Black carbon 840 INDEX

Harvey, O.R., Kuo, L.-J., Zimmerman, A.R., Louchouam, P., Amonette, J.E., Herbert, B.E., 2012. An index-based approach to assessing recalcitrance and soil carbon sequestration potential of engineered black carbons (biochars). Environmental Science Technology 46 (3), 1415-1421. http //dx.doi.org/10.1021/es2040398. 

Aromaticity is the most important property of a carbon black feedstock. It is generally measured by the Bureau of Mines Correlation Index (BMCI) and is an indication of the carbon-to-hydrogen ratio. The sulfur content is limited to reduce corrosion, loss of yield, and sulfur in the product. It may be limited in certain locations for environmental reasons. The boiling range must be low enough so that it will be completely volatilized under furnace time—temperature conditions. Alkane insolubles or asphaltenes must be kept below critical levels in order to maintain product quaUty. Excessive asphaltene content results in a loss of reinforcement and poor treadwear in tire appHcations. 

Recent advances in the application of ultrafine talc for enhanced mechanical and thermal properties have been studied [12]. A particularly important use is of finely divided filler in TPO as a flame-retardant additive. In a representative formulation, 37 parts of E-plastomer, Ml 2.0, density 0.92, 60 parts of amorphous EPR, and 4 parts of fine carbon black were dry blended, kneaded at 180°C, pelletized, and press molded into test pieces, which showed oxygen index 32 versus 31 in the absence of a filler. The oxygen index is a measure of flame retardancy. 

Notice that the carbon black hller reduces the rate of cut growth, but has only a small effect on the power index. Generally, it appears that abrasion occurs mainly in the third region, except when the abrasive track is very sharp. In this case the number of cycles to detach a small piece of rubber becomes small and the abrasion is proportional to the reciprocal of the energy density at break of the rubber compound. 

The precursors of the carbazoles are the anthrimides, in particular the 1,1 -dianthraquinonylamines (l,T-dianthrimides). These intermediates were originally used as vat dyes themselves, but very few give bright colours and the vatting process also brings about reduction to 1-aminoanthraquinone. Only one dianthrimide is currently active in the Colour Index [11] this grey vat dye is Cl Vat Black 28 (6.83). l,l -Dianthrimides are easily prepared by heating a 1-aminoanthraquinone with a 1-chloroanthraquinone in nitrobenzene or another solvent in the presence of sodium carbonate and a copper catalyst. 

One is a mixture of 1 % by particle volume of spherical absorbers with radius 0.05 jum and refractive index mbl = 1.7 + /0.7, which is appropriate to a form of carbon, and 99% by volume of larger particles with mwh = 1.55 + /10-6, which is roughly appropriate to several possible aerosol components. The subscripts bl (black) and wh (white) indicate how separate collections of these two kinds of particles would appear. Among the many optical constants reported for carbon in its various forms we have chosen those obtained from single-sphere measurements by Pluchino et al. (1980). 

SBR is the most widely used synthetic elastomer. It is an amorphous random copolymer consisting of a mixture of l.2, cis and trans isomers. Cold SBR produced at —20 C consists of 17% 1,2. 6% cis and 77% trans isomers of polybutadiene. This commercial product has a Tt of -60 C, an index of refraction of 1.534S, and a coefficient of linear expansion of 66 X 10 s cm/ cm C. Because of the high percentage of the trans isomer, it is less flexible and has a higher heat buildup, when flexed, than Hevea rubber. Although carbon black-filled or amorphous silica-filled SBR has useful physical and mechanical properties, the SBR gum rubber is inferior to Hevea rubber. 

By plotting the percentage of carbon particles separated from the vulcanizate versus the stress applied to the sample during extension, Hess et al. determined the stress at which the arbitrary quantity of 20% of the black had been separated from the matrix. This stress was indicated as the adhesion index. It appears (Fig. 12) that blacks of higher structures are associated with an increase of the adhesion index, i.e., with an enhancement of filler-elastomer interactions. 

It appears from the evolution of the adhesion index that a distinction has to be made between the interactions carbon blacks are able to have with unsaturated or with saturated (or near-to-saturated) elastomers. Thus, the adhesion index of butyl rubber is enhanced upon oxidation of the black, while the reverse is observed with polybutadiene 38). The improvement of the reinforcing ability of carbon black upon oxidation, in the former case, has been interpreted by Gessler 401 as due to chemical interactions of butyl rubber with active functional groups on the solid surface. Gessler, relating the reinforcing characteristics of the oxidized carbon black for butyl rubber to the presence of carboxyl groups on the surface of the filler, postulated a cationic... 

The top curve in Figure 8 applies to pigments with a high absorption index k and low refractive index rt (e.g., carbon black) and shows that the optimal particle size lies below a given limit. 

Important characteristics determining the quality of a feedstock are the C/H ratio as determined by elemental analysis and the BMC Index [4.7] (Bureau of Mines Correlation Index), which is calculated from the density and the mid-boiling point resp. the viscosity. Both values give some information on the aromaticity and therefore the expected yield. Further characteristics are viscosity, pourpoint, alkaline content (due to its influence on the carbon black structure), and sulfur content, which should be low because of environmental and corrosion considerations. 

In the additive approach, the loss index is increased by placing a high-loss material in contact with a low-loss material. The high-loss material heats and transfers its heat to the low-loss load. Some examples of such additives are carbon black in rubber, NaCl in urea-formaldehyde glue for wood and polyvinylchloride in polyurethane foam (2). 

Additive Approach. As mentioned previously, dimethylsilicone compounds respond poorly to microwave heating because of the low "loss index". To make the dimethylsilicone compounds respond to microwave, one can change the structure of polydiorganosiloxane as shown above, or introduce additives which have a high "loss index" such as carbon black. The latter was demonstrated by applying microwave (2450 M Hz) to a mixture of 10 g of base... 

Figure 1-4. Separation of fatty acids on pellicnlar graphitized carbon black from the mixture of ethanol and lO M aqueous NaOH. Refractive index detection. (Reprinted from reference 13, with permission.)...

Measured size distributions of salt particles are monomodal and can by parameterized by the power law, with the index varying within 0.97-4.2 (average 2.3-2.6). The density of MSA particles is close to 2.35 — 2.40 g/m The spatial distribution of Cn MSA (r > 1 pm) for different regions of the world ocean can be illustrated by the following values in the Pacific Ocean Cn = (1.2-1.5) cm in the Indian Ocean (0.9-1.0) cm" near the Australian coastline 0.4 cm near the boundaries of the Antarctic ice sheet (1.8-2.1) cm" and near the Black Sea coastline (0.32-1.93) cm" [8]. The vertical distribution of Cn MSA has some specific features. A maximum of Cn distribution is often observed at altitudes of several hundred meters (apparently, because of a decrease in the Cn MSA near the water surface, resulting from the capture of salt particles by sea waves). At altitudes 2-3 km the value of Cn MSA constitutes < 1 % of the total Cn value, which is explained by the cloud filter . However, over land, near the coastline, at an altitude of 3 km, Cn MSA is somewhat higher than at the same level over the sea surface. This is connected with a more intensive turbulence over land. In general, sea-salt aerosol particles have to be chemically composed of dried sea water 88.7% chlorides, 70.8% sulfates, 0.3% carbonates, and 0.2% other salts. 

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