Commercial carbon blacks

For accurate determination of the particle size, the particle size analyzer was used and particle sizes of carbons sjmthesized are compared with commercial carbon black (N700 and N800, KCB) in Table 2. It was confirmed from particle size analysis that particle size of carbon increased with increase of methane flow rate, as also appeared from SEM analysis. 

The carbon particle size varied from 80 to 120 run. The BET surface areas of carbon as a function of methane flow rate were compared with those of commercial carbon blacks in Table 3. The BET surface area ranges from 81 to 193 m /g with methane flow rates and this decrease is due to the increase of particle size. Carbon black which has lower surface area of 30 to 100 m /g can be used in rubber industry, while high surface area (> 700 m /g) carbon black is applied to activated carbon. 

The stability during potential cycling and ORR activity of Pt (20 wt°/o) supported on MWCNTs and carbon black was also investigated [136]. Two different potential cycling conditions were used, namely lifetime (0.5 to 1.0 V vs. RHE) and start-up (0.5 to 1.5 V vs. RHE). Pt supported on MWCNTs catalyst exhibited a significantly lower drop in normalized electrochemically active surface area (ECA) values compared to Pt supported on Vulcan (Fig. 14.10), showing that MWCNTs possess superior stability to commercial carbon black under normal and severe potential cycling conditions [137]. 

Ball et al. investigated the effect of carbon surface area on carbon corrosion at 1.2 V for 24 h and found that, for commercial carbon blacks, cumulative carbon corrosion correlated with carbon BET (Brunauer Emmett Teller) area, although when analyzed as specific carbon corrosion (weight of carbon corroded per unit of carbon area), some variation was observed. The effect of Ft on carbon corrosion has also been studied and conflicting results have been reported. Roen, Paik, and Jarvi found that Ft did increase carbon corrosion... 

Incomplete oxidation seems to be the main reason for the discrepancies in the results found in different laboratories. Surface oxides on commercial carbon blacks, with the exception of color blacks, never show this ratio because they are never completely oxidized. 

Commercial carbon black is a spherical colloidal form of nearly pure carbon particles and aggregates with trace amounts of organic impurities adsorbed on the surface. Potential health effects usually are attributed to these impurities rather than to the carbon itself. Soots, by contrast, contain mixmres of particulate carbon, resins, tars, and so on, in a nonadsorbed state. ... 

The surface of a solid may differ in many ways from its bulk composition. Especially, such solids as commercial carbon black may contain minor amounts of impurities (such as aromatics, phenol, carboxylic acid). This would render surface adsorption characteristics different from that of pure carbon. It is therefore essential that, in industrial production, quality control of the surface from different production batch is maintained. Otherwise, the surface properties will affect the application. Another example arises from the behavior of glass powder and its adsorption character for proteins. It has been found that if glass powder is left exposed to the... 

As far as toxicology is concerned, one must distinguish between soot, which is formed by the uncontrolled combustion of coal and oil, and carbon black, which is industrially produced under precisely defined conditions. Commercial carbon blacks are characterized by an atomic ratio H C of <0.1, low ash content, and high adsorption capacity. The soluble organic fraction (extractable materials) is less than 0.5 wt%. 

First, however, we should discuss sampling as it pertains to a carbon black reactor. A commercial carbon black reactor operating at production conditions may be described as being in a steady state of thermodynamic inequilibrium. 

Figure 10. Micro-PIXE spectra of polyethylene at a depth of 50 0 lm from the interface with a layer of semicon containing commercial carbon black. A) after two weeks in dry air at 55 °C, B) after two weeks immersed in water at 55 °C and C) the virgin polyethylene.

Two other commercial carbonaceous products often confused with carbon black are activated carbon and bone black. Each is produced by processes different from commercial carbon black and possesses unique physical and chemical properties. 

On the basis of the results of investigations on a large number of commercial carbon blacks synthesized under various conditions it was established [60] that the microtexture of all the materials could be described in terms of the characteristics represented in Fig. 1. Depending on the production method of a material its parameters L, Li, and y may vary. A decrease in y and an increase in L give evidence for the ordering of the particle structure. Figure 2(a) displays a schematic view of a section of a carbon black particle, where individual crystallites are visible [60]. The surface of each of the crystallites visible in this figure has a turbostratic structure. 

M is a commercial carbon black (Monarch 700. Cabot) treated in HNO, (M-HNOi) or first heat-treated at 2.S00°C in inert atmosphere and then soaked in HNO, (M-2500-HNO,) CPG is a comniercial activated carbon (CPG, Calgon Carbon Corp.),... 

Table III shows a sample of the properties of carbon black, in which the recovered carbon black is compared with the commercial carbon black ( 2, h 9 5 9 6). The reinforcing properties of the recovered carbon black are higher than those of GPF grade.

The surface of carbons can be modified from hydrophobic to hydrophilic by means of oxidation processes. Consequently, carbons can exhibit selective adsorption properties depending on their oxygen content. For instance, commercial carbon blacks with a significant oxygen content selectively adsorb methanol from a methanol/benzene mixture, whereas one with much lower oxygen content exhibits selectivity for benzene. 

P. Albers, E. Auer, K. Ruth S.F. Parker (2000). J. CataL, 196, 174-179. Inelastic neutron scattering investigation of the nature of surface sites occupied by hydrogen on highly dispersed platinum on commercial carbon black supports. 

Carbon black consists of 95-99% of elementary carbon. Besides, it typically contains many trace elements, metals and nomnetals, such as sulfur. Specific gravity (density) of carbon black is typically 1.7-1.9 g/cxo . It often contains between 0.1 and 2% of moisture. Particle size of commercial carbon black brands vary typically between 10 and 250 pm. Carbon black has a developed specific surface area, between 10 and 600 mVg. 

An example of a commercial carbon black is Regal 660, sold by the Cabot Corporation of Boston, MA., which has the following characteristics ... 

Darmstadt, H., Roy, C., and Kaliaguine, S. 1994. ESCA characterization of commercial carbon blacks and of carbon blacks from vacuum pyrolysis of used tires. Carbon 32 1399-1406. 

Charreteur F, Jaouen F, Ruggeri S, Dodelet JP (2008) Fe/N/C non-precious catalysts for PEM fuel cells influence of the structural parameters of pristine commercial carbon blacks on their activity for oxygen reduction. Electrochim Acta 53(6) 2925-2938... 

A similar problem was encountered when conductive polyaniline/PSS was used as the support. Fortunately, conducting poly(3,4-ethylenedioxythiophene) (PEDOT)/PSS composite was found to be much more stable. Before Pt deposition, a PEDOT/PSS composite possessed an electronic conductivity of 9.9 S cm while the conductivity of Vulcan XC-72 was 3.0 S cm measured under the same conditions. In other words, the conductive polymer composite was more than three times as conductive as the commercial carbon black. Pt nanoparticies with ca. 4 nm diameter were deposited onto PEDOT/PSS composite particles through the... 

Sahouli, B., et al.. Surface morphology and chemistry of commercial carbon black and carbon black from vacuum pyrolysis of used tyres. Fuel, 75(10), 1244-1250 (1996). 

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