A comparative study on particle-fluid interactions in micro and nanofluids of aluminium oxide

Stable dispersions of micro and nanosized Al2O3 particles in ethylene glycol are prepared with the aid of sonication. The temperature dependant acoustic properties such as ultrasonic velocity, adiabatic compressibility, attenuation and acoustic impedance are studied and reported in this paper. In microfluids the particle-fluid interaction is observed to decrease with increase of concentration of particles whereas in nanofluids it is observed to increase up to the critical concentration (0.6 Wt%) and above which the particle-particle interaction dominates due to agglomeration of particles. A range of concentration with significant particle-fluid interaction is identified for effective nanofluid applications.