Solution plasma process to synthesize silver nanofluids and their thermal conductivity behaviors

A solution plasma process (SPP) was recently introduced as an effective method to synthesize various metallic and nonmetallic nanoparticles. In this work, the synthesis and characterization of Ag nanoparticles (AgNPs) and Ag nanofluids (AgNFs) using the SPP were investigated. The results showed that various shapes and sizes of AgNPs could be synthesized successfully using the SPP, and their size and shape were strongly affected by discharge time. As the discharge time increased, the morphologies of the synthesized AgNPs changed from spherical to dendritic in shape. The dispersion stability of the AgNPs in the solution also showed a close dependence upon the discharge time, showing a maximum zeta potential after discharging for 300 s. The thermal conductivity of the AgNFs increased as the discharge time increased. An increase in the thermal conductivity of the AgNFs of approximately 12% was observed after discharging for 900 s at 900 V and fully developed dendritic AgNPs were observed in the solution.