Adsorption and onset of lubrication by a double-chained cationic surfactant on silica surfaces

In the context of glass fiber manufacture, the onset of lubrication by a C18 double-chained cationic surfactant has been investigated at high normal contact pressures. Comparison with adsorption kinetics demonstrates that lubrication is not directly connected to the surfactant surface excess but originates from the transition to a defect-free bilayer that generates limited dissipation. The impact of ionic strength and shear rate has also been studied.

In the lubrication of silica surfaces by double-chained cationic surfactants in aqueous dispersions, there is no direct correlation between friction coefficient and surface excess. Lubrication is primarily controled by the healing of the bilayer defects. Healing is assisted by shear and by high ionic strength.Figure optionsDownload as PowerPoint slide