Stick–Slip Friction of Stainless Steel in Sodium Dodecyl Sulfate Aqueous Solution in the Boundary Lubrication Regime

Abstract

The objective of this study is to correlate the mass and structure of the adsorbed sodium dodecyl sulfate (SDS) on stainless steel surface in aqueous solution with the boundary lubrication behavior, especially the stick-slip phenomenon of the ZrO 2 /stainless steel friction pair. Surface tension measurement, quartz crystal microbalance (QCM) technique and ball-on-flat friction test were performed in this study. The adsorption isotherm of SDS on stainless steel surface in SDS aqueous solution was measured by QCM, and four-stage adsorption behavior was found at the solid/liquid interface. As the SDS concentration increases, the mass of the adsorbed SDS molecules increases, while the structure of the adsorbed layer changes from monomers to hemimicelles. Tribological properties of ZrO 2 /stainless steel friction pair in SDS aqueous solution were verified with an UMT-3 tester. Boundary lubrication was emphasized as water-based lubrication easily fails in hydrodynamic lubrication due to its low viscosity. Stickslip phenomenon was observed in the boundary lubrication of the adsorbed SDS film under certain loading and sliding conditions. Both the static and kinetic friction coefficients were analyzed with respect to the SDS concentration and sliding velocity. The stick-slip phenomenon is related to both of the adsorbed mass and adsorption structure of the SDS boundary film.

Boundary lubrication by adsorption film

“…In addition to friction and lubrication experiments, to elucidate the mechanism of boundary lubrication, a thorough inspection of the boundary film is necessary [24]. Adsorption isotherms have long been used to study the adsorption properties of SAMs on a solid/liquid interface [30], but it was far from satisfactory to investigate the adsorption at an interface at the molecular level.…”

“…Using ZrO 2 ball and stainless steel plate as friction pair, Zhang and Meng [24] conducted a systematic study on the boundary lubrication performance, especially the stick-slip phenomenon in SDS aqueous solutions (2014). The SAMs formed on the steel surface by SDS molecules acts as boundary layer to provide lubrication during the sliding contact.…”

Friction and Adsorption Properties of Oleic Acid-Based Gemini Amphiphile at Silica/Ester Oil Interfaces

“…Based on the friction and adsorption results, we suggest the friction modification mechanism of the gemini amphiphile. The key parameter determining the friction property is the adsorption mass of the amphiphiles at the silica/ester oil interfaces, as suggested previously in the aqueous surfactant systems 7,8,10 . The larger adsorption mass of the gemini amphiphile results in the formation of a rigid interfacial film, yielding greater stiffness against the normal load.…”

Reclined trend of alkyl chain of sodium dodecylbenzenesulfonate molecules induced by friction

“…They presented a four-stage adsorption model at the solid/liquid interface. Later, Zhang et al [37] investigated the frictional behaviors of stainless steel in SDS aqueous solution, and found that the boundary lubrication behaviors are not only related to the mass and structure of the adsorbed SDS boundary film, but also affected by the driving speed and load.…”