Graphitized carbon correlations

An interesting correlation is found between the kinetic stabilities of the fullerenes ] to C70. as determined by simple Hiickel theory HOMO-LUMO energy separations, and the intensities of photoionisation signals from carbon clusters produced by laser vaporisation of graphite. This correlation provides further circumstantial evidence that the observed C34 to C70 clusters are indeed fullerenes, closed carbon cages containing only five- and six-membered rings. 

The surface polarities of M0S2 and sulphided Co-Mo catalysts, estimated from differences in the adsorption of alkanes and aromatic hydrocarbons at 473 K, decreased in the order of AI2O3 > Co-Mo/AI2O3 >MoS2- The non-specificity of the M0S2 surface was similar to that of graphitized carbon both acids and anilines were easily eluted from M0S2 The surface polarities correlated with activities for H2S elimination from saturated S compounds. 

Figure 11.4 Argon adsorption isotherm on graphitized carbon black at 87.29 K in linear scale (a) and logarithmic scale (b). (Solid lines) correlation by NLDFT. (Dashed lines) correlation with nonadditivity factor a of 0.0183. Specific surface area is taken to be 13.26m /g.

Carbon materials have been used widely in the development of sensors and actuators, particularly for electrical or electrochemical biosensors. These applications critically rely on the unique chemical and electrical properties of specific carbon materials [1,2]. It is quite common that similar carbon materials present drastically different properties in the literature. The goal of this chapter is to describe the atomic structures of each carbon material and correlate these structures with their properties so that discrepancies in the literature can be understood. Readers can then optimize the material properties for specific sensing applications by tuning carbon structures. This is particularly important for graphitic carbon materials, which present inherent highly anisotropic properties. 

Even when nitrobenzene was eliminated from the calculation, the correlation coefficient of MIPS was high for log k es> but poor for log The results indicated these graphitized carbons have different properties. It seemed to be based on the strong retention of phenol, and p-cresol, as shown in Figure 5.4, compared with the results shown in Figure 5.5. 

The hydrogen-bonding energy seemed to contribute to the retention on the graphitized carbon (Hypercarb ) column, but not to the retention on another carbon BioTechnologyResearch (BTR ) column. Therefore, only alkyl-group-substituted compounds were selected and their log k values were correlated with MI values. The correlation coefficient was 0.718 for log A ref- The log A ref values of benzene, toluene, o- grlene, m- ylene,p- g lene, o-te/t-butylphenol, 4-ethylphenol,... 

The correlation coefficient for silica was significantly improved compared to the MI values calculated using the graphitized (Hypercarb ) carbon model. The coefficients for MIPS and MIHB were 0.807 and 0.856, compared to 0.558 and 0.706 obtained with the model carbon phase. No reasonable correlation was obtained for MIES and MIVW because these interactions are not the main contributors to retention in normal-phase liquid chromatography. In terms of chromatographic behavior, phenol and p-cresol were not outliers. Their strong retention on the graphitized carbon is partly supported by the silica gel model phase. 

The precision of the correlation between the log k and molecular interaction energy values vras high, as long as the analyte structure was simple and flat, as demonstrated in Section 6.9.2. Specifically, such analyses are most successful when studying retention mechanisms on graphitized carbon phases (Section 6.3). This is because the most effective system for such analyses is a homogeneous and flexible model phase where the docking process may not cause errors. 

Figure 10.12. Correlation between bound rubber and specific surface area. The data are for 50 parts of black per 100 parts of SBR 1500. Graphon, a graphitized carbon, does not follow the correlation. (Kraus, 1965c.)...

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