Effective viscosity of nanoscale colloidal suspensions

Abstract

A comprehensive model for predicting the effective viscosity of dilute suspensions of nanoscale colloidal particles is presented in this work. The physics of complex interparticle interaction mechanisms is considered in details to characterize the rheological features of the suspension (nanofluid), expressed in terms of the effective viscosity variations as functions of the particle fraction. This is accomplished by addressing the details of the agglomeration-deagglomeration kinetics in a spatio-temporally evolving manner, in tune with the pertinent variations in the effective particulate dimensions, volume fractions, as well as the aggregate structure of the particulate system. Detailed analysis of the results reveals a profound influence of the combined particle agglomeration and breakup features as well as the interparticle interaction potentials on the rheological characteristics of the nanofluid. Predictions from the model agree well with the experimental results reported in the literature.