Abstract:
Conventional rechargeable batteries, such as lithium-ion batteries, are somewhat limited in their energy storage density. Sulfur-based batteries can provide improved energy storage density, but their use can be hampered by sulfur's low electrical conductivity. Energy storage devices, particularly batteries, can have a first electrode that includes a carbon nanotube aerogel, and an electroactive material containing sulfur that is incorporated in the carbon nanotube aerogel. Methods for forming an energy storage device can include incorporating an electroactive material containing sulfur in a carbon nanotube aerogel, compressing the carbon nanotube aerogel to form a compressed carbon nanotube aerogel, and disposing a first electrode containing the compressed carbon nanotube aerogel and the electroactive material in an electrolyte with a second electrode and a plurality of lithium ions, such that a separator material permeable to the lithium ions is between the first electrode and the second electrode.
Abstract:
Compressed carbon nanotube aerogel materials can be used in heat management and thermal shielding applications. Methods for heat management and thermal shielding of an object can include placing a compressed carbon nanotube aerogel material between an object and its surrounding environment, and establishing a thermal gradient within the compressed carbon nanotube aerogel material by exposing the compressed carbon nanotube aerogel material to the object or to the surrounding environment. When the object and the surrounding environment are in thermal communication with one another, the compressed carbon nanotube aerogel material can reduce an amount of heat transferred between the object and the surrounding environment. As a result of establishing the thermal gradient within the compressed carbon nanotube aerogel material, an electric current may be generated in some instances.
Abstract:
Identifying marks are often used for authentication and tracking purposes with various types of articles, but they can sometimes be subject to replication or removal by an outside entity, such as a person or group having malicious intent. Carbon nanotubes and other carbon nanomaterials can be used to form identifying marks that are not visible to the naked eye, thereby making the marks more difficult for an outside entity to tamper with. Various articles can include an identifying mark that is not visible to the naked eye, the identifying mark containing a nanomaterial that includes a plurality of carbon nanotubes with a registered distribution of chiralities. The registered distribution of chiralities can be further tailored to increase the level of security provided by the mark.
Abstract:
Methods for fabricating graphene nanoelectronic devices with semiconductor compatible processes, which allow wafer scale fabrication of graphene nanoelectronic devices, is provided. One method includes the steps of preparing a dispersion of functionalized graphene in a solvent; and applying a coating of said dispersion onto a substrate and evaporating the solvent to form a layer of functionalized graphene; and defunctionalizing the graphene to form a graphene layer on the substrate.
Abstract:
Polymer composites containing carbon nanotubes often exhibit high glass transition temperatures, which can complicate their use in additive manufacturing processes. Extruded filaments containing carbon nanotubes and residual solvent can have desirably lowered glass transition temperatures. Extruded filaments can contain a polymer as a continuous phase, a nanomaterial such as carbon nanotubes homogeneously mixed throughout the continuous phase, and above 0% to about 15% solvent by weight. Methods for making extruded filaments can include producing a solvated composite by dissolving a polymer and a nanomaterial in a solvent, producing a partially desolvated composite by reducing a solvent content of the solvated composite to a range of about 10% to about 30% by weight, forming particles of the partially desolvated composite, supplying the particles to an extruder, and extruding a filament having the polymer as a continuous phase and the nanomaterial homogeneously mixed throughout the continuous phase, which also contains residual solvent.
Abstract:
Polymer composites containing carbon nanotubes often exhibit high glass transition temperatures, which can complicate their use in additive manufacturing processes. Extruded filaments containing carbon nanotubes and residual solvent can have desirably lowered glass transition temperatures. Extruded filaments can contain a polymer as a continuous phase, a nanomaterial such as carbon nanotubes homogeneously mixed throughout the continuous phase, and above 0% to about 15% solvent by weight. Methods for making extruded filaments can include producing a solvated composite by dissolving a polymer and a nanomaterial in a solvent, producing a partially desolvated composite by reducing a solvent content of the solvated composite to a range of about 10% to about 30% by weight, forming particles of the partially desolvated composite, supplying the particles to an extruder, and extruding a filament having the polymer as a continuous phase and the nanomaterial homogeneously mixed throughout the continuous phase, which also contains residual solvent.
Abstract:
Compressed carbon nanotube aerogel materials can be used in heat management and thermal shielding applications. Methods for heat management and thermal shielding of an object can include placing a compressed carbon nanotube aerogel material between an object and its surrounding environment, and establishing a thermal gradient within the compressed carbon nanotube aerogel material by exposing the compressed carbon nanotube aerogel material to the object or to the surrounding environment. When the object and the surrounding environment are in thermal communication with one another, the compressed carbon nanotube aerogel material can reduce an amount of heat transferred between the object and the surrounding environment. As a result of establishing the thermal gradient within the compressed carbon nanotube aerogel material, an electric current may be generated in some instances.
Abstract:
Methods for fabricating graphene nanoelectronic devices with semiconductor compatible processes, which allow wafer scale fabrication of graphene nanoelectronic devices, is provided. One method includes the steps of preparing a dispersion of functionalized graphene in a solvent; and applying a coating of said dispersion onto a substrate and evaporating the solvent to form a layer of functionalized graphene; and defunctionalizing the graphene to form a graphene layer on the substrate.
Abstract:
Identifying marks are often used for authentication and tracking purposes with various types of articles, but the marks themselves can sometimes be subject to replication or removal by an outside entity, such as a person or group having malicious intent. This can make it easier for an outside entity to produce a counterfeit article or to sell a stolen article. Carbon nanotubes and other carbon nanomaterials can be used to form identifying marks that are not visible to the naked eye, thereby making the marks more difficult for an outside entity to tamper with. Various articles can include an identifying mark that is localized and not visible to the naked eye, the identifying mark being electrically conductive and containing a carbon nanomaterial. By electrically interrogating the article, such as through spatially measuring eddy currents about the article, the marks can be located and authenticated.
Abstract:
Metal nitride coatings containing carbon can be either electrically conductive or substantially non-conductive depending on the degree to which they have been exposed to an oxidative environment. Substantially non-conductive metal nitride coatings can be used as protective layers in electrical devices. Particularly in an electrical device containing carbon nanomaterials, the metal nitride coatings can be used to mask the device's operational characteristics. Such devices can contain an electrical interconnect containing a carbon nanomaterial and a substantially non-conductive coating on the carbon nanomaterial. The substantially non-conductive coating can contain at least one substantially non-conductive metal nitride layer and at least some carbon. Methods for making such devices and metal nitride coatings are also described herein.