Mechanism of nanocapsules formation by the emulsion–diffusion process

Abstract : A detailed investigation into the mechanisms of nanocapsule formation by means of the two stages “emulsion–diffusion” process is reported. Such widely used process is still poorly understood. An emulsion of oil, polymer and ethyl acetate is fabricated as a first step; dilution with pure water allows ethyl acetate to diffuse out from the droplets, leaving a suspension of nanocapsules at the end. It has been shown that the size of nanocapsules was related to the chemical composition of the organic phase and the size of primary emulsion through a simple geometrical relationship. As a consequence, most of the properties of the nanocapsules were decided at the emulsification step. The influence of several formulation and processing parameters of the primary emulsion was studied accordingly. The thin polymer membrane of nanocapsules was observed by means of cryo-fracture electron microscopy. Finally two experiments were designed for a mechanistic investigation of the diffusion step. A step-by-step diffusion of the organic solvent takes place by successive partition equilibria of ethyl acetate between the droplets and aqueous phase. A time-resolved experiment shows the fast diffusion (less than 20 ms) related to the small droplet size of the emulsion.
Document type :
Journal articles
Complete list of metadatas

https://hal-agrosup-dijon.archives-ouvertes.fr/hal-02291750
Contributor : Administrateur Agrosupdijon <>
Submitted on : Thursday, September 19, 2019 - 11:05:00 AM
Last modification on : Friday, September 20, 2019 - 1:24:34 AM

Identifiers

Citation

Delphine Moinard-Chécot, Yves Chevalier, Stephanie Briancon, Laurent Beney, Hatem Fessi. Mechanism of nanocapsules formation by the emulsion–diffusion process. Journal of Colloid and Interface Science, Elsevier, 2008, 317 (2), pp.458-468. ⟨10.1016/j.jcis.2007.09.081⟩. ⟨hal-02291750⟩

Share

Metrics

Record views

44