CuO–ethylene glycol nanofluids of various concentrations have been synthesized using ultrasonically assisted
two step method. Ultrasonic and thermal investigations are made on the nanofluids at different temperatures
ranging from 308 K to 328 K. The intermolecular interactions in CuO–ethylene glycol nanofluids are realized
through the ultrasonic velocity and it is found that the CuO–ethylene glycol interactions surpass the CuO–CuO
interactions. The variations of ultrasonic velocity with respect to temperature confirm the weakening of the intermolecular
adhesive forces at elevated temperatures. In addition to the interaction studies, a new methodology
is proposed to find thermal conductivity of nanofluids using ultrasonic velocity. The results, thus obtained
through ultrasonic method, are found to agree well with those obtained through the transient line heat source
technique, which confirms the aptness of the proposed method