Understanding nanofluid stability through molecular simulation

Molecular dynamics simulations were carried out to systematically study solvation and nanoparticle–particle interactions in n-hexane, water and methanol solvents. The dynamics of the n-hexane molecules was significantly influenced by the solvated nanoparticles. Water and methanol show significant structural signatures binding to the metal coordination sites of the nanoparticles while liquid hexane does not. The computed free energy profiles illustrate that the associations between nanoparticles in solution are stable and depend on the relative orientation of them. Also, these profiles indicate a low interaction potential between nanoparticles in methanol, confirming experimental observations of inherent nanofluid stability without need for added surfactant.