The conventional heat transfer liquids such as water, oil, etc., having lesser thermal properties cannot be fulfill the requirements of some of the heat exchangers system. To enhance the thermal properties of the liquid, nanoparticles are dispersed. Nanofluids (NF) have potential application in thermal transfer systems. The motto of the present work is devoted to studying thermo-physical studies on ZnO with different weight percentages of Polyvinylidene Fluoride (PVDF)-added nanocomposite-based nanofluids at various concentrations in water for heat transfer applications. The prepared nanocomposites were dispersed into the distilled water to prepare nanofluids and were characterized by ultrasonic velocity measurements to figure out the molecular interaction and thermal behavior of the nanofluids. Various physicochemical Characteristics, such as adiabatic compressibility, intermolecular free length, free volume, internal pressure, specific acoustic impedance, relaxation time, and surface tension, were determined. The mechanical properties of the PVDF ZnO NFs were analyzed based on the findings of the bulk modulus. Moreover, the thermal conductivity of the PVDF ZnO nanofluids was theoretically analyzed based on density and ultrasonic velocity measurements. The PVDF mixed with ZnO nanoparticle shows better thermal properties compared with conventional liquid say water.