A method of separating and extracting carbon nanotubes, the method includes introducing the carbon nanotubes into a two-phase system that includes a first component and a second component, the first component being different from the second component. The method includes introducing a chemical agent into the two-phase system, mixing the chemical agent and the carbon nanotubes in the two-phase system, removing the first component to extract a first portion of the carbon nanotubes contained in the first component after the mixing, replenishing the two-phase system with fresh first component, and extracting a second portion of the carbon nanotubes contained in the fresh first component. A bandgap of the carbon nanotubes in the first portion is different from the bandgap of the carbon nanotubes in the second portion.

A method of separating and extracting carbon nanotubes, the method includes introducing the carbon nanotubes into a two-phase system that includes a first component and a second component, the first component being different from the second component. The method includes introducing a chemical agent into the two-phase system, mixing the chemical agent and the carbon nanotubes in the two-phase system, removing the first component to extract a first portion of the carbon nanotubes contained in the first component after the mixing, replenishing the two-phase system with fresh first component, and extracting a second portion of the carbon nanotubes contained in the fresh first component. A bandgap of the carbon nanotubes in the first portion is different from the bandgap of the carbon nanotubes in the second portion.

Methods for characterizing a nanotube formulation with respect to one or more particular ionic species are disclosed. Within the methods of the present disclosure, this characterization provides control over the surface roughness (or smoothness) and the degree of rafting within a nanotube fabric formed form such a nanotube formulation. In one aspect, the present disclosure provides a nanotube formulation roughness curve (and methods for generating such a curve) that can be used to select a utilizable range of ionic species concentration levels that will provide a nanotube fabric with a desired surface roughness (or smoothness) and degree of rafting. In some aspects of the present disclosure, such a nanotube formulation roughness curve can be used adjust nanotube formulation prior to a nanotube formulation deposition process to provide nanotube fabrics that are relatively smooth with a low degree of rafting.

Methods for characterizing a nanotube formulation with respect to one or more particular ionic species are disclosed. Within the methods of the present disclosure, this characterization provides control over the surface roughness (or smoothness) and the degree of rafting within a nanotube fabric formed form such a nanotube formulation. In one aspect, the present disclosure provides a nanotube formulation roughness curve (and methods for generating such a curve) that can be used to select a utilizable range of ionic species concentration levels that will provide a nanotube fabric with a desired surface roughness (or smoothness) and degree of rafting. In some aspects of the present disclosure, such a nanotube formulation roughness curve can be used adjust nanotube formulation prior to a nanotube formulation deposition process to provide nanotube fabrics that are relatively smooth with a low degree of rafting.

An agglomerated solid material comprising loose carbon nanotubes and that is free from organic compounds is described, as well as the method of preparation thereof, and uses thereof, where the agglomerated solid material consists of a continuous network of carbon nanotubes comprising aggregates of carbon nanotubes with an average size d50 under 5 m, in a proportion below 60% by area, determined by image analysis by electron microscopy and has an apparent density between 0.01 g/cm.sup.3 and 2 g/cm.sup.3.

An agglomerated solid material comprising loose carbon nanotubes and that is free from organic compounds is described, as well as the method of preparation thereof, and uses thereof, where the agglomerated solid material consists of a continuous network of carbon nanotubes comprising aggregates of carbon nanotubes with an average size d50 under 5 m, in a proportion below 60% by area, determined by image analysis by electron microscopy and has an apparent density between 0.01 g/cm.sup.3 and 2 g/cm.sup.3.

A hydrophilic graphitic material is provided that may be formed by heating a graphitic material to a temperature between about 150 C. to about 1400 C. for an extended period of time under an inert atmosphere. Annealing CNT film at 500 to 1400 removes amorphous carbon to produce purified CNT film. The purified CNT film can be further densified with the treatment of alkylphosphonic acid or alkyldiphophonic acid and heating to produce a hydrophilic, densified CNT film which is mechanically robust and does not adhere to other solid surfaces. These films can be used as filtration membranes with superior membrane fouling resistance among other uses.

A hydrophilic graphitic material is provided that may be formed by heating a graphitic material to a temperature between about 150 C. to about 1400 C. for an extended period of time under an inert atmosphere. Annealing CNT film at 500 to 1400 removes amorphous carbon to produce purified CNT film. The purified CNT film can be further densified with the treatment of alkylphosphonic acid or alkyldiphophonic acid and heating to produce a hydrophilic, densified CNT film which is mechanically robust and does not adhere to other solid surfaces. These films can be used as filtration membranes with superior membrane fouling resistance among other uses.

A cross-flow filtration device includes: a filter module which includes an inner chamber and an outer chamber separated by a semipermeable membrane; a process liquid tank which is configured to accommodate a process liquid; a pump which is configured to cause the process liquid to circulate to the inner chamber in the filter module and the process liquid tank; a replenisher tank which is configured to accommodate a replenisher liquid to be replenished into the process liquid tank, at least one or more sensors which are configured to measure a pressure of the circulating process liquid; and a replenisher measurement unit which is configured to measure an amount of the replenisher liquid supplied from the replenisher tank to the process liquid tank. The process liquid tank is configured to be continuously replenished with the replenisher liquid.

A method for carbon nanotube purification, preferably including: providing carbon nanotubes; depositing a mask; and/or selectively removing a portion of the mask; and optionally including removing a subset of the carbon nanotubes and/or removing the remaining mask.