Volumetric optical heating of carbon nanotube nanofluids

In this work, we report on the thermal response and evaporation rate of nanofluids containing plasma-functionalized multi-walled carbon nanotubes (MWCNTs) subjected to localized optical (laser) heating. It is shown that an optical-to-heat energy conversion efficiency of at least 64% occurs using a 200 mW continuous wave 532 nm laser heating a 15 μL droplet, resulting in a localized heat generation rate of at least 133 W cm−3. From here evaporation of the droplet is caused by an increase of the overall fluid temperature (and therefore increased vapor pressure) and not non-equilibrium vapor production.