Effect of dispersion method on thermal conductivity and stability of nanofluid

Preparing a stable nanofluid with high thermal conductivity is of a great concern. In order to find an optimum dispersion method to achieve a better performance, five different carbon nanotube (CNT) structures, namely SWNTs (single wall CNT), DWNTs (double wall CNT), FWNTs (few wall CNT) and two different MWNTs (multiwall nanotubes) were synthesized to prepare nanofluids with three different dispersion methods namely functionalization, SDS/ultrasonic probe and SDS/ultrasonic bath. The experiments reveal that the best stability and thermal conductivity are associated with the functionalized nanofluids. Specifically, for the times after 50 h, the functionalized profiles begin to level off due to their higher stability, while the other two paths continue their declining trend.