A Comprehensive Review on the Effect of Various Ultrasonication Parameters on the Stability of Nanofluid

Abstract

Nanofluids (Engineered colloidal suspension of nanoparticles) are the new and promising heat transfer fluids with exceptional properties. Low stability, high pressure drop, and viscosity are the important drawbacks limiting the industrial application of nanofluids. The aggregation and sedimentation of nanoparticles are related to the colloidal structure of nanofluids, which directly affects the stability and viscosity. Various studies revealed that, choosing proper nanoparticle type, size, shape and concentration, base fluid type, operating conditions (pH, temperature, zeta potential, shear, and magnetic field of the solution), ultrasonication probe type, time, power, frequency and intensity, and surfactant type and concentration are the main factors responsible for the nanofluid stability. Among them, ultrasonication treatment is the simplest and most effective technique with longer nanofluid stability period. It is expected that, the present review will provide guidance and contribute towards various considerable ultrasonication factors which can prolong the stability period of the nanofluid.