Synergistic effect of silica nanoparticles and charged surfactants in the formation and stability of submicron oil-in-water emulsions.
The influence of hydrophilic silica nanoparticles on the emulsification of a triglyceride oil (Miglyol812) in the presence of charged surfactants (lecithin or oleylamine) and the long term stability of the resultant oil-in-water emulsions are reported. A synergistic effect of nanoparticles and surfactants in improving emulsification and stability to coalescence is evident only when the silica nanoparticles are initially added to the oil phase. When nanoparticles are included from the water phase, no synergistic stabilisation was observed due to electrostatic bridging or unfavourable attachment due to the repulsive electrostatic and hydration forces. Free energies of adsorption for silica nanoparticles at the oil-water interface calculated from experimentally determined interfacial tensions and three phase contact angles can be correlated to long-term emulsion stability only when silica is added from oil phase.
Ian Wark Research Institute, The ARC Special Research Centre for Particle and Material Interfaces, University of South Australia, Mawson Lakes, SA 5095, Australia.
Nasrin
N
Ghouchi Eskandar
Spomenka
S
Simovic
Clive A
CA
Prestidge
D000588:Amines / Q000737:chemistry*; D004655:Emulsions; D054709:Lecithins / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*; D013816:Thermodynamics; D014280:Triglycerides / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D000588:Amines; D004655:Emulsions; D054709:Lecithins; D013501:Surface-Active Agents; D014280:Triglycerides; D014867:Water; C022834:miglyol 812; D012822:Silicon Dioxide; C008703:oleylamine