Analysis of Particle Size Distribution and Other Parameters of Nanoparticles in Natural Ester Oil

In this article we tackle the main problem of nanoparticles which is aglomeration, sedimentation and their long term stability. It has been proved that the nanoparticles offer various benefits for improving the electrical parameters (like breakdown voltage, dissipation factor tan $\delta$, etc.) of insulating liquids. On the other hand the problematics of long term usability of this insulating nano-liquid is not much covered. Our base fluid was one of the natural esters oils - the rapeseed oil which is manufactured localy which can reduce the final price.The importance of nanoparticle surfactants is often misunderstood. Here we present comparison of several surfactant agents with recommendation for further use in combination with natural ester oil based on the chemical structure. The procedure of sample preparation is described in detail. The samples are subject to various measurements of electrical and physical properties with focus on long term usage of these fluids. The dissipation factor was measured in frequency range from 0.001 Hz to 10 kHz which offers the insight into the material behaviour.The analysis of particle size distribution was measured with cooperation with physics department of University of Zilina. The method used for this analysis was acoustic method that determine the PSD (particle size distribution) of the sample and also the attenuation dependence. From these results the FWHM (full width at half maximum) parameters were determined and the nanoparticle distribution was analysed.