Copper nanoparticles have the highest thermal conductivity, but their heat capacity Cp is not the highest. However, from my many computational tests, the copper nanoparticles give the best heat transfer in closed system.
The data were compared with that of pure water. It was observed that the heat transfer coefficient increased for the addition of alumina nano- particles with water compared to titania nanoparticles. ... Increase in jet pressure decreased the heat transfer coefficient.