GRAPHENE POWDER PROCESSING FOR WATER SOLAR DISTILLATION USING NANOFLUIDS , Nadhira Laidani, Francesca Marchetti, Hafeez Ullah, Marina Scarpa, Cecilia Maestri, Said Makhlouf, Gloria Gottardi, Ruben Bartali, Victor Micheli

Abstract: Recently graphene and graphene-based hybrid materials have attracted much attention due to outstanding chemical and physical properties. Thanks to their high thermal conductivity graphene-based nanomaterials constitute excellent candidates for water-based nanofluids. This class of new materials can be beneficially exploited in water purification technologies using renewable energy. Solar distillation efficiency to produce clean water can be improved through the use of nanofluids. In this work we studied the plasma route processing effects of graphene powders in terms of ability to produce graphene-water based nanofluids. The powders were treated by radio-frequency sputtering by which metal oxide and silicon oxide were deposited onto the surface of the graphene powders, forming hybrid graphene-inorganic nanomaterials in order to enhance the solubility in water. The surface modification was studied by means of x-ray photoelectron spectroscopy and transmission electron microscopy. The graphene based materials suspension stability in water and the surface wettability were studied by means of UV-Vis. spectrophotometry and contact angle measurement respectively. Preliminary results showed a significant improvement of the graphene solubility in water by the plasma treatment.