003-07-15 Silverbrook Research Pty Ltd Method for construction of nanotube matrix material
US6630772B1 (en) * 1998-09-21 2003-10-07 Agere Systems Inc. Device comprising carbon nanotube field emitter structure and process for forming device
US6686308B2 (en) * 2001-12-03 2004-02-03 3M Innovative Properties Company Supported nanoparticle catalyst
US6692791B2 (en) * 2001-08-29 2004-02-17 Industrial Technology Research Institute Method for manufacturing a carbon nanotube field emission display
US6787122B2 (en) * 2001-06-18 2004-09-07 The University Of North Carolina At Chapel Hill Method of making nanotube-based material with enhanced electron field emission properties
US6908572B1 (en) * 2000-07-17 2005-06-21 University Of Kentucky Research Foundation Mixing and dispersion of nanotubes by gas or vapor expansion
US6965199B2 (en) * 2001-03-27 2005-11-15 The University Of North Carolina At Chapel Hill Coated electrode with enhanced electron emission and ignition characteristics
US7147894B2 (en) * 2002-03-25 2006-12-12 The University Of North Carolina At Chapel Hill Method for assembling nano objects
US7252749B2 (en) * 2001-11-30 2007-08-07 The University Of North Carolina At Chapel Hill Deposition method for nanostructure materials

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4728576A (en) * 1987-04-10 1988-03-01 Hoechst Celanese Corporation Langmuir-Blodgett coating process
DE69830847D1 (en) 1997-03-07 2005-08-18 Univ Rice William M Carbon fibers from single-wall carbon nanotube

Patent Citations (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4249988A (en) * 1978-03-15 1981-02-10 Western Electric Company, Inc. Growing crystals from a melt by controlling additions of material thereto
US5078830A (en) * 1989-04-10 1992-01-07 Mitsubishi Metal Corporation Method for growing single crystal
US5322591A (en) * 1991-03-26 1994-06-21 The United States Of America As Represented By The Secretary Of The Air Force Hydrothermal growth on non-linear optical crystals
US5879836A (en) * 1993-09-10 1999-03-09 Hyperion Catalysis International Inc. Lithium battery with electrodes containing carbon fibrils
US6008138A (en) * 1996-03-19 1999-12-28 Robert Bosch Gmbh Process for making micromechanical structures
US6097138A (en) * 1996-09-18 2000-08-01 Kabushiki Kaisha Toshiba Field emission cold-cathode device
US20020085968A1 (en) * 1997-03-07 2002-07-04 William Marsh Rice University Method for producing self-assembled objects comprising single-wall carbon nanotubes and compositions thereof
US5801092A (en) * 1997-09-04 1998-09-01 Ayers; Michael R. Method of making two-component nanospheres and their use as a low dielectric constant material for semiconductor devices
US6197399B1 (en) * 1998-03-13 2001-03-06 Kabushiki Kaisha Toshiba Recording medium and method of manufacturing the same
US6593166B1 (en) * 1998-03-24 2003-07-15 Silverbrook Research Pty Ltd Method for construction of nanotube matrix material
US6352758B1 (en) * 1998-05-04 2002-03-05 3M Innovative Properties Company Patterned article having alternating hydrophilic and hydrophobic surface regions
US6426134B1 (en) * 1998-06-30 2002-07-30 E. I. Du Pont De Nemours And Company Single-wall carbon nanotube-polymer composites
US6277740B1 (en) * 1998-08-14 2001-08-21 Avery N. Goldstein Integrated circuit trenched features and method of producing same
US6346023B1 (en) * 1998-09-11 2002-02-12 Futaba Denshi Kogyo Kabushiki Kaisha Method of preparing film of carbon nano-tube and film of carbon nano-tube prepared thereby
US6630772B1 (en) * 1998-09-21 2003-10-07 Agere Systems Inc. Device comprising carbon nanotube field emitter structure and process for forming device
US6264741B1 (en) * 1998-11-25 2001-07-24 Sandia Corporation Self-assembly of nanocomposite materials
US6250984B1 (en) * 1999-01-25 2001-06-26 Agere Systems Guardian Corp. Article comprising enhanced nanotube emitter structure and process for fabricating article
US6280697B1 (en) * 1999-03-01 2001-08-28 The University Of North Carolina-Chapel Hill Nanotube-based high energy material and method
US6422450B1 (en) * 1999-03-01 2002-07-23 University Of North Carolina, The Chapel Nanotube-based high energy material and method
US20020130353A1 (en) * 1999-07-02 2002-09-19 Lieber Charles M. Nanoscopic wire-based devices, arrays, and methods of their manufacture
US6420092B1 (en) * 1999-07-14 2002-07-16 Cheng-Jer Yang Low dielectric constant nanotube
US6277318B1 (en) * 1999-08-18 2001-08-21 Agere Systems Guardian Corp. Method for fabrication of patterned carbon nanotube films
US20010046564A1 (en) * 2000-03-28 2001-11-29 Kotov Nicholas A. Assembly of free-standing films using a layer-by-layer process
US6334939B1 (en) * 2000-06-15 2002-01-01 The University Of North Carolina At Chapel Hill Nanostructure-based high energy capacity material
US6908572B1 (en) * 2000-07-17 2005-06-21 University Of Kentucky Research Foundation Mixing and dispersion of nanotubes by gas or vapor expansion
US6297592B1 (en) * 2000-08-04 2001-10-02 Lucent Technologies Inc. Microwave vacuum tube device employing grid-modulated cold cathode source having nanotube emitters
US6553096B1 (en) * 2000-10-06 2003-04-22 The University Of North Carolina Chapel Hill X-ray generating mechanism using electron field emission cathode
US20020122765A1 (en) * 2001-03-02 2002-09-05 Fuji Xerox Co., Ltd. Carbon nanotube structures and method for manufacturing the same
US6965199B2 (en) * 2001-03-27 2005-11-15 The University Of North Carolina At Chapel Hill Coated electrode with enhanced electron emission and ignition characteristics
US20020172639A1 (en) * 2001-05-21 2002-11-21 Fuji Xerox Co., Ltd. Carbon nanotube structures, carbon nanotube devices using the same and method for manufacturing carbon nanotube structures
US20030090190A1 (en) * 2001-06-14 2003-05-15 Hyperion Catalysis International, Inc. Field emission devices using modified carbon nanotubes
US6787122B2 (en) * 2001-06-18 2004-09-07 The University Of North Carolina At Chapel Hill Method of making nanotube-based material with enhanced electron field emission properties
US20030026754A1 (en) * 2001-07-10 2003-02-06 Clarke Mark S.F. Production of stable aqueous dispersions of carbon nanotubes
US20030012723A1 (en) * 2001-07-10 2003-01-16 Clarke Mark S.F. Spatial localization of dispersed single walled carbon nanotubes into useful structures
US6878361B2 (en) * 2001-07-10 2005-04-12 Battelle Memorial Institute Production of stable aqueous dispersions of carbon nanotubes
US6692791B2 (en) * 2001-08-29 2004-02-17 Industrial Technology Research Institute Method for manufacturing a carbon nanotube field emission display
US7252749B2 (en) * 2001-11-30 2007-08-07 The University Of North Carolina At Chapel Hill Deposition method for nanostructure materials
US6686308B2 (en) * 2001-12-03 2004-02-03 3M Innovative Properties Company Supported nanoparticle catalyst
US7147894B2 (en) * 2002-03-25 2006-12-12 The University Of North Carolina At Chapel Hill Method for assembling nano objects

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US20150102284A1 (en) * 2012-04-12 2015-04-16 Sol Voltaics Ab Methods of nanowire functionalization, dispersion and attachment
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US9368723B2 (en) 2014-02-11 2016-06-14 Wisconsin Alumni Research Foundation Dose-controlled, floating evaporative assembly of aligned carbon nanotubes for use in high performance field effect transistors
US9425405B1 (en) 2015-02-11 2016-08-23 Wisconsin Alumni Research Foundation Continuous, floating evaporative assembly of aligned carbon nanotubes

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