Systems and Methods for Synthesis of Extended Length Nanostructures

Abstract

A system for synthesizing nanostructures using chemical vapor deposition (CVD) is provided. The system includes a housing, a porous substrate within the housing, and on a downstream surface of the substrate, a plurality of catalyst particles from which nanostructures can be synthesized upon interaction with a reaction gas moving through the porous substrate. Electrodes may be provided to generate an electric field to support the nanostructures during growth. A method for synthesizing extended length nanostructures is also provided. The nanostructures are useful as heat conductors, heat sinks, windings for electric motors, solenoid, transformers, for making fabric, protective armor, as well as other applications

1 . A system for synthesis of nanostructures, the system comprising:
 a housing having a first end, an opposite second end, and a passageway extending between the first and second ends;   a porous substrate, situated within the passageway of the housing, having an upstream surface and a downstream surface;   a plurality of catalyst particles, deposited on the downstream surface of the substrate, and from which nanostructures can be synthesized upon interaction with a reaction gas;   a heating mechanism circumferentially placed about the substrate for generating energy sufficient to maintain an environment within which nanostructures are synthesized within a specified temperature range;   a pair of flanges, each capping one end of the housing; and   an inlet positioned across the flange capping the first end of the housing and through which reaction gas can be directed to the porous substrate.   
     
     
         2 . A system as set forth in  claim 1  further including an exhaust port through which reaction waste product flowing from the substrate may be removed. 
     
     
         3 . A system as set forth in  claim 1 , wherein the housing is made from a strong, substantially gas-impermeable material. 
     
     
         4 . A system as set forth in  claim 3 , wherein in the material is substantially resistant to corrosion. 
     
     
         5 . A system as set forth in  claim 3 , wherein the material is quartz. 
     
     
         6 . A system as set forth in  claim 1 , wherein the substrate is sufficiently porous so that a pressure difference between the upstream surface and the downstream surface can be substantially low, so as to permit the substrate to maintain its structural integrity. 
     
     
         7 . A system as set forth in  claim 1 , wherein the substrate is made from a material provided with pore size ranging from about 0.5 nm to about 500 microns. 
     
     
         8 . A system as set forth in  claim 1 , wherein the substrate is made from a material having a void fraction of from about 10 percent to about 95 percent. 
     
     
         9 . A system as set forth in  claim 1 , wherein the substrate is made from a material including carbon foams, glassy carbon, silica, alumina, alumina coated with silica, zirconia, zeolites, sintered titanium, titania, magnesia, yttria, copper, iron, iron nickel, iron cobalt, cobalt, steel, iron carbide, nickel, or a combination thereof. 
     
     
         10 . A system as set forth in  claim 1 , wherein the substrate is one of foam, channel plate, felt, wool, fibers, cloth, or array of needles. 
     
     
         11 . A system as set forth in  claim 1 , wherein the catalyst particles are substantially evenly distributed across the downstream surface of the substrate. 
     
     
         12 . A system as set forth in  claim 1 , wherein the catalyst particles are made from a material including iron, nickel, cobalt, iron oxides, nickel oxides, cobalt oxides, metal salts with sulfate, metal salts with sulfamates, acetate, citrate, oxalates, nitrites, nitrates, or a combination thereof. 
     
     
         13 . A system as set forth in  claim 1 , wherein the catalyst particles range from about 1 nm to about 50 nm in size. 
     
     
         14 . A system as set forth in  claim 1 , wherein the heating mechanism can maintain the temperature of the growth environment within a range of from about 500° C. to about 1400° C. 
     
     
         15 . A system as set forth in  claim 1 , wherein energy generated from the heating mechanism includes thermal energy, frictional energy, visible light photons or other types of electromagnetic radiation, chemical, electrical, or electrochemical energy, microwave radiation, eddy currents, or ultrasound shock waves or compression. 
     
     
         16 . A system as set forth in  claim 1 , wherein the flanges are substantially gas-impermeable. 
     
     
         17 . A system as set forth in  claim 1 , further including a tube for accommodating the porous substrate, the tube being situated within the passageway of the housing for providing a pathway for the reaction gas from the inlet to the substrate. 
     
     
         18 . A system as set forth in  claim 17 , wherein the substrate is situated within the tube. 
     
     
         19 . A system as set forth in  claim 17 , wherein the tube is made from a strong, substantially gas-impermeable material. 
     
     
         20 . A system as set forth in  claim 19 , wherein the material is quartz. 
     
     
         21 . A system as set forth in  claim 17 , further including:
 a first electrode situated within the pathway of the tube upstream of the porous substrate; and   a second electrode situated within the pathway of the tube downstream of the porous substrate.   
     
     
         22 . A system as set forth in  claim 21 , wherein the upstream electrode and the downstream electrode are designed to generate an electric field therebetween to provide physical support to the nanostructures growing from the substrate. 
     
     
         23 . A system as set forth in  claim 21 , wherein the upstream and downstream electrodes are designed to generate an electric field therebetween to control and maintain direction of growth to the nanostructures growing from the substrate. 
     
     
         24 . A system as set forth in  claim 21 , wherein the electrodes permit flow of reaction gas within the tube therethrough. 
     
     
         25 . A system as set forth in  claim 21 , wherein the electrodes are made from an electrically conductive material that is non-reactive and resistant to nanostructure growth. 
     
     
         26 . A system as set forth in  claim 25 , wherein the material from which the electrodes are made includes graphite, copper, titanium, vitreous carbon, a combination thereof, or other conductive materials not catalytic to carbon nanostructure formation. 
     
     
         27 . A system as set forth in  claim 17 , wherein the porous substrate is positioned circumferentially about an exterior surface of the tube at one end of the tube, and the system further includes:
 a tubular electrode having an open end and sufficiently sized so as to concentrically accommodate the porous substrate through the open end; and   a plurality of guides, positioned between the tubular electrode and the substrate, and over which growing nanostructures can be directed.   
     
     
         28 . A system as set forth in  claim 27 , wherein the porous substrate is designed to be an electrode, such that along with the tubular electrode, an electric field can be generated therebetween to provide physical support to the nanostructures growing from the substrate. 
     
     
         29 . A system as set forth in  claim 27 , wherein the substrate and the tubular electrode designed to generate an electric field therebetween to control and maintain direction of growth to the nanostructures growing from the substrate. 
     
     
         30 . A system as set forth in  claim 27 , wherein the substrate is made from an electrically conductive material including, glassy carbon, porous titania, porous zirconia, or sintered titanium powder. 
     
     
         31 . A system as set forth in  claim 27 , wherein the substrate is made from an inert material coated with an electrically conductive material including, copper, tin oxide, titania, or titanium. 
     
     
         32 . A system as set forth in  claim 27 , wherein the tubular electrode is rotatable and retractable from its position over the substrate so as to pull growing nanostructures therealong. 
     
     
         33 . A system as set forth in  claim 27 , wherein the guides include a series of rings circumferentially placed about the substrate. 
     
     
         34 . A system as set forth in  claim 1 , further including a second inlet situated across the flange capping the first end of the housing and through which an evacuation gas can be directed into the passageway of the housing to displace and remove reaction waste product within the housing. 
     
     
         35 - 70 . (canceled) 
     
     
         71 . A method for synthesizing prismatic structures, the method comprising
 providing a surface upon which a plurality of catalyst lines can be created;   generating the catalyst lines on the surface, so as to form a designed pattern from which prismatic structures can be synthesized;   directing a flow of a reaction gas to the catalyst lines in the designed pattern on the surface;   decomposing the reaction gas about the catalyst lines to generate constituent atoms;   allowing for diffusion of the constituent atoms onto the catalyst lines in the designed pattern for the synthesis of a prismatic structure.   
     
     
         72 . A method as set forth in  claim 71 , wherein the step of allowing includes growing a prismatic structure with a base pattern matching the designed pattern. 
     
     
         73 . A method as set forth in  claim 71 , wherein, in the step of generating, the designed pattern includes, triangles, squares, rectangles, hexagons, periodic tiling patterns, Penrose or Kepler aperiodic tiling patterns, random tiling patterns, or other space filling patterns. 
     
     
         74 . A method as set forth in  claim 71 , wherein the step of generating includes generating continuous catalyst lines having a width measuring from about 0.2 nm to about 50 nm. 
     
     
         75 . A method as set forth in  claim 74 , wherein, in the step of generating, the designed pattern of catalyst lines provides a base from which a graphene sheet can be assembled. 
     
     
         76 . A method as set forth in  claim 75 , wherein, in the step of generating, the design pattern includes catalyst lines having width measuring from about 0.2 nm to about 50 nm and spacing distance between lines measuring from about 20 nm to about 1000 nm. 
     
     
         77 . A method for collecting nanostructures, the method comprising:
 providing a cylindrical surface around which the nanostructures can be collected;   controlling a speed at which of the cylindrical surface may rotate to match the speed of slow growing nanostructures; and   causing the nanostructures growing from the substrate to oscillate in parallel to an axis of the cylindrical surface with an amplitude sufficiently large to accommodate fast growing nanostructures on a sinuous path upon the cylindrical surface; and   laying down the slow growing nanostructures on circumferential loci of the cylindrical surface, while laying down the fast growing nanostructures on a sinuous locus of maximum amplitude.   
     
     
         78 . A method as set forth in  claim 77 , wherein the step of causing includes applying a force to cause the nanostructures to oscillate appropriately. 
     
     
         79 . A method as set forth in  claim 78 , wherein, in the step of causing, the force includes electrostatic force, magnetic force, gas-dynamic force, contact force, or a combination thereof. 
     
     
         80 . A method as set forth in  claim 77 , further including unwinding the nanostructures for use. 
     
     
         81 . A fibrous material comprising a plurality of nanostructures grown from a plurality of catalyst particles present in a flow of reaction gas having constituent atoms that can diffuse onto the catalyst particles to permit growth of the nanostrutures to a specified length. 
     
     
         82 . A material as set forth in  claim 81  for use in thermal management applications. 
     
     
         83 . A heat conductor comprising the fibrous material set forth in  claim 81 . 
     
     
         84 . A low eddy current, low resistance winding for an electric motor comprising the fibrous material as set forth in  claim 81 . 
     
     
         85 . A low eddy current, low resistance winding for a high frequency solenoid comprising fibrous material as set forth in  claim 81 . 
     
     
         86 . A winding for a high frequency transformer comprising the fibrous material as set forth in  claim 81 . 
     
     
         87 . A fabric comprising the fibrous material as set forth in  claim 81 . 
     
     
         88 . A protective armor or clothing comprising the fibrous material as set forth in  claim 81 . 
     
     
         89 . A rope or cable comprising the fibrous material as set forth in  claim 81 . 
     
     
         90 . A yarn comprising the fibrous material as set forth in  claim 81 . 
     
     
         91 . A heat sink comprising the fibrous material as set forth in  claim 81 . 
     
     
         92 . A high strength, low eddy current, low resistance electric power transmission line comprising the fibrous material as set forth in  claim 81 . 
     
     
         93 . A material comprising at least one prismatic structure of  claim 71 . 
     
     
         94 . A material as set forth in  claim 93  for use in thermal management applications. 
     
     
         95 . A heat sink comprising the material set forth in  claim 93 . 
     
     
         96 . (canceled) 
     
     
         97 . A material comprising at least one prismatic structure formed from an array of joined graphene planes. 
     
     
         98 . A fibrous material comprising a collection of extended length nanotubes, each having a length of at least 1 cm. 
     
     
         99 . A fibrous material as set forth in  claim 98 , wherein the collection of nanotubes are twisted into a yarn. 
     
     
         100 . A fibrous material as set forth in  claim 99 , wherein the nanotubes are coated with either a epoxy resin or a high-carbon polymer. 
     
     
         101 . A fibrous material as set forth in  claim 98 , wherein the collection of nanotubes are assembled into a sheet of textile. 
     
     
         102 . A fibrous material as set forth in  claim 101 , wherein the nanotubes are coated with either a epoxy resin or a high-carbon polymer. 
     
     
         103 . A nanotube as set forth in  claim 98 , wherein the nanotube is made from a material including one of carbon, boron nitride, tungsten sulfide, vanadium oxide, boron carbon nitride, or a combination thereof. 
     
     
         104 . A material as set forth in  claim 98  for use as thermal management material. 
     
     
         105 . A heat conductor comprising the fibrous material set forth in  claim 98 . 
     
     
         106 . A low eddy current, low resistance winding for an electric motor comprising the fibrous material as set forth in  claim 98 . 
     
     
         107 . A low eddy current, low resistance winding for a high frequency solenoid comprising fibrous material as set forth in  claim 98 . 
     
     
         108 . A winding for a high frequency transformer comprising the fibrous material as set forth in  claim 98 . 
     
     
         109 . A fabric comprising the fibrous material as set forth in  claim 98 . 
     
     
         110 . A fiber comprising the fibrous material as set forth in  claim 98 . 
     
     
         111 . A tow comprising the fibrous material as set forth in  claim 98 . 
     
     
         112 . A textile comprising the fibrous material as set forth in  claim 98 . 
     
     
         113 . A protective armor or clothing comprising the fibrous material as set forth in  claim 98 . 
     
     
         114 . A rope or cable comprising the fibrous material as set forth in  claim 98 . 
     
     
         115 . A yarn comprising the fibrous material as set forth in  claim 98 . 
     
     
         116 . A heat sink comprising the fibrous material as set forth in  claim 98 . 
     
     
         117 . A high strength, low eddy current, low resistance electric power transmission line comprising the fibrous material as set forth in  claim 98 .