Sodium carbon black surfaces

The chlorine bound to the carbon black surface can be used for further reactions. On fusion with sodium hydroxide, it was completely removed. A large part had been replaced by CN groups after fusion with sodium cyanide or treatment with copper (I) cyanide (69). Reaction was observed also with ammonia. However, no amino groups could be detected on the surface by the nsiinl methods. 

Figure 4. Neutralization of carbon black surface acids on black pearls (2) in aqueous sodium hydroxide. Key 1.0...

Several examples may be quoted from the literature to illustrate the adsorption of surfactant ions onto soHd surfaces. For a model hydrophobic surface, carbon black has been chosen [22, 23], and Figure 5.5 shows the typical results for the adsorption of sodium dodecyl sulphate (SDS) onto two carbon black surfaces, namely Spheron 6 (untreated) and Graphon (graphitised), which also describes the effect of surface treatment. 

Tetrasodium hexakiscyanoferrate decahydrate [14434-22-1], Na4[Fe(CN)g] IOH2O, or yellow pmssiate of soda, forms yellow monoclinic crystals that are soluble in water but insoluble in alcohol. It is slightly efflorescent at room temperature, but the anhydrous material, tetrasodium hexakiscyanoferrate [13601 -19-9], Na4[Fe(CN)J, is obtained at 100°C. The decahydrate is produced from calcium cyanide, iron(II) sulfate, and sodium carbonate in a process similar to that for the production of K4[Fe(CN)g] 3H2O. It is used in the manufacture of trisodium hexakiscyanoferrate, black and blue dyes, as a metal surface coating, and in photographic processing. 

The amount of liberated carbon dioxide was equimolar to the HCl adsorption. Rivin confirmed also that hydrogen peroxide is formed by reaction of carbon black with formic acid in the presence of oxygen. Physically adsorbed hydrochloric acid was removed by washing with dioxane. The remaining chloride ions on the surface were replaced by hydroxide ions on treatment with sodium hydroxide. The reaction was formulated as production of a carbinol ... 

Specihcally with regard to the pyrolysis of plastics, new patents have been filed recently containing variable degrees of process description and equipment detail. For example, a process is described for the microwave pyrolysis of polymers to their constituent monomers with particular emphasis on the decomposition of poly (methylmethacrylate) (PMMA). A comprehensive list is presented of possible microwave-absorbents, including carbon black, silicon carbide, ferrites, barium titanate and sodium oxide. Furthermore, detailed descriptions of apparatus to perform the process at different scales are presented [120]. Similarly, Patent US 6,184,427 presents a process for the microwave cracking of plastics with detailed descriptions of equipment. However, as with some earlier patents, this document claims that the process is initiated by the direct action of microwaves initiating free-radical reactions on the surface of catalysts or sensitizers (i.e. microwave-absorbents) [121]. Even though the catalytic pyrolysis of plastics does involve free-radical chain reaction on the surface of catalysts, it is unlikely that the microwaves on their own are responsible for their initiation. 

We shall refer to this as the n n interaction argument. It has been formulated ba,sed on the following experiments (1) adsorption isotherms of phenol, nitrobenzene, and sodium benzenesulfonate on a series of activated carbons and carbon blacks and (2) characterization of the surface chemistry of as-received and chemically modified carbons. The authors did not report the pH in fact, this word is not even mentioned in any of their papers on this subject [450,331,332]. 

A carbon black sample is treated with excess of iodine. The excess iodine is then titrated with a sodium thiosulfate solution. The result is expressed as adsorbed iodine per unit of mass of the sample. The iodine number depends on amount of volatiles, surface porosity, and extractables. The iodine number correlates with the nitrogen specific surface area. It is a simple method used to evaluate the quality of carbon black. 

The existence of quinonic groups in carbon black was first proposed by Studebaker and associates (73), based on reduction experiments with sodium borohydride or hydrogen over platinum. Carbon black undergoes some of the typical reactions of quinones. It inhibits the free radical polymerization of vinyl monomers (74—76) and, after completion of the induction period, becomes grafted to the polymer molecules. This activity is lost on reduction. Gruver and Rollmann (77) have shown that quinones are also responsible for some of the antioxidant activity of carbon black (78). Hallum and Drushel (79) proposed that surface quinonic groups... 

Adsorption of sodium bis(2-ethy hexyl)sulfosuccinate from benzene solution onto carbon blacks follows the Langmuir equation and depends on the amount of oxygen on the surface. No adsorption onto heat-treated hydrophobic carbon (Graphon) could be detected (Abram, 1962). 

It was established already in the first period of works on sodium ion batteries that contrary to the lithium ion, the sodium ion is not intercalated into the interlayer space of graphite. Sodium ions penetrate nongraphitized carbon materials, but the nature of this penetration is not intercalation. In the case of oil coke, the capacity values of 90 - 95 mAh/g were obtained, which approximately corresponds to the composition of NaC24. In the case of carbon black electrodes, capacity of about 200 mAh/g was obtained. Quite suitable materials for the negative electrode could be different varieties of nanoporous hard carbon (obtained, e.g., by pyrolysis of glucose). In this case, intercalation of sodium ions is provided not only by their intercalation into the interlayer space, but also by their adsorption on the inner nanopore surface. The capacity of electrodes of nanoporous hard carbon reaches 300 mAh/g. Most recently, negative electrodes of carbon nanotubes with nearly similar sodium intercalation capacity were described. 

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