This work investigates polarization phenomena induced by nanoparticle inclusions in paraffin oil, an insulating organic liquid. Fine metal oxide powders and nanopowders of Al 2 O 3 , TiO 2 , CuO, Cu 2 O and Fe 2 O 3 were tested at concentrations up to 5% w/v in the liquid matrix. Emulsification was attained by ultrasound treatment. The relative dielectric constant and loss tangent (tanδ) of both pure oil and emulsions were recorded in the 20 Hz-1 MHz frequency range. Results depend both on grain size and on the specific compound. In the case of alumina nanoparticles, dielectric behavior is dominated by grain surface polarization phenomena induced by adsorbed water. This effect can be partially cancelled out by the addition of titania nanoparticles. Titanium and (to a lesser extent) ferric oxide increased the dielectric constant at middle and high frequencies. Copper (I) and (II) oxides exhibit a distinct relaxation mechanism at the high end of the frequency range.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.