The University of North Carolina at Chapel Hill

Xintek, Inc.

Duke University

Bo Gao

Otto Z Zhou

Soojin Oh

Guozhen Yue

Jie Liu

Saion Sinha

Jianping Lu

Qi Qiu

Chunsheng Du

Huaizhi Geng

Cheng Qian

Changkun Dong

Mei Lu

A method for depositing a coating of a nanostructure material onto a substrate includes: (1) forming a solution or suspension of containing the nanostructure material; (2) selectively adding 'chargers' to the solution; (3) immersing electrodes in the solution, the substrate upon which the nanostructure material is to be deposited acting as one of the electrodes; (4) applying a direct and/or alternating current electrical field between the two electrodes for a certain period of time thereby causing the nanostructure materials in the solution to migrate toward and attach themselves to the substrate electrode; and (5) subsequent optional processing of the coated substrate.

Deposition method for nanostructure materials

A method for attaching nanostructure-containing material onto a sharp tip of an object includes forming a suspension of pre-formed nanostructure-containing material in a liquid medium. An electrode is immersed in the suspension. The sharp tip of the object is arranged to be in contact with the suspension. A voltage is applied to the immersed electrode and to the sharp tip. The nanostructure-containing material attaches to the sharp tip of the object.

Method and apparatus for attaching nanostructure-containing material onto a sharp tip of an object and related articles

Methods and devices are provided relating to the homogeneous deposition of a composite film of carbon nanotubes by electrophoresis. The methods comprise linking carbon nanotubes to matrix particles prior to electrophoretic deposition. The methods improve the adhesion of the composite film to the substrate and reduce the surface roughness. Carbon nanotube films and electron field emission cathodes fabricated by this process demonstrate enhanced electron field emission characteristics.

Methods and devices for electrophoretic deposition of a uniform carbon nanotube composite film

Carbon nanotube material having an outer diameter less than 10 nm and a number of walls less than ten are disclosed. Also disclosed are an electron field emission device including a substrate, an optionally layer of adhesion-promoting layer, and a layer of electron field emission material. The electron field emission material includes a carbon nanotube having a number of concentric graphene shells per tube of from two to ten, an outer diameter from 2 to 8 nm, and a nanotube length greater than 0.1 microns. One method to fabricate carbon nanotubes includes the steps of (a) producing a catalyst containing Fe and Mo supported on MgO powder, (b) using a mixture of hydrogen and carbon containing gas as precursors, and (c) heating the catalyst to a temperature above 950&#xb0; C. to produce a carbon nanotube. Another method of fabricating an electron field emission cathode includes the steps of (a) synthesizing electron field emission materials containing carbon nanotubes with a number of concentric graphene shells per tube from two to ten, an outer diameter of from 2 to 8 nm, and a length greater than 0.1 microns, (b) dispersing the electron field emission material in a suitable solvent, (c) depositing the electron field emission materials onto a substrate, and (d) annealing the substrate.

Method of synthesizing small-diameter carbon nanotubes with electron field emission properties

A method of forming an electron emitter includes the steps of: (i) forming a nanostructure-containing material; (ii) forming a mixture of nanostructure-containing material and a matrix material; (iii) depositing a layer of the mixture onto at least a portion of at least one surface of a substrate by electrophoretic deposition; (iv) sintering or melting the layer thereby forming a composite; and (v) electrochemically etching the composite to remove matrix material from a surface thereof, thereby exposing nanostructure-containing material.

Fabrication and activation processes for nanostructure composite field emission cathodes

A field emission ion source has nanostructure materials on at least an emitting edge of the anode electrode. Metal is transferred from a metal reservoir to the emitting edge of the anode, where the metal is transferred to an emitting end of the nanostructure materials and is ionized under an applied electric field. Plural ion sources can be combined to form a field emission ion source device. The numbers of emitting sources are selectable through electric or mechanical switches and different ion extraction potentials can be applied. Various nanostructure materials include: single wall carbon nanotubes and bundles, few-walled carbon nanotubes and bundles, multi-walled carbon nanotubes and bundles, and carbon fiber. Nanostructure-containing material is integrated into the anode by electrophoresis, dielectrophoresis, CVD, screen printing, and mechanical methods. Metal, preferably alkali metal, is transferred into the nanostructure-containing material by one or a combination of following intercalation methods: vapor transport, solution, electrochemical, and solid state reaction.

Field emission ion source based on nanostructure-containing material

A nanostructure based material is capable of accepting-and reacting with an alkali metal such as lithium. The material exhibits a reversible capacity ranging from at least approximately 900 mAh/g-1,500 mAh/g. The high capacity of the material makes it attractive for a number of applications, such as a battery electrode material.

Nanostructure-based high energy capacity material

A carbon-based material containing an allotrope of carbon, such as single-walled carbon nanotubes, is capable of accepting and intercalated alkali metal. The material exhibits a reversible capacity ranging from approximately 650 mAh/g-1,000 mAh/g. The high capacity of the material makes it attractive for a number of applications, such as a battery electrode material. A method of producing a single-walled carbon nanotube material includes purifying an as-recovered nanotube material, and depositing the purified material onto a conductive substrate. The coated substrate is incorporated into an electrochemical cell, an its ability to accept intercalated materials, such as an alkali metal (e.g.&mdash;lithium) is measured.

Nanotube-based high energy material and method

A nanostructure based material is capable of accepting and reacting with an alkali metal such as lithium. The material exhibits a reversible capacity ranging from at least approximately 900 mAh/g-1,500 mAh/g. The high capacity of the material makes it attractive for a number of applications, such as a battery electrode material.

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Carrboro, NC, United States of America

Bo Gao