Enhanced lubrication by core-shell TiO2 nanoparticles modified with gallic acid ester
KAUST DepartmentChemical Engineering
Chemical Engineering Program
Clean Combustion Research Center
Combustion and Pyrolysis Chemistry (CPC) Group
Physical Science and Engineering (PSE) Division
Online Publication Date2020-02-13
Print Publication Date2020-06
Embargo End Date2022-02-13
Permanent link to this recordhttp://hdl.handle.net/10754/661661
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AbstractNanoparticles (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.
CitationHong, F. T., Schneider, A., & Sarathy, S. M. (2020). Enhanced lubrication by core-shell TiO2 nanoparticles modified with gallic acid ester. Tribology International, 146, 106263. doi:10.1016/j.triboint.2020.106263
SponsorsThe research reported in this publication was funded by the Office of Sponsored Research (OSR) at King Abdullah University of Science and Technology (KAUST). Francesco Tutino in the Clean Combustion Research Center helped with synthesizing the surface modifying agent ODG. Dr. Sergei Lopatin in KAUST Imaging and Characterization Core Lab performed imaging of the core-shell ODG@TiO2 NPs using TEM-EELS. Dr. Long Chen in KAUST Imaging and Characterization Core Lab assisted with the experimental setup for the nanoindentation of derived tribofilms. Dr. Daliang Zhang and Dr. Nini Wei in KAUST Imaging and Characterization Core Lab characterized the cross-sectional tribofilm using TEM-EDS-FIB. Dr. Mohamed Hedhil and Dr. Nimer Wehbe in KAUST Imaging and Characterization Core Lab for carrying out the XPS analysis. We would also like to appreciate reviewers' valuable comments and suggestions.