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The ability of thermal carbon analysis to determine CNTs was evaluated in the presence of a polymer (Polystyrene, PS). Samples placed in an Au (Pt) foil boat were measured using a thermal-carbon analyzer, and the results were compared with gravimetric measurements of sample masses obtained using an ultra-microbalance. First, debris from the polymer without CNTs (i.e., PS debris) was analyzed. The amount of PS debris detected in the organic carbon (OC) fraction was found to be in good agreement with the gravimetrically measured mass of the PS debris, while the amount of pyrolyticallygenerated carbon soot detected in the elemental carbon (EC) fraction was negligible. Next, single-wall CNT (AIST/TASC Super-Growth) powder was analyzed, and the amount of the CNT powder detected in the EC fraction was found to be 95-96% of the gravimetrically measured mass of the CNT powder. Subsequently, a mixture of the PS debris and the CNT powder was analyzed, and the amounts of detected OC and EC were found to be comparable to the gravimetrically measured masses of the PS debris and the CNT powder, respectively. Finally, debris from 5 wt% CNT-PS composites was analyzed, and amounts of OC and EC detected were found to be approximately comparable to the estimated masses of the PS and the CNTs in the debris of CNT-PS composite, respectively. The results therefore indicate thermal carbon analysis is capable of determining CNTs in the presence of PS.

The aerosol particles released during the grinding of polystyrene (PS)-based composites with well- and poorly dispersed single-wall carbon nanotubes (CNTs) and multiwall CNTs were measured using real-time aerosol measuring instruments. Increases in the concentration of aerosol particles were recorded during the grinding of the samples. However, similar increases were observed even when CNT-free polystyrene was ground. Electron microscopic analysis of the released particles revealed that particles with protruding CNTs were observed for the well-dispersed CNT-PS composites, but free-standing CNTs were not found. On the other hand, particles like agglomerated CNTs were found for the poorly dispersed CNT-PS composites.

The performance characteristics of gap type arresters used in 6kV distribution systems were observed to change with repetitive operations at a large impulse current. It is considered that the change of the performance is due to both the contamination of a spacer holding the gap and the physical and chemical changes of surface conditions of the gap electrodes. The effects of the electrode surface conditions on the arrester performance are still not clear. In this study, the relationship between the change of the 50% flashover voltage of an arrester and the physical and chemical changes of electrode surface versus the number of operation times N is examined. The results obtained with an X-ray photoelectron spectroscope (XPS) and an electron probe micro-analyser are used.

We investigated the particle release caused by the grinding of polystyrene-based composites with and without single-wall carbon nanotubes (CNTs). In the results of real-time aerosol monitoring, considerable increases in the number concentration of nano-sized aerosol particles were observed during the grinding of both CNT-containing and CNT-free polystyrene. When a thermodenuder was used, the number of released nanoparticles was reduced by over 99.9%, indicating that the nanoparticles were presumably volatile particles released by the friction heat produced by grinding the composite. In an electron microscopic analysis of the aerosol particles, micron-sized particles with protruding fibers (probably CNTs) were observed, whereas free-standing CNTs were not observed.