Carbon black desorption mechanism

With appropriate choices of kinetic constants, this approach can reproduce the NSC experimental data quite well. Park and Appleton [63] oxidized carbon black particles in a series of shock tube experiments and found a similar dependence of oxidation rate on oxygen concentration and temperature as NSC. Of course, the proper kinetic approach for soot oxidation by 02 undoubtedly should involve a complex surface reaction mechanism with distinct adsorption and desorption steps, in addition to site rearrangements, as suggested previously for char surface combustion. 

The discussion in the Introduction led to the convincing assumption that the strain-dependent behavior of filled rubbers is due to the break-down of filler networks within the rubber matrix. This conviction will be enhanced in the following sections. However, in contrast to this mechanism, sometimes alternative models have been proposed. Gui et al. theorized that the strain amplitude effect was due to deformation, flow and alignment of the rubber molecules attached to the filler particle [41 ]. Another concept has been developed by Smith [42]. He has indicated that a shell of hard rubber (bound rubber) of definite thickness surrounds the filler and the non-linearity in dynamic mechanical behavior is related to the desorption and reabsorption of the hard absorbed shell around the carbon black. In a similar way, recently Maier and Goritz suggested a Langmuir-type polymer chain adsorption on the filler surface to explain the Payne-effect [43]. 

Detailed proof of this mechanism was achieved by using carbon-14 tagged copolymers of long chain methacrylates with vinyl pyridine. Carbon black dispersions stabilized with the tagged polymer were electrodeposited and then anode and cathode were assayed for carbon-14 in a scintillation counter. The carbon was deposited on the anode, but the clean cathode had the higher C-14 count, showing that the cations in the oil phase were indeed the dispersant polymer. The adsorption-desorption process which allowed dispersants to desorb from particles and to... 

Concerning CO/O2 reaction on perovskite oxide, the "suprafacial" mechanism is assumed, as well as for the carbon black/oxygen reaction. Carbon adsorption on the catalyst surface could be made tlirough the C-C bond or the C-0 surface complexes, assuming that C is bonded to the Mn ion with donation of carbon lone pair into the empty 3dz orbital to form s bond accompanied by back donation of the t2g electrons of Mn ion to anti-bonding i orbital of C-0 or C-C. Moreover, the mechanism begins by simultaneous adsorption of carbon and oxygen, the interaction between adsorbed species causes the CO2 formation, the desorption of which releases the catalytic active sites. 

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