Comparison of Dorris–Gray and Schultz methods for the calculation of surface dispersive free energy by inverse gas chromatography

The surface and structural properties of graphite fluoride

“…Both methods provided similar surface free energies, although it should be noted that the values of the surface free energy from the Schultz method were systematically lower by %5 mJ/m 2 (data not shown). This is consistent with the study by Shi et al [30], who demonstrated that the Dorris and Gray estimates are always larger than the Schultz estimates. In addition, the method of Dorris and Gray is temperature corrected so it is better suited for measurement at elevated temperatures (our case as we carried out iGC experiments at 80°C).…”

“…where the surface area of a methylene group a CH 2 is 6 Å 2 and its surface energy c CH 2 is 35:6 À 0:058t mJ/m 2 , where t is temperature in°C [27,30]. All measurements were conducted using an SMS iGC-SEA 2000 instrument (Surface Measurement Systems, UK) in silanized columns (3 mm diameter, 30 cm long) filled with 23.9 mg of graphite fluoride (Sigma-Aldrich) at 80°C using He carrier gas at flow rate of 10 sccm.…”

Differentiating Defect and Basal Plane Contributions to the Surface Energy of Graphite Using Inverse Gas Chromatography

“…24 The Dorris-Gray method was used in this case as it is known to be more accurate at higher operating temperatures. 25 In the Dorris-Gray method a series of n-alkanes are used as probes to measure the free energy of adsorption, The experiments described here were performed using a Surface Energy Analyser (SEA). The SEA is the latest generation of IGC apparatus and makes measuring the surface energy of highly energetically heterogeneous materials such as graphite more reliable through the ability to inject precise amounts of probe molecule, corresponding to a specific surface coverage.…”

Accuracy verification of surface energy components measured by inverse gas chromatography

“…Shi et al found that the values of d S vary according to the calculation methods, and then they normalized this variation by determining the ratio between Dorris-Gray and Schultz methods [5]. It was also found that the calculated surface components of the same sample vary up to 16% depending on the used n-alkane series, and they attributed this discrepancy to uneven differences in the literature parameters of n-alkanes which are their dispersive free energy ( d l )…”