Pourjavaheri-Jad, F.Parthasarathy, R.Kao, N.Ngothai, Y.2013-04-042013-04-042012Proceedings of CHEMECA 2012: quality of life through chemical engineering, held in Wellington, New Zealand, 23-26 September, 2012: pp.150-1599781922107596http://hdl.handle.net/2440/76427In this study, nano-emulsions were prepared using 19.2 wt% n-Dodecane (C12H26) and n-Decane (C10H22) oils as the dispersed phases, 4 wt% Brij 30 (C12E4) as surfactant and 76.8 wt% ultrapure water as the aqueous phase by phase inversion temperature (PIT) method. PIT points were determined by measuring the conductivity of the mixture as a function of temperature. The stability of nano-emulsions was determined by measuring the mean size, polydispersity index (PDI) and size distribution of droplets using dynamic light scattering (DLS) technique and monitoring them as a function of time. The nano-emulsions were also characterised using refractive index (RI), surface tension and pH measurements. The efficiency of reversibility test was also investigated on systems aged for various durations (i.e. 3, 4, 5, 9 and 470 days). Experimental results show that n-Dodecane system has higher conductivity values than n-Decane system and as a consequence the PIT values for n-Dodecane system were found to be higher than those for n-Decane system. All freshly produced nanoemulsions were found to be similar in appearance being opaque white with opal shine. But they were found to lose the shine and became duller with ageing. n-Dodecane systems seem to produce less stable nano-emulsions than n-Decane systems. They were also found to have larger droplets and higher RI values but mostly lower pH compared to n-Decane systems. Surface tension values for the reversed n-Decane system were found to be lower when compared to those for fresh one. Both n-Decane and n- Dodecane systems lead to an increase in droplet size over the study period of 3 days. Also, the variations in PDI and size distribution of droplets over the study period are significant in this work.en© 2012 Engineers AustraliaO/W nano-emulsionsPITn-Dodecanen-DecaneBrij 30reversibilityConference paper002012593020941Ngothai, Y. [0000-0002-0199-4225]