The effect of concentration of surfactant and electrolyte on the pit and droplet sizes nanoemulsions of n-dodecane in water

Nanoemulsions are transparent or semi-transparent systems mostly covering the size range of 50-200 nm. In the research, the production of nanoemulsion of n-dodecane in water was studied by phase inversion temperature method (PIT), and the effect of the changes in NaCl and surfactant concentration on PIT and droplet size of n-dodecane was studied. The changes in conductivity with temperature were measured for emulsions containing 20 wt % dodecane, 4 and 8 wt % Brij30, and NaCl of various concentrations in aqueous phase. The results showed a decrease in PIT with a rise in concentration of NaCl and also Brij30. There was a linear model fitted to the data. Analysis of variance (ANOVA) shows that, the significance value (p-value) is less than 0.05, and the effect of the changes in concentration of surfactant Brij30 on the decrease in PIT and droplet size was the more than that in concentration of NaCl in aqueous phase. The lowest mean droplet diameters were in the range of 8.6-14 nm.