Experimental investigation of mass transfer of active ions in silica nanofluids

In this paper the effect of silica nanoparticles on mass transfer was studied in circular tube by using electrochemical limiting current technique in both laminar and turbulent flow regimes. Underdeveloped concentration and fully developed hydrodynamic profile was considered. Silica nanoparticles with the size range of 7–13 nm was used to prepare electrolyte nanofluid. Base fluid was composed of equimolar potassium ferri-ferrocyanide and sodium hydroxide. Measurements for laminar regime indicated that mass transfer coefficient increased with nanofluid volume fraction up to 0.0057% and decreased with increasing the volume fraction of nanoparticles further. Maximum enhancement in mass transfer reached 21% at Reynolds number of 326. In turbulent flow regime no enhancement was recognized due to the addition of silica nanoparticles to the base electrolyte solution.