Effects of NaCI and KCI concentrations on oil/water nano-emulsions produced by PIT method

Abstract

The present work investigates the effects of NaCl and KCl salt concentrations in the ranges of 0 to 1.0 M on n-Dodecane-in-water/brine nano-emulsions produced by phase inversion temperature (PIT) method. PIT points of the oil/brine solutions were found using conductivity measurements. The stability of the nano-emulsions was determined by measuring the mean size, size distribution and polydispersity index of droplets using dynamic light scattering technique and monitoring them as a function of time. The results showed that both NaCl and KCl salts depress the PIT points. However, the system without salt produces the most stable nano-emulsions. The system containing KCl solution shows lower droplets growth rate at low salt concentrations and higher droplets growth rate at high salt concentrations as compared with those for NaCl system within the 3 days ageing period used in this study. Also the variations in the size and size distribution of droplets with change in salt concentration are significant within the salt concentration range used in this study.