The present invention provides: a film that comprises single-layer carbon nanotubes having shapes which enable the characteristics thereof to be sufficiently exhibited; and a process for producing the film. The film, which comprises single-layer carbon nanotubes, has portions where single-layer carbon nanotubes are densely present and portions where single-layer carbon nanotubes are sparsely present, the dense portions forming a pseudo-honeycomb structure in a surface of the film.

A method of producing a composite product is provided. The method includes providing a fluidized bed of carbon-based particles in a fluidized bed reactor, providing a catalyst or catalyst precursor in the fluidized bed reactor, providing a carbon source in the fluidized bed reactor for growing carbon nanotubes, growing carbon nanotubes in a carbon nanotube growth zone of the fluidized bed reactor, and collecting a composite product comprising carbon-based particles and carbon nanotubes.

A method termed “superacid-surfactant exchange” (S2E) for the dispersion of carbon nanomaterials in aqueous solutions. This S2E method enables nondestructive dispersion of carbon nanomaterials (including single-walled carbon nanotubes, double-walled carbon nanotubes, multi-wall carbon nanotubes, and graphene) at rapidly and at large scale in aqueous solution without a requirement for expensive or complicated equipment. Dispersed carbon nanotubes obtained from this method feature long length, low defect density, high electrical conductivity, and in the case of semiconducting single-walled carbon nanotubes, bright photoluminescence in the near-infrared.

A method termed “superacid-surfactant exchange” (S2E) for the dispersion of carbon nanomaterials in aqueous solutions. This S2E method enables nondestructive dispersion of carbon nanomaterials (including single-walled carbon nanotubes, double-walled carbon nanotubes, multi-wall carbon nanotubes, and graphene) at rapidly and at large scale in aqueous solution without a requirement for expensive or complicated equipment. Dispersed carbon nanotubes obtained from this method feature long length, low defect density, high electrical conductivity, and in the case of semiconducting single-walled carbon nanotubes, bright photoluminescence in the near-infrared.

There is provided a pH responsive optical nanoprobe comprising metallic SWCNTs or graphene coated with a transition metal M. The coated metallic SWCNTs or graphene have an absorption spectrum comprising an optical resonance, and have a Raman scattering spectrum responsive to optical excitation at said optical resonance comprising at least one pH-dependent peak having at least one of a Raman shift value and an intensity that is function of a solution pH, when the nanoprobe is in contact with a solution at said solution pH. There is also provided a method to measure the pH of a solution, by contacting the solution with the nanoprobe; illuminating the nanoprobe with an excitation light beam having a wavelength at said optical resonance, thereby generating a Raman signal from the nanoprobe according to said Raman scattering spectrum; measuring a spectral distribution of the Raman signal; and determining the pH of the solution from the spectral distribution.

Ultrasensitive, miniaturized, and inexpensive ion and ionizing radiation detection devices are provided. The devices include an insulating substrate, metallic contact pads disposed on a surface of the substrate, and a strip of an ultrathin two-dimensional material having a thickness of one or a few atomic layers. The strip is in contact with the contact pads, and a voltage is applied across the two-dimensional sensor material. Individual ions contacting the two-dimensional material alter the current flowing through the material and are detected. The devices can be used in a network of monitors for high energy ions and ionizing radiation.

A density of a nanofiber sheet can be changed using an edged surface, and in particular an arcuate edged surface. As described herein, a nanofiber sheet is drawn over (and in contact with) an arcuate edged surface. Depending on whether the arcuate surface facing a direction opposite the direction in which the nanofiber sheet is being drawn is convex or concave determines whether the nanofiber sheet density is increased relative to the as-drawn sheet or decreased relative to the as-drawn sheet.

Described are methods for preparing radionuclides, such as radionuclides having a high specific activity. The disclosed methods include irradiating target nuclide materials, in solution, with a neutron source. The radionuclides can be separated from the target nuclide material by providing a solid carbon nanostructured material, as a suspension of solids, proximal to the target nuclide material in solution and using the recoil to drive adsorption of the radionuclide onto the solid carbon nanostructured material to transfer the radionuclides from the liquid phase (in solution) to the solid phase (adsorbed to the suspended solid carbon nanostructured material). One or more surfactants can be incorporated into the solution to facilitate formation of a stable suspension of the solid carbon nanostructured material.

Described are methods for preparing radionuclides, such as radionuclides having a high specific activity. The disclosed methods include irradiating target nuclide materials, in solution, with a neutron source. The radionuclides can be separated from the target nuclide material by providing a solid carbon nanostructured material, as a suspension of solids, proximal to the target nuclide material in solution and using the recoil to drive adsorption of the radionuclide onto the solid carbon nanostructured material to transfer the radionuclides from the liquid phase (in solution) to the solid phase (adsorbed to the suspended solid carbon nanostructured material). One or more surfactants can be incorporated into the solution to facilitate formation of a stable suspension of the solid carbon nanostructured material.

Provided is a fibrous carbon nanostructure that is easy to surface modify. A symmetry factor of a peak of a first derivative curve of a thermogravimetric curve obtained through thermogravimetric analysis of the fibrous carbon nanostructure in a dry air atmosphere is 3.70 or less. The first derivative curve of the thermogravimetric curve can be a temperature derivative curve of the thermogravimetric curve or a time derivative curve of the thermogravimetric curve.