Mass-Transport through Interfaces

Licentiate thesis, 2013

Many of the products in our daily life consist of layered structures, where packaging materials and wound care products can be mentioned as examples. These structures often consist of different kind of polymeric materials and between these materials interfaces are formed. Considering the applications of the mentioned products, the permeability properties of the materials is of high importance. Another structure that may be interesting in future barrier materials or implants to the human body is biodegradable composite materials. In these composite materials, several interfaces are formed where the matrix and the filler material meet, which may result in new barrier properties. In this thesis, the permeability of both layered and composite structures have been studied in diffusion cells, using different radioactive labeled molecules as tracers. Measurements have shown that the permeability decreases in layered structures compared to the pure materials. A second study has shown that the permeability in a composite material can be controlled by the addition of a more hydrophilic polymer that covers the filler material. In a nano-composite material, it seems like an addition of 5 wt% nano-filler is enough to reduce the permeability of the material. Hopefully, the results in this thesis can be used for the design of materials where it is important to control the permeability.