New Methodology to Study the Dispersive Component of the Surface Energy and Acid-Base Properties of Silica Particles by Inverse Gas Chromatography at Infinite Dilution

A new methodology was proposed to determine the dispersive component of the surface energy gamma(d)(s) of a solid taking into account the effect of the temperature on the surface area of n-alkanes, methylene group (a(-CH2-)) and polar molecules, thus defeating the method used by Dorris-Gray Schultz et al. We determined the correct gamma(d)(s) of the surface energy, the specific free energy, enthalpy and entropy of adsorption of polar molecules as well as the acid base constants of silica particles with an excellent accuracy. We confirmed the dependence of the dispersive component of the surface energy on the variations of the surface areas of organic molecules used in IGC technique at infinite dilution. The specific properties of interactions of silica particles were determined. The new proposed model took into account this thermal effect. Obtained results proved that the other used IGC methods gave inaccurate values of the specific parameters of silica surface, except for the vapor pressure method that led to excellent results of the specific free energy, enthalpy and entropy of adsorption, and the acid-base constants of the silica particles.

Automated summary

A new methodology was proposed to determine the dispersive component of surface energy of a solid, with a focus on the effect of organic molecules' surface area variations on surface energy. Results showed that other methods gave inaccurate values, except for the vapor pressure method.