Nanoparticle enhanced evaporation of liquids: A case study of silicone oil and water

Evaporation is a fundamental physical phenomenon, of which many challenging questions remain unanswered. Enhanced evaporation of liquids in some occasions is of enormous practical significance. Here we report the enhanced evaporation of the nearly permanently stable silicone oil by dispersing with nanopariticles including CaTiO3, anatase and rutile TiO2. An evaporation rate as high as 1.33 mg/h·cm2 was measured in silicone oil when dispersed with 100 nm-sized CaTiO3 particles. Dependence of evaporation rate on the chemistry, size and structure of the particles suggests that some weak absorption sites on the particles half floating on the liquid surface are responsible for the facilitated evaporation of liquid molecules. Enhanced evaporation is also observed for water when dispersed with anatase TiO2 particles. The results can inspire the research of atomistic mechanism for nanoparticle enhanced evaporation and exploration of evaporation control techniques for treatment of oil pollution and restoration of dirty water.