Anisotropic carbon nanotube–polyester composites have been realized by polymerization of the nanotube–monomer dispersion in a constant magnetic field (see Figure for method). Magnetic susceptibilities, electrical conductivities, and mechanical properties of the composite show clear anisotropy, indicating magnetic field‐induced alignment of carbon nanotubes in the polymer matrix.

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A novel approach for selective diameter control of single-walled carbon nanotubes (SWNTs) is performed in the gas-phase growth using two kinds of carbon sources with different decomposition properties; the one carbon source (1st carbon source) is the organic solvent which is difficult to decompose in the reactor and the another carbon source (2nd carbon source) is facile to decompose. The diameter distributions of SWNTs synthesized with various conditions of the flow rate of the 2nd carbon source were investigated by resonant Raman scattering, optical absorption, and photoluminescence (PL) mapping measurements. It was found that increasing the flow rate of the ethylene tends to decrease the diameter of synthesized SWNTs, probably due to the earlier nucleation of SWNTs induced by the ethylene addition. The controlling the flow rate of the ethylene used as a 2nd carbon source can selectively tune the diameter distribution of SWNTs in our growth system.

Band gap photoluminescence (PL) is observed from "as-grown" single-walled carbon nanotubes (SWNTs) in solid form. The relative PL intensities for six specific semiconducting SWNTs are compared directly to those of the micelle-encapsulated SWNTs' solutions to investigate the influence of the micelle dispersion process on PL measurements. The results indicate that sodium dodecyl sulfate (SDS) and sodium cholate (SC) selectively solubilize smaller-diameter nanotubes, whereas sodium dodecylbenzene sulfonate (SDBS) solution does not exhibit significant diameter selectivity within the diameter range studied here (d(t) = 0.829-0.966 nm).

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