Pickering nanoemulsions: An overview of manufacturing processes, formulations and applications
Résumé
There is an increasing demand for emulsions that maximize properties such as low viscosity, a large fraction of dispersed phase, high transparency and long shelf life. However, since these emulsions generally consist of nanosized dispersed droplets, they result in a large water-oil interface that requires large quantities of surfactants, some of which are targeted by current regulations (i.e., REACH since 2007) due to health and environmental concerns. For more eco-friendly emulsions, surfactants can be replaced by solid particles, forming the so-called Pickering emulsions. Among their other advantages, Pickering emulsions require a lower particle concentration and provide high stability because particles are considered to be irreversibly anchored at the interface (contrary to small surfactants). Combining nanosized droplets and particle-stabilized emulsions leads to Pickering nanoemulsions. Since their first appearance in 2012, they have received increasing attention, but several points remain challenging; depending on particle wetting properties, they do not necessarily spontaneously adsorb at the interface, and the process to produce drop sizes in the nano range might require more energy than surfactant nanoemulsions. This review describes the recent advances in terms of manufacturing processes and destabilization mechanisms of Pickering nanoemulsions. It describes the particles used to stabilize the oil-water interface and strategies to improve their wetting properties, as well as examples of applications for the design of formulations in the pharmaceutics, food packaging and enhanced oil recovery sectors.
| Origine | Fichiers produits par l'(les) auteur(s) |
|---|---|
| Licence |