New article in Journal of the American Chemical Society

posted Feb 22, 2011, 7:22 PM by Shin-Hyun Kim   [ updated Feb 22, 2011, 7:26 PM ]
An article in  Journal of the American Chemical Society on Amphiphilic microparticles has been accepted for publication 
We use microfluidic device to prepare monodisperse amphiphilic particles in the shape of a crescent-moon and use these particles to stabilize oil droplets in water. The microfluidic device is comprised of a tapered capillary in a theta (θ) shape that injects two oil phases into water in a single receiving capillary. One oil is a fluorocarbon while the second is a photocurable monomer which partially wets the first oil drop; silica colloids in the monomer migrate and adsorb to the interface with water but do not protrude into the oil interface. Upon UV-induced polymerization, solid particles with the shape of a crescent-moon are formed; removal of fluorocarbon oil yields amphiphilic particles due to the selective adsorption of silica colloids. The resultant amphiphilic microparticles can be used to stabilize oil drops in a mixture of water and ethanol; if they are packed to sufficient surface density on the interface of the oil drop, they become immobilized, preventing direct contact between neighboring drops thereby providing the stability.
Shin-Hyun Kim, Alireza Abbaspourrad, and David A. Weitz, “Amphiphilic Crescent-Moon-shaped Microparticles formed by Selective Adsorption of Colloids,” Journal of the American Chemical Society, In press (2011).