Ultrasonics-Aided Dispersion of 1D Nanocarbons in Lubricating Oils For Enhanced Lubrication

This work reports ultrasonics-aided dispersion of one-dimensional (1D) multiwalled carbon nanotubes (MWCNTs) in an additive-free mineral base oil (BO) (group-2 dewaxed N500) and a commercial synthetic engine oil (CO) (ENI TriStar 15W40) to improve the oils' friction and wear-preventive properties. The lubricant additives, i.e., the MWCNTs, were prepared using a customized vertical fluidized bed reactor. The MWCNTs improved the BO's friction and wear-preventive properties and functioned synergistically with the predispersed additives in CO. Dispersing 0.1 wt % of the MWCNTs in BO improved the latter's antifriction property by 64%, and dispersing 0.1 wt % of MWCNTs in CO resulted in the reduction of the coefficient of friction (CoF) by 48%. The wear-preventive properties of the BO and CO improved by 60% and 30%, respectively, because of the addition of 0.1 wt % of MWCNTs. This work also clarifies the processes that improve lubrication performance, thereby decreasing friction and wear. This study advances the practical use of ultrasonication in process intensification in preparing stable 1D nanocarbon-additive lubricants with enhanced lubricating properties.