Oil/water droplet formation by temperature change in the water/c(16)e(6)/mineral oil system.
Droplet sizes of oil/water (O/W) nanoemulsions prepared by the phase inversion temperature (PIT) method, in the water/C16E6/mineral oil system, have been compared with those given by a theoretical droplet model, which predicts a minimum droplet size. The results show that, when the phase inversion was started from either a single-phase microemulsion (D) or a two-phase W+D equilibrium, the resulting droplet sizes were close to those predicted by the model, whereas, when emulsification was started from W+D+O or from W+D+Lalpha (Lalpha = lamellar liquid crystal) equilibria, the difference between the measured and predicted values was much higher. The structural changes produced during the phase inversion process have been investigated by the 1H-PFGSE-NMR technique, monitoring the self-diffusion coefficients for each component as a function of temperature. The results have confirmed the transition from a bicontinuous D microemulsion at the hydrophile-lipophile balance (HLB) temperature to oil nanodroplet dispersion in water when it is cooled to lower temperatures.
Morales
D
D
Institut d' Investigacions Químiques i Ambientals de Barcelona (IIQAB), Consell Superior d' Investigacions Científiques (CSIC), Jordi Girona, 18-36 Barcelona 08034 Spain.
Solans
C
C
Gutiérrez
J M
JM
Garcia-Celma
M J
MJ
Olsson
U
U
D004655:Emulsions; D008899:Mineral Oil / Q000737:chemistry*; D008956:Models, Chemical; D044367:Phase Transition; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry*
D004655:Emulsions; D013501:Surface-Active Agents; D014867:Water; D008899:Mineral Oil