In order to explore mechanism of concentration and type of inorganic salts on polarization and deformation of water droplet during electric dehydration

water droplets of various salt concentrations and types were studied microscopically in pulsed electric field of both high frequency and high voltage. Water droplets of all tested sodium chloride (NaCl) concentrations showed a trend that the deformation degree increased first but decreased later when the electric frequency and duty ratio were increased. The deformation degree of water droplet increased with increase of NaCl concentration

as a result of increased electric conductivity and ion collision. The electric force on multivalent ions

which is several times stronger than that on monovalent ions

enhanced velocity and momentum of their collision

so the deformation degree of water droplet increased upon increase of ionic valence. Furthermore

the ion activity and hydrolysis affected the deformation degree. In the same high-voltage pulsed electric field

the deformation degree of sodium-containing water droplets changed in the order from high to low as Na3PO4> Na2CO3> Na2SO4> NaCl> NaNO3 whereas that of chlorine-containing water droplets changed in the order as MgCl2> CaCl2> KCl> NaCl> NH4ClCl. The experimental findings shall facilitate investigating mechanism of electrostaticde-emulsification at high voltage and high frequency.