Parametric Charactrization of Coaxial Drop Dripping Encapsulation Process

Encapsulation of one compound to another is a process that shapes our lives in many aspects. For instance, drug delivery, nutraceuticals and children’s food with minerals and vitamins production, among many other applications, all depend on the encapsulation process. The desired features for an effective encapsulation process include capsule size control, encapsulating the right amount of the core liquid, and ensuring that the capsule external wall strength is suitable for the application. In this study, we present a detailed characterization on encapsulation via coaxial drop dripping into a liquid bath. The liquid bath contains an ionic solution capable of inducing the gelation of the drop external liquid consisting of a viscous solution made of a polymer of opposite charge. A parametric mapping of the successful encapsulation conditions is established, this include the inner and outer flow rates and the viscosity of the external liquid. Simple relations are produced to predict the amount of liquid encapsulated and the size of the capsules. We observe that the concentration of the external liquid solution is one of the key controlling parameters, which influence the strength of the capsule after drying, along with the wall thickness and the capsule size.