Molecular dynamics simulation on the friction properties of nanofluids confined by idealized surfaces

• Molecular dynamics simulation was used to study nanofluid׳s friction properties.
• Phase transition pressure of nanofluids is higher than that of base fluid.
• Nanofluids have better load-carrying capacity than base fluid.
• Mechanisms that nanoparticles result in better friction properties are explained.
• Effect of particle size on friction behaviors is studied to verify the mechanisms.

We performed molecular dynamics simulations to study friction property differences between base fluids and nanofluids in shear flow field. The results show that with the increase of load, liquid–solid transitions take place for both base fluids and nanofluids. Specifically, the transition pressure for nanofluids is higher than that of the base fluid and the nanofluids show excellent friction-reducing properties when the load is high (exceeds the transition pressure of base fluid). Additionally, nanofluids have a greater load-carrying capacity than base fluids. In this work, we explained the mechanisms responsible for the nanoparticles׳ favorable friction properties, and to verify these mechanisms we additionally studied the effect of nanoparticle radius on friction behaviors.