Fraction of black carbon

The value of the partition coefficient, Kip, is given by the product, focKioc, where/ic and Kjoc apply only to the natural organic matter into which the sorbate can penetrate. The value of Kif is less well understood, but recent observations suggest it should be related to the quantity of adsorbent present (e.g., the fraction of black carbon in a solid matrix, /bc) and the particular compound s black-carbon-normalized adsorption coefficient (e.g., Klhc). Typical values of the Freundlich exponent are near 0.7. Hence, in a first approximation the data should fit ... 

The thickness is 2 nm for the GH layer and 3-8 nm for the SH layer, therefore the total thickness of the GH and SH layers is 5-10 nm. Generally, the thickness of the SH layer is smaller in fine carbon-filled mbber than in the coarse one. In the case of the fine carbon black like HAF, its diameter being about 30 nm, the thickness is 2 nm for the GH layer and 4—5 nm for the SH layer, for example. When the volume fraction of HAF carbon is 20% in SBR, the total thickness of both layers (6-7 nm) corresponds to the volume fraction of 30%-35% to the total mbber. The 2 nm thickness of the GH layer is a little less than 10% of the diameter of a fine carbon black (20-30 nm), but it is only 1% of that of a coarse carbon black (100-200 nm). 

Brodowski, S., Amelung, W., Haumaier, L., Abetz, C., and Zech, W. (2005). Morphological and chemical properties of black carbon in physical soil fractions as revealed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Geoderma 128, 116-129. 

The dispersion of agglomerates is strongly dependent on mixing time, rotor speed, temperature, and rotor blade geometry [3], Figure 3.28 [6,4] shows the fraction of undispersed carbon black as a function of time in a Banbury mixer at 77 rpm and 100°C. The broken line in the figure represents the fraction of particles smaller than 500 nm. 

Figure 3.28 Fraction of undispersed carbon black, larger than 9 /im, as a function of mixing time inside a Banbury mixer. The open circles denote experimental results and the solid line a theoretical prediction. The broken line denotes the fraction of aggregates of size below 500 nm.

Figure 12.19 The chemical shifts of 129Xe in carbon black filled EPDM as a function of the type of carbon black and the volume fraction of the carbon black in the material...

Figure 2. Dependence of the acidity of 86/13 silica-alumina at a pK of 4.6 (aqueous) on the fraction of Black Pearls L carbon black in binary mixtures using...

A recent approach suggests that one differentiate between structures of conductive carbon blacks by using the resistivity vs. density or volume fraction of the carbon black. High shear forces that are generated by intensive mixer or extruders... 

There are complexities. The wetting of carbon blacks is very dependent on the degree of surface oxidation Healey et al. [19] found that q mm in water varied with the fraction of hydrophilic sites as determined by water adsorption isotherms. In the case of oxides such as Ti02 and Si02, can vary considerably with pretreatment and with the specific surface area [17, 20, 21]. Morimoto and co-workers report a considerable variation in q mm of ZnO with the degree of heat treatment (see Ref. 22). 

The furnace process involves injecting low end fraction of cmde oil, eg. Bunker Euel C, into a heated chamber. The temperature, shape of the injectors of the oil, rate of injection, and other factors are controlled to produce black fillers of different particle si2e and stmcture. The particle si2e and stmcture control the reinforcing character of the carbon black. There are 30 common grades of carbon black used in the mbber industry. There are numerous specialty grades produced, and several hundred are used in plastic, conductive appHcations, and other uses. 

Figure 18.1 is the typical stress-strain curves of the filled rubber (SBR filled with fine carbon black, HAF),

When carbon black (fine carbon black) is dispersed homogeneously and its volume fraction

less than nearly 0.2, the SH layers of adjacent carbon particles are still separated from each other in matrix mbber. In this case, the molecules in the SH layer shde, orient, and extend along the extension direction and finally produce strands of oriented molecules under large extension, as shown in Figure 18.8. In this situation, as the molecules inside the SH layer are extended much more... 

As a next step, we can roughly estimate the modulus of the gel (without carbon black) from Figure 18.13. Although the modulus of carbon gel is 9-10 times larger than that of the fiUed NR vulcanizate at 20°C, we must consider the difference of the content of carbon black in both materials. Although the volume fraction of carbon black is 0.20 (corresponding to 50 phr) in the filled NR vulcanizate, since the gel (without carbon black) is about 45% of the total NR, the volume fraction of carbon black in the carbon gel is 0.36. On the other hand, if we compare the modulus of... 

Now, we show the relation between the ratio of 8 to Tq, 8/ro and the volume fraction of carbon black (p in Table 18.1, when the diameter of the hard particle (including carbon black, the GH layer and a little more contribution from the cross-links at the surface of particle) is tq and the distance between the hard particles is 8. In the carbon black-filled rubber (ip g 0.23-0.25), the fact that the stress of the filled system is 10-15 times larger than that of the unfilled rubber as shown in Figure 18.1 indicates that more than 90% of the stress of the system is supported by the supernetwork and the remainder of the stress results from the matrix rubber. In the present calculation, however, we can ignore the contribution from the matrix mbber. 

By relating the endpoint of crushed DBF absorption to the void space within and between equivalent spheres of aggregates, and assuming the spheres to be packed at random, Wang et al. obtained the following equation for the effective volume fraction of carbon black ... 

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