Nanotube/metal substrate composites and methods for producing such composites

Abstract

Carbon nanotubes are grown directly on metal substrates using chemical vapor deposition. Metal substrates are comprised of catalysts which facilitate or promote the growth of carbon nanotubes. The nanotube coated metal substrates have applications including, but not limited to, heat transfer and thermal control, hydrogen storage, fuel cell catalytic reformers, electronics and semiconductors, implantable medical devices or prostheses, and tribological wear and protective coatings.

1 . Method, comprising producing a composite by contacting a metal substrate with a feedstock to form nanotubes, and using the composite in devices for one of electrical energy storage and retrieval, gas adsorption and desorption, sensing, catalysis, heat transfer, fuel cells, solar collectors and medical prosthesis.  
     
     
         2 . Method according to  claim 1 , wherein the device for electrical energy storage and retrieval is one of a battery electrode and an ultracapacitor electrode.  
     
     
         3 . Method according to  claim 2 , wherein the metals comprising the metal substrate have an electrical resistivity of about no more than 9 microohms-cm.  
     
     
         4 . Method according to  claim 1 , wherein the device for sensing is a chemical sensor.  
     
     
         5 . Method according to  claim 1 , wherein the device for gas adsorption or desorption is one of hydrogen storage and a catalysis device including a catalytic converter or a cracking catalyst for oil production.  
     
     
         6 . Method according to  claim 1 , wherein the device for heat transfer is selected from the group consisting of heat sinks, heat pipes, heat exchangers, spray cooling apparatus, single-phase convection apparatus and two-phase convection apparatus.  
     
     
         7 . Method according to  claim 6 , wherein the metals comprising the metal substrate have a thermal conductivity of at least 90 W/m-K.  
     
     
         8 . Method according to  claim 1 , wherein the feedstock is a hydrocarbon feedstock.  
     
     
         9 . Method according to  claim 1 , wherein the nanotubes are carbon nanotubes.  
     
     
         10 . Method according to  claim 1 , wherein the producing of the composite includes 
 (a) cleaning the metal substrate;    (b) introducing the metal substrate into a furnace;    (c) heating the metal substrate;    (d) contacting the feedstock with the metal substrate to form the nanotubes; and    (e) optionally subjecting the metal substrate to one of air, oxygen and plasma to remove amorphous carbon.    
     
     
         11 . Method according to  claim 10 , wherein the metal substrate is a metal alloy.  
     
     
         12 . Method according to  claim 10 , wherein said furnace is a CVD furnace heated to between about 500° and 1200° C.  
     
     
         13 . Method according to  claim 10 , wherein said feedstock comprises compounds selected from the group consisting of ethylene, methane, propane, acetylene, carbon monoxide, methanol, ethanol, benzene, toluene and xylene.  
     
     
         14 . Method according to  claim 1 , wherein the metal substrate comprises at least one metal selected from the group consisting of Cu, Al, Be, Co, Cr, Fe, Hf, Ir, Mn, Mo, Nb, Ni, Os, Pb, Pd, Pt, Rh, Ru, Sb, Ta, Ti, V, Y, Zr, and oxides thereof.  
     
     
         15 . Method according to  claim 1 , wherein the nanotubes are one of single-walled and multi-walled nanotubes.  
     
     
         16 . Method according to  claim 15 , wherein the nanotubes are perpendicularly oriented.  
     
     
         17 . Method, comprising directly coating a surface of a copper alloy body with carbon nanotubes, and using the body to exchange heat between a gas or liquid.  
     
     
         18 . Method according to  claim 17 , wherein a hydrocarbon feedstock is used in the direct coating.  
     
     
         19 . Method, comprising directly coating a surface of a copper alloy body with carbon nanotubes, and using the body to evaporate and condense fluids.  
     
     
         20 . Method according to  claim 19 , wherein a hydrocarbon feedstock is used in the direct coating.  
     
     
         21 . Method, comprising directly coating a surface of a metal alloy body with nanotubes to form a composite, and optionally coating the coating with at least one of a wear-resistant material, a corrosion-resistant material, a self-lubricant material, a low-friction material and a combination thereof.  
     
     
         22 . Method, comprising directly coating a surface of a metal alloy body with carbon nanotubes, and using the body in a corrosive environment.  
     
     
         23 . Method according to  claim 21 , wherein the metal alloy is one of Allac®, Nickelvac, Carpenter, Elgiloy®, Haynes®, Stellite®, Stoody®, Tribaloy®, Hastelloy®, INCONEL®, NIMONIC™, NILO™, Allegheny Ludlum, Monel™, INCO™, Deloro®, Osprey Metals, INCOLOY®, Nichrome™, and Super Alloys, as well as other alloys based on stainless steel, carbon steel, copper (UNS series 600, 700, 800 and 900), nickel, brass, and titanium.  
     
     
         24 . Method, comprising directly coating a surface of a copper alloy body with carbon nanotubes, and using the surface for spray cooling applications.  
     
     
         25 . Method, comprising directly coating an inner surface of a copper alloy body of selected configuration or copper alloy wicking material with carbon nanotubes, and using the body or wicking material for heat pipe applications.  
     
     
         26 . Method, comprising directly coating a copper alloy body surface with carbon nanotubes, and using the surface for one of a battery electrode and an ultracapacitor electrode.  
     
     
         27 . Method, comprising directly coating a surface of a copper alloy body with carbon nanotubes, and using the body as an implantable medical device or prosthesis.  
     
     
         28 . Method, comprising directly coating a surface of a copper alloy body with carbon nanotubes, and using the body as a heat sink for electronics cooling.  
     
     
         29 . Method, comprising directly coating a copper alloy with carbon nanotubes to form a composite, and coating the composite with a thermoset or thermoplastic polymer.  
     
     
         30 . Method, comprising directly coating a surface of a metal alloy body with carbon nanotubes.  
     
     
         31 . Method according to  claim 30 , wherein the metal alloy body is selected from a group of metal alloys consisting of Allvac®, Nickelvac, Carpenter, Elgiloy®, Haynes®, Stellite®, Stoody®, Tribaloy®, Hastelloy®, INCONEL®, NIMONIC™, NILO™, Allegheny Ludlum, Monel™, INCO™, Deloro®, Osprey Metals, INCOLOY®, Nichrome™, and Super Alloys, as well as other alloys based on stainless steel, carbon steel, copper (UNS series 600, 700, 800 and 900), nickel, brass, and titanium.  
     
     
         32 . Method according to  claim 30 , wherein the metal alloy body is selected from a group of metal alloys consisting of two or more elements in the following weight percentage ranges: Cu from 0% to about 95%, Fe from 0% to about 76%, Ni from 0% to about 78%, Mo from 0% to about 85%, Y203 from 0% to about 1%, Mn from 0% to about 15%, Zn from 0% to about 39%, Cr from 0% to about 52%, Co from 0% to about 63%, Pb from 0% to about 15%, Sn from 0% to about 13%, Al from 0% to about 12%, Si from 0% to about 4%, W from 0% to about 16%, Ti from 0% to about 98%, Ag from 0% to about 50%, Zr from 0% to about 10%, and other minor constituents.  
     
     
         33 . Method, comprising directly coating a substrate with carbon nanotubes, and removing the carbon nanotubes for reuse thereof.  
     
     
         34 . A continuous coating process, comprising 
 (a) heating a metal alloy substrate fed continuously into and out of a CVD furnace;    (b) introducing one or more feedstock gases into the CVD furnace;    (c) growing nanotubes on the substrate while substrate is conveyed through the furnace;    (d) optionally providing different heating zones and gas compositions along the conveyed length of the substrate through the furnace;    (e) cooling the substrate to ambient temperature and pressure.    
     
     
         35 . Process according to  claim 34 , wherein the metal alloy is a copper alloy.  
     
     
         36 . Process according to  claim 34 , wherein the feedstock gases are compounds.  
     
     
         37 . A copper alloy substrate-carbon nanotube composite made by 
 (a) cleaning the copper alloy substrate;    (b) introducing said substrate into a furnace;    (c) heating the substrates and flowing hydrocarbon vapors thereover, and    (d) optionally subjecting the substrate to one of air, oxygen and plasma to remove amorphous carbon.    
     
     
         38 . Composite according to  claim 37 , wherein substrate is introduced on a continuous basis.  
     
     
         39 . Composite according to  claim 37 , wherein the furnace is a CVD furnace which is heated to between about 500° and 1200° C.  
     
     
         40 . Composite according to  claim 37 , wherein the hydrocarbon vapors are combinations of ethylene, methane and hydrogen.  
     
     
         41 . Composite according to  claim 37 , wherein the copper alloy substrate contains at least one additional metal selected from the group consisting of Al, Be, Co, Cr, Fe, Hf, Ir, Mn, Mo, Nb, Ni, Os, Pb, Pd, Pt, Rh, Ru, Sb, Ta, Ti, V, Y, Zr, and oxides thereof.  
     
     
         42 . Composite according to  claim 37 , wherein the carbon nanotubes are single-walled or multi-walled nanotubes.  
     
     
         43 . Composite according to  claim 37 , wherein the copper alloy is selected from the group consisting of UNS series 700, 800 or 900 alloys.  
     
     
         44 . Composite according to  claim 37 , wherein said hydrocarbon vapors comprise compounds selected from the group consisting of ethylene, methane, propane, acetylene, carbon monoxide, methanol, ethanol, benzene, toluene and xylene.  
     
     
         45 . Carbon nanotubes produced by 
 (a) growing carbon nanotubes on a metal or metal alloy substrate, and    (b) removing the carbon nanotube coating from the substrate.    
     
     
         46 . Method, comprising directly coating a metal alloy substrate with nanotubes, and applying a polymeric coating thereover.  
     
     
         47 . Method according to  claim 46 , wherein the nanotubes are compounds selected from the group consisting of BN, WS2, V2O5, MoS2, SiO2, Al2O3 and ZrO2.  
     
     
         48 . Method according to  claim 46 , wherein the nanotubes are carbon.  
     
     
         49 . Method according to  claim 1 , wherein the nanotubes are compounds selected from the group consisting of BN, WS2, V2O5, MoS2, SiO2, Al2O3 and ZrO2.  
     
     
         50 . Method according to  claim 1 , wherein the nanotubes are carbon.  
     
     
         51 . Method according to  claim 1 , wherein the nanotubes constitute substantially all of the coating material.  
     
     
         52 . Method according to  claim 21 , wherein the nanotubes comprise a combination of carbon and inorganic nanotubes.