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Emulsion-templated synthesis method. Chem 750 Antony Han University of Waterloo. What is emulsion method?. More than 50 years after being known Heterogeneous mixtures At least one immiscible liquid is dispersed in another in the form of droplets.
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Emulsion-templated synthesis method Chem 750 Antony Han University of Waterloo
What is emulsion method? • More than 50 years after being known • Heterogeneous mixtures • At least one immiscible liquid is dispersed in another in the form of droplets. • At least one of the liquids will be water or an aqueous solution. • Oil-in-water (O/W) • Water-in-oil (W/O) • Used in a wide range of common practical application
Ternary phase diagram Typical ternary phase diagram based on oil, surfactant, and water Soft Matter, 2005,1,206-218
Polymerisation of an emulsion • in the dispersed phase • - colloids • in continuous phase • - porous materials • both phases • - composites Soft Matter, 2005, 1, 107-113
Emulsion preparation Soft Matter, 2005, 1, 107-113 Size does matter – in nano world.
Nano-emulsion • Non-equilibrium systems – cannot be formed spontaneously • Need energy input • High-shear stirring • High-pressure homogenizers • Ultrasound generators
Temperature is critical • At high temperature: • - macro-emulsion (right) ~1μm • At around 40 ºC: • - nano-emulsion (left) ~35 nm Current Opinion in Colloid & Interface Science 10 (2005) 102-110
Application TEM micrographs showing (A) SWNT bundles with an adsorbed polystyrene layer in a 8.5% weight SWNT-PS composite and (B) bare Carbolex SWNTs bundles. Nano Lett. Vol. 2, No. 8, 2002, 797
Application Pharmaceutical Research, Vol. 21, No. 8, August 2004, 1428