The influence of carbon nanotubes on mass transfer and hydrodynamic in a liquid-liquid extraction system

A single-drop liquid-liquid extraction system in the presence of carbon nanotubes was studied in this investigation. Carbon nanotubes have a striking effect on heat transfer and due to the similarities between mass and heat transfer, these nanotubes were investigated in a mass transfer system. Furthermore, carbon nanotubes were compared with silica nanoparticles to specify the effects of molecular structure on mass transfer. Toluene, acetic acid and nanoparticles as dispersed phase and ionized water as continuous phase were chosen. The surface of carbon nanotubes were modified using dodecyl iodide in order to provide appropriate stability in the dispersed phase. The FT-IR test showed the acceptable modification of nanotubes. The angle of hydrophobicity which was measured by contact angle test, was 134º. Terminal velocity and drop size slightly decreased with nanoparticle concentrations. Equivalent drop diameters and terminal velocity were in the ranges 0.55-0.7 cm and 10.5- 11.4 cm/s, respectively. The maximum enhancements of 27% and 119% for overall mass transfer coefficient were achieved in carbon nanotubes and silica nanoparticles, respectively. The increment in drops’ diameter increased the overall mass transfer coefficient.