Scientific Results

A Comprehensive Physical Profile for Aqueous Dispersions of Carbon Derivatives as Solar Working Fluids

Year: 2020

Authors: Sani E., Vallejo J.P., Mercatelli L., Martina MR., Di Rosa D., Dell’Oro A., Lugo L.

Autors Affiliation: CNR-INO National Institute of Optics, Largo E. Fermi, 6, I-50125 Firenze, Italy; Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, E-36310 Vigo, Spain; Department of Energy, Systems, Territory and Constructions, University of Pisa, Engineering (D.E.S.T.eC.), Largo L. Lazzarino, I-56122 Pisa, Italy; INAF, Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze, Italy

Abstract: The application of nanofluids in direct solar absorption, heat transfer or direct solar steam generation entails carrying out a comprehensive study taking into account several physical quantities. Long-term stability, rheological, thermophysical and optical properties of dispersions must be known to assess their potential for envisaged applications. Two low-concentration nanofluids, 0.005 and 0.05 wt%, of sulfonic acid-functionalized and polycarboxylate chemically modified graphene nanoplatelets in water were considered in this work. Elemental analyses of the nanopowders and pH evaluations of the colloids were carried out. The rheological behaviour of dispersions at di erent temperatures was studied by rotational rheometry. Thermal conductivities were measured by the transient hot wire method and densities by the oscillating U-tube technique. Additionally, a brief report of the optical properties was included to provide a comprehensive physical analysis.

Journal/Review: APPLIED SCIENCES-BASEL

Volume: 10 (2)      Pages from: 528-1  to: 528-13

KeyWords: water nanofluid; graphene; solar energy; heat transfer; viscosity

DOI: 10.3390/app10020528