Carbon black conductivity

Rubber which is deliberately rendered electrically conductive by the inclusion in the unvulcanised mix of certain types of carbon black. Conductive rubber for use in, e.g., aircraft tyres has a resistivity below about 105 to 107 ohm-cm. The changeover from the use of channel blacks to oil-based furnace blacks has conferred a degree of conductivity (sometimes unwanted) on many black rubber products, and it should no longer be assumed that any black rubber is a good electrical insulator. See Antistatic Rubber. 

FIGURE 7.8 SEM pictures of a LiCo02 positive electrode (left) and of a surface-treated graphite negative electrode (right) both containing TIMREX KS6 graphite and SUPER P Li carbon black conductive additives. 

Conductivity in plastic coatings is achieved through the use of a conductive pigment, most often conductive carbon black. Conductivities of the order of 1 Mfl/cm2 are required for effective transfer efficiencies of subsequent topcoat applications. Without the use of a conductive primer, plastics in themselves would not be conductive, and hence would be very unreceptive to topcoat transfer efficiencies of greater than 20 percent. 

Another common reason to add a filler to a polymer is to increase either electrical conductivity or thermal conductivity. Polymers typically have electrical conductivity from 10 to 10 S/cm though the addition of a moderately conductive filler such as carbon black conductivities of lO -lO S/cm are possible highly conductive fillers such as silver can raise this value to 10 -10 S/cm. Applications include static dissipative devices and surge protectors. The impact of adding a highly thermally conductive filler to a polymer is much smaller at low-volume fractions vs. the impact of an electrically conductive filler on electrical conductivity. However, if a highly loaded stiff product is acceptable, polymer composites are capable of dissipating substantial amounts of heat. 

Carbou blacks are couductive, and this also influences their performance as a catalyst support, due to the shifting of electron density between them and the catalytic metal crystals on them. This not only allows for a more intimate interaction between the support and the catalytic metal, but it also provides another method to optimally adjust the reactant s adsorption strength for the best activity and selectivity. The level of carbon black conductivity was found to be a... 

Li Qiu yu, et al. 2011. Carbon black conductive fiber in the application of blended wool fabric [J]. Journal of wool spinning technology, 11(10) 103-106. 

Electrode is processed by spreading a paste containing activated carbon, polytetrafluoroethylene (binder), and carbon black (conducting agent) mixed in a solvent (n-methyl-2-pyroHdone) onto a current collector such as aluminum, then solvent is evaporated and material compressed into an electrode. 

The most suitable carbon blacks and typical ranges used are N 330, N 550 (up to 60 pphr), N 770 (up to 80 pphr), and N 990 (up to 100 pphr). N 220 can be used in a blend with other carbon blacks. Conductive compounds often use N 472 carbon black. 

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