XIAO Huaide, WANG Qiang. Determination of preasphaltene surface properties by inverse gas chromatography[J]. CIESC Journal, 2018, (6): 2621-2626.DOI: 10.11949/j.issn.0438-1157.20171472.
The surface properties of the preasphaltene were characterized by inverse gas chromatography
surface dispersion free energy and acid-base constant. The polar adsorption free energy DGsp and the polar adsorption enthalpy DHsp of the polar probe on the surface of the preasphaltene were obtained by the adsorption of polar probes. The results show that the surface free energy of the preasphaltene decreases with the increase of the temperature at the temperature of 60-100℃. The acid constant Ka is equal to 0.91
the base constant Kb is equal to 2.98
and Kb/Ka is equal to 3.27. It can be seen that the surface of the preasphaltene is amphoteric
and the alkaline effect is stronger than acid effect.