Solubility of diamondoids

In Chapter 1, the thermodynamic properties of diamondoids are reported by by G. R. Vakih-Nezhaad. In this chapter, the author focuses on two main subjects. First, thermodynamic properties of pure diamondoids (adamantane and diaman-tane), and second, solubilities of diamondoids and phase behavior of the binary systems consisting of diamondoids and other hydrocarbons are presented in detail. 

Solubilities of Diamondoids and Phase Behavior of the Binary Systems... 

In this section the experimental data and modeling of the solubilities of diamondoids in supercritical solvents such as carbon dioxide, methane, and ethane are presented first, followed by the solubilities of these components in liquid organic solvents. In the last part of this section high-pressure phase behavior of the binary systems of diamondoids containing butane and isobutene is explained. 

Table 1.8 Correlation of the solubility of diamondoids in supercritical solvents.

Trends of solubility enhancement for each diamondoid follow regular behavior like other heavy hydrocarbon solutes in supercritical solvents with respect to variations in pressure and density [38, 39]. Supercritical solubilities of... 

As mentioned before, adamantane and diamantane are the first two members in the diamondoid series, and the most prevalent diamondoid compounds in natural gas. Their measured solubilities in methane, ethane, and carbon dioxide, which are three major components of natural gas, have been reported here [15]. The experimental solubilities of adamantane (CioHie) in ethane, carbon dioxide, and methane at 333 K are presented in Table 1.6, whereas solubility data for diamantane (C14H20) in ethane and carbon dioxide at 333 K and in methane at 353 K are presented in Table 1.7. The solubility of diamantane in methane is also reported in Table 1.7. Solubility data are reported in terms of the solute mole fraction y2 in the supercritical phase. The solubility data for adamantane in carbon dioxide produced... 

The solubilities of adamantane and diamantane have been determined in various liquid organic solvents at ambient temperature. Data were obtained by adding approximately 0.05 grams of diamondoids to a vial. A Mettler AMIOO scale, with a precision of 0.0001 gram has been used in all measurements of Reiser et al. [13]. The solubilities of adamantane and diamantane in liquid solvent are listed in Table 1.11. 

The supercritical fluid and liquid solubilities reported in Figs. 9-12 suggest that diamondoids will preferentially partition themselves into the high-pressure, high-temperature, and rather low-boiling fraction of any mixture including crude oil. 

Adamantane and diamantane are usually the dominant diamondoids found in petroleum and natural gas pipeline deposits [74, 75]. This is because diamondoids are soluble in light hydrocarbons at high pressures and temperatures. Upon expansion of the petroleum fluid coming out of the underground reservoir and a drop in its temperature and pressure, diamondoids could deposit. 

Diamondoids possess great capability for derivatization. This matter is of importance in reaching suitable molecular geometries needed for molecular building blocks of nanotechnology. These molecules are substantially hydrophobic and their solubility in organic solvents is a function of that (adamantane solubility... 

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