Preparation of a mica–organic hybrid solid lubricant and characterization of its lubrication mechanisms

A mica–organic hybrid solid lubricant was synthesized by an intercalation technique, where an alkyl ammonium cation was inserted into mica's interlayer region. And the lubrication performance and its mechanism were investigated. X-ray diffraction (XRD) showed that the distance between the silicate layers increased from 12.4 Å to 36.3 Å after the intercalation reaction. Owing to the increase in the interlayer distance, the intercalated mica showed a significantly improved lubricity. The results of Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) revealed that the intercalated organic cation retained a localized positive charge in mica's interlayer region and weakened electrostatic attraction to the silicate layers. This effect promotes mica's cleavage ability, resulting in a low coefficient of friction. [Display omitted] •A mica is intercalated with alkyl ammonium cation.•A d-spacing of a mica increases by intercalation reaction.•The lubrication performance is improved by the intercalated alkyl ammonium cation.•The improvement of the mica's lubricity is due to a decrease in interlayer adhesion strength.