PHYSICAL BASE OF ASSOCIATED LAYER MODEL APPLIED TO NANOFLUID VISCOSITY DESCRIPTION

Read more The paper presents the mechanistic model for explaining the experimental data on the nanofluids viscosity, which is based on the assumption about the layer of liquid on the nanoparticles surface, which associates with them the mechanical solid inclusions. This allows us to supplement the Batchelor formula with the parameter whose selection allows us to fit it with the experimental data. Independent methods of estimating the associated layer thickness from experimental data are also presented. Its value is ~ 10 nm, which is in agreement with the papers on the flows of fluids in thin hydrophilic quartz capillaries. The physical cause of this layer formation is supposed in the structuring action of the nanoparticles surface, which is expressed in the ordering of the water molecules dipole momentum directions in the near-surface layers. This leads to the difference in the optical properties of the adjacent to the particles water layers and the bulk water, which allows one to explain the fundamentally different results of measuring the dimensions of nanoparticles in a liquid by various optical methods, both among themselves and in comparison with the nanoparticles specific surface. The methods of direct influence on the particles size distribution are also proposed which can allow us to verify the assumption (on which the considered associated layer mechanistic model essentially relies) of the possibility to group different nanopowders and introducing into the group a general parameterized function of the particle size distribution.

Keywords:
nanofluid, viscosity, structured water.
УДК 532.526:538.9

PHYSICAL BASE OF ASSOCIATED LAYER MODEL APPLIED TO NANOFLUID VISCOSITY DESCRIPTION