Abstract

Carbon nanoparticles are very useful in solar thermal applications, since they absorb much of the solar spectrum, are cheap and have excellent optical properties. Carbon nanoparticles-thermal oil-based nanofluid was prepared using two-step method with diphenyl sulfone as surfactant to achieve that nanoparticles remain suspended even at high temperatures. The stability was studied using two Dynamic Light Scattering systems at room and high temperature and also evaluated before and after exposing the nanofluid to a thermal treatment so that conditions closer to those in real applications were replicated. The results of this study contribute to the knowledge about these solar nanofluids stability and their promising use as an alternative to the conventional solar collectors.