Potentials of composite nanoparticles interaction with each other and with molecules of the carrier medium

Abstract

Studies of nanofluids have showed that they have non-standard properties. In particular, transport processes in nanofluids, their viscosity and thermal conductivity are not described by classical theories. At present the molecular dynamics (MD) method is widely used to model transport processes in nanofluids. This method, in its turn, requires knowing appropriate interaction potentials. To stabilize nanofluids, in particular, to prevent aggregation of nanoparticles sur-factants are used. In addition to homogeneous nanoparticles, composite nanoparticles are of great practical interest. The purpose of this paper is to construct interaction potentials of surfactant coated nanoparticles and composite ones with each other and with molecules of the carrier medium. A nanofluid consisting of a carrier fluid (gas or liquid) and surfactant coated nanoparticles or composite ones is considered. The particles are assumed to be solid and spherical. The interaction between the atoms of the nanoparticles and molecules of the carrier medium is described by Len-nard-Jones potentials with the appropriate parameters. Also, Lennard-Jones potentials describe the interaction of atoms of two nanoparticles with each other. The interaction potential of a mole-cule of the carrier medium with this nanoparticle is given as a sum of the potentials of this mole-cule with all the atoms of the nanoparticle. Similarly, the interaction potential of two nanoparticles is determined. In both above cases, the solid is approximated by the continuum model. The potentials obtained are intended for modeling of transport processes in nanofluids containing surfactant coated nanoparticles and composite ones as a dispersed element and their flows. kinetic theory fluid laminar-turbulent mathematical