The variation of the physical properties of nanofluids with temperature and surfactant concentration

In recent years, interest in nanofluids has increased to enhance energy efficiency and improve heat transfer performance. Nanofluids, obtained by adding nanoparticles to base fluids, exhibit superior thermal performance compared to conventional heat transfer fluids. The high thermal stability and low tendency of titanium dioxide nanoparticles to chemically react make them widely preferred in nanofluids. In this study, water-based nanofluids were prepared using TiO2 nanoparticles. The volumetric solid fractions of the nanofluids are 0.5%, 1%, and 3%. In the study, three different surfactants (Sodium dodecyl sulfate, Tween 80, Cetyltrimethylammonium bromide) were used in fixed amounts. The viscosity and thermal conductivity coefficients of the nanofluids were determined at four different temperatures (25-30-35-40 °C). According to the data obtained in the study, the nanofluids with the highest thermal conductivity are those prepared with CTAB (cetyltrimethylammonium bromide). With the increase in temperature and solid concentration, the thermal conductivity coefficients have increased. The nanofluids with the highest viscosity are those prepared with SDS (sodium dodecyl sulfate). While the viscosity values decrease with the increase in temperature, the viscosity values increase as the solid content ratio increases.