FTIR observation of cleavage state of a mica–organic hybrid solid lubricant under reciprocating sliding conditions

Abstract

The lubrication performance of a mica–alkyl ammonium cation hybrid solid lubricant fabricated via an intercalation reaction was investigated by using a cylinder-on-disk tribotester and FTIR spectroscopy, and a cleavage mechanism was proposed. In micas with different contents of the intercalated organic cations, the results indicated a high correlation between the friction coefficient of residual mica and the absorption wavenumber of in-plane Si–O bonds. When the friction coefficient was lower, the absorption band shifted to a higher wavenumber as the sliding progressed. The IR shift was caused by a change in an interaction between mica and the alkyl ammonium cation derived from its cleavage. • Lubrication performance of mica is improved by an intercalated alkyl ammonium cation. • The improved lubricity is due to the promotion of the mica's cleavability. • The absorption wavenumbers for in-plane Si–O bonds were higher as sliding progressed. • The IR shift is caused by mica's cleavage.