Salts electrical conductivity

Phenazine, 5-methyl-, TCNQ salt electrical conductivity, 1, 348 (65CJC1448) Phenothiazine X-ray, 3, 1010 (68CC1656)... 

UV, 4, 15 <58AC[Pg.16]

UV, 4, 15 (58AC(R)738> Dibenzotetrathiafulvalene, TCNQ salt electrical conductivity, I, 348 (76JOC730)... 

It is believed that to avoid any risk of explosion, the electrical conductivity of jet fuel should fall between 50 and 450 pS/m. This level is attained using anti-static additives which are metallic salts (chromium, calcium) added at very low levels on the order of 1 ppm. 

Dislocation theory as a portion of the subject of solid-state physics is somewhat beyond the scope of this book, but it is desirable to examine the subject briefly in terms of its implications in surface chemistry. Perhaps the most elementary type of defect is that of an extra or interstitial atom—Frenkel defect [110]—or a missing atom or vacancy—Schottky defect [111]. Such point defects play an important role in the treatment of diffusion and electrical conductivities in solids and the solubility of a salt in the host lattice of another or different valence type [112]. Point defects have a thermodynamic basis for their existence in terms of the energy and entropy of their formation, the situation is similar to the formation of isolated holes and erratic atoms on a surface. Dislocations, on the other hand, may be viewed as an organized concentration of point defects they are lattice defects and play an important role in the mechanism of the plastic deformation of solids. Lattice defects or dislocations are not thermodynamic in the sense of the point defects their formation is intimately connected with the mechanism of nucleation and crystal growth (see Section IX-4), and they constitute an important source of surface imperfection. 

The salts had a high electrical conductivity, and it was claimed that the values of the molar conductances at infinite dilution showed the formation of a binary and ternary electrolyte respectively. 

As early as 1889 Walker (320), using samples of thiazole, 2,4-dimethylthiazoie, pyridine, and 2,6-dimethylpyridine obtained from Hantzsch s laboratory, measured the electrical conductivity of their chlorhydrates and compared them with those of salts of other weak bases, especially quinoline and 2-methylquinoline. He observed the following order of decreasing proton affinity (basicity) quinaldine>2,6-dimethyl-pyridine>quinoline>pyridine>2,4-dimethylthiazole> thiazole, and concluded that the replacement of a nuclear H-atom by a methyl group enhanced the basicity of the aza-aromatic substrates. 

Mercury cells are operated to maintain a 21—22 wt % NaCl concentration in the depleted brine and thus preserve good electrical conductivity. The depleted brine is dechlorinated and then resaturated with soHd salt prior to recycling back to the electroly2er. 

Further improvements in anode performance have been achieved through the inclusion of certain metal salts in the electrolyte, and more recently by dkect incorporation into the anode (92,96,97). Good anode performance has been shown to depend on the formation of carbon—fluorine intercalation compounds at the electrode surface (98). These intercalation compounds resist further oxidation by fluorine to form (CF ), have good electrical conductivity, and are wet by the electrolyte. The presence of certain metals enhance the formation of the intercalation compounds. Lithium, aluminum, or nickel fluoride appear to be the best salts for this purpose (92,98). 

The metallic salts of trifluoromethanesulfonic acid can be prepared by reaction of the acid with the corresponding hydroxide or carbonate or by reaction of sulfonyl fluoride with the corresponding hydroxide. The salts are hydroscopic but can be dehydrated at 100°C under vacuum. The sodium salt has a melting point of 248°C and decomposes at 425°C. The lithium salt of trifluoromethanesulfonic acid [33454-82-9] CF SO Li, commonly called lithium triflate, is used as a battery electrolyte in primary lithium batteries because solutions of it exhibit high electrical conductivity, and because of the compound s low toxicity and excellent chemical stabiUty. It melts at 423°C and decomposes at 430°C. It is quite soluble in polar organic solvents and water. Table 2 shows the electrical conductivities of lithium triflate in comparison with other lithium electrolytes which are much more toxic (24). 

Table 2. Comparative Electrical Conductivity of Lithium Salts...

Solutions of alkah metal and ammonium iodides in Hquid iodine are good conductors of electricity, comparable to fused salts and aqueous solutions of strong acids. The Hquid is therefore a polar solvent of considerable ionising power, whereas its own electrical conductivity suggests that it is appreciably ionized, probably into I" and I (triodide). Iodine resembles water in this respect. The metal iodides and polyiodides are bases, whereas the iodine haHdes are acids. 

The popularity of MSA as an electrolyte in electrochemical appHcations has developed as a result of the following unique physical and chemical properties (/) exhibits low corrosivity and is easy to handle, (2) nonoxidizing, (7) manufacturing process yields a high purity acid, (4) exceptional electrical conductivity, (3) high solubiHty of metal salts permits broad appHcations, (6) MSA-based formulations are simpler, (7) biodegradable, and (8) highly stable to heat and electrical current. 

Bismuthides. Many intermetaUic compounds of bismuth with alkafl metals and alkaline earth metals have the expected formulas M Bi and M Bi, respectively. These compounds ate not saltlike but have high coordination numbers, interatomic distances similar to those found in metals, and metallic electrical conductivities. They dissolve to some extent in molten salts (eg, NaCl—Nal) to form solutions that have been interpreted from cryoscopic data as containing some Bi . Both the alkafl and alkaline earth metals form another series of alloylike bismuth compounds that become superconducting at low temperatures (Table 1). The MBi compounds are particularly noteworthy as having extremely short bond distances between the alkafl metal atoms. 

Zinc—bromine storage batteries (qv) are under development as load-leveling devices in electric utilities (64). Photovoltaic batteries have been made of selenium or boron doped with bromine. Graphite fibers and certain polymers can be made electrically conductive by being doped with bromine. Bromine is used in quartz—haUde light bulbs. Bromine is used to etch aluminum, copper, and semi-conductors. Bromine and its salts are known to recover gold and other precious metals from their ores. Bromine can be used to desulfurize fine coal (see Coal conversion processes). Table 5 shows estimates of the primary uses of bromine. 

---