Agglomeration Rate Estimation of Mineral Oil based ZnO Nanofluids by Dielectric Spectroscopy

In this paper, an advance method is proposed to predict the agglomeration rate of nanofluids using dielectric spectroscopic method. For this purpose, mineral oil based zinc oxide (ZnO) nanofluids are prepared in the laboratory with different concentrations (0.01%, 0.03%, 0.05%, and 0.07%). First, ZnO nanoparticles are synthesized by low temperature hydrothermal method in the laboratory. By employing X-ray diffraction method, the average diameter of the ZnO nanoparticles is found to be 28.21nm. After that, ZnO nanofluids are prepared using two-step process. After the preparation of nanofluids, frequency domain spectroscopy is conducted with different concentration of nanofluids. From frequency domain spectroscopy, Low Frequency Dispersion of dielectric dissipation factor and real component of complex capacitance are evaluated. Using these aforementioned parameters, an empirical relationship is established to estimate the agglomeration rate of ZnO nanofluids. This study further helps to prepare a long term stable nanofluids which may be used as a good alternative to mineral oil.