Solid surface energy graphite

The London dispersive component of the surface free energy, y, of a solid may be shown to be a predominant property for the prediction of behavior of nonpolar adsorbents such as polyolefins or of practically nonpolar adsorbents like some carbon materials (natural graphites and carbon fibers). In this section, we propose a simple approach for the determination of the ys using nonpolar probes such as n-alkanes in inverse GC at infinite dilution. We also discuss the evaluation of the London dispersive component of the surface energy (or enthalpy, / ), starting from the variation of the adsorption characteristics, of a series of long-chain n-alkanes molecules, with temperature. 

Mesophase pitch, derived from coal tar, reacts smoothly with fluorine to give pitch fluoride [147, 148] with a composition between CFi 3 and CFi 6, as a yellowish white solid which differs from graphite fluoride in that it is soluble in some fluorocarbon solvents. Consequently, thin films of pitch fluoride may be deposited on materials and the resulting surfaces have been claimed to have even lower surface energies than PTFE. 

In practice, these solid-vacuum interfacial energies are not likely to be seen, since the diamond surface and the graphite prism-face surfaces will reconstruct or react with adatoms such as hydrogen and oxygen to reduce their surface energy. Under atmospheric conditions, diamond is terminated by a range of hydride and oxide... 

The processes involved in AES are similar to those shown in Fig. 16. However, electrons rather than X-ray photons are used to excite AES spectra. The data obtained in an AES experiment are sometimes presented as a plot of the number of electrons N T) ejected from the surface of a solid versus the kinetic energy T of the electrons. A typical plot of this type is shown for graphite in Fig. 38 [44. ... 

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