Surface area of carbon black

Specific surface area of carbon blacks before and after graphitization, determined by electron microscopy (A,) end by nitrogen adsorption (A ]t... 

Another standard industry method for surface area is based on the adsorption of cetyltrimethylammonium bromide (CTAB) from aqueous solution. This is ASTM method D3765-85 (2). This method measures the specific surface area of carbon black exclusive of the internal area contained in micropores that are too small to admit the large CTAB molecules. Eor mbber-grade nonporous blacks the CTAB method gives excellent agreement with nitrogen surface areas. 

Table 3 BET Surface Area of carbon blacks by CH4 flow rate...

Cetyltrimethylammonium bromide, latex auxiliary. Also used as an adsorbent to measure the total surface area of carbon black. 

Specific Surface Area. The specific surface area of industrial carbon blacks varies widely. While coarse thermal blacks have specific surface areas as small as 8 m2/g, the finest pigment grades can have specific surface areas as large as 1000 m2/g. The specific surface areas of carbon blacks used as reinforcing fillers in tire treads lie between 80 and 150 m2/g. In general, carbon blacks with specific surface areas >150 m2/g are porous with pore diameters of less than 1.0 nm. The area within the pores of high-surface-area carbon blacks can exceed the outer (geometrical) surface area of the particles. 

Details of several different methods for determining the specific surface area of carbon black are described in ASTM D 3037. The different types of equipment used and procedures are included in separate sections. Another standard gives full details of procedure of conventional Brunauer, Emmett, and Teller (BET) method based on multilayer gas adsorption. The results of determination are in both cases given in the surface area in square meters per gram of substance. 

Figure 7.21 shows that bound rubber increases as the surface area of carbon black increases.This is a classical experiment which shows that the amount of bound rubber depends on the surface area of the filler. High structure carbon blacks... 

Figure 15.37. Electric conductivity vs. surface area of carbon black incorporated into butyl rubber. [Adapted, by pennission, from Nasr G M, Badawy M M, Gwaily S E, Shash N M, Hassan H H, Polym. Degradat. Stabil., 48, No.2,1995, 237-41.]...

Figure 15.37 shows that conductivity of butyl rubber increases with surface area of carbon black increasing. ... 

Figure 15.41. Properties of SBR vs. specific surface area of carbon black. [Adapted, by permission, from Byers J T, Meeting of the Rubber Division, ACS, Cleveland, October 17-20, 1995, paper B.]...

Dispersion is also an important factor. Light reflection depends on the surface area of carbon black after dispersion. If large agglomerates are present light reflection (and UV protection and opacity) is reduced. It is a frequent practice to use fully dispersed masterbatches offered either by carbon black manufacturers or compounders to achieve good results. ... 

Puri, B.R. and Bansal, R.C. (1965). Iodine adsorption method for measuring surface area of carbon blacks. Carbon, 3, 227-30. 

The attentive reader will note that a density of 1.5 g/cm was used in estimation of the geometric surface area of carbon black, which is a relatively disordered form... 

Cetyl triethyl ammonium bromide (CTAB) adsorption is widely used in carbon black industry (Janzen and Kraus, 1971 Kraus and Jansen, 1978 Bele et al., 1998). This method consists of making a suspension of a known mass of carbon black into a water CTAB solution of known concentration. Carbon black is then filtered and the quantity of adsorbed CTAB is determined by titration of the remaining CTAB in the filtrate. Surface area of carbon black is then deducted from the amount of CTAB adsorbed, using a previously determined calibration with a reference carbon black. 

Results showed that, the tensile strength of filled vulcanizates increase up to 30 minute plasma duration, then stays constant for PPS while the maximum is obtained at 15 minute plasma duration for PPB (15). At 30 minute plasma, it was shown that surface area of carbon black stays the same for PPS case, while it is some 6 % lower for the PPB - which is somewhat expected because of differences involved in their polymerization kinetics in plasma. The T of system... 

Magee R W (1994) Evaluation of the external surface area of carbon black by nitrogen adsorption. 68 590-600... 

Given that the cathodes were identical in all three lots of cells, the large variation in first cycle coulombic efficiency can be explained by comparing the total surface area of the anodes. In Chap. 1, Table 1.7 it was noted that MCMB 6-28 has a surface area of 4 m g In Sect. 1.4, the surface area of carbon black was stated to be >50 m g For this experiment, the carbon black surface area was about 60 m g . Therefore, Lot 2 had 5.3 % less anode surface area than Lot 1. Lot 3 had 21 % less surface area than Lot 1. The importance of total surface area of anode becomes clear when it is noted that SEI formation is mostly a surface reaction between anode and electrolyte. Variations in the first cycle coulombic efficiency are so important because the inefficiency during formation is irreversible. 

Since the surface area of carbon black is expressed in square metres per unit weight, the smaller the primary particles the larger the surface area. Surface area affects the jetness (intensity of black colour), the UV absorption, and the conductivity of the carbon black. Greater surface area increases both jetness and UV resistance, because more surface is available for the absorption of visible and UV light. 

D3765 Testing CTAB Surface Area of Carbon Black... 

---