Multilayer Carbon Nanotube Capacitor

Abstract

Multilayer carbon nanotube capacitors, and methods and printable compositions for manufacturing multilayer carbon nanotubes (CNTs) are disclosed. A first capacitor embodiment comprises: a first conductor; a plurality of fixed CNTs in an ionic liquid, each fixed CNT comprising a magnetic catalyst nanoparticle coupled to a carbon nanotube and further coupled to the first conductor; and a first plurality of free CNTs dispersed and moveable in the ionic liquid. Another capacitor embodiment comprises: a first conductor; a conductive nanomesh coupled to the first conductor; a first plurality of fixed CNTs in an ionic liquid and further coupled to the conductive nanomesh; and a plurality of free CNTs dispersed and moveable in the ionic liquid. Various methods of printing the CNTs and other structures, and methods of aligning and moving the CNTs using applied electric and magnetic fields, are also disclosed.

1 . A capacitor comprising:
 a first conductor;   a first plurality of fixed carbon nanotubes in an ionic liquid, each fixed carbon nanotube comprising a magnetic catalyst nanoparticle coupled to a carbon nanotube and further coupled to the first conductor; and   a first plurality of free carbon nanotubes dispersed and moveable in the ionic liquid.   
     
     
         2 . The capacitor of  claim 1 , wherein for each fixed carbon nanotube of the first plurality of fixed carbon nanotubes, the magnetic catalyst nanoparticle coupled to the first conductor supports the carbon nanotube at a first location, and wherein the capacitor further comprises:
 a support structure coupled to the first conductor and supporting one or more fixed carbon nanotubes of the first plurality of fixed carbon nanotubes at least at one or more second locations separate from and spaced apart from the first location.   
     
     
         3 . The capacitor of  claim 2 , wherein the support structure is separate and distinct from the first plurality of fixed carbon nanotubes. 
     
     
         4 . The capacitor of  claim 2 , wherein the support structure is a nanofiber support structure. 
     
     
         5 . The capacitor of  claim 4 , wherein the nanofiber support structure is formed by electrospinning a polymer, and wherein the polymer is at least one polymer selected from the group consisting of: polypyrolle; polianiline; polythiophene;
 polyterthiophene; derivatives of polythiophene and polyterthiophene; poly(3,4-ethylenedioxythiophene) (PEDOT); poly(3-(4-fluorophenyl)thiophene) (MPFT); poly(3-(3,4-difluorophenyl)thiophene) (MPFT); poly(3-(4-trifluoromethylphenyl)-thiophene) (PTFMPT); poly(1-cyano-2-(2-(3,4-ethylenedioxylthienyl))-1-(2-thienyl)vinylene (ThCNVEDT); poly(3-methyl thiophene)(PMeT); and mixtures thereof.   
     
     
         6 . The capacitor of  claim 2 , wherein the support structure is a screen and is spaced apart from the first conductor. 
     
     
         7 . The capacitor of  claim 2 , wherein the first conductor is coupled to a substrate or wherein the first conductor is a conductive substrate. 
     
     
         8 . The capacitor of  claim 7 , wherein the support structure is a plurality of elongated extensions or pillars extending from the substrate, or the first conductor, or the conductive substrate. 
     
     
         9 . The capacitor of  claim 7 , wherein the support structure is a plurality of walls or sides of a plurality of cavities of the substrate, or the first conductor, or the conductive substrate. 
     
     
         10 . The capacitor of  claim 1 , wherein for each fixed carbon nanotube of the first plurality of fixed carbon nanotubes, the magnetic catalyst nanoparticle is coupled to the carbon nanotube at a first end of the carbon nanotube. 
     
     
         11 . The capacitor of  claim 10 , wherein each fixed carbon nanotube of the first plurality of fixed carbon nanotubes is open or uncapped at a second end opposite the first end coupled to the magnetic catalyst nanoparticle. 
     
     
         12 . The capacitor of  claim 1 , wherein each carbon nanotube of the first plurality of free carbon nanotubes is open or uncapped at least at one end. 
     
     
         13 . The capacitor of  claim 1 , wherein each fixed carbon nanotube of the first plurality of fixed carbon nanotubes is single-walled and wherein each carbon nanotube of the first plurality of free carbon nanotubes is multi-walled or single-walled. 
     
     
         14 . The capacitor of  claim 1 , wherein each fixed carbon nanotube of the first plurality of fixed carbon nanotubes is substantially perpendicular to the plane of the first conductor. 
     
     
         15 . The capacitor of  claim 1 , wherein each carbon nanotube of the first plurality of fixed carbon nanotubes and each carbon nanotube of the first plurality of free carbon nanotubes has an interior diameter greater than a Helmholtz diameter of an ion of the ionic liquid. 
     
     
         16 . The capacitor of  claim 1 , wherein each carbon nanotube of the first plurality of fixed carbon nanotubes and each carbon nanotube of the first plurality of free carbon nanotubes has an interior diameter between about 0.5 nm and 1.5 nm. 
     
     
         17 . The capacitor of  claim 1 , wherein the ionic liquid is at least one ionic liquid selected from the group consisting of: butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-methyl-3-propylimidazolium iodide, 1-ethyl-3-methylimidazolium thiocyanate, 1-methyl-1-propylpiperidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-2-methylpyridinium bis(trifluoromethylsulfonyl)imide, 1-butyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, diethylmethylsulfonium bis(trifluoromethylsulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, and mixtures thereof. 
     
     
         18 . The capacitor of  claim 1 , wherein the magnetic catalyst nanoparticle is at least one catalyst selected from the group consisting of: cobalt, molybdenum, nickel, iron, ruthenium, mixtures thereof alloys thereof and their compounds. 
     
     
         19 . The capacitor of  claim 1 , wherein at least some of the carbon nanotubes of the first plurality of fixed carbon nanotubes and at least some of the carbon nanotubes of the first plurality of free carbon nanotubes has a chirality of (n, m) where n=m or where the quotient of m minus n is divided by three ((m−n)/3) is an integer. 
     
     
         20 . The capacitor of  claim 1 , further comprising:
 a semipermeable membrane.   
     
     
         21 . The capacitor of  claim 20 , wherein the semipermeable membrane comprises polytetrafluoroethylene (PTFE). 
     
     
         22 . The capacitor of  claim 20 , wherein the first plurality of free carbon nanotubes are not coupled to the first conductor, are not coupled to the first plurality of fixed carbon nanotubes, and are not coupled to the semipermeable membrane. 
     
     
         23 . The capacitor of  claim 1 , wherein the first plurality of free carbon nanotubes are translationally and rotationally moveable in the ionic liquid. 
     
     
         24 . The capacitor of  claim 1 , wherein the first plurality of fixed carbon nanotubes and the first conductor form a first electrode, and wherein the capacitor further comprises:
 a semipermeable membrane between the first electrode and a second electrode, the second electrode comprising:   a second conductor;   a second plurality of fixed carbon nanotubes in the ionic liquid, each fixed carbon nanotube comprising a magnetic catalyst nanoparticle coupled to a carbon nanotube and further coupled to the second conductor; and   a second plurality of free carbon nanotubes moveable in the ionic liquid.   
     
     
         25 . A capacitor comprising:
 a first conductor;   a first conductive nanomesh coupled to the first conductor;   a first plurality of fixed carbon nanotubes in an ionic liquid and further coupled to the first conductive nanomesh; and   a first plurality of free carbon nanotubes dispersed and moveable in the ionic liquid.   
     
     
         26 . The capacitor of  claim 25 , wherein the first conductive nanomesh is metallic. 
     
     
         27 . The capacitor of  claim 26 , wherein the first conductive nanomesh comprises gold or palladium nanorods. 
     
     
         28 . The capacitor of  claim 25 , wherein the first conductive nanomesh comprises metallic nanorods having a diameter of less than about  100  nm and a length between about 200 nm and about 1.0 microns. 
     
     
         29 . The capacitor of  claim 25 , wherein the first conductor is coupled to a substrate or wherein the first conductor is a conductive substrate. 
     
     
         30 . The capacitor of  claim 25 , wherein each fixed carbon nanotube of the first plurality of fixed carbon nanotubes is open or uncapped at least at one end and wherein each carbon nanotube of the first plurality of free carbon nanotubes is open or uncapped at least at one end. 
     
     
         31 . The capacitor of  claim 25 , wherein each fixed carbon nanotube of the first plurality of fixed carbon nanotubes is single-walled. 
     
     
         32 . The capacitor of  claim 25 , wherein each carbon nanotube of the first plurality of free carbon nanotubes is multi-walled or single-walled. 
     
     
         33 . The capacitor of  claim 25 , wherein each carbon nanotube of the first plurality of fixed carbon nanotubes and each carbon nanotube of the first plurality of free carbon nanotubes has an interior diameter greater than a Helmholtz diameter of an ion of the ionic liquid. 
     
     
         34 . The capacitor of  claim 25 , wherein each carbon nanotube of the first plurality of fixed carbon nanotubes and each carbon nanotube of the first plurality of free carbon nanotubes has an interior diameter between about 0.5 nm and 1.5 nm. 
     
     
         35 . The capacitor of  claim 25 , wherein the ionic liquid is at least one ionic liquid selected from the group consisting of: butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-methyl-3-propylimidazolium iodide, 1-ethyl-3-methylimidazolium thiocyanate, 1-methyl-1-propylpiperidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-2-methylpyridinium bis(trifluoromethylsulfonyl)imide, 1-butyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, diethylmethylsulfonium bis(trifluoromethylsulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, and mixtures thereof. 
     
     
         36 . The capacitor of  claim 25 , wherein each fixed carbon nanotube of the first plurality of fixed carbon nanotubes is substantially perpendicular to the plane of the first conductor. 
     
     
         37 . The capacitor of  claim 25 , wherein at least some of the carbon nanotubes of the first plurality of fixed carbon nanotubes are metallic, conductive or ballistic. 
     
     
         38 . The capacitor of  claim 25 , wherein at least some of the carbon nanotubes of the first plurality of fixed carbon nanotubes and at least some of the carbon nanotubes of the first plurality of free carbon nanotubes has a chirality of (n, m) where n=m or where the quotient of m minus n is divided by three ((m−n)/3) is an integer. 
     
     
         39 . The capacitor of  claim 25 , further comprising:
 a semipermeable membrane.   
     
     
         40 . The capacitor of  claim 39 , wherein the semipermeable membrane comprises polytetrafluoroethylene (PTFE). 
     
     
         41 . The capacitor of  claim 40 , wherein the first plurality of free carbon nanotubes are not coupled to the first conductor, are not coupled to the first plurality of fixed carbon nanotubes, and are not coupled to the semipermeable membrane. 
     
     
         42 . The capacitor of  claim 25 , wherein the first plurality of free carbon nanotubes are translationally and rotationally moveable in the ionic liquid. 
     
     
         43 . The capacitor of  claim 25 , wherein the first plurality of fixed carbon nanotubes, the first conductive nanomesh and the first conductor form a first electrode, and wherein the capacitor further comprises:
 a semipermeable membrane between the first electrode and a second electrode, the second electrode comprising:   a second conductor;   a second conductive nanomesh coupled to the second conductor;   a second plurality of fixed carbon nanotubes in an ionic liquid and further coupled to the second conductive nanomesh; and   a second plurality of free carbon nanotubes dispersed and moveable in the ionic liquid.   
     
     
         44 . A capacitor comprising:
 a first conductor;   a first plurality of fixed carbon nanotubes in an ionic liquid, each fixed carbon nanotube comprising a magnetic catalyst nanoparticle coupled to a carbon nanotube and further coupled at a first location to the first conductor;   a support structure coupled to the first conductor and supporting one or more fixed carbon nanotubes of the first plurality of fixed carbon nanotubes at least at one or more second locations separate from and spaced apart from the first location; and   a first plurality of free carbon nanotubes dispersed and moveable in the ionic liquid.   
     
     
         45 . A capacitor comprising:
 a first conductor;   a metallic nanomesh coupled to the first conductor, the metallic nanomesh comprising gold or palladium nanorods having a diameter of less than about 100 nm and a length between about 200 nm and about 1.0 microns;   a plurality of fixed carbon nanotubes in an ionic liquid and further coupled to the metallic nanomesh; and   a plurality of free carbon nanotubes dispersed and moveable in the ionic liquid.