Carbon black, superconductive

Other unusual additives include oxetanes, vinylic macromono-mers, silicon carbide, superconductive carbon blacks, silver-coated fly ash, metal oxides, Tb for green emission, antibacterial agents, and organic-inorganic hybrid copolymer fibers. In an interesting reversal, transition element acetylacetonate salts were decomposed in a PDMS matrix to give membranes with catalytic activity. ... 

Very pure superconductive carbon blacks are produced by Akzo Nobel under the name Ketjenblack. Due to their unique morphology, substantially lower amounts can be used compared with conventional blacks, giving improved processing and mechanical properties for electroconductive products. 

Additives used in final products Fiiiers aramid fiber, caicium carbonate, carbon black, carbon fiber, carbon nanotubes, glass beads, glass fiber, iron powder, metal flakes, nano-CaCOj (nucleating agent), PTFE fiber, talc, zinc whisker Antistatics polyetheresteramide, quaternary ammonium compound, superconductive carbon black Release fluoropolymer, N,N -ethylene bisstearamide, paintable silicone Slip PTFE Thermal stabilizer triethanolamine ... 

Nevertheless the heat capacity of a carbon resistor was not so low as that of crystalline materials used later. More important, carbon resistors had an excess noise which limited the bolometer performance. In 1961, Low [61] proposed a bolometer which used a heavily doped Ge thermometer with much improved characteristics. This type of bolometer was rapidly applied to infrared astronomy as well also to laboratory spectroscopy. A further step in the development of bolometers came with improvements in the absorber. In the early superconducting bolometer built by Andrews et al. (1942) [62], the absorber was a blackened metal foil glued to the 7A thermometer. Low s original bolometer [61] was coated with black paint and Coron et al. [63] used a metal foil as substrate for the black-painted absorber. A definite improvement is due to J. Clarke, G. I. Hoffer, P. L. Richards [64] who used a thin low heat capacity dielectric substrate for the metal foil and used a bismuth film absorber instead of the black paint. 

Fullerene, black and shiny like graphite, is the subject of active current research because of its interesting electronic properties. When allowed to react with rubidium metal, a superconducting material called rubidium fulleride, Rb3C6o, is formed. (We ll discuss superconductors in more detail in Section 21.6.) Carbon nanotubes are being studied for use as fibers in the structural composites used to make golf clubs, bicycle frames, boats, and airplanes. On a mass basis, nanotubes are up to ten times as strong as steel. 

The necessity of concision has led to some restrictions. We have eliminated recapitulations, for example, thermodynamics or ciystallograplty we have not discussed materials that seemed far from the interests of our potential readers, such as monociystals (jeweliy and technical uses), ceramics for chemistry (catalysis and filtration), or superconductive oxides finally, we have not dealt with black ceramics (graphite and carbons) or with deposits of diamond or hard carbon. 

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