Negative dielectrophoretic technique for separation of o/w nanoemulsion

Dielectrophoresis (DEP) is an efficient electro-kinetic technique with great potential for demulsification. We present an experimental study to the dynamic behavior of particles underDEP using AC-electric field. DEP is produced by polarization effects when particles are exposed to non uniform electric field. DEP is applied to remove of sunflower oil-particles innanometer scale which have dispersed to the water [oil in water emulsion (o/w)]. In a DEPfield the polarized particles experience a force that can cause them to move to regions of high or low electric field, depending on the particle polarizability (electrical conductivity) comparedwith the suspending medium. According to the low conductivity (using electrical conductivity measurement) of dispersed phase (oil conductivity) in comparison to water as continuous phase, DEP-force will tend to move the particles towards the weakest or minimum region of the electric field (dd -dc = - 0.095), the negative number means, it is about a negativedielectrophoretic process (n-DEP). The oil-particle size is shown using AFM (Atomic force microscope) between 25 nm to 250 nm. The largest part of particles is between 50 nm to 60 nm.

Keywords:

Dielectrophoresis , Separation , o/w Emulsion , Non-uniform electric field