A molecular dynamic investigation of viscosity and diffusion coefficient of nanoclusters in hydrocarbon fluids

Abstract

Straight chain alkanes modified by metal oxide nanoclusters have gained wide recognition in applications in tribology, energy and thermal storage. This paper investigates the system’s rheological properties and diffusion coefficient in a reflection of the nanocluster’s nanofluidic dispersibility and stability in the domain of thermal and diffusive properties. A computational model working on CuO nanoclusters in an alkane (C20H44) fluidic system has been developed at an atomic-molecular level. The simulation results are used to assess the outcomes of the suspension’s fluidic stability and thermal diffusive capabilities. A COMPASS force field was employed, and periodic boundary conditions were defined to address the molecular dynamic (MD) simulation results in the dispersion system. The MD viscosity quantification using stress autocorrelation function shows a monotonic decay for 303–323 K temperatures. These results of autocorrelation calculations were used for validating viscosity results obtained from MD simulation. The viscosity of the CuO-Alkane system was found out to be 1.613 mPa s at 303 K. The diffusion coefficients were also calculated for the CuO-Alkane system using mean square displacement and it was found that at 303 K this system gives 4.302 E−11 m2/s rate of diffusion