Mobility and in situ aggregation of charged microparticles at oil-water interfaces.
Particle mobility, aggregate structure, and the mechanism of aggregate growth at the two-dimensional level have been of long-standing interest. Here, we use solid-stabilized emulsions as a model system to investigate the mobility of charged microparticles at poly(dimethylsiloxane) (oil)-water interfaces using confocal laser scanning microscopy. Remarkably, the rate of diffusion of the charged colloidal-sized polystyrene particles at the oil-water interface is only moderately slower than that in the bulk water phase. The ambient diffusion constant of solid particles is significantly reduced from 1.1 x 10(-9) cm2/s to 2.1 x 10(-11) cm2/s when the viscosity of the oil phase increases from 5 cSt to 350 cSt. In addition, we successfully observe the in situ structural formation of solid particles at the oil-water interface.
Sowmitri
S
Tarimala
Srinivas R
SR
Ranabothu
Jeremy P
JP
Vernetti
Lenore L
LL
Dai
D004058:Diffusion; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004655:Emulsions / Q000737:chemistry; D008856:Microscopy, Fluorescence; D009821:Oils / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D012828:Silicones / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D014783:Viscosity; D014867:Water / Q000737:chemistry*
D004129:Dimethylpolysiloxanes; D004655:Emulsions; D009821:Oils; D011137:Polystyrenes; D012828:Silicones; D014867:Water; C013830:baysilon