ENHANCING DISPERSION STABILITY OF NANO-STRUCTURED TITANIUM OXIDE /GRAPHENE OXIDE IN MINERAL AND BIO-BASED ENGINE LUBRICANT FORMULATIONS
S.J. Hettiarachchi*
Institute of Technology, University of Moratuwa, Sri Lanka
Session: Technical Session B
Abstract
New strategies are needed to reduce friction and wear in internal combustion (IC) engines. This will help save energy, extend the life of engine components, reduce the depletion of fossil fuel reserves, and decrease the production of waste crankcase oil, addressing current environmental issues. Nano-additives have shown promising results in improving the tribological performance of lubricants. However, the stability of nanoparticle dispersion in nano-lubricants remains a challenge for the effective use of nanomaterials as lubricant additives. This research investigates the efficacy of nanocomposite materials containing graphene oxide (GO) and reduced graphene oxide (r-GO) for reducing friction. Ultrasonication was used to create four different formulations: added graphene (G) and GO to the mineral-based engine oil (15W40), TiO2/G, and TiO2/r-GO with formulated coconut oil (FCO) as the base stock to blend sample lubricants. The dispersion stability of all four samples was tested using a UVvisible spectrophotometer, keeping 15W40 as the reference. Tribological performance was assessed using a linear reciprocating tribometer (LRT) test rig, which confirmed that lubricants containing GO and r-GO nano-additives exhibited improved lubricity. The sample containing 15W40 with GO as nano-additives and the sample with FCO containing TiO2/r-GO as nano-additives showed a 26% and 23% reduction in Coefficient of Friction (COF) over 15W40, respectively. The addition of GO and r-GO improved the dispersion stability of sample lubricants, leading to an enhancement in tribological characteristics due to the oxygen-containing functional groups attached to nanocomposite structures.
Keywords: nano-additives, dispersion stability, oxygen functional groups, engine lubrication
DOI: 10.64752/TPSS2483