Easy preparation method of stable copper-based nanoparticle suspensions in lubricant engine oil

Nanolubricants, thanks to their ability to reduce friction and wear, are increasingly studied in the transport and automotive sectors. These systems are generally produced with a two-step procedure by dispersing nanoparticles into base oils. Very recently, one-step methods have received increasing attention for the production of highly stable nanosuspensions at lower cost. Degradation-decomposition of the base oil can however occur during the synthesis affecting the final performances. In this work, copper-based nanolubricants were produced using a new procedure that preserves the base oil from the degradation induced by the synthesis and allows producing highly stable nanolubricant. The produced fluid showed a monodisperse distribution of nanometric particles and a good stability up to at least 60 days from its production. The as-produced nanolubricants showed notable performance reducing the friction coefficient even up to 32.7% for Cu concentration of 0.01 vol% at 80°C.