Transport Processes and Relaxation Phenomena of Nanoparticles in Fluids

摘要

The fast development of nanotechnologies requires studying of transport processes of nanoparticles in fluids. In turn, to control these processes it is necessary to study mechanisms of nanoparticles velocity relaxation in gases and liquids. The key for the solving of these problems is the description of the nanoparticles diffusion in liquids and gases. There are some different approaches to describe the nanoparticles diffusion. In particular, in some papers there are statements, that nanoparticles diffusion can be described like the diffusion of ordinary Brownian particles. On the other hand, there are attempts to describe nanoparticle diffusion with the help of some kinetic theories, the modified Enskog theory for example. Strictly speaking we have not basis to describe the nanoparticles diffusion by the both ways. The nanoparticles have the sizes of the order of hydrodynamic infinitesimal scale. Therefore we can't use the hydrodynamic description. However we can't also use the standard kinetic theory because the molecule-particle interaction is collective one. The gas molecule interacts simultaneously with all atoms of a nanoparticle. The size of nanopaticle lies between the molecule and large dispersed particle ones (R ～10{sup}(-5) ÷ 5·10{sup}(-4)m). Therefore gas nanosuspensions (gas + nanoparticles) and nanosuspensions (liquid + nanoparticles) are essensially differed from gas mixures, ordinary gas suspensions and suspensions, The given paper is devoted to the rewire of the results of the studing of nanoparticles transport processes in gases and liquids obtained last years by the author and his group.