Abstract: Various examples are provided for vertically aligned ultra-high density nanowires and their transfer onto flexible substrates. In one example, a method includes forming a plurality of vertically aligned nanowires inside channels of an anodized alumina (AAO) template on an aluminum substrate, where individual nanowires of the plurality of vertically aligned nanowires extend to a distal end from a proximal end adjacent to the aluminum substrate; removing the aluminum substrate and a portion of the AAO template to expose a surface of the AAO template and a portion of the proximal end of the individual nanowires; depositing an interlayer on the exposed surface of the AAO template and the exposed portion of the individual nanowires; and removing the AAO template from around the plurality of vertically aligned nanowires embedded in the interlayer.

Abstract: Various examples related to fabrication of thermally stable ultra-high density particle-in-cavity (PIC) nanostructures. In one example, a method includes disposing an anodized aluminum oxide (AAO) template onto a surface of a substrate; removing, from the AAO template, a support layer disposed on a side of the AAO template opposite the surface of the substrate; etching nanocavities into the surface of the substrate using the AAO template as an etch mask; and removing the AAO template from the surface of the substrate. The method can include fabricating the AAO template on an aluminum substrate by anodization of an aluminum film and removing the AAO template from the aluminum substrate after formation of the support layer on the AAO template.

Abstract: Various methods and systems are provided for cryogenic heat transfer by nanoporous surfaces. In one embodiment, among others, a system includes a cryogenic fluid in a flow path of the system; and a system component in the flow path that includes a nanoporous surface layer in contact with the cryogenic fluid. In another embodiment, a method includes providing a cryogenic fluid; and initiating chilldown of a cryogenic system by directing the cryogenic fluid across a nanoporous surface layer disposed on a surface of a system component.

Abstract: Various examples related to fabrication of thermally stable ultra-high density particle-in-cavity (PIC) nanostructures. In one example, a method includes disposing an anodized aluminum oxide (AAO) template onto a surface of a substrate; removing, from the AAO template, a support layer disposed on a side of the AAO template opposite the surface of the substrate; etching nanocavities into the surface of the substrate using the AAO template as an etch mask; and removing the AAO template from the surface of the substrate. The method can include fabricating the AAO template on an aluminum substrate by anodization of an aluminum film and removing the AAO template from the aluminum substrate after formation of the support layer on the AAO template.

Abstract: Various examples are provided for vertically aligned ultra-high density nanowires and their transfer onto flexible substrates. In one example, a method includes forming a plurality of vertically aligned nanowires inside channels of an anodized alumina (AAO) template on an aluminum substrate, where individual nanowires of the plurality of vertically aligned nanowires extend to a distal end from a proximal end adjacent to the aluminum substrate; removing the aluminum substrate and a portion of the AAO template to expose a surface of the AAO template and a portion of the proximal end of the individual nanowires; depositing an interlayer on the exposed surface of the AAO template and the exposed portion of the individual nanowires; and removing the AAO template from around the plurality of vertically aligned nanowires embedded in the interlayer.

Abstract: The present disclosure describes a new type of selective nitrophobic surface membrane in a plasma actuator that separates oxygen from nitrogen in the atmosphere, thereby increasing the presence of oxygen near an exposed electrode of the plasma actuator. Accordingly, the plasma flow created in the presence of oxygen at the exposed electrode generates more force than plasma flow created in the presence of nitrogen.

Abstract: Various methods and systems are provided for cryogenic heat transfer by nanoporous surfaces. In one embodiment, among others, a system includes a cryogenic fluid in a flow path of the system; and a system component in the flow path that includes a nanoporous surface layer in contact with the cryogenic fluid. In another embodiment, a method includes providing a cryogenic fluid; and initiating chilldown of a cryogenic system by directing the cryogenic fluid across a nanoporous surface layer disposed on a surface of a system component.

Abstract: The present disclosure describes a new type of selective nitrophobic surface membrane in a plasma actuator that separates oxygen from nitrogen in the atmosphere, thereby increasing the presence of oxygen near an exposed electrode of the plasma actuator. Accordingly, the plasma flow created in the presence of oxygen at the exposed electrode generates more force than plasma flow created in the presence of nitrogen.

Abstract: The subject invention provides a two-phase liquid-liquid extraction process that enables sorting and separation of single-walled carbon nanotubes based on (n, m) type and/or diameter. The two-phase liquid extraction method of the invention is based upon the selective reaction of certain types of nanotubes with electron withdrawing functional groups as well as the interaction between a phase transfer agent and ionic moieties on the functionalized nanotubes when combined in a two-phase liquid solution. Preferably, the subject invention enables efficient, bulk separation of metallic/semi-metallic nanotubes from semi-conducting nanotubes. More preferably, the subject invention enables efficient, bulk separation of specific (n, m) types of nanotubes.

Abstract: Various methods and systems are provided for reducing elasto-capillary coalescence of nanostructures. In one embodiment, a method includes providing a plurality of wet nanostructures on an electrode with a counter electrode positioned in air opposite the wet nanostructures. An electric field is applied between the counter electrode and the wet nanostructures using a voltage source, thereby reducing aggregation of the nanostructures. In another embodiment, an elasto-capillary coalescence reduction apparatus includes an electrode configured to receive a plurality of wet nanostructures, a counter electrode positioned in air opposite the wet nanostructures, and a voltage source coupled to the electrode and the counter electrode. The voltage source is configured to apply an electric field across the electrode and the nanostructures, which causes each of the nanostructures to repel a neighboring nanostructure.

Abstract: Various methods and systems are provided for preparing a polymer nanocomposite. In one embodiment, among others, a method includes providing a first immiscible solution including an aqueous solution including polymer-coated nanoparticles and a first monomer and a second immiscible solution including an organic solution including a second monomer. The first and second immiscible solutions are in contact along an interface. A polymer nanocomposite, including the polymer-coated nanoparticles dispersed within the polymer matrix, is extracted from the interface. In another embodiment, a system includes a vessel and an extraction assembly. The vessel includes a first immiscible solution layer in contact with a second immiscible solution layer along an interface. The first immiscible solution layer includes an aqueous solution including polymer-coated nanoparticles and a first monomer. The second immiscible solution layer includes an organic solution including a second monomer.

Abstract: Polymer coated carbon nanotube (NT) particles having NT particles with a solid polymer layer around the surface of each NT particle are presented. The NT particles can be isolated NTs or can include bundles of NTs. A method for preparation of the polymer coated carbon NT particles involves an aqueous dispersion that has a water insoluble first monomer contained in an emulsion-like nano-environment about the NT particles that undergoes an interfacial polymerization with a water soluble second monomer added to the dispersion.

Abstract: In embodiments of the invention, bundles of carbon nanotubes are separated from individual nanotubes via interfacial trapping of bundled carbon nanotube bundles at an emulsion interface between suspension-phase and a solution-phase. The separation method comprises dispersing a mixture of individual and bundled carbon nanotubes in a solution comprising surfactant; adding at least one solvent to the surfactant solution to form a two-phase mixture; agitating the two-phase mixture to form an emulsion interface between the solution-phase and a suspension-phase, where nanotube bundles selectively segregate to the emulsion interface. Single-walled carbon nanotube suspensions exhibit strong fluorescence, which can be used to assess the degree of separation and determine if a repeated extraction of any remaining bundled carbon nanotubes remaining in the suspension-phase is desired. In another embodiment of the invention, separation of carbon nanotubes by type is carried out by interfacial trapping.

Abstract: The subject invention provides a two-phase liquid-liquid extraction process that enables sorting and separation of single-walled carbon nanotubes based on (n, m) type and/or diameter. The two-phase liquid extraction method of the invention is based upon the selective reaction of certain types of nanotubes with electron withdrawing functional groups as well as the interaction between a phase transfer agent and ionic moieties on the functionalized nanotubes when combined in a two-phase liquid solution. Preferably, the subject invention enables efficient, bulk separation of metallic/semi-metallic nanotubes from semi-conducting nanotubes. More preferably, the subject invention enables efficient, bulk separation of specific (n, m) types of nanotubes.

Abstract: In accordance with the invention there are systems and methods of separating a mixture of carbon nanotubes comprising dispersing carbon nanotubes into a fluid to form a dispersion of individually-suspended carbon nanotubes and focusing the dispersion of individually-suspended carbon nanotubes into a single file stream of carbon nanotubes. The methods can also include characterizing the single file stream of carbon nanotubes and sorting the carbon nanotubes based on their properties.