Abstract
Nanoparticles (NPs) added to oils have been demonstrated to enhance engine lubrication, but sedimentation issues are barriers to their implementation. Here, we engineer TiO2 NPs with polyphenol derivatives (2-octyldodecyl gallate, ODG), not only to improve dispersion stabilities but also to introduce phenol-related tribochemical reactions. To that end, we compare dispersion and lubrication performances of ODG modified TiO2 (ODG@TiO2) NPs with unmodified ones in two base oils, polyalphaolefin and commercial engine oil. Surface analysis results reveal the triboactive role played by ODG in ODG@TiO2 NPs, which helps them to reduce more friction than with non-modified NPs, to generate thicker tribofilms, and to strengthen surface mechanical properties. Thus, we expect further explorations of polyphenol derivatives to improve NPs properties in lubricant applications.
∙Straightforward surface modifying method using polyphenol derivatives (2-octyldodecyl gallate, ODG) enhances dispersion stabilities and lubrication performances of TiO2 nanoparticles(NPs) in oils∙The blends with ODG modified TiO2 NPs reduce more friction than with unmodified ones in two base oils, polyalphaolefin (PAO) and Helix 10W30 engine oil (HEO)∙The ODG modified TiO2 NPs generate thicker tribofilm with ZDDPs contained in HEO