Thermo-physical profile of zinc oxide nanoparticles dispersed in aqueous solution of propylene glycol

Abstract In this investigation zinc oxide (ZnO) nanoparticles were synthesized by precipitation method using Zn(CH 3 COO) 2 as a starting material. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X- ray spectroscopy (EDX). These nanoparticles were dispersed in 10% aqueous solution of propylene glycol in various concentrations with the help of ultrasonicator to obtain nanofluids of different concentrations. Ultrasonic velocity ( u ), density ( ρ ) and viscosity ( η ) of these nanofluids were measured experimentally as a function of temperatures ( T  = 303.15 K, 308.15 K and 313.15 K). Using these experimentally measured values various acoustic parameters such as adiabatic compressibility ( β ad ), intermolecular free length ( L f ), relaxation time ( τ ), acoustic impedance ( Z ), free volume ( V f ) and attenuation coefficient ( α/f 2 ) were evaluated with a view to investigate molecular interactions.