Permeation rate of charged solutes through an oil phase using tetraglycerin-condensed ricinolate as a lipophilic surfactant in a monodispersed W/O emulsion mixture system

To examine the permeation rate of encapsulated material through an oil phase in W/O/W emulsions, permeation experiments of inorganic salts and ampholites through the oil phase were carried out in a W/O emulsion mixture system. Inorganic cations permeated through the oil phase, while inorganic anions did not. The permeation rate was expressed by a kinetic equation based on the concentration gradient between the different internal aqueous phases as a driving force. The overall mass transfer coefficient of inorganic cations was increased by increasing the concentration of surfactant, tetraglycerin-condensed ricinolate (TGCR) in the range of 2.0 to 15.0wt%. It was found that TGCR became the carrier for the transportation of cations. Furthermore, positively charged ampholites permeated, but negatively charged ampholites did not. The overall mass transfer coefficient of positively charged ampholites decreased with increase in their molecular weight.