Evaporation characteristics of N-tetradecane pendant droplets containing carbon nanotubes and cerium dioxide nanoparticles

Two disparate types of nano-fuels comprised of N-tetradecane (C14) with carbon nanotubes (CNT) and cerium dioxide (CeO2) nanoparticles were prepared, and their main physical parameters were compared. The visualized evaporation experiment of single pendant droplet was conducted at the environment temperatures from 100 celcius to 200 celcius, and the effects of nanoparticles' concentration, size, and properties on the droplet evaporation performances were interpreted. It was found that the droplet evaporation process of different types of nano-fuels followed the classical D-2-law well in the definite temperature range. However, nanoparticles have completely inverse effects on the droplet evaporation under low and high temperatures. At 100 celcius, due to the intensified surface tension and viscosity, the pendant nano-fuel droplets evaporated more slowly than C14 droplets, and the evaporation restraint was enhanced with the increase of nanoparticles' concentration. However, when the environment temperature was over 150 celcius, the droplet evaporation rate of nano-fuels was higher than that of C14, and it rose up with the increase of nanoparticles' concentration. At the same concentration, the droplet evaporation rate declined with the increase of the particle size. In addition, the role of CNT in enhancing the droplet evaporation was more pronounced.