Thermal conductivity, viscosity, and optical properties of nanofluids based on water and carbon nanoparticles

The present study deals with the optical and thermophysical properties of nanofluids based on spherical carbon nanoparticles stabilized in water by sodium dodecyl sulfate. Nanoparticles with a mean diameter of 11 nm are synthesized using electric arc sputtering in helium at a pressure of 3 Torr. For a concentration of carbon nanoparticles in the nanofluid equal to 0.01 %, the extinction coefficient varies from 400 to 200 m⁻¹ in the wavelength range of 180–1100 nm. For mass fractions of nanoparticles within 0–0.04%, the viscosity is not found to depend on the concentration. With an increase in concentration, the thermal conductivity of nanofluids in the same range of concentrations is found to be lower than the thermal conductivity of water by up to 4%.