Reactivity of graphite

Jorne et al. [36] investigated the reactivity of graphites in acidic solutions that are typically used for Zn/Cl2 cells. The degradation of porous graphite is attributed to oxidation to C02. The rate of C02 evolution gradually decreased with oxidation time until a steady state was reached. The decline in the C02 evolution rate is attributed to the formation of surface oxides on the active sites. 

Discussion of relative effects of the metals of the reactivity of graphite... 

One method of oxidizing nanodiamond surfaces has already been presented in Section 5.3.4 as a means of sample purification. The differing reactivity of graphitic and diamond carbon is utilized here. The unordered graphitic structures are oxidized and removed as gaseous products, whereas diamond particles are only modified on their surface. 

Reactivities of Graphite Edge Sites and Hydrogen Reactions on These Sites... 

The general reactivity of graphite with the various classes of chemicals at ambient temperature is given in Table... 

The effect of reactivation of graphite fibers by anodic oxidation has been reported by Fujii [423]. 

Fused Salt Electrolysis. Only light RE metals (La to Nd) can be produced by molten salt electrolysis because these have a relatively low melting point compared to those of medium and heavy RE metals. Deposition of an alloy with another metal, Zn for example, is an alternative. The feed is a mixture of anhydrous RE chlorides and fluorides. The materials from which the electrolysis cell is constmcted are of great importance because of the high reactivity of the rare-earth metals. Molybdenum, tungsten, tantalum, or alternatively iron with ceramic or graphite linings are used as cmcible materials. Carbon is frequently used as an anode material. 

Some pigments promote corrosion owing to their content of soluble salts, their reactivity, or their electrochemical action, and thus should be avoided. Rust of the spotted type can be the consequence of their presence in a paint, especially the hrst coat, e.g. of graphite (noble to steel), some red oxides of iron, gypsum, ochre or lamp black. 

The physicochemical properties of carbonaceous materials can be altered in a predictable manner by different types of treatments. For example, heat treatment of soft carbons, depending on the temperature, leads to an increase in the crystallite parameters, La and Lc and a decrease in the d(0 0 2) spacing. Besides these physical changes in the carbon material, other properties such as the electrical conductivity and chemical reactivity are changed. A review of the electronic properties of graphite and other types of carbonaceous materials is presented by Spain [3],... 

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