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The effect of applied thermal history on the rheological properties in a molten state and the electric properties in a solid state is evaluated using mechanically blended samples composed of polycarbonate and multiwalled carbon nanotubes (MWNTs). It is found that MWNTs orient perpendicular to the applied compression direction owing to the squeeze flow at compression molding, which is prominent for the sample compressed at low temperature. The orientation of MWNTs reduces the interparticle contacts between MWNTs and thus decreases the electrical conductivity. Postprocessing annealing procedure at high temperature, however, leads to random orientation due to Brownian motion and then improves the electrical conductivity. The transition from an electrical insulator to a conductor by the redistribution process, which is called dynamic percolation, is well detected by the rheological measurements. POLYM. COMPOS., 2011. © 2010 Society of Plastics Engineers

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Ultraviolet and C 1s and N 1s X-ray photoelectron spectra of a ferromagnetic charge-transfer complex, TDAE−C60, where TDAE is tetrakis(dimethylamino)ethylene, have been measured. The appearance of a new peak above the highest occupied band of C60 at 1.2 eV below the Fermi level with a peak onset of 0.5 eV indicates that an electron is transferred from TDAE to C60 and that TDAE−C60 is not metallic but semiconductive. The N 1s core spectrum of the complex shows a wide band consisting of two components, and the intensity of the higher binding energy one decreases under X-ray irradiation. The observed components could be ascribed to nitrogen atoms in TDAE0 and TDAE2+ on the basis of the electrostatic potential model in combination with the CNDO/2 molecular orbital calculation. Possible appearance of the charge density wave state along the TDAE chain in the c-direction of TDAE−C60 crystal has been suggested.

X-ray photoelectron spectra of four porphyrins which hardly aggregate were measured. The C1s and N1s peak positions of these porphyrins showed almost identical values, so that these values can be used as a standard.

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