Lamellar compound

These coatings are also employed as soHd lubricants in engine components. Refractory materials such as M0S2 and WSe2 are lamellar compounds and provide very effective soHd-state lubrication in spacecraft bearings and components used in radiation environments where conventional organic Hquid lubricants are not stable (see Lubrication and lubricants). 

Alkali-metal graphites are extremely reactive in air and may explode with water. In general, reactivity decreases with ease of ionization of M in the sequence Li > Na > K > Rb > Cs. Under controlled conditions H2O or ROH produce only H2, MOH and graphite, unlike the alkali-metal carbides M2C2 (p. 297) which produce hydrocarbons such as acetylene. In an important new reaction CgK has been found to react smoothly with transition metal salts in tetrahydrofuran at room temperature to give the corresponding transition metal lamellar compounds ... 

Lamellar compounds, arising from the attack of moderately strong reductants (such as potassium metal) or oxidants (such as AsFs)... 

Residue compounds, arising from the decomposition of lamellar compounds by thermal or in vacuo treatment. 

The effect of delicate adjustments of the catalytic site parameters on the activation modes of hydrocarbons (such as CH4) is further supported by Ichikawa s studies [51] on lamellar compounds. Graphite-K-lamellar entities promote the H -D c.xchangc in methane, but the rate greatly depends on C/K ratio Cj4K gives higher rate (X 2) thanC K at 300°C. Molecular sieves are also active for Ol4- D]0 exchange reactions at 600 C 52]. 

Molecules and ions can penetrate between the layers of graphite to form interstitial or lamellar compounds. These so-called intercalation compounds are of two types, namely, nonconducting compounds, in which the planarity of the graphite layers is destroyed, and conducting compounds, in which the planarity of the graphite layers is preserved (see Intercalation Chemistry) ... 

Although a lamellar crystal structure is favourable for solid lubrication, the inter-lamellar spacing and the nature of the inter-lamellar bonding are of major importance in determining the resistance to inter-lamellar shear, and therefore the sliding friction, of lamellar compounds. 

It is well known that graphite and fluorine gas do not interact at room temperature and ordinary pressures. At higher temperatures (380-600 °C), the lamellar compounds (CjF) and (CF) are formed, in which the carbon atoms are disposed in puckered sheets (Riidorff Riidorff 1947a Kita et al. 1979). In the presence of HF, graphite is spontaneously intercalated by fluorine, at room temperature. The first accounts (Riidorff Riidorff of such a... 

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