Molecular Deposition Polymeric Nanocomposite Films and Their Tribological Properties in Sliding against Steel

Multilayer polymeric nanocomposite films were prepared by alternative deposition of poly(sodium 4-styrenesulfonate) (coded as PSS) as polycation and poly(allyamine hydrochloride) (coded as PAH) as polyanion. Thermal gravimetric analysis was used to examine the bulk thermal stability of the polymers, while UV-visible absorption spectrometry, ellipsometry measurement and contact angle measurement were conducted to characterize the films. The friction and wear behavior of the polymer ultra-thin films sliding against SAE-52100 steel was examined on a DF-PM ball-on-block one-way reciprocating friction and wear test rig, with emphasis on the effect of heat-treatment of the tribological behavior of the films. As the results, the tested polymeric molecular deposition films records reduced friction coefficient. The friction reduction effect of ultrathin films is attributed to surface adhesion reduction and surface micro-modification. Therefore it reduces the friction coefficient of silicon single crystal sliding against SAE-52100 steel. Tribological behavior of polymeric nanocomposite films on silicon single crystal is correlative with the number of bilayers. The antiwear life of the molecular deposition films with more number of bilayers is longer than fewer bilayer films. Their antiwear life is considerably increased after proper heat-treatment.