Tribological investigation of MPTS‐MPTES SAMs

Abstract

PurposeThis paper's aim is to study the tribological properties of hyrid monolayer composited by γ‐mercapto‐propyl trimethoxysilane (MPTS) and γ‐methacryloxy propyltrimethoxysilane (MPTES), and estimated the action mechanism.Design/methodology/approachMPTS‐MPTES were self‐assembled on a hydroxylated silicon substrate to form a two‐dimensional hybrid monolayer. Atomic force microscope (AFM), X‐ray photoelectron spectrometry and contact angle measurement were used to characterize the MPTS‐MPTES hybrid self‐assembled monolayer (SAM). The macrofriction and wear behaviors of the film sliding against an AISI‐52100 steel ball were examined on a unidirectional friction and wear tester, and the worn surface morphologies were observed on an AFM.FindingsThe tribological results show that the friction coefficient of silicon substrate reduces from 0.86 to 0.18 after the formation of the MPTS‐MPTES hybrid SAM on its surface, and the thin film has a long wear life (2,620 sliding pass). It is demonstrated that the MPTS‐MPTES SAM exhibited good wear resistant property with a low friction coefficient, and the superior friction reduction and wear life were attributed to the low surface energy and the characteristics of the hybrid SAM.Research limitations/implicationsThe film's tribological performance under dynamic load is not estimated.Practical implicationsA hybrid monolayer with superior tribological property was synthesized on a silicon substrate by self‐assembly process, and maybe it is the potential solution for micro‐electromechanical‐system lubrication.Originality/valueThis paper provides a study way of hybrid SAM on a silicon substrate as lubricating coating.