Utilisations nouvelles pour les matières plastiques, avec la libération contrôlée de liquides^*

New uses for polymeric materials, for controlled release of liquids

Faculté des Sciences, Université de Saint-Etienne

Abstract

Some polymers are capable of absorbing a liquid when they are put in contact with it, and to deliver this liquid afterwards when this pre-saturated polymer is immersed in another liquid. The process is controlled by transient diffusion with constant or concentration dependent diffusivity. Various models with analytical solutions when the diffusivity is constant and with numerical analysis in other cases are described and tested. Various polymeric devices made of a core and shell with two different polymers are thus built and tested for delivering an active agent in water, for agriculture applications. These models are in fact able to describe the process of transfer in many other cases, and they are a powerful method for selecting the right polymer and determining the best parameters.