Experimental Study on the Thermal Conductivity of Silver Nanoparticles Synthesized Using Sargassum Angostifolium

A simple, fast and one-pot synthesis procedure based on the bio-reduction ability of an algal extract solution has been used to produce silver nanoparticles (AgNPs). The obtained colloids have been characterized by UV–Vis, TEM and XRD. Then, the thermal conductivity of the nanofluids containing 0.2, 0.4, and 0.6 wt% AgNP synthesized using Sargassum Angostifolium in deionized water was measured in the range of 25–85 °C. The thermal conductivity increases with increasing the temperature and particle concentrations. A maximum detraction and enhancement of 33% at 0.2 wt% and 25 °C and 31% at 0.6 wt% and 85 °C were observed. Silver–water nanofluid for each concentration has critical temperature of 51, 49 and 47 °C for mass fraction percentage of 0.2, 0.4 and 0.6, respectively. There is a decrease in thermal conductivity value below critical point of temperature so adding nanoparticle for application below these points is not recommended. The measurement of the thermal conductivity of this new kind of nanofluid showed that it is an ideal fluid for heat transfer because of great value in synthesizing nanoparticles with well-controlled sizes.