Surface energy characteristics of toner particles by automated inverse gas chromatography

Inverse gas chromatography (IGC) was applied to the surface energy study of surfaces of toner particles. The dispersive component of the surface energy was determined for three toner materials by infinite dilution IGC. The values obtained were comparable to the values obtained from contact angle experiments. Previous adhesion experiments by atomic force microscopy suggested that the toner is a hydrophilic material with multiple adsorption energy sites. Both aspects were at least qualitatively confirmed by finite concentration IGC. Several indications for surface heterogeneity were found: (i) the difference between the dispersive component of the surface energy determined by IGC and the unexpectedly low total surface energy as determined by droplet analysis, (ii) the strong tailing behavior of the peaks of the injected polar probes, (iii) the decrease of the net retention volume with increasing n-pentane concentration, and finally (iv) the broad energy site distribution function with a dominant site at 28 kJ/mol, as determined by finite concentration IGC for n-pentane as molecular probe.